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Chameleon DAC listening and modifications - Page 11

post #151 of 1144
same here, I come from a Gold crown DAC and really bought the Valab design for the NOS sound that imho can sing a very musical tune indeed.
I also count myself a crazy DIYer so I do not mind it one bit to part with some good money to improve the design to its max, as I know that I wuold not be able to buy the equivalent sound Quality for a sane amount (AN indeed springs to mind, and the fact that I'd be unable to leave it unmodded...).

Where I totally agree with you is the fact that cost/benefit should be worthwile, but the beauty of this modding is that each individual gets to decide where the buck stops.(I only hope that enough folks make a well informes decision as I'd be sorry for the epensive learning curve of the thread reading mod follower having to execute and pay each suggested 'current' hottest mod)

I bought this very design as it promised me the easiest road to NOS DAC nirvana, sure would have loved to buy the Chameleon but I guess I'll build my own dac as a future project.
post #152 of 1144
You really do make some excellent points peete. Some here are of the mindset that this design can't be beat at any price point. As they have already spent big money on the old valab. And have purchased more then one dac based on this design. It's easy to get lost in it all. But i do wonder how this dac really stacks up to something from Audio GD with it's PCM-1704 UK chips. Or how it compares to a sabre dac. Unfortunatly this dac has had very little to no comparisons, and while the previous valab thread is massive, it's a pretty small group of people. I have a pretty limited budget and can't really afford to try out alot of hardware, and I got sucked into this for it's value proposition, but i've already spent quite abit myself, as i've purchased 3 of these dac's, destroyed one in a mod attempt, and purchased expensive, incorrect modding parts. Etc. However I have learned a great deal during it all, and that has value, the valab introduced me to DIY.

On another topic, I did email Michael about the AC in my +5v rail and he was not to concerned with it. Said it was normal. I think something was lost in translation though as I did have a hard time interpreting is email.

Quote:
That is very good and very normal. We you measure them next day, you will also get little different values. We thought the minor AC is well below your meter tolerance. I don't know how accurate your meter is. If your meter is not accurate enough, the minor AC reading in no meaning even it is 0VAC. You can hold the probes with one hand for + probe and the other for - probe without touching the others, and measure the AC voltage from your meter. Maybe you can tell us the read AC voltage for your left and right hand. ^-^

Michael,
This would make sense to me if my meter picked up small AC varience on both rails. However it does not, it's an Auto-Ranging meter, and can never "lock" on to anything on the +7.5v rail, but does lock and settles down to 0.036 on the +5v rail. What is interesting is when I measure it on the Chameleon side, using the Chameleon ground and the +5v input on the chameleon, it is much much lower, something like 0.003 volts AC. So im not to worried about it. Just trying to figure out if this SNR im hearing is just working as intended or if there's a problem somewhere. As great as the Chameleon sounds, and it's an obvious upgrade over the older dac's, im not sure I'd have jumped on it if I had known about this SNR. I'd consider it a signifigant issue, as most dac's these days have SNR's well over 95DB, and many even go into 110DB. Those considering this dac, should be well aware of this before they jump the gun.

I blame wood for the misconception lol In the second post of this thread he said the additional dac's would lower SNR by -3 DB. I was already pretty happy with the SNR of the old Valab so I found that as great news. That did not quite work out, oh well. I'd be less concerned with it if someone would chime in and say for sure if you do this, this and this, your SNR will be cut by xx amount. I can't afford to lay out 100$ on Blackgate's for somthing that "may" make the issue better. It also seems like alot of you are listening to your Valab thru speakers, oddly enough, this being head-fi. Obviously it's much less of a problem on speakers as your ear is not a inch from a hissing driver.
post #153 of 1144
Obviously this thread proves the point that there is no such thing as an outdated chip, there are chips that do the job (old and new) and those that do a mediocre job and very very few that many would consider the best chip(s) ever made. None of those "best ever" are current production Sigma Delta types.

I should add that the A-gd formula for the REf1 is a tried and true topology that has been used (in various forms) by the likes of Levinson (when it was building the SOTA and setting the standard for redbook many years back) In fact Kingwa said that SOTA dac was one of the inspirational catalyst behind his RE1 design which adds some considerable twists (ACSS/CAST stages/DSP1 digital input processor/filter)...anyway. An interesting option with the A-gd RE1 Dac is the fact that I can set it for 0X over sample via the DSP1 input processor dip switches (you can change half dozen other setting as well) which is NOS mode. I tried it for a few weeks like that but went back to 8X OS and left it there. It's an astoundingly good...no great dac.

Anyway you guys are attempting to remedy the shortcomings you've targeted in the Valab and with impressive results thus far. I commend that pioneer zeal to do the seemingly crazy stuff and tackle what are the shortcomings. After all how else are breakthroughs made 90 % of the time ?...not by following convention.

MikeW,

You make the case for my argument inadvertently or not. You see those that have limited funds end up spending way more then can actually afford (despite good intentions) by reading these kind of threads. I know first hand about that all to well....all those caps, resistors, OPA's transistors, film caps of all stripe and manner add up, and fast. Don't even mention raw cable material....that's another endless money pit. Anyway the real point is to hopefully steer the budding and veteran DIY enthusiast along a path that leads to the most bang for their finite bucks.

