[Bill Allen]

Yea there is probably some sort of measurable difference that could account for "some" of the changes we are hearing as we roll different parts through the Valab. To an engineer, most of the things we discuss would be chalked up to pure Hippy Logic, and yes some are easily explainable. However I have never met an audio engineer that didn’t live in a box, governed by rules of a “man made origin”. Physics at the quantum level and even at the electromagnetic interaction level are unknowable; listening to them talk on these subjects is just their “geek speak” Hippy Logic. Your best "audio" engineer’s are the one who embrace the electronic weirdness while loosely applying the golden rules.

Think of a young Police Officer trying to do the right thing, in short order the ones with common sense discover they can only loosely control what’s in front of them at any given moment. However society has set up a system where “he/she” has the right to enforce all these “manmade” rules. Yes some of these rules are self evident, the rest are simply reactions to the reactions to the reactions. Separating these reactionary rules from self evident truth are not us humans long suit, so don’t blame the cops. Er Engineers.

Drop “this” brand of logic into the ultra simple Valab DAC, add in some Aristotle philosophy, now imagine the flowering of your own personal Electronic Renaissance.

Look Mom … NO RULES!!!

 

[hifi2001]

Quote:

Originally Posted by Bill Allen /img/forum/go_quote.gif HiFi2000, The Valab DAC is without a doubt the best tool I have ever used for determining what a Cap "actually" sounds like. Every coupling cap gave a different result with the Valab. I tried a bunch and the results were a can of “mixed nuts”.

Bill,

I couldn't have agreed with you more. The reason why I bought the Valab DAC was because of its DIY potential. As long as I'm learning something along the way I'll say the experience/time/money spent was worth it... I built my 300B SET based on Thorsten Loesch's Legacy 300B SET ( ok Thorsten encouraged me to

) and my two way horn loaded speakers is based on plans from pispeakers.com. My is the 4 pi model with JBL pro speakers... You can google to get additional info... What I learned in those projects is priceless.
Since I only get one shot to buy those output caps (my wife keep a close eye on my DIY spendings

) I decided to scrounge into my "future cap project" bin to see how my system reacted to either high or low cap values.

I decided to post my findings here is so that when people read ours comments they don't take what we say as gospel. It should be treated as a starting point that is out of focus perhaps . It is up to individuals to bring it in to focus.

Bill, if you don't mind, I definitely like to hear your findings on those NG Jupiters... You don't know how much money you have saved me so far

My order of K72 Russian Teflons came in Yesterday and I tried the bypass trick. Yes it does introduce a slight sharpness back into the music as expected. Keep in mind that it is based on zero burn in time. If I were to quantify how much sharpness the Teflons introduced, I would put it around less than 8%.
Until my order for the old gen Jupiter caps comes in I'm stuck with 0.22uF Mundorf Supreme on one side and 0.47 uF K40Y-9 on the other side both bypassed with 0.047uF K72 Teflons. Right now, the top of my case is open, I'll deal with packaging the parts when the Jupiters comes in... And by the way, this is all based on stock I/V resistors. I have 330R AB and Takman carbon resistors on order.

For those that are thinking of replacing output caps, I would suggest that you don't try and remove the 10uF leads from the PCB. Instead, cut the leads off closer to the cap so that you use the existing leads as termination point for the new caps. The circuit traces going to those output caps comes off easily if you are not careful

Cheers.

 

[Ranchu]

Random site, good to know beforehand.

HOW TO HANDLE THE POLICE

 

[Realrift]

Hi guys,

After a lot of guidance from those on here and reading the thread a few times, I have done a few mods on the dac.

I first rewired the RCA outputs to the bottom of output caps pins (basically bypassing the board traces and connecting wire on the topside). I also wired a ground wire to the ground of the RCA plugs (which are linked together). I harvested some silver stranded wire from a broken dac I had and used this for the rca's. The ground wire was two strands of solid core copper wire soldered together (this is from cut up cat-5e wire).

I initially tried also disconnecting the filter network and making a bridge across where they were, but got a loud hum and clicks from both channels when changing volume. I replaced the filter network

.

Minor mods but the dac seems to be quieter when no music is being played and volume on preamp is maxed out. The voices seem a bit recessed but perhaps it is the caps still breaking in. Will add some 0.01 bypass caps to see if it helps.

Cheers,
Rift.

