View Full Version : Murata regs + Caiman = Problem??
mcebrian
07-05-2011, 01:40
Hi! I just upgraded my Caiman with Murata regs, and I'm a bit sad with the upgrade. Both new regs (5,12v) are in place (correctly soldered).
It works, but, there is a high level background noise that was not there before. Very annoying!!
Steps already taken:
Use a medical-grade PSU 16V (instead of 15v because of Vdrop from the diode) :: Result: NONE. Same noise.
Try to put two caps 100uF 25V between pin 1 and 2 of the regs (as described in datsheet). :: Result: NONE.
Same noise is at the headphone output as at the fixed line output. Noise is the same with the GATOR on or with the original PCB.
In my (bad quality) scope it appears as a constant 20-24mv wave when you generate a test signal (-120db no matters frequency) with the computer.
I paid for the Muratas and at the end it turns out that they perform worse?? At lest regarding noise performance.
On cans, background noise is perfectly audible from 12 o'clock knob volume position.
Parts involved:
Murata 7805SR-C 0.5A max Part n: B036C
Murata 7812SR-C 0.4A max Part n: B046C
They are switching regulators, not sure why you selected those, what was your reason ?
mcebrian
07-05-2011, 03:18
Because I think they are recommended by Stan and many others: http://theartofsound.net/forum/showpost.php?p=84950&postcount=55
and they cost about 20€ not 100€ like the belleson which I prefer of course!
:(
If memory serves me well there is 1-2 guys in here with the same problem
Gazjam posted this on another forum yesterday:
"though I will be replacing the Murata 12V regulator with a Dexa UWB discreet to eliminate switching nose Im getting with the Gator in place"
When they get eyes I am sure that they will let you know... in the meanwhile you could give the search engine a spin
I never tried these particular regs but their reported to be a noticeable improvement over the stock fitted ones, maybe you have one which is faulty :confused: Do you still hear this noise without any music playing? I'd have thought they would have filtering at the switching frequency .
What noise is it ? hum, hiss, buzzing?
mcebrian
07-05-2011, 12:10
If memory serves me well there is 1-2 guys in here with the same problem
Gazjam posted this on another forum yesterday:
"though I will be replacing the Murata 12V regulator with a Dexa UWB discreet to eliminate switching nose Im getting with the Gator in place"
I read it also! Thanks!!
I never tried these particular regs but their reported to be a noticeable improvement over the stock fitted ones, maybe you have one which is faulty :confused: Do you still hear this noise without any music playing? I'd have thought they would have filtering at the switching frequency .
What noise is it ? hum, hiss, buzzing?
No, I can't hear any noise without music playing. (due to auto mute relay I suppose). It's like white noise. The typical background noise with a spike around 15 Khz
Thank you guys! I think that the only solution would be to trash the murata 12v reg...
StanleyB
08-05-2011, 09:30
I'll try to find out if there has been any changes in the specs of the latest Murata regs and the ones that were used initially for this mod. So keep the regulators close by in case there is a simple solution.
I can also report that I noticed this noise since I installed the Muratas about a week ago. Seems to be a problem with the Gator board only (mine is from the first batch with replaced R1 & R2 to 15k to reduce Gain), as the noise is absent when running the Caiman with the passive mod. With the passive mod the Muratas a big improvement ...
Cheers,
cz
Yup, I am having the same problem.
I recently fitted a gator board and thats when I started hearing the noise. I'd describe it as a low volume mid/high frequency "whistle".
It wasn't there with the passive mod, only with the Gator in place.
My Murata's are from the original batch of mods. Stan reckoned it was probably switching noise from teh Murata's, the noise i'm hearing being "switching noise" from the regulators.
Most folk get their Gator's to play nice with the Murata's, so maybe its system dependant? Not sure how though but its maybe a possibility.
I read here that a couple of guys had the problem and solved it by hooking up an extra cap somewhere near the Murata.
Cant remember the details sorry! Would be good if one of those guys pitched up? :)
If its switching noise...the solution might be to get a non switching regulator.
as someone said though..they are pretty pricey...
Glad its not just me thats having this problem!
*EDIT*
any chance it could be power supply dependant?
I shortened the cable on my Maplins CB Radio linear supply and Im pretty sure the noise is even louder??
odd...
chapter three
08-05-2011, 13:30
I never heard this with my Caiman/Gator which had Muratas but it distorted in my system with Mk 1 Gator, Mk 2 was fine.
I moved on to an M2Tech Young which I find significantly better than the Caiman/Gator in all aspects. Night and day etc.. YMMV..
Yup, I am having the same problem.
I recently fitted a gator board and thats when I started hearing the noise. I'd describe it as a low volume mid/high frequency whistle".
It wasn't there with the passive mod, only with the Gator in place.
My Murata's are from the original batch of mods. Stan reckoned it was probably switching noise from teh Murata's, the noise i'm hearing being "switching noise" from the regulators.
Most folk get their Gator's to play nice with the Murata's, so maybe its system dependant? Not sure how though but its maybe a possibility.
I read here that a couple of guys had the problem and solved it by hooking up an extra cap somewhere near the Murata.
Cant remember the details sorry! Would be good if one of those guys pitched up? :)
If its switching noise...the solution might be to get a non switching regulator.
as someone said though..they are pretty pricey...
Glad its not just me thats having this problem!
*EDIT*
any chance it could be power supply dependant?
I shortened the cable on my Maplins CB Radio linear supply and Im pretty sure the noise is even louder??
odd...
I'm one of the persons noticed the same noise/hiss issue with Muratas..
Here is some history of my troubleshooting:
http://theartofsound.net/forum/showpost.php?p=184749&postcount=25
http://theartofsound.net/forum/showpost.php?p=184970&postcount=37
http://theartofsound.net/forum/showpost.php?p=189291&postcount=41
http://theartofsound.net/forum/showpost.php?p=192878&postcount=48
http://theartofsound.net/forum/showpost.php?p=198841&postcount=60
To sum it up :
1. issue is there also with original Caiman PCB, but it's more emphasized with Gator PCB and still there with Gator PCB and Gator caps mod to enhance bass drive on HD800.
2. applying caps in parallel to Murata's Vin an GND changes the behavior of the issue - instead of faint tone about 1khz on background you will get unpleasant noise into whole spectrum (audible during critical listening - it sound harsh/digitally and also on spectral analysis) - therefore i've removed the caps at the end..
3. shortening cable between PSU and caiman (to about 23cm) did not helped.
4. the same situation if using original caiman psu or laboratory linear psu
5. i've replaced Muratas by freshly delivered new Muratas directly from USA - situation still the same.. I've ordered three pairs on top of one pair I already got from Tirna, just to be sure...
6. "SOLUTION" - there is one solution which is not nice, but actually WORKS with Murata's. You have to set PSU voltage to exactly 12,9Volt . I'm in this setup for some time already and I found this the only way to get rid of the background tone/noise after fitted the Muratas into Caiman.