The last thing I want to do is blunt enthusiasm for any piece of kit.

If NOS is your thing I would contend this unit would be fun to play around with....
DAC Kit DIR9001+TDA1541A 2.0B OS/NOS with HDAM on eBay (end time 04-Feb-10 10:32:37 GMT)

Track down a pair of SA2 Double Crown TDA1541s and you'll have the reference of reference NOS DACs arguably speaking (as long as you build a no holds barred I/V stage for it).

Anyway I've bugged you guys and intruded enough in this thread..keep up the good work guys and remember simpler is almost (almost) always better.


Peete.
post #154 of 1144
MikeW, Lowering the noise floor means you will hear more low level detail, as indeed new owners have been reporting. Noise, as in 'hiss', is just noise.

Pricklely Peete, thanks for the kind words there, funny thing, Ive had my eye on those ebay dacs myself.
post #155 of 1144
sigh , double crown and TWO at the same time....if I could just find a reliable reasonably priced source for them.....
post #156 of 1144
Quote:
Originally Posted by Wood View Post
MikeW, Lowering the noise floor means you will hear more low level detail, as indeed new owners have been reporting. Noise, as in 'hiss', is just noise.

Pricklely Peete, thanks for the kind words there, funny thing, Ive had my eye on those ebay dacs myself.
Agreed...a blacker background can be achieved through optimization of the PSU sections (all of them). The low voltage supplies for the dac and receivers pay particular attention to. Diodes matter ! UF4007/SA4007 are terrific performers.



Wood...I've been eyeballing that balanced output discrete I/V module for use in a Denon 3910 SACD player I have sitting beside me that is currently in the planning/concept stage. As in I don't have money for the parts so I'm dreaming about doing it

Peete.
post #157 of 1144
Its good that this thread is moving towards examining the power supply, I know from playing around with Tripath amps that the output sig is really just the power supply, modulated. And I agree, Pricklely Peete, that if you put a dueland or something like that as coupler without cleaning up the PSU your probably, going to end up with a worse sound then if you stick that cap in something more refined.
Completly sympathise with the I/V module, how many a good dac, cdp ruined by a crappy op amp

qusp you mentioned before you were working on some designs for low noise regulators, do you think these might work in the DC-30?

marcelnl, your making me nostalgic now, I will at some time have to dig up my Radford CD1 from basement that died on me a few years ago, I think that might have a crown or 2. She was so sweet that girl.
post #158 of 1144
Thread Starter 

time for a little flip flopping

Just got a little distortion like a split sound board and started unplugging the transformers, swapping tubes on the headphone amp .... when I finally removed the upsampling board. There ya go, sound focus returned, snapped in. Sound is grainier but with more weight and authority. Timbre seems more immediate on certain things.

The issue on the board may be the connection as it just started only three two days ago. But the sound did drop back closer to the VALAB NOS DAC.

Definitely a notch away from the smooth resolution and top end shimmer. But the weight is worth the sound. Now I am not so sure which I like better.
post #159 of 1144

A/N DAC VS. Valab

I had an A/N DAC 2.1 Signature edition kit that I had upgraded a lot. I put in better P/S caps (Mundorfs), better tubes, and better output caps (V-Caps). Very nice sound indeed. The NOS sound (naturalness) is there in spades with nice amounts of detail, etc. I had even built a case for it but I still sold it after hearing the Valab DAC even before much modding at all. The simplicity of the circuit and paralleled DAC chips are probably why it sounded better. Of course, after modding it was even better. That DAC was part of Bill Allen's reasoning for trying the NOS DAC's in the first place along with how the A/N gear sounded at a couple of shows that he (we) had attended. To say that the DAC's are too cheap to spend time and money modifying is somewhat counter-intuitive. IMO to get the sound out of "commercial" gear with all of the necessary markups one would have to spend at least $1500. Now, after spending all that money and the thought in one's mind that it has to be as good or better would you really go headlong into modding right away knowing that your resale value would plummet? Besides, the vast majority of DAC's in that price range are not going to be NOS. That is just my opinion. Take it for what it is worth from someone who decided a couple of years ago that if I really wanted the ultimate sound that I would have to modify or build from scratch to get what I wanted especially if I wanted to keep the cost down. That in the case of the Valab included spending the money on Dueland output caps that equaled the cost of the DAC and power supply together. Was it worth it? Ask Bill Allen. He heard it in comparison to his DAC with the same mods except he used the Jupiter caps. I mention this to illustrate that inexpensive does not mean cheap. Putting value in the basic design and parts counts most.
post #160 of 1144
I could not stay away from the solder iron hehe, Put the 3 Uf Dynamicaps in, and pulled the Silver mica's. I did listen to it a bit with the Dynamicaps and with the mica's in, then I pulled them out. Hard to say what I prefer, the Mica's where definatly warming everything up, but hiding some high end sparkle and detail. I think I like it better without them, but this could be subjective. The dynamicap's are definitely a step over the Wima's. Dac's got about 120 hrs on it now. I may put the mica's back in, in a few days to give it another listen. I may order some better resistors soon, going to be awhile before I can afford better output caps though. As the Mundorf silver/oil are quite pricey. Does anyone have a recomendation for a decent quality RCA Jack without going overboard and spending 40$ each? Are the cardas and vampire jacks better then stock?


