Bernie - if you've not yet installed the Silmics, regs and linear PSU then I would hold judgement as all these mods improve detail while removing harshness. I don't find the Auricaps in any way bright, but the detail is marvellous.
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Bernie - if you've not yet installed the Silmics, regs and linear PSU then I would hold judgement as all these mods improve detail while removing harshness. I don't find the Auricaps in any way bright, but the detail is marvellous.
Will do Martin. I've probably put the cart before the horse in this instance. I don't mean to be critical of the Auricaps. They do sound very good. On some songs the bass is thunderous!
If you proceed with a linear PSU, then will you need a new case.
Also, have you in your mind the 10 or 15uF MKP Obbligato Premium capacitors. They fit in a new case perfect and produce a marvellous sound!
Why? I and several others have built an external linear PSU, merely replacing the switched mode one that comes with the Caiman.Quote:
Originally Posted by lemon
Seperate boxes all over the place are a thing of the past imho..Quote:
Originally Posted by MartinT
I think what this chap is saying is you'll need a seperate case to house the linear PSU inside of. Best not to have a 230V transformer exposed for all to touch :eek:Quote:
Originally Posted by lemon
On that note i agree & i somehow very much doubt anyone could fit a linear PSU in the standard case along with the DAC itself :lol:
So it does make some kind of sense at the end of the day... Unless you feel like putting the Caiman in a bigger case & fitting a suitable PSU in there as well ;)
Yep, my wife has a £50.00 Sanyo one boxer in the Kitchen and says "why do I need more"! :eek:Quote:
Originally Posted by Andre
Chris
Hello,
I'm Sorry but writing in English is difficult for me, anyway I would like to give fedback regarding the mod suggested.
I'm living in a small studio and the acoustics of the room is quite complicated, currently my system consists of: PC »» TC7520 »» Marantz PM7003 »» ELAC BS244.
I was having the following problems:
- The bass was loose and exaggerated compared with the midrange.
- The midrange seemed unfocused, without detail and separation of instruments.
Even with my old speakers and amplifier it was the same problem, I tried several op-amp's but I was never completely satisfied with the sound, since I replaced my old amp and my DYI open-bafels by the Marantz and the ELAC speakers the problem became even more evident.
I was considering buying a new DAC, because I was convinced it was the weakest link of my chain (on the room acoustics I can't do anything yet).
A few days ago I decided to try this mod, I used a pair of Mundorf M-cap 0.1uf to bypass some ordinary 4.7uf electrolytics (Used parts from other projects) and I must say that the change is huge.
Now I have detailed and tight bass, the mid-range is focused and three-dimensional, alive and with excellent detail and separation of instruments.
The only problem is that before attempting this mod I had ordered some "M-Cap ZN" (some say it is one of the most neutral cap regardless of cost) but now I'm so fond of the sound that I do not know if I want to reopen the DAC:lolsign:.
This mod has saved me a lot of money, but more than that is allowing me to hear music again with pleasure and without being obsessed with the failures of quality when playing back and thinking about changing equipment:).
Thank you all for this excellent forum
Hi Alexandre, nice to see you on AoS :). I am glad that the passive mod has once again shown how great a mod it is for very little money.
hi,
I had the passive mod done and is sounding very very good indeed.
I noticed that with no music playing into the DAC and the volume of my integrated amp is turn to the max, I can hear quite a lot of hiss from my speaker for both channel. But when I switch to another input of the amp, there is no hiss anymore. Could you please advise is the hiss coming from the DAC passive mod or not? :scratch: Before the mod I think with the Opamp board there wasn't hissing...if I recalled correctly.
Hi goody
The passive mod gives the Caiman higher output impedance, which will not suppress input noise in your preamp as well as with the op-amps in place. Unless you can hear hiss during music playback (unlikely), it is of no consequence.
Thanks Martin. The hiss could not be heard during music playback and had no consequence during playback.
While most time we check the quietness of the system by setting the volume to max with no music playback...Is there a way we could get rid of those hissing at all? :rolleyes:
Only by using larger capacitors, which probably won't fit unless you want to use electrolytics. Also don't forget that the gain is lower so you are having to use a higher position on the volume control.
In my case, the sound quality is so much better with the passive mod that I'm not bothered, and I get no hiss anyway :)
Hi, I m using 15uF bypass with 0.47uF caps. What are your values?