This have one immediately noticeable drawback - the selected input LED indicators on caiman doesn't work reliably as Caiman require 15V to work properly, but once the desired input is selected it stays there and so I can live with that. Second drawback is not so noticeable but i believe to achieve the best sound quality Caiman requires between 15 to 16 Volt.
7. My hypothesis: Murata's start do regulating only if powered with 13.0 and more Volts. Therefore setting 12.9 Volt causes that power just pass thru Muratas without any action by Muratas. Therefore I believe the tone/noise (which BTW changes frequency dependently on input voltage) is cause of Murata's regulation.
8. I'm just hobbyist and therefore not able to design solution how to filter muratas properly, but if someone would be able to find some way how to get rid of the noise produced most probably by Muratas, i would really appreciate that :) I did not want to experiment further as Caiman PCB is now quite wounded by too many soldering during replacement of the regulators, but once there would be final solution I would go for it.. I was even thinking about going back to "cheaper" LINEAR regulators ...
Fantastic post Tomas, thanks.
Sounds like you have already thought of all the "what it's" and came back to the conclusion it's switching noise from the Murata's.
Not everyone gets it though...?
I had thought about swapping for a different PSU and different things, but you saved me doing that. :)
I feel though running the Dac at a lower voltage is a bit of a compromise...might as well get it running to it's maximum potential.
Anyways, for me it's a case of swapping out the Murata for something non switching.
Just to confirm though...
I've both 12v and 5v Murata's fitted, but would I only need to swap out the 12v, as that's the one which feeds the Gator?
This would dampen the dent on the wallet if I only needed one. :)
Gaz - what Tomas has said pretty much proves that it's the 12V reg producing the noise, otherwise it would continue if the 5V one was responsible even if the input voltage were reduced to below 12.9V.
I don't have a Gator so I cannot say for certain that a 12V Dexa will cure the problem, but in passive mode there is absolutely no output whistle even if an ear is placed up to the speaker. I therefore believe that the Dexa has better noise performance than the Murata and is less likely to go into oscillation. However, if you have removed the big reservoir cap you must replace it with something to give stability close to the regs: I have 2 x 2.2uF polypropylene caps there.
OK, with my tin hat on.........
These Murata smps regs sound like they are more trouble than they are worth. I've said it time and time again, the psu is everything. Why not just push the boat out and try one of the decent linear regs out there? I believe mark from audiocom is a member here. I purchased a whole load of supereg 2's from him very cheap a while ago. They are 3 pin 78xx compatible. You could go even better and try a more expensive reg like a fidelity audio SPower (again 3 pin 78xx compatible) or even an off board reg like teddy or a more simple and much cheaper lm317 tracking pre reg (schema in the 317 datasheet or pcb's from Avondale).
Quite simply, my comments of a year ago seem to have been confirmed. Has anyone actually looked at the output and measured for noise etc.
There are affordable alternatives that have been designed with audio in mind, is it time to stop messing about saving £10 here and there and just bite the bullet??????
Thanks for that Martin, that confirms what you advised earlier about only needing a 12v reg.
I haven't replaced the big reservoir cap in my Dac,but will swap it out later.
For the moment though, will the Dexa run fine with the big cap in place?
You mentioned before that the Dexa is happier with 16v rather than the 15 I get from my Maplin linear supply, just need to source a good cheap linear supply.
UV101,
Any affordable Murata alternatives you can think of?
The Dexa reg is about £30 but it's spec looks very very good.
Gaz - be careful with increasing the voltage to 16V only because that is the big electrolytic's rating, if I remember correctly. May be better to replace it and go for 16V to ensure that the 12V has plenty of voltage drop across it.
Ian - I quite agree with you, which is why I have a SuperTeddy powering it at 16V and two high quality Dexa regulators, +12V and +5V, in place with the electrolytic replaced with large polypropylenes.
UV101,
Any affordable Murata alternatives you can think of?
The Dexa reg is about £30 but it's spec looks very very good.
78xx compatilble
Fidelity Audio SPower RRP £42 (http://www.fidelityaudio.co.uk/regs.shtml) High Current (Nominal 500mA can heatsink)
Audiocom Super Reg 3 RRP £32 (http://www.audiocominternational.com/super-regulator-p-33.html) Low current? Unable to heatsink (Poss Mark can confirm the current rating)
HifiCollective Class D (DEXA) RRP £29.70 (http://www.hificollective.co.uk/components/nclassd_reg.html) Unable to see current rating but looks to be heatsink mountable (Not tried these myself)
Tent Labs shunt reg €39 (approx £35) (http://www.tentlabs.com/Components/cdupgrade/shunt/index.html) Low current (Not sure of suitability for this use)
Off board options
Super Teddy Reg €46 (approx £41) (http://www.teddypardo.com/DIY/SuperTeddyReg.html) High Current
Avondale TPR2 Price to be confirmed (http://avondaleaudio.com/diy-audio/tracking-pre-regulator/)High Current - I've built a couple of TPR1's and they were excellent VFM approx £5 per PCB unpopulated. Not sure on the options now as the product range looks like its being updated.
Personally I like the SPower. I now build my own modified version of this regulator. In general, most of these boutique reg use some kind of feedback to as a noise cancelling circuit.
I know I keep harping on trying to persude you to spend your hard earned cash on nice low noise regulators but there is a reason I have 4 in my Squeezebox with another 5 on the DAC I use with it and 17 in my CDP! Marco's CDP had the works at Audiocom with so his will have a few. I really is worth the investment!!!!!
Trust me.......Treat yourself!!!!!
StanleyB
09-05-2011, 10:23
I would personally advise against going above 16V on the power supply.
I hope to start on another round of mods soon. I even made the TC-7520SEG case 2mm higher so that I can stick my THS4032 safely in it. But in the mean time I am playing about with the standard regs and a few test mods.
I would personally advise against going above 16V on the power supply.
I hope to start on another round of mods soon. I even made the TC-7520SEG case 2mm higher so that I can stick my THS4032 safely in it. But in the mean time I am playing about with the standard regs and a few test mods.
Hi Stanley - Is there a 16v Smoother pre reg? If so, would there be an issue running a higher voltage rail if this was replaced with a suitable 25v cap for example?
StanleyB
09-05-2011, 11:10
~You would have to change the caps on the audio PCB to 25V or more. The headphone section is directly driven from the external power supply instead of from the 12V regulator PSU.
Ian - I quite agree with you, which is why I have a SuperTeddy powering it at 16V and two high quality Dexa regulators, +12V and +5V, in place with the electrolytic replaced with large polypropylenes.
I know the superteddy is a good PSU and better than stock, obviously as you have bought one!
Is it WORTH it Martin, in bang for buck terms?
If it is..im going to do it right.
To my ears, yes. It isn't cheap to put the whole PSU together with a transformer, rectifiers, smoothing caps etc. in a case. I probably spent £100 on it in total. There's a picture story of it hereabouts.
The best sound I have achieved by far is by building two adjustable linear PSU's, one to deliver 12v and one to deliver 5v. You can then scrap the internal regulators and feed the supplies directly to the reg points.
The twin linear PSU can be built for around £120.00 if you shop around a bit and it can be as simple or as complex as you like.
