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Chameleon DAC listening and modifications - Page 12

post #166 of 1144
Peete-
do me a favor and tell me what you are really doing on this thread.

Do you own do own a Valab DAC?

Have you modded one?

Have you personally listened to one?

Do have any real interest in listening to one?

Do you have any plans in buying, modding and listening to a Chameleon DAC .... yourself?

Seriously!
post #167 of 1144

For the love of Pete!

Woody- thanks for post based on actual experience from owning and modding an actual Chameleon DAC. Yes something is seriously wrong with the analog filter circuit.

Driguy- thanks for your observations.

Mike W- quit encouraging Pricklely Pete ... for Pete's sakes!
post #168 of 1144
Quote:
Originally Posted by Bill Allen View Post
Peete-
do me a favor and tell me what you are really doing on this thread.

Do you own do own a Valab DAC?

Have you modded one?

Have you personally listened to one?

Do have any real interest in listening to one?

Do you have any plans in buying, modding and listening to a Chameleon DAC .... yourself?

Seriously!
I'm helping out or at least I'm trying to. Do I need to listen to a Valab in order to know where to apply upgrades ? A PSU is a PSU. The suggestions I have can work with just about any DAC PSU.

Should I have a buy this DAC in order to comment on possible improvements ? I don't think so Bill or I would hope that is not the case.

Look some members in the thread have been asking about PSU mods so I thought I might help out. That said if I have offended anyone I apologize for that.

Anyway...for those interested in some PSU mod ideas/suggestions for the Valab C these 3 come to mind after studying the internal shots of PSU.....

Use UWB (Ultra Wide Bandwidth) voltage regulators in place of the stock units http://www.partsconnexion.com/prod_pdf/dexa.pdf Both +9V and -9V are available. Makes the swap painless and may allow for removal of the variable resistor pots on each rail. I could be wrong about that so if in doubt ask Valab.

Double mains filter capacity (from 1000uf 25V to 2200uf 25V) using either Rubycon ZL/ZA/ZLG series or Nichicon FG/KZ series elctrolytic caps (make sure you have enough space for these to fit before ordering) and then bypass those caps with Rifa/Eros .68uf 50V film box caps. The base line headroom of the circuit/parts spec should be beefy enough to handle the additional inrush current that the larger amount of mains filter capacity will draw when the dac is powered up. This inrush is like a large momentary spike that quickly settles in a few seconds. A good idea to check with Valab if you have doubts or to be safe.

If the stock diodes are not Ultra fast types replace them with Fairchild UF4007 (1A 1000V) or Telefunken/Vishay SF4007 (1A 1000V). The stock units look to be good ones but it's impossible to say until the part number is known.

The price tag for doing all of these upgrades is around 135USD (roughly speaking) which is a bit high but not too bad The lions share of the cost is taken up by UWB regulators which makes the other 2 pretty cheap to implement. Of course the biggest gains in performance are with the first 2 suggestions. The diodes although least important of the three are by no means a trivial step. Having UF/SF4007's in place is something I do right away in my mods (where they can be used as a compatible sub). Hopefully the stock parts are already Ultra/Super fast types and this last step can be skipped.

These suggestions are just that, suggestions. The formula above has worked in many of my projects with some of them being a collaborative collective effort on all manner of low voltage (and some higher voltage) ss topologies/linear power supplies. They are all (SS DAC/amp/preamp/CDP/DVDP) pretty similar in makeup in terms of PSU design and parts selection.

Peete.
post #169 of 1144
I guess it would help if he owned the dac , however it's not necessary to own it if you've got skills working with this kind of stuff. Does Steve Nugent own and use one? If he's got good idea's on mods for the PSU, I'd like to hear it. I understand your desire to keep this thread more focused then the old 110 page Valab thread, but im not sure how practical it is, this is, afterall a Discussion forum. Perhaps once we've got a proven set of mods we can make a consolidation post with all "Good stuff"

I ordered some of those fancy pants TX 2575's will be fun to try them out. I've never paid 10 bucks for a resistor, hope they are worth it.

Edit: I would really like to know more about the new Teradak DC-30W before I jump to far into modding the existing one. Would be nice if Michael offers an upgrade kit.
post #170 of 1144
Ok the effect of adding those iv resistors blew the soundstage all around my listening room. Last time I heard anything like that was with a very high end turntable (can’t remember what it was) that I auditioned in the mid 80’s against a Radford cd1 CDP. The Radford was one of the best CDP’s you could get at that time, for any money, and put up a credible fight but the turntable just annihilated it. It was from then I more or less gave up hope for cd, until I heard an (out of my pockets) AN Dac, and later, the, (in my pockets), Valab. After changing the IV’s I was getting at least some of that again, so I just had to indulge.