You mean to say that during no playback and the volume is set to max, you don't have any hiss at all...dead quiet? Is this your case?
Then something could be wrong with my dac, right? please let me know how to get rid of that hiss if you know..what's contributing it.
Realistically speaking, you need the Gator upgrade board for your particular situation.Quote:
Originally Posted by goody
Let me explain why I say that. The WM8716 DAC chip does not have an inbuilt analogue filter, unlike say its nearest direct equivalent, the PCM1716 as used in the TC-7520. Wolfson recommends an external low pass analogue filter after the output of the WM8716. Both the standard as well as the Gator audio board have such a filter.
The passive mod breaks all the established rules as far as filtering the audio sampling residues is concerned. The payback of that is that you'll get a near unadulterated digital to analogue output. But it has a low level unfiltered sampling noise residue. The noise is at about -80dB level, so if you turn your volume control to max you are likely to pick it up.
Thanks Stan. By adding the low pass filter after the Wolfson, would the unadulterated sound be significantly impacted or not?
If you mean the active low pass filter as fitted on the Gator, then the answer is that the jury is still out on that. Existing Gator owners are in the whole still grinning from ear to ear and most have been unable to tear themselves away from the music to come and give a detailed before-and-after update.Quote:
Originally Posted by goody
If you mean adding a passive filter that you yourself knock up, then I would have to say that it is very likely to impact on the sound.
It's like fitting a racing exhaust on a car. You can't hide the noise, but boy do you get some extra performance or what ;).
You know, I think a little added "clean" noise can actually enhance our listening, smoothing over any slight non-linearities down at minus 80 and lower. I wonder if this is what many valve output stages/buffers do?
Yes.Quote:
Originally Posted by goody
I have spent about 2 hours reading this whole thread. It starts off with electrolytic capacitor ($) and end with polypropylenes capacitor ($$$$$). =D Here is my very entry level setup.
Laptop>TC-7520(Fixed)>CA 340A>PSB Alpha B1
My TC-7520 used to have THS4032 for the fixed. After reading this thread, I remove the active board and inserted two 2.2uf electrolytic capacitors. It is just a normal cap. I was surprise on how this mod changes the sound. I am poor at describe sound but I love my current mod. I decided to purchase polypropylenes capacitor. Input impedance of 100k is recommended to use 0.8uf, my a340 is 40k so will be 2uf. The cap in my mind was the Claritycap ESA 2uf 630V. Is there other alternative for the brand and value I should consider?
Hi Larry,
Just a quickie, mate - when you get a minute could you add your basic location details to your proflle? This is now the requirement for all members of AoS.
Cheers! :cool:
Marco.
I apologise. I have update my profile.
Hi Larry
2-2.2uF seems to be a good value and should suit your input impedance. We have had good results from ClarityCaps and AuriCaps so take your pick.
I wanna add my experience with passive mod on the caiman
removed the analog section and connected wm8716 exit to the rca via two big MKP film foil cap, Audyn Mcap Plus 3.3uF
Dramatic improvement in clarity, definition, smothness, 3D... every aspect improved noticeably
but
the bass became too light for my taste
With this combination the bass is stronger, better defined, rock solid, tigth, but lack that depth in the very low frequency, that was present with the opamp stage
so just for fun I bypassed those two big caps with two small rubycon 47u
the bass is back !!!
but
midrange and high are messed up :rolleyes:
in Italy we say "you can't have the bottle full and the wife drunk" .... ;)
ok
so I replaced everything with two MKP film foil, always Audyn Mcap plus, but 6.8u (I had them on another DAC)
ok, this seem a reasonable compromise
mid and high seem loosing nothing, and bass quite a bit deeper, probably 10u
would be better, but when you speak about resolution on coupling cap, less is more, I mean, the bigger the cap, the greater the attenuation and phase shift due to dielectric absorption
But what I really can't understand is why I need such a big cap value when the math tell me that 3.3u should be more than enough (my amp has a MEASURED input impedance of 44k)
a fellow here in another thread told me it could be just a matter of dac output impedance
hmm, good explanation, but a lot of people in this thread affirmed they had good result with lower capacity, 2.2 or even 1.6u
this puzzle my mind
Hi Goody. What method of passive mod did you have done? If you've had caps wired directly between the DAC chip output and the RCA sockets then you've bypassed the Caiman's onboard muting relay. If the caps are inserted into the sockets where the opamp board used to be then you've not bypassed the muting relay. The muting relay turns off the audio output when the music is stopped and therefore prevents any hiss from getting to your amp. This could explain the hiss you're now hearing. :)Quote:
Originally Posted by goody
Hi, Thanks for your inputs. I had the passive mod without bypassing the muting relay (with caps inserted into sockets).Quote:
Originally Posted by HighFidelityGuy
Hi Goody, that is really strange. With the DAC in mute mode, you shouldn't get any noise at all. It suggests that your preamp has a lot of self-noise when not loaded down with an input. If you unplug the DAC and turn the volume up (careful), do you get the same noise?