I posted how to do this a while back with some photos but unfortunately can't find the thread.
I run the Caiman with this and the passive output mod through the variable outputs straight to a power amp - fantastic!
Regards
Chris
I posted how to do this a while back with some photos but unfortunately can't find the thread.
This http://theartofsound.net/forum/showthread.php?t=9144
mcebrian
28-05-2011, 15:01
[PSU+GENERAL]
Finally, I bought two Belleson SPJ Super Regulators 12V and 5V respectively...
+ More on this later... :steam:
I have also swapped all tantalum caps to Elna Silmic II and the main reservoir cap to two Elna Silmic II (2x4700uF) (Because of new 16v PSU).
This was the best upgrade I made so far. Imaging improvement is INCREDIBLE
[HEADPHONES]
Also, I swapped the op-amp for 2xLT1028ACN. Simply the best. Stunning!! (Checked against: AD797BR, OPA627, OPA827, AD8066, AD826, AD8022, ADA4627-1B,OPA2107, AD8620,OPA2107,etc.)
If you want to improve the headphones output, just throw away the AD826 for one of these: LT1028ACN, AD797BR, ADA4627-1B period.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
[REGULATORS AND NOISE]
So, when I bought the Bellesons I was very happy because I thought I was going to end forever the background noise story... (110$ pair) -140dB noise spectrum...
I soldered everything up, turned on, and... NOOOOO! The noise was still there!!! I got really upset!!
What was going on? Is it the 12V regulator?? I took the scope and started measuring again:
[BELLESON SPJ 12V]
Fixed output: 10mVp-p background noise. Same as Murata reg. Too noisy for me
Variable output: Unmeasurable noise till full volume: 2mVp-p then. PERFECT
Headphones: measured 100mVp-p at the headphone output at 2-3 o'clock position of volume pot.
This translates to real world in audible background hiss from 10 o'clock position using headphones.
* Measured Dynamic range at headphone output: 90dB
So I decided to conduct more test: I took an LM340T 12V reg and soldered it a Tantalum 22uF cap Input-ground and a 0.1uF cap Ground-Output.
When I replaced the Belleson 12V regulator (59$) with a LM340T (0.76$ regulator) i repeated the test.
[LM340T]
Fixed output: 7-8mVp-p background noise. Better but not perfect.
Variable output: Unmeasurable noise till full volume 1mVp-p then. PERFECT AGAIN.
Headphones: measured 18mVp-p at the headphone output at 2-3 o'clock position of volume pot. WOWWWWW!! What an improvement!!
* Measured Dynamic range at headphone output: >=100dB.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
So! What's going on?? If you use a expensive regulator Caiman+GATOR performance is MUCH WORSE (noise-wise).
Dynamic ranges:
Murata(18$):80dB
Belleson SR SPJ(59$):90dB
LM340T(0.76$): >100dB
Why??? It souldn't be this way ... :scratch: I measured more and more things, but couldn't find a reason! The only repeating pattern I found was that Murata and Belleson output is >12V (12.10V) and LM340T and 7812CV is just below 12V.
Noise measured at the output of the regulatos (Murata, Belleson) is 3-1mVp-p! Where is this noise coming from??
Any ideas???
Depends on what the internal voltage reference of those regulators is like. If it's zener-like, it will regulate well but be noisy. Have you tried a Dexa in the 12V position? I don't get noise at any sensible volume level at all.
mcebrian
28-05-2011, 23:10
Belleson is resistor based and should be clearly 'better' than Dexa! But... it is not with the Caiman!! (http://www.belleson.com/comparenewclassd.php). I do not recommend it to Caiman users
I test noise using a special noise track I made with all spectrum freq. at or below -140dB cause under normal operation relays won't switch unless you play music so you can't test for noise.
Why??? It souldn't be this way ... :scratch: I measured more and more things, but couldn't find a reason! The only repeating pattern I found was that Murata and Belleson output is >12V (12.10V) and LM340T and 7812CV is just below 12V.
Noise measured at the output of the regulatos (Murata, Belleson) is 3-1mVp-p! Where is this noise coming from??
Any ideas???
Hi nox, seems that you've gone even further with trobuleshooting this noise issue with other than default regulators, I'm really interested once this is sorted out wat is the root cause and fix it for my Muratas :)
*EDIT* Hmm, I've just got an idea - what about putting some resistor after the 12v regulator's Vout to trim the output voltage to 12.0 ?
Reid Malenfant
29-05-2011, 17:44
Noise measured at the output of the regulatos (Murata, Belleson) is 3-1mVp-p! Where is this noise coming from??
Any ideas???
I notice that the much higher performance regulators are causing you problems :scratch:
Have you possibly considered that it's not the lower noise spec of the better regulators but something to do with their much wider bandwidth that may be problematic?
Any circuitry connected to these regulators will only have a certain amount of PSRR (power supply rejection ratio) & this decreases with increasing frequency. As the super regs have a much wider bandwidth it could be possible for them to upset any circuits being powered by them at ultrasonic frequencies? Just thinking off the cuff here, it might need looking into.
What you need to remember is that the Caiman & Gator were designed to run & run well on industry standard regulators. You'd need to ask Stan if he ever substituted them for either of those you mention & if so did he test for stability?
I'd get a 100MHz oscilloscope on the rails & take a look & see what's going on if i was you ;)
I have replaced the ST L7805 reg with the Murata, mainly because I did not like the heat dissipation of the linear reg and series resistor at its input. Also the input resistor modulates the variations in current consumed from the 5v into unnecessary ripple at the input of the reg.
A side bonus with the 5v Murata, is less current counsumed from the 15v supply, which might in turn, make it less noisy. In order to reduce switching HF ripple, I have added more capacitance on the 5v.
The L7812C does not dissipate hit, as the current is moderate and the voltage drop is low. A linear reg seemd to be better choice than a switched one for that case. It was replaced with the L7812A which has 7.5X lower noise, and also better line regulation and load regulation. All that at a negligible price.
78xx data sheet: http://www.st.com/stonline/products/literature/ds/2143.pdf pages 14 Vs. 23.
Have also added protection diodes between the output and input of the regulators. As adviced at Fig 28 of the data sheet, not needed in the Caiman, but just in case.
As for the sound, it was good before and it is at list as good after the modifications. (Do not have two Caimans to do the comparison at the same time). I am happy with the end result.
HighFidelityGuy
05-08-2011, 20:51
Did anyone manage to solve this issue?
I installed a Gator board a couple of weeks ago and have just noticed that I now get a slight background hiss and whistle. I'm using a SuperTeddyReg linear supply, Gator board, Murata regs and every other Caiman mod including film reservoir caps.
Depends on what the internal voltage reference of those regulators is like. If it's zener-like, it will regulate well but be noisy. Have you tried a Dexa in the 12V position? I don't get noise at any sensible volume level at all.
Another guy (Canetoad) put in the Dexa's instead of the Murata's with his gator and has zero background noise.