 

[hifi2001]

reposting

Quote:

Originally Posted by Bill Allen /img/forum/go_quote.gif HiFi2000, The Valab DAC is without a doubt the best tool I have ever used for determining what a Cap "actually" sounds like. Every coupling cap gave a different result with the Valab. I tried a bunch and the results were a can of “mixed nuts”.

Bill,

Your statement is so true.

One of my main reasons for acquiring the Valab DAC was because of its initial low cost and relatively simple DIY potentials... Since this is a hobby for me I wanted to buy something where I can learn something in return just like the lessons I've learned while building my DIY 300B SET amp based on Thorsten Loesch's 300B Legacy amp and my 2-way horn loaded speakers, based on the 4Pi Pro speakers from pispeakers.com. The experiences I learned from those projects alone were priceless...

I decided to chime in with my observations here because I wanted to let people know that the results we report here is just a starting point. Please don't take our findings as gospel but rather a data point towards that elusive audio nirvana we all want to reach

There is no right or wrong in this hobby.

Bill, please report back your findings with those NG Jupiters. You don't know how much money you have saved me with your reports

Thanks!

My order of 0.047uF K72 Russian Teflons came in the other day and I did the bypass trick across 0.22uF Mundorf Supreme on one side and 0.47uF K40Y Russian PIO on the other. And sure enough with those Teflons in the sound sounded slightly sharper in the upper freq range. Keep in mind that this observation is based on zero burn in time. I'm going to leave it in until my order of Jupiter caps, from partsconnexion, I have on order is in and do further eval then. Quantitatively speaking the Teflons increased overall sound sharpness by about roughly 10-15%, this is still less than those stock 10uF caps.

When swapping out output caps, I would suggest that one do not remove the 10uF output caps with soldering iron, the heat from the soldering iron (I used a 30W iron) can easily remove the circuit traces on the PCB, instead, cut the leads off closer to the cap so that you leave the existing leads as termination point for the new caps. I wished I did this before I pulled the 10uF cap

 

[PatOMalley]

I had a similar noise, but it was a snap, when changing sources on the preamp after rewiring the output wire. You need to make sure you are at the correct legs of the caps. This would affect the filter network as well if at the wrong side of the cap.

 

[krisno]

I just orderd 2x 330R Takman Carbon film resistors, are those good for I/V or should I have gotten the Takman Metal film version??

The order is allready placed but if you are quick I can redo it. I read something about carbon resistors not tolerating heat?? and the dac is warm!

K

 

[hifi2001]

Quote:

Originally Posted by Bill Allen /img/forum/go_quote.gif HiFi2000, The Valab DAC is without a doubt the best tool I have ever used for determining what a Cap "actually" sounds like. Every coupling cap gave a different result with the Valab. I tried a bunch and the results were a can of “mixed nuts”.

Bill,

Your statement is so true.

One of my main reasons for acquiring the Valab DAC was because of its initial low cost and relatively simple DIY potentials... Since this is a hobby for me I wanted to buy something where I can learn something in return just like the lessons I've learned while building my DIY 300B SET amp based on Thorsten Loesch's 300B Legacy amp and my 2-way horn loaded speakers, based on the 4Pi Pro speakers from pispeakers.com. The experiences I learned from those projects alone were priceless...

I decided to chime in with my observations here because I wanted to let people know that the results we report here is just a starting point. Please don't take it as gospel but rather a data point towards that elusive audio nirvana we all want to reach

Bill, please report back your findings with those NG Jupiters. You don't know how much money you have saved me with your reports

Thanks!

My order of 0.047uF K72 Russian Teflons came in the other day and I did the bypass trick across 0.22uF Mundorf Supreme on one side and 0.47uF K40Y Russian PIO on the other. And sure enough with those Teflons in the sound sounded slightly sharper in the upper freq range. Keep in mind that this observation is based on zero burn in time. I'm going to leave it in until my order of Jupiter caps, from partsconnexion, I have on order is in and do further eval then. Quantitatively speaking the Teflons increased overall sound sharpness by about roughly 10-15%, this is still less than those stock 10uF caps.

When swapping out output caps, I would suggest that one do not remove the 10uF output caps with soldering iron, the heat from the soldering iron (I used a 30W iron) can easily remove the circuit traces on the PCB, instead, cut the leads off closer to the cap itself so that you leave the existing leads as termination point for the new caps. I wished I did this before I pulled the 10uF cap

Cheers.

 

[Realrift]

Quote:

Originally Posted by krisno /img/forum/go_quote.gif I just orderd 2x 330R Takman Carbon film resistors, are those good for I/V or should I have gotten the Takman Metal film version?? The order is allready placed but if you are quick I can redo it. I read something about carbon resistors not tolerating heat?? and the dac is warm! K

Hi K,

Not sure about the choice b/w the two but I have gone for carbons myself.