Next went in the BG FK, to the decoupling of the TDA1543. Funny thing that, the spare holes provided are exactly the right size for BG caps that have thicker than standard legs, wonder who’s idea that was....? Whoever it was, hearty thanks. Another layer removed now, blacker backgrounds, more authority. Putting the BGs in was a worry, not because that’s 16 caps to remove and solder in (not with those handy holes), but because BG’s take a month 24/7 before the torture stops. But actually it’s very fine.


Up until now the un-burnt in Wimas have been left in place. Yet the Chamleon has easily surpassed my modded Valab, unburnt. Just reminded me that the coupling caps are just one factor in a chain, no need to break the bank on expensive ones and change them every five minutes, because it would be the least effective mod cost/sq ratio if you did. Just stupid actually.

Anyway regardless, out came the Wimas and in went $8 worth of BG NX Hiq in super E config that are burnt in enough to be passable. Another Veil lifted deeper richer sound and inching closer and closer to the recording.

24 hours later and things settling in nicely. Decided to do the yellow wire mod. The yellow wire measured with european 220VA input, gives 14VA (thanks marcelnl ) . The result was exactly as described by Pat and Bill. Bass more articulate and real, which gives the whole, SQ more Mojo.

I then wired with silver wire the + RCA spidf directly to the Pulse transformer, wasn’t expecting much (why don't I listen?). But this made a big difference. Everything is more immediate, It ties all the previous mods together, gives a very engaging sound, essential mod, if you prefer realism to HI-FI.

Very happy with where I am now, thanks guys, great work. I’ve now got a Nos dac that kicks butt, no more mumbling in the corridors about nos dacs rolling off the extended frequencies, or lacking detail and energy anymore, thank you very much!!

Three free, quick mods will take you most of the way there,
1. Remove the low level filter caps.
2. Yellow wire mod.
3. Direct Spidf to Pulse transformer.

Fancy caps are just the icing on the cake.

Next up SSOM, and a bit more BAMM! (Bill Allen Madman Mod)

Bill, Pat, guys, I noticed with the Spidf mod you remove the Russian cap, and bypass it with wire, is this not bypassed by the attaching the + rca input directly to the pulse? And do you do anything with the – rca input? Thanks
post #171 of 1144
Quote:
Originally Posted by Pricklely Peete View Post

Use UWB (Ultra Wide Bandwidth) voltage regulators in place of the stock units http://www.partsconnexion.com/prod_pdf/dexa.pdf Both +9V and -9V are available. Makes the swap painless and may allow for removal of the variable resistor pots on each rail. I could be wrong about that so if in doubt ask Valab.

Double mains filter capacity (from 1000uf 25V to 2200uf 25V) using either Rubycon ZL/ZA/ZLG series or Nichicon FG/KZ series elctrolytic caps (make sure you have enough space for these to fit before ordering) and then bypass those caps with Rifa/Eros .68uf 50V film box caps.

If the stock diodes are not Ultra fast types replace them with Fairchild UF4007 (1A 1000V) or Telefunken/Vishay SF4007 (1A 1000V). The stock units look to be good ones but it's impossible to say until the part number is known.


Peete.
Hi,

I only have a Valab Dac, but tried a lot of things out.

And I can't really recommend these DEXA regs....it changed the sound a lot, but not only to the better. Bass and dynamics improved, as did the soundstage, but there was an annoying mechanical quality to the whole music. It lost its flow somehow, and the midrange its beauty. Hard to describe, but I just didn't like it.
But maybe in the digital supply it is better, as I only tried them for the analogue supply for the dac chips.
But it showed that regulation can be improved, but as the Chamaleon sucks quite a bit of current, its not easy to find a good solution..
This series reg: The σ11 Regulated Power Supply could fit the bill, although a shunt regulator would be better.
One could use one for the analogue and one for the digital supply.
Cost would be about the same as the Teradac supply, but one has to build it.
But should be a lot better.

For the caps: I found that the Pana FM are very good, the ones you mention are not better, just different.

And the diodes should be soft recovery ones, this is more important than speed.
I had good results with 11DQ10 or the 3 A type 31DQ10; these are shottky type.