Canetoad
06-08-2011, 10:34
That's right. I had Muratas to go in but read a few posts about noise. I went with Dexas instead and I have zero noise. They are excellent! Cost a bit more but sound great with the Silmic IIs and the Gator board. I'm very happy! :)
If I had stayed with the passive mod I would have used the Muratas without a problem. Anybody who'd like a set of Murata regs for use with the passive mod, PM me.
HighFidelityGuy
06-08-2011, 15:49
Another guy (Canetoad) put in the Dexa's instead of the Murata's with his gator and has zero background noise.
Thanks.
That's right. I had Muratas to go in but read a few posts about noise. I went with Dexas instead and I have zero noise. They are excellent! Cost a bit more but sound great with the Silmic IIs and the Gator board. I'm very happy! :)
If I had stayed with the passive mod I would have used the Muratas without a problem. Anybody who'd like a set of Murata regs for use with the passive mod, PM me.
Ok thanks. That gives me some confidence but the possibility remains that you may not have had the problem even with the Murata regs, as from what I've read not everyone encounters the problem. :doh: What power supply do you use?
I was thinking about the issue today and I started to wonder if the problem could be due to the Caiman not being optimised to work with these super regulators. :scratch: Reading through the application notes for the Murata regs I noticed that it says that if you put filtering caps in parallel with the input or output they should be low esr. I haven't had chance to trace the tracks around the regs in the Caiman but it looks like there is a 220uF lytic and a small tant cap near both regs. In my Caiman the lytic caps have been swapped for Elna Silmic II. I can't find any info on the esr ratings of the Silmic II caps, so I'm wondering if their esr is a bit too high? I'm guessing the tant caps are bypassing the lytics to reduce the esr but perhaps it's not quite enough. Does anyone think this is likely to cause the issue and would swapping the Silmic II's with lower esr caps be of any benefit. :confused:
Canetoad
06-08-2011, 16:08
I'm currently using a Maplins CBR linear supply but am working on a replacement of my own construction based on info gained here on AOS.
My Caiman with Dexas is fed from a SuperTeddy PSU set to 16V.
Canetoad
07-08-2011, 08:49
Hi Martin, That's what I am going to do with my PSU. I have the STR and will be using a hexfred rectifier and 80VA tx.
How much capacitance should I use? I have a Panasonic 22000uF TSUP but it's a bit big to fit in the Maplins case. Can you explain what different values would achieve? :scratch:
I have much less than that, Bernie, primarily because I had to fit the thing into my case! The Caiman's current draw is not great (in my case, I have removed the op-amp board) and 3300uF cap of high quality (low ESR) should be fine. The STR does amazingly good regulation so you just need to ensure that the resrvoir voltage does not sag to below about 22V.
HighFidelityGuy
07-08-2011, 13:58
Thanks Martin and Bernie.
Martin, have you swapped the 220uF caps near the regs with Elna Silmic II's or anything else?
Dave - I swapped all my electrolytics for Elna Silmic IIs.
HighFidelityGuy
07-08-2011, 20:48
Dave - I swapped all my electrolytics for Elna Silmic IIs.
Thanks. It sounds like you have almost the exact same setup as me with the exception of the Gator. Would you consider trying out a Gator if I sent you one? I have a spare. It would be interesting to see if you encountered the same noise issue. I'd obviously pay for the postage both ways. Cheers. :)
Sorry Dave - I removed the two board sockets and hard-soldered my passive caps in place (to retain the muting relays). I reckoned I had reached the limit of Caiman performance and have been happy with it ever since.
HighFidelityGuy
07-08-2011, 21:30
Sorry Dave - I removed the two board sockets and hard-soldered my passive caps in place (to retain the muting relays). I reckoned I had reached the limit of Caiman performance and have been happy with it ever since.
Ah, no probs. Thanks anyway. :cool:Back to the drawing board. :hmm:
Canetoad
08-08-2011, 06:57
Dave - I swapped all my electrolytics for Elna Silmic IIs.
Dave,
I replaced all mine with Elna Silmic II as well. I did it all at the same time. Gator I have fitted was one of the first batch made if this is any help.
This is how mine looks, with op-amp board sockets removed and AuriCaps hard-soldered in. Regulators are Dexa, reservoir caps are Panasonic film, all other electrolytics are Elna Silmic II. It sound superb driven from a SuperTeddy set to 16V.
http://www.mtc.me.uk/images/Caiman AuriCap.jpg
great pic martin,
I've ordered a set of the Dexa's to replace the Murata's
+12 Volt - DEXA-70911
+ 5 Volt - DEXA-70908
and your pic is a good help to install them.
Daft question though?
I've not looked into it yet, but off the top of your head which regulator is the 12v and which is the 5V? :mental:
I'm sure I can find it out easy enough, but just wondering if you know off the cuff?
thanks.
As far as I can remember, the one at the back is the +5V for all the DAC circuitry, the one near the front is the +12V for the op-amps. But PLEASE CHECK before going by my memory.
sure, will do.
Not wanting to quote you...just getting an idea! :)
thanks.
Canetoad
08-08-2011, 10:45
As far as I can remember, the one at the back is the +5V for all the DAC circuitry, the one near the front is the +12V for the op-amps. But PLEASE CHECK before going by my memory.
I'm pretty sure that's correct as well. :)
Canetoad
08-08-2011, 10:48
This is how mine looks, with op-amp board sockets removed and AuriCaps hard-soldered in. Regulators are Dexa, reservoir caps are Panasonic film, all other electrolytics are Elna Silmic II. It sound superb driven from a SuperTeddy set to 16V.
http://www.mtc.me.uk/images/Caiman AuriCap.jpg
Martin, could you tell me where you got the Panasonics from?
I found a Panasonic 4700uF 35 volt TSUP that may fit into the Caiman case. It's 25 or 30mm high. Would this be OK to use in place of the 10000uF standard cap? I want to run mine at 16 volts when I've finished the new PSU too.
HighFidelityGuy
08-08-2011, 11:03
great pic martin,
I've ordered a set of the Dexa's to replace the Murata's
+12 Volt - DEXA-70911
+ 5 Volt - DEXA-70908
and your pic is a good help to install them.
Daft question though?
I've not looked into it yet, but off the top of your head which regulator is the 12v and which is the 5V? :mental:
I'm sure I can find it out easy enough, but just wondering if you know off the cuff?
thanks.
Good luck, I really hope this sorts out the problem. :) If so I'll order some too.
Martin is right, the reg near the sockets is the 5V and the one near the buttons is the 12V. :)
Martin, could you tell me where you got the Panasonics from?
From memory, they are 2.2uF Panasonic film caps in parallel to make 4.4uF. You don't need a large reservoir cap if you are feeding the Caiman from a regulated supply.
I bought them from eBay.
I fitted an Oscon as a replacement for the standard Caiman big cap that burst on me...cant remember the uF value of it, but voltage wise its 20v.
Not sure if that helps, but there you go!