I wouldn't imagine the resistors would get so hot in the dac as to affect their function, but if you are concerned then you could always add some ventillation holes. The latest version of the dac comes with holes in the lid.

In other news, I have just done the DIR9001 mod to change sampling frequency to 512fs, added some 0.01uf bypass caps to the output and formalised the DC input by drilling a hole in the back if the dack and putting in a DC input jack (thanks to Bill for the idea). The DC input is still wired to the legs of the 1000uf power caps. I still can't close this lid due to caps but it makes the dac easier to move around without carrying a trailing power wire.

I may try a different cap on the noise filter before getting the courage to try and remove it again. I believe it is a 560pf cap (it says 562J on it).

Cheers,
Rift.

PS. I am using the USB input but just did the coax mod for... would you believe completeness?

 

[rhodes54]

This topic seems to be more alive than ever! Nice to read that new ideas are blowing a fresh wind over the current Valab Mods.

I´ve been working for two full days on my dreamdac. The Valab has been released from its original home and moved into its new 'Dream' house.
It was much more work than I expected but the result is amazing.

The only thing left is the Paul Hynes Power supply. I expect it to arrive next week.

By the way: I replaced the original blue power supply by a 30VA Torodial transformer and even that is a nice step forward.

I will make pictures for you tonight and post them here together with the full list of mods I did.

 

[dannie01]

Pictures please rhodes54 especially the innards and the front, back panel of the dream house.

 

[Jogi]

Hi all,

wonderful world: suddenly my USB input resurrected from the dead, no clue why.
I tried everything before, two different computers, but no yellow light.
Maybe Kevin from Valab decided to send powerful REIKI rays from Taiwan, and not to waste energy with a useless mail response....


Anyway, two more tweaks...one is for the gentlemen with a reclocking board: there is a little 0,1µF SMT cap under the board, right under the crystal, and an empty solder pad for a 10µF cap. Maybe they left it empty for economic reasons, but it is yery worthwhile to throw a 100µF oscon or similar cap with low esr in that place, the SMT cap can be kicked out completely, as it works just as a bypass.
Dubai mentioned this mod above, and he is absolutely right to call this another bottleneck removed. It is not a miracle, since the supply for the board is somehow poor, so some more capacitance is a little cure to this.

Then for the USB input on the newer revisions: there is one little blue film cap close to the USB receiver CM108, it goes to leg 1, which seems to be the input leg, therefor this cap has some importance.
I managed to smuggle a very good 0,22 oilcap in the tight space, 0,1 should be enough.
Removes harshness quite a lot and adds weight, coulors and resolution.


@Krisno: who told you that carbons don't like heat? They were soldered since many years directly to countless tube sockets in tubed radios and amps, since all resistors were carbon ( or wirewound) at that time.
So no problem in the Valab, as it gets just warm compared to a tube amp. And soundwise should be nice....


Cheers,

 

[krisno]

I changed it to the metal film , I read some bad things about carbon, so well... I guess the difference won't be too dramatic. But of course I had hoped to go for the Shinkoh.

K

 

[PatOMalley]

I'm not into PC for music. Just passing this along.

This company is selling a low jitter server and look at the DAC it is partnered with:

Let me try that link again:
http://www.pacificvalve.us/index.html

 

[hifi2001]

I have been doing a bid of research on the up and coming external power supply for our DAC. Here is the specifications I was able to get from TeraDak for the DC-30W power supply:

==> 115 or 230VAC input voltage. Internally, there is a jumper to select the input voltage.
==> Dual output DC Voltages: +7.5V@1.25A and+ 5V @1.25A,
==> It can work from 5C to 50C
==> It includes EMI filter and fuse before rectifier
==> it includes a DC-to-Dc cable, adapter for DAC, socket for DAC, and 3 power lines for DAC internal modification

It uses decent choice of parts and there is no drilling on the existing DAC. All that is required is a soldering iron and a screw driver/allen key. It comes with a DC plug faceplate that replaces exisiting IEC plug.

Now the good part. Price. It hasn't been announced yet, but the ball park price I heard sounded reasonable to me. I would like to organize a group deal but I'm awaiting approval from the moderator to post further info on what I am thinking... (I read the posting rules and was bid confused on what I can say here

....) so until then please keep all discussions towards improving our DAC