These are my suggestions ...

Best regards, and have fun with your reptiles,

Juergen
post #172 of 1144
Quote:
Originally Posted by Jogi View Post
Hi,

I only have a Valab Dac, but tried a lot of things out.

And I can't really recommend these DEXA regs....it changed the sound a lot, but not only to the better. Bass and dynamics improved, as did the soundstage, but there was an annoying mechanical quality to the whole music. It lost its flow somehow, and the midrange its beauty. Hard to describe, but I just didn't like it.
But maybe in the digital supply it is better, as I only tried them for the analogue supply for the dac chips.
But it showed that regulation can be improved, but as the Chamaleon sucks quite a bit of current, its not easy to find a good solution..
This series reg: The σ11 Regulated Power Supply could fit the bill, although a shunt regulator would be better.
One could use one for the analogue and one for the digital supply.
Cost would be about the same as the Teradac supply, but one has to build it.
But should be a lot better.

For the caps: I found that the Pana FM are very good, the ones you mention are not better, just different.

And the diodes should be soft recovery ones, this is more important than speed.
I had good results with 11DQ10 or the 3 A type 31DQ10; these are shottky type.

These are my suggestions ...

Best regards, and have fun with your reptiles,

Juergen
Cool...how long did you have the DEXA's in place ?You are correct about the current limitation of shunt regs/super regs etc....without knowing the total current draw of the dac/analog section it would be prudent to research thoroughly before laying down the green. The sigma is a nice PSU, no doubt about that, but that means scrapping the Valab. Not something many are willing to do methinks. A dual mono approach like Bill has suggested may be the key to using the shunt regs....hmmmm. No easy choices in this game but that's part of the fun

Well fast recovery IMO is better suited to PSU of digital gear but the difference between the two (UF/SF vs soft recovery) is pretty small and certainly an improvement whichever way you go (Hex/Fred etc..) over the stock diodes (if they happen to be 1N4004 or the equivalent of that). I've used both types (soft recovery and SF/UL) in dac and CDP mods to great effect. I like the SA/UF types better so it's a matter of personal preference vs spec.

Nice work Wood That super E config is a great choice.

Peete.
post #173 of 1144
How does the Blackgate PK series compare to the FK? Would it be a worthwhile upgrade to use PK instead? They are a hell of alot cheaper. 95c vs 5.25 each.

Anyone have recomendations on a 0.1 UF film cap for the SPDIF input, I was thinking of a Sonicap Gen 1.

I know the trend is to bypass this cap altogether, but i'd like to change it's value to 01.uf as suggested and leave it in play, no one's done that yet.

Im trying to put together a parts order now, will wait for feedback on the Blackgate PK's. (33 uf)
post #174 of 1144
The DEXA was in place about 3 weeks, and then I managed to kill the DIR9001. There was a little burn in effect, but not enough to convince me...
The current limit of the DEXA is 0,63A, which is too low for this dac; for the Valab it was o.k.
Good thing about the Sigma: you can leave out both the noisy regs in the Valab, or the pots and cheap TL regs in the Chameleon.
Of course this exercise is not for beginners...
And you are right, all those diodes are better than the 1n400 types; compared to the upgrade to a very good power supply this effect is negligable.
post #175 of 1144
Blackgate Pk are very good caps in there own right, they are a mini version of the Blackgate Standard. I dont know if they are the best for this position though because of current handling requriments, best to go for Blackgate Standard which are similair price. However the Blackgate Standard are closer in quality to other highly regarded caps, so you have much more choice here, for instance Elna Cerafine or Silmic2, and Oscon sep, Pansonic FM or FS.

But Blackgate FK/NX IMHO are in a class of there own.
post #176 of 1144
Pete- thanks for your concise wording and clearing up your intentions. The power supply is indeed the final frontier with the Chameleon DAC.

I am just trying to keep the thread focused on our successful "proven mods" early on before the thread dibbles into personal "what should I do" banter. Most of the answers to these innocent questions are found in the beginning of the Valab thread but nobody wants to do any research. That drives me crazy. Do some homework people.

Woody & Driguy have very systematically applied the suggested mods and achieved the same outstanding results I have. Thanks Woody for spelling it out so "everyone" could understand. It takes a lot of time & effort to write concisely I know because I do this myself. Writing from the hip, as it were, is what makes a thread get long winded and blowing in all directions.