Dave,
I'll let you know how I get on with the Dexa's and if it solves the background noise you too seem to be getting.
fingers crossed :scratch:
HighFidelityGuy
08-08-2011, 22:36
Dave,
I'll let you know how I get on with the Dexa's and if it solves the background noise you too seem to be getting.
fingers crossed :scratch:
:cheers:
Hi, I'm going to repost this here as I think it belongs better in this thread:
I replaced the regs with Muratas and they are working fine (strangely as many of you are getting problems) I have also upgraded the caps on the main board with Elnas using the kit from Tirna. However, one of the channels the left, (white) channel is only running at half the volume of the right on all outputs. Can anybody tell me which caps control the left analogue side for all outputs that might affect the volume? Much appreciated.
StanleyB
12-08-2011, 11:03
One mod I never recommend is changing the caps on the main PCB. Without anti-static precautions you can easily kill the WM8716, or cause damage to the output stage in the WM8716. You'll need a scope to see if the signal out of pins 13 and 16 of the WM8716 are different in output level, which would indicate a possible faulty IC. But also clean off any soldering residue ( that brown lacquer looking gunk). It can cause a high resistance path, which can reduce the signal.
Hi, I'm going to repost this here as I think it belongs better in this thread:
I replaced the regs with Muratas and they are working fine (strangely as many of you are getting problems) I have also upgraded the caps on the main board with Elnas using the kit from Tirna. However, one of the channels the left, (white) channel is only running at half the volume of the right on all outputs. Can anybody tell me which caps control the left analogue side for all outputs that might affect the volume? Much appreciated.
Check the computer ribbon cable that links each board. After a few mods this can fail on one or two connections. I have had to replace mine with wire instead as the DAC has been in bits quite a few times!
Regards
Thanks Stan and Chris M. I will take some time with the multimeter and source the problem.
Any news about the Dexas Dave? :)
I'm keen to hear if the replacement solved whistling ;)
HighFidelityGuy
18-08-2011, 16:13
I'm waiting for Gaz to get his installed seen as he'd already ordered some. If they fix the problem for him then I'll order a set ASAP. :)
Hey Dave,
Back from a weeks camping holiday in sunny(not) Scotchland.
Back at home Monday, the Dexa's should be sitting inside my front door.
I'll fit them as soon as i get a new tip for my soldering iron or ASAP.
Whichever's sooner :)
Fingers crossed, heres hoping the whistles gone...as im out of ideas. :scratch:
HighFidelityGuy
20-08-2011, 00:24
Hey Dave,
Back from a weeks camping holiday in sunny(not) Scotchland.
Back at home Monday, the Dexa's should be sitting inside my front door.
I'll fit them as soon as i get a new tip for my soldering iron or ASAP.
Whichever's sooner :)
Fingers crossed, heres hoping the whistles gone...as im out of ideas. :scratch:
Excellent, thanks Gaz! I'll keep my fingers crossed for you. :thumbsup:
Well, the verdict's in on the Dexa regulators vs. Murata's...
the Murata's were the culprit, the whistle is gone. :)
Took my Dac over to Tirna Electronics last night to let Jimmy Dripps to let him do the work for me.
(I struggled to remove the Murata's myself and quickly decided best to leave it to the experts :doh:)
Got home plugged the Dac in last night - ahhh...thats better.
Speaking with Jimmy about my dac problems, he gave his theory on what might be causing the noise problem with the Murata's.
Not everyone with them has had the same problems myself and others have had.
Why?
Jimmy thinks its a case of bad luck having a mismatched pair of regulators which operate at a frequency too close to one another.
He says (and I misquote) that this could cause oscillation in the regulators leading to an an audible "beat" which manifests as background noise when playing the Dac.
I mentioned that I would be putting up my Murata's on AOS as an upgrade for someone and he was generous enough to swap over one of my regulators for a different one from his spares.
A nice gesture and a genuinely nice bloke.
Have to say as well, over and above the whistling being gone my Dac is sounding better than ever.
Read up on these Dexa regs and they are offered as upgrades to existing kit by several 3rd party modding websites - even for kit like the Rega Saturn cd player and Wadia transports.
An upgrade to the Saturn..Wadia? Must be good then!
Forum posts on DIY sites too talk about the Dexa's being a great upgrade to existing kit, so think I've made the right choice fitting them in my Dac.
One question though...?
I've always found new components tend to improve over time, is this the case with these Dexa regulators too?
Good improvement in soundstage focus and detail right out the box, but I'd say there was a shade less "impact" and front to back stuff from what I remember before?
Overall a good bit better than before, but just something I noticed.
Should it potentially improve over time?
So really...I've modded my Dac now about as far as I can take it, nothing left to do - extremely happy to have my (improved) sounds back. :)
With all the SB Touch software mods and my improved Dac, things are sounding good.
Canetoad
25-08-2011, 10:55
One question though...?
I've always found new components tend to improve over time, is this the case with these Dexa regulators too?
Good improvement in soundstage focus and detail right out the box, but I'd say there was a shade less "impact" and front to back stuff from what I remember before?
Overall a good bit better than before, but just something I noticed.
Should it potentially improve over time?
I was thinking the same thing the other day when I was listening to it a bit louder than usual. I was thinking it might improve after I fit a new linear supply set to just under 16v. Currently I'm only running on just over 15v and the internal diode is cutting that back by about .6/7v. Once the Dexas are being fed a full 15v I'll see if the sound improves.
They still sound very good though.:eyebrows:
I was thinking the same thing the other day when I was listening to it a bit louder than usual. I was thinking it might improve after I fit a new linear supply set to just under 16v. Currently I'm only running on just over 15v and the internal diode is cutting that back by about .6/7v. Once the Dexas are being fed a full 15v I'll see if the sound improves.
They still sound very good though.:eyebrows:
How long you had the Dexa's in Bernie?
I've a linear PSU set to about 15.6v, good improvement over Maplins linear CB radio supply.
Internal diode?
Is this the resistor just next to the 5v regulator?
I removed this and replaced it with a wire link, would this mean I would have no voltage drop then?
ta.
Canetoad
25-08-2011, 11:13
No I gather it's a protection diode near the large cap. I'm using the CB Maplins supply and I'm getting 15.1v from it. I have the bits for a new linear supply using a Superteddyreg as per MartinT's PSU but haven't put it all together yet.
ah..I see.
Another potential thing to do with my Dac..:eyebrows:
Anyone have experience of removing this diode?
Is it advisable with my linear psu running about 15.6v..I know Stan advises not to go over 16V but I'm just wondering about the effect of removing the diode with the combination of the Dexa's and a 15.6V linear supply.
the Dexa regs have some voltage drop but not a lot.
Is there a pic anywhere or some info on this?
More importantly...is it worth even bothering about :)
Cheers.
StanleyB
25-08-2011, 12:20
Don't remove that diode. It's there for reverse voltage protection. My DACs use a dual power supply voltage regulation design, which consists of an external and internal regulation circuit. The external circuit supplies the raw voltage, which is stored in those big caps inside the DAC's case. The diode prevents the internal supply feeding back into the external supply, and perhaps knocking it out.
thank you Stan. :)
I'll leave it well alone then.
HighFidelityGuy
26-08-2011, 16:33
Well, the verdict's in on the Dexa regulators vs. Murata's...
the Murata's were the culprit, the whistle is gone. :)
Took my Dac over to Tirna Electronics last night to let Jimmy Dripps to let him do the work for me.
