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Chameleon DAC listening and modifications - Page 13

post #181 of 1144
The Salas shunt design is very respectiful, and no doubt will provide a very worthwhile upgrade.

Myself, I will see first what Teradak have cooking, be nice to have something to retrofit into the box I have.

But its the way to go...
post #182 of 1144
only capable of 2 amps for the low voltage option....but it must be good if it's using 2sk170BL ;-)

http://diyaudioprojects.com/Solid/Je...ga-Le-Monstre/
post #183 of 1144
Got parts ordered so far :

2 Texas components TX2575 175R
16 47 UF Elna Silmic2
6 100uf Elna Silmic2
1 10uf Elna Silmic2
Vampire CM1F RCA Jacks
0.1 UF SoniCap Gen 1
2 50k PRP Resistors
3 47R PRP Resistors
3 1k PRP Resistor
Jupiter 4/9 Copper hookup wire.

Replace I/V with TX2575
Replace Dac coupling caps with 47uf Silmic 2
Replace Digital Input board 100UF Caps with Silmic2
Replace Reclocker Board caps with Silmic 2, 100 and 10uf caps.
Replace RCA Jacks with Vampire CM1F
Replace 0.01 K40y with SoniCap 0.1 Film capacitor
Replace Output Impedance Resistors with PRP 50k (To match my Headamps 50k input impedance)
Replace Small green resistor in corner of dac board with PRP 47r
Replace green resistor on digital input board with 47r PRP
Replace green resistor on reclocker board with PRP 47r
Replace 3 Green resistors on Dac board with PRP 1k
Rewire all jacks with Jupiter Cotton Insulated Copper wire.

My only concerns are fitting the 100UF Silmic2's on the Digital board and reclocker, as they are not SMT caps.

If there's any glaring mistakes here or suggestions i'd like to hear it.

I realize some of these resistors may not be in the signal path, but they where only 32c each, and I was ordering parts anyways.

Thanks for you help Wood, you saved Bill some headache

PS: all of the above parts cost less then a single mundorf 4.7 UF! Or 16 Blackgate FK!
post #184 of 1144
I'd stay clear of the 47 Ohm ' green resistors' for now as I seriously suspect those are 47uH coils I see in the schematic....
Replacing the output resistors imho is not worth any hassle, chop them off and be done.
post #185 of 1144
Quote:
Originally Posted by marcelnl View Post
only capable of 2 amps for the low voltage option....but it must be good if it's using 2sk170BL ;-)
]
One TDA needs about 50mA, with the 16 chips this is around 0,8A. So the 2A should be enough, as this is not a power amp with big peaks in the curent demand.
And yes, should be very nice...
post #186 of 1144
Yes, there is some confusion if those are "Chokes" or "Resistors" and what is the difference. As for the output resistors, it's more curiosity on my part. Im weary of making specific changes to suit my setup, I don't like to do things that could bite me in the ass down the road, like removing input caps and taking things out that are there for a reason. What if I get another amp down the line, or sell it, etc.
post #187 of 1144
Quote:
Originally Posted by Jogi View Post
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...
Right on Jogi......nice find !!!

MikeW that's quite the list. Your going to be having loads of fun over the next 2 weeks

