[awkwardbydesign]

Thanks Bill,
But that is $135 shipped, (with VH's cheapest plugs) and I have to make them up. The point was to try to save money!

 

[krisno]

The holy grail of bypass is here.....

My 1.0uf Jupiters always sounded very realistic but a bit slow and loss of details on the upper end. I bypassed them with Vishay Roderstein ERO KP1832 0.015uf's...... The sound is now just what one has been dreaming of. It sharpens up the jupiters a bit, better highend extension and it seems seemless! The ERO KP1832 are just fantastic stuff...

Jupiters without this bypass is only 'halfway'. Positioning is better also.... But I use this highly modded X-can V2 hybrid tubeamp, so even with AKG K 701, the combination might sound different on SS as tubes masks some of the sound.

But this is a combo nobody speaks of here in this forum, but it is perfect.... forget 4.7uf + 0.22uf, try 1.0uf jupiter and 0.015 ERO KP1832 ! They are cheap on ebay

 

[Bill Allen]

Speaking from experience the older Jupiter Caps require a Cryo treatment before they open up on the top end. If you have not Cryo'd your "Orange Jupiter's" then its safe to say you have yet to hear them. Bypass or no Bypass!

The newest generation of Jupiter Caps come Cryo'd from the factory and no longer require a bypass cap. They are transparent to the point they almost vanish, but be forewarned they require a long break-in period. Highly recommended!

Now for the last time, the very last time I assure you from me, if you use 1.0uf coupling caps you "will be" rolling off the bass response. If you listen to headphones or ported bass speakers most likely you will not even hear a difference. I.E. Don't waste your money on larger value caps. "However", larger value caps are required and make a big difference with full range speakers.

That's all I got to say about that!

 

[tubes]

I spoke with the Vice President of Scientific Conversion today about their transformers. Man, I have to admit most of what he told me sailed right on over my head. Anyway, he told me the sc944-05 is old technology and probably to go with the 947-02, it's shielded and is surface mount but has 8 pins so I'll have to grill him on how to hook it up. He wanted to know some things about the Valab to make sure it's a good match. I'll report back later when it's wired up.

 

[Bill Allen]

The point of this entire thread is to get the most from your Valab DAC and to a smaller degree, but equally important, your entire system.

Anyone with true experience in this hobby "knows" that your system is only as good as it's weakest link. Every player should keep it real by being aware of what that weak link is ... at any given moment. Clearly it moves, and it obvious that no amount of upgrading your DAC with quality parts is going to compensate for a flaw somewhere else in your system. That's a fact.

The Valab with it's $200 price point means there are players using it in very low cost systems. Where you put your upgrade dollars really depends on that weak link. For the Valab DAC itself the 3 big ones are the coupling caps, power supply, and now thanks to Pat, the input transformer on the coax digital. Change these 3 items and you Valab DAC will take a major step forward no matter what system you put it in.

Blackgate's on the DAC chips, pure silver wiring, SSOM, naked I/V resistors make a big difference only if you own a system that can resolve those difference's. It's all relative ... like the Universe! I think most people would be shocked by just how different our individual results are with the Valab. While the internet allows us to share idea's, sharing listening experience's will remain subjective unless we could visit each other in real space and time. Road trip anyone.

I will traveling to Tony's place in Albuquerque this week to compare our Valab DAC's. Both are identical except mine has the NG Jupiter couplers and his has the Duelund Copper Caps. Tony runs a Northstar Transport and I will be introducing computer audio to his system for the first time. Featuring my SSD Mac Mini/Empirical Audio Offramp 3 w/Ultraclock and the Amarra Music Player. The rubber is about to hit "the road".

Below is nice little subjective review on extreme coupling caps. (Once again the NG Jupiter Cap's are MIA).

Jimmy’s Junkyard » Blog Archive » Extreme Capacitors Battle (2nd Session)

 

[PatOMalley]

All those mods had a most serious bang.
As equal to those is the output impedance coupling via either transformer or tube buffer. Impedance coupling both on input and output have had a large impact. Larger than the output coupling caps. As equal to or more than the power supply.

I took Bill seriously when he talked about jitter. Which is why I wound up with the Lundhal input transformer. Which is why I will change that input resistor to a nude Vishay. I thought the Cinemag on output was going to do the trick but the Yaqin whipped it in my system - but only after bypassing the output caps in it. The Yaqin goes against the KISS and who knew?

My system is not the most expensive, etc .... my.audio - OMalley but it is tweaked to a point that is very human and personable.

I've had a great time modding this thing. This has been more hands on than vinyl at times. And the mods mentioned above pay off in large unambiguous benefits.