(I struggled to remove the Murata's myself and quickly decided best to leave it to the experts :doh:)
Got home plugged the Dac in last night - ahhh...thats better.
Speaking with Jimmy about my dac problems, he gave his theory on what might be causing the noise problem with the Murata's.
Not everyone with them has had the same problems myself and others have had.
Why?
Jimmy thinks its a case of bad luck having a mismatched pair of regulators which operate at a frequency too close to one another.
He says (and I misquote) that this could cause oscillation in the regulators leading to an an audible "beat" which manifests as background noise when playing the Dac.
I mentioned that I would be putting up my Murata's on AOS as an upgrade for someone and he was generous enough to swap over one of my regulators for a different one from his spares.
A nice gesture and a genuinely nice bloke.
Have to say as well, over and above the whistling being gone my Dac is sounding better than ever.
Read up on these Dexa regs and they are offered as upgrades to existing kit by several 3rd party modding websites - even for kit like the Rega Saturn cd player and Wadia transports.
An upgrade to the Saturn..Wadia? Must be good then!
Forum posts on DIY sites too talk about the Dexa's being a great upgrade to existing kit, so think I've made the right choice fitting them in my Dac.
One question though...?
I've always found new components tend to improve over time, is this the case with these Dexa regulators too?
Good improvement in soundstage focus and detail right out the box, but I'd say there was a shade less "impact" and front to back stuff from what I remember before?
Overall a good bit better than before, but just something I noticed.
Should it potentially improve over time?
So really...I've modded my Dac now about as far as I can take it, nothing left to do - extremely happy to have my (improved) sounds back. :)
With all the SB Touch software mods and my improved Dac, things are sounding good.
Hi Gary,
That's excellent news! Many thanks for the update. I'll get some Dexa's ordered ASAP. Where did you get yours from?
Cheers. :cool:
BTW, your PM box is full. ;)
Hi Gary,
That's excellent news! Many thanks for the update. I'll get some Dexa's ordered ASAP. Where did you get yours from?
Cheers. :cool:
BTW, your PM box is full. ;)
Hi Dave,
I got them from Partsconnection in Canada. Quick delivery - cheapest prices.
UK sellers looking for £30 each + delivery, I paid abut £45 delivered for them both.
Buy with confidence. :)
Very good news, Gaz, I'm glad that the Dexas worked for you.
I think I may have been the very first person to put Dexa regs into my Caiman and there has been a small flurry of Dexa upgrades of late. My Caiman continues to sound superb :)
Canetoad
28-08-2011, 08:50
As does mine. :)
Very good news, Gaz, I'm glad that the Dexas worked for you.
I think I may have been the very first person to put Dexa regs into my Caiman and there has been a small flurry of Dexa upgrades of late. My Caiman continues to sound superb :)
Cheers martin.
Did you find the Dexas changed at all over time?
Just wondering about burn in n' stuff. :)
Not to anything like the extent of the coupling caps, which took much longer to settle down.
Thanks Martin.
I've been out and about for a couple of days and left the system running till I got back.
Came home this morning and its sounding great.
happy camper here. :)
HighFidelityGuy
01-09-2011, 15:09
My Dexa's have arrived and I'm hoping to get them installed tonight. I'll report back ASAP. Wish me luck. :)
Canetoad
01-09-2011, 17:00
Luck! :)
My Dexa's have arrived and I'm hoping to get them installed tonight. I'll report back ASAP. Wish me luck. :)
No luck needed Dave, the background noise will be a thing of the past.
Wish I could say the best way to get the Murata's out - Jimmy Dripps did mine.
Good step up in sound quality with the better regs - well worth it.
Good luck! :cool:
HighFidelityGuy
01-09-2011, 22:27
Thanks chaps. :)
I'm happy to report that my Dexa's are installed and they've cured the hiss and the whistle! :carrot:
The Murata regs were quite tricky to remove as their pins fit quite tightly in the PCB holes. The 5V reg was the worst as it's on a double sided board with through plated holes. Despite being very careful I managed to pull out all three of the through plating tube things. :doh: It wasn't a major issue though you can just solder the pins on both sides of the board. I also ended up needing to replace both ribbon cables with individual cables as they pretty much fell off. I'm not surprised really as I've taken the PCB's out of the case quite a few times and they're quite brittle. So those two little slip ups made the job take longer than it should have but the excellent result was worth the effort and time.
I'll report back in a few days on sound quality once the new regs have bedded in. :cool:
HighFidelityGuy
02-09-2011, 09:39
On the subject of heat output from the Dexa regs, the 5V one definitely gets rather hot. I removed the 10 Ohm 1W resistor from behind the 5V reg when I installed the Murata regs. So no doubt the excess heat from the 5V reg is due to the fact it's dropping 10-11V. Ideally we could do with dropping the input voltage to the 5V reg down to about 8V. Does anyone know what resistor value would achieve that? :scratch:
EDIT: I guess I need to know how much current the 5V part of the Caiman draws through the resistor so I can plug that into ohms law. Does anyone know what the current usage is? Cheers. :)
I've left mine without a heatsink, since the tilt required to get the Dexa inside the cover makes adding a heatsink difficult. I too have bypassed the dropper resistor.
HighFidelityGuy
02-09-2011, 11:58
Thanks Martin. I'm sure the Dexa regs work ok without a heatsink but when you read the installation info on the NewClassD (http://www.newclassd.com/index.php?page=70) it does recommend that if the original reg had a heatsink then you should also use a heatsink with the Dexa. So I'm just trying to follow their guidelines. :)
I've left mine without a heatsink, since the tilt required to get the Dexa inside the cover makes adding a heatsink difficult. I too have bypassed the dropper resistor.
Hi Martin,
do you mean you removed the resistor behind the 5v reg and replaced it with a wire link?
Thats how my dac is...would be great if I could stop tinkering with it now!
Dave,
have you sen this post?
http://theartofsound.net/forum/showpost.php?p=246625&postcount=41
Yes, Gaz.
Hmm, nice heatsinks in Paul CZ's shots. Looks like they had the attentions of a hacksaw.
Yes, Gaz.
Hmm, nice heatsinks in Paul CZ's shots. Looks like they had the attentions of a hacksaw.
a hacksaw!!! you make it sound so cheap and brutal. I am sure that it was done with a delicate touch and the use of a fairy's brom
Yes, Gaz.
Hmm, nice heatsinks in Paul CZ's shots. Looks like they had the attentions of a hacksaw.
Excellent, no more tinkering for me. (he says....again) :)
Not ever having used the Muratas, I'm intrigued that two of you report a sound quality difference when swapping to the Dexas. Could you say what that difference is?
Perhaps Stan needs to switch to recommending the Dexas as the upgrade regs from now on. Certainly I've had no issues with mine at all since I put them in.
Not ever having used the Muratas, I'm intrigued that two of you report a sound quality difference when swapping to the Dexas. Could you say what that difference is?