edit: seems rather bright without the silver mica's in place, maybe it needs more burn in. I happen to have some 0.01 UF RelCap RTE which are pretty good caps, I put them in the mica position, listening to them now.
post #161 of 1144
Well after a very long stay at customs the Chameleon finally landed in my lap. Straight out the box, compared to a modified and burnt in Valab, sound was less transparent and held back somehow, but the low and high frequencies are more extended, more balance across the spectrum.

Next using only spdif/usb out from the computer with the reclocker in place it is an improvement over not, using, the reclocker overall. Without the reclocker I felt more was getting more through, but the sound was just ordinary/pedestrian compared to using the reclocker.
With Async device I use in place, the sound with the reclocker was an improvement again, but I felt something was being held back.

Reclocker out, and only using external async device, unsurprisingly was the best comb. If I didn’t have an external async device I would use the internal reclocker.

Now I did notice at full volume and no music playing with the reclocker in place there was some very slight hiss. With normal music playing this hiss was not apparent at all. Without the reclocker there was still some hiss but this was at so low level it was barely perceivable.

As I am not going to wait a month only to mod the chameleon anyway, so I started straight away by snipping one leg on each low level filter cap. Wow it was like being in a time machine and going into the future. It sounded like at least a couple of weeks burn in on the unit had taken place. It was so much fun (after suffering for the last month with BG’s burning in) I was tempted to solder them back in place, and do it again! Blacker background and sound opened up all round. That hiss seemed to have left the building as well.

Back to my Valab now. The Valab is still ahead with its purity realisim and transparency in the midrange, but the Chameleon is definitely well ahead with the extended low and high, and the soundstage is wider. The Chameleon is now sounding more like a conventional Dac but with all the musicality in place. The thing that strikes the most is the bass is much more defined, more inner detail.

Now its the turn for a couple of Allen Bradley 180r 2watt for the IV. I thought I would play with these first as my Texas are in the post.
Well after putting them in, and firing up again I have to stop writing and listen to some music, stunning, simply stunning. If I can drag myself away, I will look at the coupling and TDA1543 decoupling caps another time and re-plan my day and revaluate my understanding of musical reproduction. I will try and find words to explain what just happened to the SQ later.....
post #162 of 1144
has anyone tried switching the reclocker to "24 bit" it looks like there's a smd "bridge" that you can solder to go between 16 and 24 bit.

Im really enjoying the way these Relcap RTE's are sounding in the 0.01 filter slot. Without a cap there at all I was getting a little bit to much brightness/grain. The Relcap's seem to have a similiar effect to the mica's but to much lesser degree, they let alot more of the high frequency energy though, while still offering a slightly smoother/fuller sound overall. It's a synergy thing I guess. I could be happy without a cap there, but i'd have to use a warmer tube in my amp, it was to bright for me to use my favorite tube (Tung Sol, black glass). Which I find very well extended.


Quote:
Now I did notice at full volume and no music playing with the reclocker in place there was some very slight hiss. With normal music playing this hiss was not apparent at all. Without the reclocker there was still some hiss but this was at so low level it was barely perceivable
I wonder if this is the same hiss im hearing that has been bothering me. Why is the reclocker causing this, and is there anything we can do about it. I did notice when I took the Silver mica's out the hiss was lower, I also noticed it's lower with the Relcap RTE's, but not as much as no cap at all.
post #163 of 1144
MikeW try billet copper CMC jacks (silver plated or gold plated) USA made at around 28US a pair for the gold plated ones. The silver plated jacks are few dollars more IIRC.
I use these (in all manner of gear) and find them every bit as good as the much more expensive Cardas (billet copper + plating) or Edison price jacks (which are just solid copper milled).

Peete.

EDIT: Nice work with the new caps ...have you thought about WIMA Black Box film caps ? They are the only WIMA's I like in the signal pathways. They sound terrific although not in the same class as the Duelunds, K75-10/T-3 combo or Mundorf Silver/gold in oil but they are also 1/2 to 1/3 the cost of the Duelunds and Mundorf caps. The Russian combo is 1/2 the cost of the WIMA's..
post #164 of 1144
What V regulators (LM317T as an example) are those in the PSU ? Can someone tell me the type/brand, series, uf amount and V values of the mains filter caps please. The diodes look like hi q types already but the model number would be appreciated to confirm.

I can think of at least 3 mods for the PSU that would really help but I will wait until someone can post the answers to the questions I've asked. I would greatly appreciate that info

Peete.
post #165 of 1144
The big caps are Panasonic FM 1000 UF, not sure on the voltage rating. The voltage regulator is linked below. I'd love to see what kind of mods you can come up with, whatever we do, we have to keep heat under control.

MJE15030

http://www.datasheetcatalog.org/data...rtgucl9jwy.pdf
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