[Bill Allen]

I added an external DC power jack some time ago in this forum to check the possibility of adding battery power supply. The best sounding battery I could come up with was a large Lithium Ion Laptop Extender Pack. Removing the AC power supply noise provides a very open, detailed see through sound stage, problem is a major lack of dynamic's which leaves the music lifeless. My friend Gary had warned me this would be the case as he played down this avenue himself. Our hope is the new super capacitors which are just becoming available will make battery power a reality. But as always at the cutting edge, they are expensive.

Plugging in various DC power supply's I have laying around paints all kinds of sonic landscapes with the Valab.
This you have to hear for yourself, wildly different. (In the end I am holding out for Rhodes to report back on the Paul Hynes power supply.) Hooking up my bench DC power supply and swinging the voltage changes the sound, but no position sounded good to me. I discovered my Bench Supply is for testing purposes only, it sounds like crap, just like the other power supply's I have laying around.

Power supply's are a black art!

I think as Jogi describes, having a "quality" power supply with the ability to adjust the input voltage may make all the difference.

Jogi or Dubai could you take pictures and further elaborate exactly what type of power supply you are using and the mods you performed to them.

 

[Bill Allen]

Quote:

I am playing catch up on this thread and it appears that the group is definitely leaning towards using large film caps like the ones pictured above. There are certainly benefits to using these boutique caps irregardless of the fact that they don't fit inside the wee VALAB case. I for one have had tremendous results with nice film caps in many of my projects, so I do understand the reasons behind this mod. However, playing the Devil's Advocate, in regards to the VALAB, please be advised that by performing this output cap mod using large film caps one is potentially "opening" the DAC up to all kinds of stray EMI and RFI from other components in your rack (leaving the lid off) and inside the VALAB itself and therefore potentially degrading the sound quality. This is the main reason why (to Bill Allen's chagrin ) that I am sticking with my BG-N's - small, inconspicuous, encased in metal case and therefore able to deflect any EMI and RFI nasties lurking inside my VALAB. Plus for $2.50 a piece they sound good enough for this DIY'r on a budget. This is just my two cents, realizing I am in the minority and will be potentially flamed, but to quote Martin Luther, "Here I stand." _

Mrdon-

So you are hijacking pictures and making sonic observations without ever having tried film caps for yourself in the Valab.

What about cosmic background radiation?

Nothing drives me more crazy on forums than this kind of mentality. Your not a minority your a moron.

Feel better.

 

[krisno]

Bill Allen

I like your style hehe.....

Btw: You were one of the first to do the black gate mod on the Valab, did it make more than neglible difference?

Secondly, WHERE have you connected the input lead of your Jupiter output caps??

I must say, the jupiters are magic, but when that is said. They do add some coloration(But not as much as the eyes might believe.. hehe) and mindeling of instruments. It really is not that upfront as the obbligato's... Right now they are running whitenoise, 48hours straight, running another 24hours now, so maybe they open up??

Also, I might have been mistaken. These Jupiters are made today and not 40years ago. I thuoght they were NOS.. my mistake!

K

EMI , radiation, whatever, is not a problem!!

 

[Jogi]

Bill,

fully agree on the power supply thing, I guess every supply will sound different.
The one I took is nothing special, it has a 1,5A EI transformer, and is stabilized with a transistor.
But I and also Dubai changed the supply cap to 10000 µF DNM Slitfoil and the diodes to 11dq10 Shottky, which changes quite a lot to the better.
Its this one here:Conrad Electronic - System Information

I don't know if these slitfoils are sold in the US though, the manufacturer is Aerovox UK.

What do you mean by super capacitors btw, are these with capacities up to 10F? I saw some in the Digikey catalogue and thought, that they might be interesting, very low ESR.

I had a look at the stock trannie, its just 9VA, and that is exactly what the dac is sucking; I measured between 0,9 and 1 ampere/10 Volts.
That means there is no headroom at all, and its not a miracle that a bigger PS gives some relief to soundstage and dynamics.

But before everybody runs and buys power supplys: I found something interesting on this page:TeraDak-DC30W - Windows Live
This is from the manufacturer of the dac, and seems to be designed for it.
As far as I can see on the pics there are two secondaries from the nice 3A C-core trannie, that means digital and analog supply separated.
Its stabilized and has little shunt regulators, good Panasonic FM caps onboard and EMI filter choke at the input.
Dubai has sent a mail to him, so lets wait for the response.


@Krisno

the cap comes to the resistor leg, which is closer to the transformer. If you connect it to the other leg, there will be no sound, so it will be obvious

And of course the Jupiters add colourations. Every cap does, even a wire. Its really like cooking, curry doesn't fit to apple pie, but I love Chicken Curry ...

It all depends on the mixture....and your personal taste...


Cheers

 

[PatOMalley]

Quote:

Originally Posted by Jogi /img/forum/go_quote.gif snip - But before everybody runs and buys power supplys: I found something interesting on this page:TeraDak-DC30W - Windows Live This is from the manufacturer of the dac, and seems to be designed for it. As far as I can see on the pics there are two secondaries from the nice 3A C-core trannie, that means digital and analog supply separated. Its stabilized and has little shunt regulators, good Panasonic FM caps onboard and EMI filter choke at the input. Dubai has sent a mail to him, so lets wait for the response. -snip

This looks great. Thanks for finding this. Yay.