Perhaps Stan needs to switch to recommending the Dexas as the upgrade regs from now on. Certainly I've had no issues with mine at all since I put them in.
Good point Martin.
the majority of folk had no problem with the Gator/Murata combination so it was a sound recommendation.
BUT...
the Murata's are switching regs, probably not whats ideal in a dac. I remember someone saying at the time (DJSR was it?) that it seemed an odd choice.
Regarding the Murata background noise, best theory I've heard came from Jimmy Dripps of Tirna (and I no doubt misquote), who thought it was a case of both regulators operating at a frequency too close to each other (just bad luck) and this caused an audible "beat" which manifested itself as the noise.
The improvement?
Apart from the obvious removal of the background tone I have a more solid soundstage with better placement.
Also the front to back stuff seems more obvious to me.
Biggest change though (in my system) is that it plays tunes better.
Rythyms flow better, it seems smoother but with more detail?
Maybe the hallmarks of cleaning up the power going to the dac chip?
Dunno..but it works. :)
a hacksaw!!! you make it sound so cheap and brutal. I am sure that it was done with a delicate touch and the use of a fairy's brom
... well, that is my weapon of Choice ;-)
http://tapatalk.com/mu/574e8830-227e-9a2c.jpg
HighFidelityGuy
02-09-2011, 19:05
The improvement?
Apart from the obvious removal of the background tone I have a more solid soundstage with better placement.
Also the front to back stuff seems more obvious to me.
Biggest change though (in my system) is that it plays tunes better.
Rythyms flow better, it seems smoother but with more detail?
Maybe the hallmarks of cleaning up the power going to the dac chip?
Dunno..but it works. :)
I was going to hold back on my comments on sound quality but after doing some listening tonight and then reading the above comments I felt that I ought to chip in and say that I'm hearing pretty much the same improvements. I've got a bigger sound field, more detail and texture but with a smoother presentation that's not fatiguing. I'm finding I can crank the volume a bit more and get a bigger sound without things getting too forced. :eek:
I think that some of this will be due to the lower noise floor now that I've not got a constant hiss and whistle muddying everything but I'm surprised by the sound field improvements. I wasn't expecting that, so it's a nice bonus. As I also replaced the ribbon cables with solid silver wire I guess that change could be playing a part in what I'm hearing but I can't be sure. Either way I don't really care as I'm loving the sound I'm getting now, it's definitely the best I've heard from my system yet and with any luck it might improve further over the next week or so as the new bits run in. :fingers:
So now the only thing I want to do is cool down the 5V reg a bit and I'll be very very happy. :cool:
Dave?
Ironic thing is that it was you who organised the group buy on the Murata's....
what goes around comes around...:)
Regarding the Murata background noise, best theory I've heard came from Jimmy Dripps of Tirna (and I no doubt misquote), who thought it was a case of both regulators operating at a frequency too close to each other (just bad luck) and this caused an audible "beat" which manifested itself as the noise.
Hi Gazjam, I'v tried two different pairs of muratas, one pair from Tirna and later one pair directly from US (tried to resolve the whistle), but both pairs had the same issue so it would be quite surprising if in both cases I'd hit some specific frequency. I'll probably try to combine those pairs in between them before buying Dexas if my PCB would allow me to experiment further because I also Melted junctions of PCB for 5v reg already :/
btw I had to replace ribbon wire too, seems to Br quite common issue when modding too much :)
Tomas
Hi Tomas,
Honestly?
I'd go for the Dexa's and be done with it.
They should improve the sound of your Dac as well as removing the whistle noise.
I attempted to fit the Dexa's myself, got as far as being unable to remove the Murata's properly before realising its time to call in an expert! :rolleyes: :)
HighFidelityGuy
03-09-2011, 10:05
Dave?
Ironic thing is that it was you who organised the group buy on the Murata's....
what goes around comes around...:)
:sofa: Yeah, hindsight's great isn't it. :lol: It seemed like a good idea at the time with the info that was available back then. I guess the Murata's turned out to be a bit of a waste of time and money for some people but at least they provided an improvement for a year or so.
I think this experience proves quite well just how difficult it is to choose components that complement each other to produce the best end results in a product. You really can't rely on the spec sheets to tell you how components are going to work together. So I'm now starting to understand why some manufacturers spend years developing some products by trying hundreds of combinations of components until they find the perfect balance. It's more of an art than a science in some ways I guess. :)
HighFidelityGuy
03-09-2011, 11:20
I decided to do some heatsink butchery of my own and took a hacksaw to an old graphics cart. I ended up with some L shaped sections with lots of little fins on the back. Due to the space restrictions around the 5V reg I had to trim that heatsink down quite a lot but I have some small memory chip sinks which I'm going to attach to the main one with thermal adhesive. The 5V reg now runs much cooler so that's put my mind at rest. Here's what it all looks like so far:
http://i2.photobucket.com/albums/y48/DTM2000/Hi-Fi/Beresford%20DACs/Dexaheatsinks01.jpg
The sink on the 12V reg is waaaay bigger than it needs to be and currently obscures one of the screws that secures the PCB to the chassis. So I'm going to tweak that later. As you may have noticed I've removed the two pairs of output connectors. I removed the fixed output a while ago as I wanted to hard wire that output to a short home made silver interconnect that connects to my passive preamp below. I then removed the variable output to make space for the 5V reg's heatsink. I've also removed the headphone output socket to allow me to solder the Gator board in place and I've removed the USB input to make way for an extra optical connector. What with them and all the other mods there's not many original parts left in my Caiman. :lol:
Canetoad
03-09-2011, 20:12
Dave, when you do replace the USB with a toslink let me know where you sourced the parts. I'm thinking of doing the same thing myself. :)
I've just replaced the Maplins CB supply on mine with a bespoke PSU I put together myself. I'm running it at 15.8v so that the Dexas should now be getting round 15v. The sound has improved even more! I actually heard something I hadn't heard before on the Steely Dan - Do It Again track. There's definitely extra detail now that the noise floor has obviously improved. Music has more impact and dynamics too. I'm very pleased with my setup now! Even my wife noticed the difference with the new PSU.
I'm going to build another PSU to power my Touch now. :eyebrows:
HighFidelityGuy
03-09-2011, 23:14
Dave, when you do replace the USB with a toslink let me know where you sourced the parts. I'm thinking of doing the same thing myself.
No probs. :) I bought some Toslink sockets ages ago to do this but I've just not got round to it. I'm hoping the ones I got are the right ones. I think I got them from Farnell but I'm not sure now. I'll have to check. I think there may be a slight issue with the chassis cut-out for the USB socket being slightly in the wrong place for a Toslink socket but I think it will be easy to get round with a little metal working. I'll let you know how I get on. :)
HighFidelityGuy
05-09-2011, 10:53
Dave, when you do replace the USB with a toslink let me know where you sourced the parts. I'm thinking of doing the same thing myself. :)
I've just dug out the Toslink socket I have. It's THIS (http://uk.farnell.com/toshiba/torx177pl/receiver-fibre-optic/dp/1225766?Ntt=122-5766) one from Farnell. I'm in the progress of modifying my regulator heatsinks a little more so I'll hopefully install the Toslink socket tomorrow when I build the DAC back up. I'll let you know how I get on. :)
Odd thing happened tonight....