Hi Martin,Quote:
Originally Posted by MartinT
Yea, without the DAC at the input of the integrated amp and the volume turn up to max, there is no hissing (it's quiet).
According to Stan's response, the Wolfson WM8716 DAC chip does not have a internal filter before its output (raw output) so about -80dB sampling noise get through into my integrated amplifier when I turn the volume max without music playback.
btw does sampling noises translate to audible hissing to our ears? please advise.
Could you maybe try a different set of interconnects with different shielding? Perhaps RFI is getting in and causing noise? There should be no sampling noise from the DAC when in mute mode, i.e. no disc is playing.
My response was based on the assumption that you had bypassed the mute circuit. But if you have not bypassed the mute circuit then my previous response is not valid. The DAC sampling noise etc. cannot bypass the relay when the relay is open.Quote:
Originally Posted by goody
I think that what you are experiencing is an impedance mismatch, which can produce a noise.
The passive mod is obviously causing you a problem, so revert back to the original board.
Hi Martin, I tried with a different set of interconnects and the noise is gone. It's quiet now.Quote:
Originally Posted by MartinT
Thank you all for helping. I am glad I can continue enjoying the passive mod. :)
Excellent, glad you're sorted.
I have tried many different caps on the passive mod :-
Black Gates 10uf
Polypropylene (Clarity Caps 1uf) (ICW 2.2uf, 3.3uf 4.7uf)
Ampohm 2.2 (monster depth charge stylee - about £20 each retail)
Nichicon Muse 47uf
Elna Silmic 2.2uf, 10uf,
Today I found the best cap for my system by a loooooong way.
Price 21p each......Jamicon 2.2uf 16v. A pathetic looking excuse for a capacitor. Looks like a Rabbit dropping. And they say you can't polish a turd.
Crazy thing this audio lark!
How much! I'm not made of money (slugs and snails and little puppies dogs tails)Quote:
Originally Posted by Puffin
Very interesting...Quote:
Originally Posted by Puffin
I'm now convinced that those Audyn cap plus 6.8uF are not the best for my system, amazing details for classical, but bass, while fast and well controlled, still lack of depth, for jazz and blues I feel an overall lack of energy and warmth
also they tend to the bright side, in the end quite fatiguing listening after a while
I'm wondering if going for a bigger film & foil, like Obbligato (10-22uF) or some 'lytics
Stan stated he had best results between 22u and 47u, but I can't accept the idea of a 'lytic in the signal path
maybe that beloved reverberating bass is just a kind of distortion introduced by electrolytic caps...... :scratch:
I'm curious to read more comparison between passive mods and gator, could be my next move after Christmas holidays :eyebrows:
Hi, I wonder whether there will be any significant improvement by upgrading the clock of the digital circuit of dac? Is it feasible to do this? Has any of us tried before? Please advise.
I don't see why a more accurate clock couldn't be fitted, there are enough of them out there after all ;) The only problem might be the power supply as the Caiman appears to only run off of a single rail DC supply & i'm not sure about aftermarket clocks :scratch: I'd have thought 5V DC would be the order of the day though.
____________________________
Just bought a Caiman + today so i'll see what all the fuss is about when it gets here ;) It'll be interesting to see how it compares to my Monarchy Audio dual 20 bit DAC when running as standard & when subtly modified :eyebrows: One or the other will find it consigned to duty of the arse end of a Theta Data Basic transport, it'll be nice to get that spinning again.
Someone will be getting some feedback in the private exhibitions section shortly :)
Caiman 2 beckons I reckon... Bigger, wider case, option to split and isolate the supplies and plenty of room for upgrading later. Could this be done economically Stan?
