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These Dexa regulators from Parts Connexion look interesting. If the "100 times better ripple rejection, 10 times lower noise" claims are true then they should make a substantial difference over the stock 7805/7812 regulators. I'm ordering a 5V and 12V module just for the fun of using something different and will report on my findings when received. I should have the Caiman PSU soon, ready for them.
http://www.partsconnexion.com/regulator_dexa.html
The Murata versions are similar in spec, and a fraction of that price.
Understood Stan - I was feeling adventurous and just thought I'd try them. Think of it as adding to our pool of component knowledge.
If spending that sort of money I'd have gone for the Paul Hynes , anyway let us know how you get on with the Dexa's Martin
So I finally had some time to put in the new non-polarised caps this morning, they're still settling in, but I can hear a pleasant improvement.
Here are a couple of photos of the operation.
http://img685.imageshack.us/img685/2187/p1020644.jpg
http://img43.imageshack.us/img43/883/p1020655v.jpg
The capacitors quite literally only just fit into the case. So much so that, I placed a couple of stickers on the underside of the lid over the op-amp board to ensure i dont get any chances of a short.
I also fitted a couple of OP1234 op-amps. Must admit I like the improvements.
Stan if you could please let me know the minimum capacitor value to get rid of the DC offset without limiting the bass I would really appreciate it.
Since I don't have a camera I`ll explain what I did, disconnect the 3 wires(labeled L,G,R (for left, right and ground)) on the far right side of the board, on the closest board to you when looking at the DAC front on. Then I disconnected the line out connectors to the board. Then soldered a "high quality" capacitor from electronics store near me to fix the DC offset, between the left and the negative connector and the same for the right and the positive connector).
Having been quietly following the Beresford DAC phenomena since the 7510 days - I finally gave in and ordered a Caiman from Stan about a month ago to partner my Shigaclone.
I have to agree with almost everything already said about this fantastic DAC - out of the box it was good, but obviously burning in - within a day it was something else - now with a couple of hundred hours under it's belt it is a wonderous thing and like most others, I have been rediscovering my CD collection.
Inevitably the urge to see what could be extracted from this beast had me rolling opamps recently - I'm fortunate to have a good stock of so-called 'audiophile' opamps hanging around from various projects so i got to it. My usual favourite is the THS4032 - but in the Caiman it just wasn't right IMO - I went through most of the usuals - OPA627, AD845,AD846,AD847, OP2132,LT1364 + more - in the end i returned to the stock LM4562's that Stan fitted. Nice one Stan - I reckon you got it bang on with these! - Other opamps can do some things better but in my system none of them had the balance that the stock ones have :clap:
So - then I flirted with the resistor & cap in the feedback loop - but didn't get on with that either - again the balance seems better with just the stock resistor and MCL5/6 left empty. After that it was the 4 line stage coupling caps on the analogue board - a quad of 3.3uF Wima polys replaced the lytics and have removed a thin veil - the jury is still out on them and I turned my attention to the power supply.
Because just one 7805 feeds all the +5v in the device - I started to take a look at just how many seperate regs it would take to give every user it's own supply. The truth is - I think there are at least 9 different users points!! - the important ones are obviously the DAC and receiver chip - but in reality the DAC itself has 4 seperate supply points - and the receiver has 2. I began by knocking together a trio of +5V LM2940's on a small piece of vero - then looked at the Caiman board to see where I could seperate the single supply and inject some fresh volts.
the bottom line is - splitting these supply points is not THAT easy - injecting seperate volts for the receiver digital and analogue supplys was pretty straightforward - but finding a suitable place to seperate the digital supply for the DAC chip wasn't easy - mainly because of the size of the device and the fact that pins 8 & 9 (+5V dig & +5V R.Analogue) share the same local decoupler and bypass! - this was super tricky and not for the faint hearted. But - I now have 3 extra +5V regs feeding the dig and analogue parts of the receiver and the dig supply of the DAC chip - all on a neat little piece of vero that fits inside the case still - I'll get a pic or 2 up soon. The existing +5V reg still supplys everything else - Eventually, I may seperate the Wolfson analogue supplys too with an additional 3 regs.
So how does it sound? - quite stunning IMO!! - seperation is the word here - really, the ability of this DAC now to extract micro details in the music is just outstanding. The tonal balance has not been affected too much either - it might have become a little brighter - although I suspect this may actually be because all those little cymbal splashes are now more evident.