Peete.
post #188 of 1144

Some mods and listening impressions

I would like to second Bill's kudos to Wood for the concise and well written comments on the sound so far. Pretty much took my thoughts and wrote them down.
Before going too far though I would like to comment on the sound of the Chameleon right out of the box as the team at Teradak really deserve some thanks for all of the work done to make this an outstanding product right out of the box. With no mods at all and just 24 hours of break-in one can easily hear the potential in this gear.The choice of the Wima caps is a very good one IMO. Yes, my caps sound better but really, as is, the thing just puts out very fine music. I am sure that with further break-in that it would have been marginally better. Wood hit it exactly when he wrote that the Valab was perhaps a little more easy to listen to but certainly not as detailed. The Valab is more forgiving as is any equipment that is not as high in resolution. See the fans of copper paper in oil coupling caps for an example of this preference in listening. I still think the Valab is a smoking good DAC and it is very satisfying to listen to but after listening to the Chameleon for just one day I just had to have that resolution that was lacking. I just want to be sure that no-one gets the impression that the Valab is a slacker in the sound department.
I have made the following changes so far:
1. BlackGates on the individual DAC chips. I have these on the Valab as well. As Wood has noted; very surprisingly there is very little if any of the BK pain that normally accompanies putting these in. Perhaps it is because they are in parallel with the signal path and not in a direct line with it. I cannot say but the improvement is not night and day. Definitely more break in before a comment on the efficacy of this mod but past experience says it will be worthwhile.
2. I installed both units into a box that I made that previously housed the Valab with my Dueland (4.7 VSF) coupling caps. They are much too big to put inside of the DAC case. These are very nice caps and I think that not much needs to be said regarding their sound that is new especially as I was using them on the Valab.
3. I installed 200 ohm Caddocks for I/V resistors that I was using in the Valab (doubled up for that use). Again, same reference as the Valab so the two units are on a level playing field. Very good I/V resistors are really a very (relatively) inexpensive way to boost the performance of the DAC as has been noted in posts here already.
4. Replaced the 0.1uF cap on the secondary of the pulse transformer with a Mundorf Silver/Gold/Oil of the same value that I had sitting around from a previous project. A little over the top perhaps but I had no better use for it at the present time and it is broken in so there you have it. Well, this is almost a "must do' mod IMO. Not night and day as the next mod but very nice overall for not too much money especially for the tweakers that probably have a film cap of this value to use. It just gives things a nicer overall sound and more of the realism that the whole NOS thing gives you. Again, credit goes to the gang at TeraDak for choosing such a nice original component that the change is subtle and not needed straight away. Be VERY careful with this mod as mentioned in a couple of posts. Just clip the cap lead close to the body of the cap on the output side to give yourself something to solder to other than the very small wire that is there unless you really like soldering super small stuff. I do not, my eyes are just not that good even with help. After clipping that end of the lead then de-solder the side that is on the secondary of the pulse transformer. That way the sturdy side of the cap will be holding up the cap instead of the small wire holding up the cap.
5. Cut out the filter cap! Easiest to do and the biggest sound improvement for NO MONEY! My favorite!! All of your other mods will be much easier to hear without this in the way. IMO the only thing I would change in the delivered product would be to have this filter on a switch or to have it eliminated all together. Way too much music is drained away with it in the circuit and for those not inclined to modify gear I feel there is potential for some disappointment that need not happen. From a business standpoint I am sure that the folks at Teradak realize that they only get one chance at a customer and that an unsatisfied one can really make the introduction of a new product fail. A switch for this would let the O'scope jockey's measure and be happy and anyone with ears will be very happy when they switch it out.
Overall the sound of the unit is fantastic! Just what I was hoping for and expecting with the additional DAC chips. That wonderful natural "real" sound that NOS does really well along with the higher resolution that comes from the added DAC's and probably the re-clocking as well. I have not bypassed the re-clocker yet even though I have a pretty low jitter transport (Northstar). I am just content to sit and listen and be amazed at how much music there is in my collection and the Chameleon puts it out there in a very pleasing manner. Good thing I don't have to get up early in the morning. This thing can really keep you up at night.
Tony
post #189 of 1144
Thread Starter 

so, ok

Quote:
Originally Posted by marcelnl View Post
I'd stay clear of the 47 Ohm ' green resistors' for now as I seriously suspect those are 47uH coils I see in the schematic....
Replacing the output resistors imho is not worth any hassle, chop them off and be done.
I had a set of TAKMAN carbon resistors doing duty at out and just chopped them off. One thing I now notice is a cleaner spread across the field. More cohesion, or rather, nothing getting in the way of the stereo spread - it is all as one. Thanks marcelnl.

Another thing I tried is removing the CineMag 600ohms transformers coupling the machine at output to the Hagerman Clarinet line preamp. Sound became thing and loss of weight, authority and bass. Back in went the transformers and the whole deal colored up nicely - is it distortion? Ha. This sound pisses down from a great height on that argument.

I think that the output caps come a far far second to getting the transformers in play. Now this is using an extra set of wires and sets of RCAs but still it is mandatory in my hookup. Can't live without em now.

If this seems like a little over the top then I persuade any one of you to fetch a set of 1:1 600ohm transformers from Cinemag and set them up. It is not harder that hooking up output caps. Prove me wrong. I dare you.