Is it asking to much to show some discretion before putting paper to pen.
post #177 of 1144
Thanks Bill, happy to make a humble contribution.

Now about the ' - ' side of the RCA input, does that stay in place, and I didnt quite understand why the Cap is bypassed?
post #178 of 1144
Quote:
Originally Posted by Bill Allen View Post
Pete- thanks for your concise wording and clearing up your intentions. The power supply is indeed the final frontier with the Chameleon DAC.

I am just trying to keep the thread focused on our successful "proven mods" early on before the thread dibbles into personal "what should I do" banter. Most of the answers to these innocent questions are found in the beginning of the Valab thread but nobody wants to do any research. That drives me crazy. Do some homework people.

Woody & Driguy have very systematically applied the suggested mods and achieved the same outstanding results I have. Thanks Woody for spelling it out so "everyone" could understand. It takes a lot of time & effort to write concisely I know because I do this myself. Writing from the hip, as it were, is what makes a thread get long winded and blowing in all directions.

Is it asking to much to show some discretion before putting paper to pen.
No problem Bill. I'm one of the few to read the entire thread before poking my nose in the door and I must say it's been a fun experience seeing the evolution and thought process develop in real time which is why such threads are of special interest to me personally. We DIY types can occasionally get tunnel vision when it comes to parts choice, relative merit etc...it's only human nature (I'm certainly not exempt from that folly). I try to guard against that even if it doesn't come across as such. My limits with the written word needing some considerable polish to make that clear.

My original foray was/is well intentioned with the above commentary taken into account since all of these parts can quickly end up being way more expensive than the cost of the stock unit. I only wanted to float a trial balloon about taking these costs into serious consideration since most of us have limited funds, rather, it's good to think about the economy of the collective mods vs sinking less money into parts on a better base unit likely being a better result sonically speaking or so the theory goes. Then again where is the fun in that was the likely thought process of those reading my first posts in this thread. I think I've established my intentions as being good as I had hoped.

Anyway......I have suggestions for the DAC coupling caps that have done a terrific job for me. 47uf 25V Elna Silmic (if you can find some) bypassed with a Eros poly sound great (not quite a good as BG's but nearly as good) and if you can't find Silmic the follow on Silmic II's are also darn good. A very nice warm cap with buttery smooth top end...the poly bypass adds to the effect greatly. Not a rolled off effect at all. Try it out for an experiment ..I bet you'll like it. I use nothing but PIO's for this job (since I have hundreds of the damn things) but the PIO caps are hard to install in small places so they can't always be used (enter the box caps). Elna Cerafine are not bad either but I prefer the first gen Silmic for this particular job.

Another option is to bypass the BG FK/PK with Hi-Q NX .1uf 50V. It works like gangbusters.

Jogi...that's too bad the DIR9001 went ppppppffffft on you. I've experienced that myself (CS8416 was the victim in my case). The Burson super reg II's can handle 150ma but I fear that isn't even close to enough for the Chameleon. Tentlabs shunt regs I just checked out...the 3.3v is limited to 100ma with the 15V down to 25ma. I wonder if a home brew DIY design here could be created ? Maybe it's not worth perusing (the regs) in light of the possible technical limitations of the application at hand and it's needs.

On the other hand ....Bill could you lay out the dual mono supply theory ...I really like that idea and the thought process behind it. I may have a great solution for a PSU reg board that is quite unique and very stable under high current demand loads. It's biased heavily into Class A so it needs a good size heatsink. I have used a similar unit with a Jaycar current follower SS head amp design to great effect. Two of them in dual mono mode could proved 700ma at +15-15V all day long. 1.4 Amps should be enough for the 16 dac chips I would imagine. It can scale to 3 or 4A I believe at a lower V. I have to check with the builder.

Peete.
post #179 of 1144
Yep the Silmic 2!
post #180 of 1144
Maybe this could do the job:Group Buy Interest Page
This is a shunt capable of up to 3A current, which is for sure enough.
It should outperform the valab supply very easily, and can be built for digital and analogue separately.
Downside is only the heat, it requires a big heatsink; and again its not suitable for beginners.
But if someone with knowledge would build it and keep the progress posted here, it should be pretty easy. No hard wiring, just populating a PCB, and little maths to adjust it to the needs of the dac.
And there is a big thread on DIY Forum...
And cheaper than all this cap rolling, which I consider to be the spices, not the meal...
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