Was listening to some classical music, quiet stuff just chilling out.
Crap, whassat?
I heard a background noise not dissimilar to what I heard with the Murata's but a lot quieter.
Putting my ear up to the speaker there it was, like before it only kicked in when music was playing.
Thinking it was my Dac (aww what now?!!:rolleyes:) I switched everything off and back on, made sure all cables were in tight and sat back down.
Noise still there, but as time went on I noticed the "tone" of it changed when I was going through the SB Touch's menus...weird.
Unplugged the Touch and the noise was gone.
Almost like I could hear the noise the Touch was putting back in to the system?
Its the original PSU and I'm thinking as the Dacs far more transparent now with the Dexa's I'm now hearing the crap the switcher on the Touch is leaking out?
Possible you think?
So I'm thinking about changing the PSU on the Touch, any suggestions for a linear supply...?
*EDIT*
The problem being mains related I thought about maybe trying a filter, so I managed to track down a Belkin PF30 for £42 online and ordered one of those.
(Pretty good writup on here and elsewhere from folks with a high bullshit radar, so worth a punt. I figure if it doesnt help in my system I can pass it on in the classifieds)
So..linear supply for the Touch...hmnnn.
Cant afford foo really unless its justified though.
Thanks. :)
It does sound like it's the Touch PSU. Is it a switching wall-wart?
Canetoad
06-09-2011, 06:52
I've just dug out the Toslink socket I have. It's THIS (http://uk.farnell.com/toshiba/torx177pl/receiver-fibre-optic/dp/1225766?Ntt=122-5766) one from Farnell. I'm in the progress of modifying my regulator heatsinks a little more so I'll hopefully install the Toslink socket tomorrow when I build the DAC back up. I'll let you know how I get on. :)
Thanks Dave. I'll take a look at these. Let me know when you get it installed.
Canetoad
06-09-2011, 06:59
Gaz,
I'm currently using a Maplins adjustable PSU on my Touch till I can get a dedicated linear supply for it. Part number is L11BQ. It's on special at the moment for £19.99. I paid about £30 for mine.
Might be a good stop-gap till you get something better. :)
HighFidelityGuy
06-09-2011, 09:39
Thanks Dave. I'll take a look at these. Let me know when you get it installed.
Well I fitted one of the Toslink connectors I got from Farnell and it doesn't work properly. I just get clicks and pops. So I wouldn't recommend trying that one. I'm not sure if it's the connector that's the wrong type or whether something else needs modifying to make that input work with a Toslink socket. :confused:
StanleyB
06-09-2011, 09:51
It should have worked right away. I'll have a think about the symptoms.
HighFidelityGuy
06-09-2011, 10:51
Thanks Stan! Much appreciated.
I don't think I've done any mods which could have knackered that input. I'm sure I tested the USB input when I first got the DAC and then I removed it about a year ago as I didn't need it and it was getting in the way when doing mods. The other optical input works fine. :)
It does sound like it's the Touch PSU. Is it a switching wall-wart?
Thanks Martin.
The Touch psu is a switching supply, not had any probs with it before though and its supposed to be a lot more electrically "clean" than the previous SB3 one.
Theres no other switching supplies in my system and I'm targeting this as I can hear the noise change when I adjust the menu's on the Touch.
The only thing thats changes really is getting the Dexa's fitted to the Dac.
Maybe its the supply itself?
I think I have a similar rated switching supply in my box o' bits, I'll troubleshoot by swapping that in that and see if it changes things.
Gaz,
I'm currently using a Maplins adjustable PSU on my Touch till I can get a dedicated linear supply for it. Part number is L11BQ. It's on special at the moment for £19.99. I paid about £30 for mine.
Might be a good stop-gap till you get something better. :)
I have one of those Bernie :)
Used it in my old 7510 dac, need to dig it out.
Its a switching supply I think though, but I'll try that along with the other suitable psu I have, just to check if its my Touch supply thats causing the noise.
Theres no other switching supplies in my system and I'm targeting this as I can hear the noise change when I adjust the menu's on the Touch.
Are you running optical between your Touch and your Dac?
I am just pondering about how the noise travels... piggybacking on the music, cables or via the mains... well you did state that you only hear it when music is playing
Hi Jan,
no, I'm ruiunning a coax cable between my Dac and Touch.
The Bdac uses a linear power supply.
When musics not playing the Dac has a mute circuit in place..silent when that kickes in.
*update*
The noise goes away when I take the standard Touch psu out and swap it for another. I guess somethings happened to the supply over time - no idea what.
Ah well - at least the noise is away.
*update 2*
FedEx delivered my Belkin PF30 today - installing it tonight, so wonder what to expect :)
For you guys that have one (or three!) in place, what would you suggest as a good way to use it with your kit?
For instance should I still plug my amp into the mains and not the "high current" socket?
If so, whats the best use for the high current one...the telly?
What about the Switched and Always On sockets...?
Stick the Dac and Squeezebox in the "Always On" ones?
I'll be plugging in...:
Plasma telly
Virgin Box
Dac
SB touch
Amp
Router
USB Hard Drive (used for streaming movies to the telly)
thanks.
Reid Malenfant
07-09-2011, 18:30
Hi Gary, i'd try this route as it works for me ;)
The amp i'd plug straight into the mains. I'd plug the TV into the switched socket as not only does that remove standby power but it has it's own filtering (handy as it'll have an SMPS).
Any other devices powered by SMPS connect to the "digital" socket/s. All other devices connect to "analogue" sockets.
I'm not sure the digital/analogue description will be correct as i'm attempting to remember the back of the PF40s.
Hope that helps :)
Bit confused mark, sorry! :)
the back panel looks like this:
http://www.salonhifi.ru/img/i832_b1.jpg (ignore different socket types)
Reid Malenfant
08-09-2011, 18:14
Ah, ok... Well regard the audio & video filters as seperate. Plug your TV into the high current socket. Anything powered by SMPS into the video sockets (my thinking is most video stuff these days uses SMPS as the norm) & anything with a normal mains PSU into the audio sockets :)
Your amp into the wall as before.
That's a bit better innit ;)
Cheers Mark :)
have to say, I would have been happy just for the Belkin having tidied up the mess at the back of my rack, but I never expected the sound improvements Im getting.
My mains must have been crap...
Reid Malenfant
09-09-2011, 17:54
Pleased it's made an improvement :) I can't say i'm surprised though as the filters work both ways, so any junk that any SMPS powered kit will generate will be filtered out (hopefully) by the other filters feeding the kit with a standard PSU ;)
They do a good job of isolation i find, of course they'll still filter crap that's on your ring mains to :cool:
Distributed filtering and different filters help a lot, I find. I have two PS Audio Harvesters, a Russ Andrews Silencer and an Isotek Isoplug plugged in around the house.
The Harvesters are excellent for seeing how noisy my mains is: sometimes they appear dead and other times they are flickering madly, absorbing the noise.
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