Next up is swapping those IV resistors via the Bill output mod. Thanks Bill!
post #190 of 1144
Those cinemags are terrific ! Stick with them I say and don't look back.

Peete.
post #191 of 1144
It looks like those other green things on the DAC board itself are also Inductors, they look wonky like the other ones. Fat and chubby instead of skinny in the middle. Is there such a thing as "high end" inductors?

Are the silver mica filter caps we are removing the same thing as the 5600pf SMD caps on the old valab?

What would happen if I mistook the 1 MH inductor on the Valab 3.0 for a 1MH resistor and replaced it with a 1MH resistor when it broke in half?
I don't know, but im going to radioshack tomorrow to find out!
post #192 of 1144
high end inductors definitely exist, yet not in the realm of circuit boards.....just check for Mundorf flat wire inductors (aimed at loudspeakers).

PLS double check with teradak before replacing the 'green resistor' with an inductor, but my feeling about that being right is pretty strong.

Pat, you might well be looking at some galvanic coupling effect that is cured by the cinemags and if it sounds better I'd stick with them too.
post #193 of 1144
I would just like to echo Driguy’s lucid comments. The Valab certainly gives you the midrange purity and musicality of the Chameleon. In this respect the Chameleon does not walk all over the Valab, it takes what it does well and extends it further.

Its only when you directly compare the two you see how the Chameleon finds even more to present. If I was on a tight budget and wanted to check the NOS sound, the Valab would be the logical choice, as indeed it was for me. When ready to move up... well Valab’s seem to be fetching a good resale price now, so it’s not so hard to go to the Chameleon. I will not be selling my Valab, its home will be a second system/backup Dac.

Again I agree about the choice of coupling caps, those Wimas have got to be the best price/SQ ratio out there. Much better than the usual electrolytic coupling caps you would normally get included at this price point and even higher. If you’re not upgrading you will have to give them time to burn in and you will find they snap at the heels of the likes of Mudorf’s and Obbligators. Thats why I left them in late into my modding.

I like the idea of a filter switch, but something has to be done about those filter caps. It’s no problem for us guys. Quick snip, snip and we are there, but it would be crazy if the product is stillborn over that. It’s nice to have an exclusive product, but that should only be after adding to the Chameleon, not taking things out, seriously I think we all want to see Michael get something out of all his work. I just hope they are aware of this in the up and coming 6moons review...

Driguy, I missed that cap change on the secondary, If you mean the one on the input board, I will give a Russian Teflon a try there, thanks.


Mike, changing non critical resistors is something that has on the whole not been investigated with these dacs, so I, for one, will be very interested what you find there.

Be aware that the little tantalum smd caps have a dark brown strip that indicates the positive end, its counter intuitive its looks like the negative.

The digital boards on the Chameleon are more tightly packed to reduce trace length so keeping the replacement cap legs short is the way to go.

The inductors in the low level filter are bypassed if you lift one leg of each those filter caps anyway, if you haven’t already tried that, I would. All of us who have, found great benefit from this, and if it doesn’t work for you just resolder the legs.

A lot of changes there so try to make mental notes of changes in SQ as you go. I always regret when I steam in and change everything at once and then not know what change had the most benefit, or indeed what change made things worse.
post #194 of 1144
Driguy, ok did that cap change on the secondary, never, never ask me to do that again .
Despite going very slowly the small wire still popped of the trace. Fortunately managed to solder directly to the tiny trace without lifting it, phew! Unfortunately, however, it is an essential mod, increases the transparency no end I need to get a schematic to see if there is an easier way to do this as there are definitely going to be tears and curses over this one. Anyone got any ideas here?
post #195 of 1144
Quote:
Originally Posted by Wood View Post
Driguy, ok did that cap change on the secondary, never, never ask me to do that again .
Despite going very slowly the small wire still popped of the trace. Fortunately managed to solder directly to the tiny trace without lifting it, phew! Unfortunately, however, it is an essential mod, increases the transparency no end I need to get a schematic to see if there is an easier way to do this as there are definitely going to be tears and curses over this one. Anyone got any ideas here?
Hi Wood,

Just contact Michael. He will provide all Chameleon owners the schematic of both the Chameleon and DC-30W.
I've got it too. It's very handy when modding and of course to understand the design. :-)
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