 

[Bill Allen]

Jogi,

Yes good work all around on the power supply's for the Valab. The TeraDak version looks like it will be big bang for the buck. Can't wait to get my hands on one ... or two.

Super Caps/Ultra Caps, are ultra low ESR caps that are finding there way into all kinds of battery power supply applications, including the latest generation of electric cars. They stand to solve a lot of our low voltage battery power supply issue's. Audio applications are just starting to be explored.

Here is a link to a Ultracap forum. DIY - Do It Yourself - UltraCapacitors.org*-*Ultra Capacitor - Super Capacitors - Super Battery?

Krisno,

the Blackgate FK's and the value's I used are a proven recipe of Steve Nugent of Empirical Audio. Its all about balance here and yes they make a big difference in how the Valab Dac sounds. Adding just the right power supply should further the cause. I have to admit that the Paul Hynes power supplies Home Page really have my interest. But that's my high end tastes talking.

 

[Ranchu]

It's good when people feel they can share their ideas whether it irritates you (or me, or Kim Jong Il) or not, don't you think?

I have my dac now, I like it a lot, I have also received 4 rifa phe 426 6.8mf caps two bucks a piece, and plan on those TI resisitors.

Opened the dac, checked it out, I'm getting a plan.

I'm optimistic about how it will sound, and look forward to telling you all what I find. I chose these for a lot of the reasons he mentions, mostly that they'll fit (I like that), and I can't afford to blow 80 bucks or more on caps.

I hope you're not offended, that's not my intent.

 

[Bill Allen]

Ranchu,

to tell you the truth I prefer when people share results, however constructive ideas are also well received.

Pushing someones buttons will get also get results ... potentially.

Especially when invited too!

Sorry MrDon I just couldn't help myself.

 

[Bill Allen]

For those of you not afraid to try some film caps in your Valab Dac. I have a big bag full of brand new Cryo'd 1uf Obligatto Caps.

$20 a pair.

For you folks that like a darker richer sound I also a bag of used 1uf Jensen Copper foil caps.

Also $20 a pair.

Free shipping anywhere in the US or Canada.

PM me if interested.

 

[Ranchu]

True words, Bill.

Thank you btw for your posts here, all you guys enthusiasm for this thing encouraged me to get one, it sounds much more like music than my previous oversampled things and I'm very happy I did!

Amazing!

 

[krisno]

Jogi

So the best place to tap into the signal pathway(for the caps) is to solder the input leg onto the leg of the I/V transistor closest to the transformer? This is what you all do?

Bill

That Teradac PSU looks great, but it seems I need to buy another DAC (again) to be able to connect that PSU.

Was it hard to remove the NEC 10uf and attach 10uf black gates instead?? My soldering skills are not great, but I should try it if it helps. Also I would replace the Rubicon PSU cap's also..

Thanks for everything...

Kris

 

[Jogi]

Bill,

interesting, those caps, I'll keep an eye on this. Maybe its something for a dac which needs less power, as the storage is not as high as with batteries.
And for your JensensM sent...I love their sound in certain cases.


@Krisno

yes, that simple, I soldered it directly to the resistor leg. You should swap the resistor, it does sound nasty.

And for the power supply:
I was also asking myself, how to connect this thing to the dac.
I guess one has to drill a hole in the back plate, mount some kind of plug or bushing, and from there solder 4 or 5 wires to certain points on the PCB. Should be done in half an hour.

The NEC caps are easy to desolder, just apply enough heat and flip them off their place with the soldering tip; take care not to create a solder bridge somewhere.
I took 100µf/16 volt Panasonic FM at that spot, they tend to sound more dynamic and open than BG, without harshness.
The BG can sound more pleasing and warmer, but not as transparent as the Panas; again its up to your taste.


Cheers,


Juergen

 

[krisno]

Jogi .. but that NEC for BG/Pana did it make a serious improvement, or just neglible? You know, other TDA1543 dac's are just piggybacked, with no caps between each.

I am in such doubt. I have spend alot on CAPS, but I wonder if I should try to assemble the DDOE MK2 dac. A PSU of your own choosing, and also it has what seems a very nice USB solution.

 

[dubai2000]

Bill,

am interested in those Jensens too , but how on earth can I send you a PM?

Found it - PN has been sent

 

[Jogi]

When you take FM caps, it is no risk, they are about 15ct a piece, and they are much better than the stock NEC.
It does make a difference, it contributes say 5% to the best possible performance, where the Power supply is 30%, output caps 20%, the resistor 15, the other caps onboard 15, and fancy regulators another 10 %, IMHO.


I agree, when you are not that experienced, it can leave you with a lot of doubts about all this.
The best thing is - giving it a try, collecting experiences, and after a while you know your taste and what part at which point makes sense or not.
And, very important to me, there is no such thing as "best sound", the journey never ends, or to quote Frankie Zappa, the torture never stops

There is always the itch, that it could be just a little bit better....And in the end its fun.

But maybe you have a real problem in the system, as you reported screaming sound and harshness. The dac alone does NOT sound like this for sure, and maybe another one would make it even worse.
I don't see much of a difference betwen the Valab and the DDDac, I don't think it would be a big step, it may sound different, but better...?
I would first squeeze everything out of the Valab, before changing Dacs like underwear.
And there is quite something to squeeze, you actually just started.