Well I am still staring at the final drawing, with various components from different suppliers under reliability test, or waiting to be tested. Only after that is completed can I begin with the first production PCB layout and see what is possible. So realistically speaking, we are still ages away from a beta sample, let alone production.
I am not going to increase the case size by more than a millimeter here or there. Empty space still cost money to create. I am mainly doing a Caiman upgrade, so I don't want to burden the final price with senseless add ons that would shock my customers with a sudden price jump. Everything has to fit inside £300, and that includes delivery.
That reminds me that I also want to upgrade the TC-7510. I used to be accused of upgrading that every week, so the last upgrade was in 2008. Enough time to allow for the next upgrade I reckon :).
Too early for details Stan, but good luck with it. :)
Far too early indeed. But hopefully it will be in many stockings next Christmas :).
Something tells me this is probably a no go :eyebrows: Just took a look inside & unless i missed something (though i didn't look underneath the PCBs) it looks like the clock is on board one of the ICs & probably can't be bypassed :scratch:Quote:
Originally Posted by Reid Malenfant
Time to check out the specs on the chips :doh: Not until i can be bothered though :eyebrows:
I wondered about the possibility of upgrading the clock a while ago but couldn't see one on the main PCB's. There's nothing under the PCB's either. Perhaps we should move discussion of this to the main 7520 mods section HERE to avoid confusion, or create a new thread. :)
EDIT: I've made a new thread on this subject HERE.
http://lh4.ggpht.com/_Z3EJ2JsDjZY/TN...PassiveMod.jpg
Hi there....
I want to install this passive mod to my caiman.
my rotel RA 1062 specs are:
Preamplifier
Frequency response: 10 - 100kHz at +-3dB
Signal to noise ratio: Line level: 95dB
Input impedance: Line in: 33 kohms +/-5%
Input sensitivity: Line level: 160mV
Preamplifier output: Nominal output level: 1000mV
which caps would be useful? 47u rubycon or other?
thank´s a lot :-)
greets
vid
Hi Vid,
Start with the 47uf Rubycon bipolars and work from there (they are not bad)! Those big yellow ones were from eBay and I can sell you mine if you want to try them.
You can spend some serious dosh on different caps if you wish.
Regards
Chris
You could use any capacitor value between about 2.4uF and 47uF. The exact choice will depend on your budget and whether or not you care if the caps are too big to fit in the case. Some people don't mind running the DAC with the lid off and massive caps sticking out the top. There's a good calculator HERE for working out the values. You need to put 33000 in the Ohms box and then pick a -3db Frequency based on what the info on the page says. Personally I choose much lower values of around 1Hz to ensure phase anomalies are kept well away from the audio range of 20Hz-20KHz.
If you want to spend as little as possible and still be able to put the lid on I'd recommend THESE. They have been proven to be some of the best sounding bipolar electrolytic caps that are easy to get hold of. Many people believe polypropylene or polyester film caps sound better but these are bigger and more expensive. The ClarityCap SA range seems to get a lot of praise for being excellent value for money. So they could be a good entry into poly caps. If you want to try the ClarityCaps I would check the dimensions of the 2.6uF version and see if you think that will fit, then work your way up the uF range until you find the highest value that will fit or that you can afford.
If you fit them as shown in the photo you attached then the mod is easily reversible.
Make sure you discharge your self on something earthed at regular intervals while working in the DAC as the Wolfson DAC chips are very susceptible to static electricity damage. Also if you use bigger caps make sure the cap's legs don't short against anything else inside the DAC. Some insulating tape will prevent that.
Good luck. :)
I recommend the yellow caps as in the picture. I have a few spare that you can have at cost if you email or PM me.Quote:
Originally Posted by vid
well...
thank you very much! I will test some of my mundorf´s and the rubycon.
greets from austria :-)
vid
Hi!
I am not sure how to connect the caps into the caiman
would it work´s with this parts?
http://www.conrad.at/medias/global/c...FB.EPS_250.jpg
thank you ;)
greets
vid
If you're just going to connect them as the yellow ones are above then you can just push the capacitor leads into the holes. You don't need any special connectors or anything.
This image explains better:
http://www.hifiwatcher.com/wp-conten.../capacitor.gif