Anyway ....................................... the main reason for this post was to say that Farnell UK have a couple of dozen of those Murata +5V switching regs in stock - no. 1703410 - I ordered one to see what it can do - should be here tomorrow.
thanks to Stan for a great product and thanks to all the contributors to this and the other great DIY threads on AoS.
hmm...i thought this was the right place to ask this.... :doh:Quote:
Originally Posted by toad
what are the BG equivalents....?
the 47uF 6.3V NX Hi-Q or something rated higher...?Quote:
Originally Posted by toad
Quote:
Originally Posted by toad
Sorry Toad, I'd say 6.3v is a bit too low voltage in this application, go for 16v or higher.
If your struggling with the taller caps I guess you could lay them on their sides, the grey caps Stan recommends are pretty good though and fit ( a little tight but still fit)
Edit, if your set on using BG's with their unique colouration :whistle: the BG N 33uf 16v may fit, not sure, you'd have to measure the space in the case, measurements for these caps are 6.3mm dia x 11mm length
thanks leo....
drat...that wasn't the reply i was hoping for as i ordered them a week ago... :scratch:
alright then....16v caps it is...
You got a multimeter Toad? you may be able to use a couple or more of the 6.3v BG's rather than waste them, I can't remember the voltages going to all those caps, if you measure the stock ones you'll know which maybe ok if that makes sense, long as the voltage is lower than say 6v, I personally like plenty of headroom regarding the caps max rated voltageQuote:
Originally Posted by toad
The 6.3v you have spare, well you could try them on the dacs 5v supply pins, BG N types are suited as both coupling or decoupling:)
Ever seen an exploded electrolytic? Personally, I wouldn't risk the nice insides of the Caiman.
Yes and also tants, not the prettiest of sights:lol:Quote:
Originally Posted by MartinT
thanks again leo for the assistance...
i do have a MM...
i'll have a boo at those caps to see who is doing what....
where would the dac's 5v supply pins be located...?
This any use ?Quote:
Originally Posted by toad
http://www.wolfsonmicro.com/uploads/...nts/WM8716.pdf
Chris:)
Ok, I've got the two Dexa regulators (+12V and +5V modules marked 'NewClassD') in place. Angled as shown, they just fit snugly inside the cover. They also feature tiny blue LEDs to show that they're working properly. Output voltages are spot-on using the Caiman 15V PSU. I have deliberately not performed the capacitor upgrades yet as I wanted to hear what the regulators do.
Listening to it now, the Caiman has improved focus (up to that of my Ayre C-5xe) and extended and growly bass (almost up to the Ayre's admittedly high standard). It sounds fab playing films and CDs from my Blu-ray player as transport. I cannot test Sky HD as I have no signal since my dish got clogged with snow.
Altogether a very worthwhile improvement and fun!
http://farm9.staticflickr.com/8057/8...9cf400d8_b.jpg
Hi Martin,
Nice work. How much did the Dexa's cost?
Can you detect much sound difference over the stock regulators?
Regards
Chris
Thanks. They cost $39.95 each from Parts Connexion here:
http://www.partsconnexion.com/regulator_dexa.html
As I said, the main improvement is over focus, which is now extremely good. This gives very precise positioning in the stereo stage and a spacious feel with very low noise floor.
Before I go ahead can I please confirm which are the four electrolytic capacitors to be replaced for just the fixed line level output?
The 4 with red dots on, top and bottom left ones input to op-amp, top and bottom ones on right are op-amp output
http://i273.photobucket.com/albums/j...soms/dac-1.jpg
That's great - thanks Leo. Doing them now.
No probs Martin, let us know how you get on:)
Done. Oh yes, another subtle improvement in clarity and focus. I just watched Quantum of Solace on Sky HD (now that the snow's off my dish) and the soundtrack is superbly delineated and detailed. This is one very fine DAC indeed and worth the modding cost.
More information on the Dexa 'NewClassD' regulators, made in Denmark:
http://www.newclassd.com/index.php?page=70
as promised several days ago a few pics of my Caiman - at the moment!
1. The output board with the Wima film caps - after listening to this for a week or so I've decided to keep them - 3u3 was the largest value i could find whilst keeping the physical size small enough to fit neatly - I've got away with it with my Puresound and theres no hint of any bass lightness. At the same time I fitted a couple of ZA's to decouple the non-inverting input too. - haven't touched the headphone amp yet!
http://img.photobucket.com/albums/v7...o/IMGP2006.jpg
2. The regulator board fitted neatly to the rear panel - at the moment this contains 3 x LM2940 +5v regs with each having a small inductor and caps to keep it stable. Eventually i will swap out each one with an Audiocom super reg i have in another project - see what difference it makes. I also have another few of those Murata 7805SR switching regs which will go in here at some point - for the time being i was just curious to see what difference it would make if i seperated the supplies. Currently these 3 feed the Wolfson dig. supply, the CS dig. supply and CS analogue supply. The board is fed from the incoming 15V supply - I added a couple of veropins to some redundant padded holes in the board - you can just see one of them in the last pic.
http://img.photobucket.com/albums/v7...o/IMGP2023.jpg
3. An overview of the digital board showing the Murata reg fitted in the original location and a smattering of cap upgrades - ZA's, OScons and the odd BG I had lying around. The multicoloured link wires replaced the original grey ribbon which wasn't really flexible enough to allow for repetitive board removals! The replacement caps haven't been in too long yet but after just a few hours the low freqs have more slam - and the highs seem crisper - hopefully things will improve further as things settle in.
http://img.photobucket.com/albums/v7...o/IMGP2022.jpg
This is work in progress and I have some other ideas but am trying to keep it slow - it's quite a challenge to work within the tight spaces but I'm enjoying it - be warned though, it is not for the inexperienced - especially splitting the supplies which can be a real headache. This thing is certainly a giant killer though and I have never heard my system (Puresound/Triangle) sound like it does at the moment - all those little reverb clues in the music are much more evident now - puts a huge grin on your face!!
Oh and something I noticed recently - Farnell are waivering the US delivery charge for the remainder of January - this means that the Murata +12V switching regs can be had for less than £15 - I've just ordered a couple - as I mentioned in my previous post the +5v ones are UK stock and are a bit less than £12 each - they are great value for money and in my experience give some of the so called 'low-noise' regs a run for their money.
Nice work here-we-go-again (what is your name?), did you work from a circuit diagram or did you trace the +5V rails from the PCB tracks? What have you done about +12V - I see the heatsink is missing, but what regulator have you got in there?
hi Martin - glad you like - oh and a circuit diagram would be great!! but no I just followed the +5v as it meandered it's way around the board. Study and print off the datasheets for the receiver and DAC then split/seperate as necessary. The main difficulty arises from the fact that this is obviously a double sided board and the tracks frequently hop from one side to the other through plated holes - check, check, then check again BOTH SIDES before cutting the track at a suitable point, drilling a hole and wiring up - remembering to include the decoupling cap and bypass in the new supply. You could get away without drilling but I wanted it to look reasonably neat.
The receiver wasn't too difficult to suss out and of course it's a larger package which helps - the DAC is not funny at all and takes much head scratching. The positioning of the DAC de-coupling caps and bypasses around the chip makes seperating the supplies here really tricky - but just about possible. I hope I don't sound patronising, but it is seriously tricky and only for the experienced - so very easy to ruin the thing.
Regarding the +12v, I haven't attacked that yet - just removed the heatsink in preparation while the board was out - it doesn't even get warm.
oh and my name's Graeme - sorry must get a sig. sorted sometime!
I'd like to try the Murata reg's but as Stan said the shipping is a bit pricey. Orders over £50 get free delivery on Mouser, so if two or three (or more) other people are interested in trying these then I'd be happy to place the order and post them out. I'll order in pairs (one 7805SR-C and one 7812SR-C) and only charge the price it costs me to order them plus the postage to you, which should be cheap. If anyone is interested drop me a PM. :)
Top idea Dave.
Please count me in and I have also sent you a pm. Anyone done both regs and liked what they heard?
Regards
Chris
Yes, I like the improvement in focus, imaging and detail very much.Quote:
Originally Posted by chrism
Dave - did you read my post? - both of them?Quote:
Originally Posted by HighFidelityGuy
get to the Farnell UK web site - the +5v Murata is UK stock and is £11.85 - there are NO delivery charges with Farnell - the stock no. is 170-3410
The +12v Murata, stock no. 165-4856 is £14.27 - but it is USA stock which normally attracts a £15.95 delivery surcharge - for the remainder of January that surcharge IS BEING WAIVERED - Look at the webpage.
so for a TOTAL of less than £27 you can have both Murata regs - delivered. the +5v one will be next day, the +12v one takes 3 days-ish - mine took only 2 days - from Philadelphia!!!
FWIW - my +12v reg is now fitted to the front board along with a Ruby ZA decouple. It has made a substantial improvement again to the amount of detail that this DAC can get out of the music - the pair have probably made more difference than the +5v one did - extremely impressive.
Hi Graeme,
Thanks for the info, I must have missed where you mentioned that.
Despite the Farnell shipping surcharge being wavered Mouser is cheaper (with free delivery) as they charge less for the parts. So if I can get another one or two people to chip in we'll save money overall.
If nobody else chips in Farnell would be the cheaper option.
Cheers. :)
I'm happy to join you. Do you know how much its likely to be?Quote:
Originally Posted by HighFidelityGuy
Excellent, thanks James.
The reg's are £8.15 each. So £16.30 for a pair. You then just need to add postage. The packages should be bellow 100g each so this will be a couple of pounds or so depending on what postage method we go for. I'd probably prefer to use "1st class signed for" for the added traceability. So you're looking at approx £18.30.
Does that sound ok to everyone?
That sounds fine with me.Quote:
Originally Posted by HighFidelityGuy
Thanks Dave. :)
Im very tempted to get 2 sets given their price. 1 pair for my Caiman and one pair spare for future mods.....hmm....decisions. :lol:
Hi Dave,Quote:
Originally Posted by HighFidelityGuy
There are at least three of us wanting the regulator/capacitor mods done to our 7520's. We have asked Tirna to read the thread so they can quote. If everything goes to plan they will need three sets so will contact you. Hope you dont mind hanging on a few days just so we can firm things up.
That's fine, I'm not in a rush. Just let me know when it's all sorted. I'll then double check with everyone how many I need to order and take it from there.
Cheers. :)
Hi Dave,
Can you please count me in as well for one pair.
Jerry,Quote:
Originally Posted by Covenant
Let me know too. I'm a novice with the soldering iron and need some Tirna assistance!
Cheers
Ade
Sure Ade-the more the merrier. As soon as we know more from Jimmy at Tirna we will be in touch.
Hi Jerry,
(Gentle prod with a blunt stick!)
Have you managed to contact Tirna to see if they would like any as I am eager to obtain mine and if it's going to be a while will probably just go for it.
Regards
Chris
Hi Chris,
I will prod Tirna again-he is looking at prices.
I've just finished installing a full set of the non-polarized Rubycon caps into my 7520 that I use at work for headphone duties. Although the caps probably need to run in I definitely noticed an improvement in the subtle background detail. This added an extra air to the sound and is a nice improvement. I'm definitely going to do this mod on my Caiman back at home ASAP. Hopefully I'll have that done in time for the Murata regs arriving once that's all sorted out.
On the subject of the regs, Jerry asked me to send him my email address, which I've done, so one of us will let you all know what's happening soon.
i'll just chime in with my impressions of my recent caiman mods...
a couple of weeks back i installed the new murata regs, just the regs...
i immediately noticed an increase in mid and higher frequency detail and clarity...almost to the point of brightness...certainly the digital 'sharpness' of my stock duet became much more apparent...
as a result, the sound seemed tilted upwards and the lower mids and bottom seemed hollowed and somewhat muted...
then i took delivery of a handfull of elna silmic II 47uf 25v's....(thanks to rockstars recommendation)....i'm into them now for ~50hr...AH HAH...the bottom is back with vengence...Stan is dead on were he states earlier in the thread that the murata's and re-capping are complimentary....
Hi Dave.Quote:
Originally Posted by HighFidelityGuy
If its not too late can I jump on the bandwaggon and put my name down for a set. I've just this weekend taken the plunge and ordered a Caiman as a start of upgrading my Hi-Fi. At some point in the future I'm sure I'll want to tinker with it.
Obviously I'm a complete unknown in this group but have been lurking anonymously for the last couple of weeks. Dave I'll PM you with my email.
Cheers :)
Graybags,
Quick you'd better move fast before the 'first post police' collar you!
Head over to the Welcome section & let folks know some simple stuff like your first name, whereabouts (roughly) you live, what your system is, what type of music you like.....all that sort of stuff.
Welcome!!
:lol::lol::lol::lol::lol:Quote:
Originally Posted by The Grand Wazoo
Wot he said, but I'll say "welcome" anyway!
Has anyone got an update on whether Tirna want me to source the regs for them or not yet? If possible I'd like to work out how many we need quite soon so I can place the order next week
Cheers.
Through following this thread I taken the plunge and ordered the Murata Regs and Non-Polarized Caps to upgrade my Caiman.
Has anyone undertake a mod of replacing the standard fitted RCA sockets line out/variable out with higher quality RCA sockets such as CMC, WBT and Cardas. Was it an easy mod removing the standard sockets from the PCB, which RCA's did you replace them with, what wire did you use, and what were the audible results of the mod if any ?
Looked at this thread for Modwright RCA upgrades and some of the claims made
http://www.agoraquest.com/viewtopic...._page_number=1
Your thoughts, your experiences please
Frizzup
I wouldn't bother TBH,doubt it would make much if any difference.I'd say you'd be better off doing some of the othermods.