Quote:

Originally Posted by Bill Allen /img/forum/go_quote.gif The point of this entire thread is to get the most from your Valab DAC and to a smaller degree, but equally important, your entire system. Anyone with true experience in this hobby "knows" that your system is only as good as it's weakest link. Every player should keep it real by being aware of what that weak link is ... at any given moment. Clearly it moves, and it obvious that no amount of upgrading your DAC with quality parts is going to compensate for a flaw somewhere else in your system. That's a fact. The Valab with it's $200 price point means there are players using it in very low cost systems. Where you put your upgrade dollars really depends on that weak link. For the Valab DAC itself the 3 big ones are the coupling caps, power supply, and now thanks to Pat, the input transformer on the coax digital. Change these 3 items and you Valab DAC will take a major step forward no matter what system you put it in. Blackgate's on the DAC chips, pure silver wiring, SSOM, naked I/V resistors make a big difference only if you own a system that can resolve those difference's. It's all relative ... like the Universe! I think most people would be shocked by just how different our individual results are with the Valab. While the internet allows us to share idea's, sharing listening experience's will remain subjective unless we could visit each other in real space and time. Road trip anyone. I will traveling to Tony's place in Albuquerque this week to compare our Valab DAC's. Both are identical except mine has the NG Jupiter couplers and his has the Duelund Copper Caps. Tony runs a Northstar Transport and I will be introducing computer audio to his system for the first time. Featuring my SSD Mac Mini/Empirical Audio Offramp 3 w/Ultraclock and the Amarra Music Player. The rubber is about to hit "the road". Below is nice little subjective review on extreme coupling caps. (Once again the NG Jupiter Cap's are MIA). Jimmy’s Junkyard » Blog Archive » Extreme Capacitors Battle (2nd Session)

 

[r8833]

Damm! SC944-05 are the old ones.. I just got mine today. I googled scientific conversions and there is a lot of talk about the sc-944-05 ..didn't know they got updated. I should have called them to find out which was the best

for the dac caps I use have installed rubycon ZA's in one and sanyo os-con in the other with excellent results. Black gates getting hard to find

 

[r8833]

Quote:

Originally Posted by krisno /img/forum/go_quote.gif ... forget 4.7uf + 0.22uf, try 1.0uf jupiter and 0.015 ERO KP1832 ! They are cheap on ebay

try 4.7 + .22 + kp1832

 

[rhodes54]

Yesterday I brought my DAC to work to adjust the output of the DAC once more using a scope this time.
We made a nice setup with an Audio Precision analyzer to generate a 0dB/1Khz sinewave test tone to feed the coaxial digital input of the DAC. An oscilloscope was connected to the analog output of the Valab so we could see the sinewave on the scope and adjust the DAC.

Well, what we saw on the scope is not what you would like to see: A kind of rippled sinus which got a bit better on lower frequencies but it really became problematic above 4-5 Khz. On 10 Khz there was hardly a sinus recognisable anymore. If you would see this without listening to the DAC you would think it was broken...
Could it be something with the scope? We connected a Benchmark DAC-1, Apogee Rosetta 200 and Prismsound Dream DA-2 but they all gave a perfect sinus.
Could it be a problem with my DAC? I took my other, non modded Valab and connected it: A perfect sinus... What the heck!?
Did my heavily modded Valab suddenly die? Quickly back to our listeningroom to listen. No problem at all. 'Playing the stars from the sky' as we say in dutch... What the...!?

We had no clue until I thought of our SSOM: the bypassed filtersection.
I took my non-modded stock Valab and did a quick SSOM. Back to the scope with it. Ahh, there you go: the same disaster above 5Khz as I saw with my DAC. After doing a few more tests we concluded that the distortion is caused by nothing else than harmonics.
Not that i'm scared of harmonics, on the contrary: I love them. But what I saw here is pure distortion, and that is what we are currently listening to. The highs are not what they should be at all, but I have to admit that they not unpleasant to listen to.

Knowing this I decided to start experimenting with the output filter stage soon. I might try a ferritebead with a nice silver mica cap connected to the starground to see if the results get better without losing that nice open sound we got after removing the filterstage.

More to come...

 

[krisno]

I am using 0.5mm silver hookup cable to the coupling caps , is this inhibiting bass reproduciton? is 0.5 silver wire just to 'small'? They said it was OK at hifi collective?

Thanks!

I am btw running my coupling caps out in the open, would a metal 'box' around them improve sound at all?

K

 

[PatOMalley]

Move along, nothing to see here...

 

[PatOMalley]

Quote:

Originally Posted by Bill Allen /img/forum/go_quote.gif Last November ... [snip] #3): Is also an early 2009 board "without" DIR9001 mod, ... [snip] 4th Conclusion; I could honestly live with all 3 DAC in their present incarnations, and I am very picky. However, DAC #3 is clearly superior in all regards. ... [snip] Peace!

On the strength of the above I undid the DIR9001 mod the other night on my late 2008 version and some nice things happened. Some detail is lost but some nice smooth depth is there. "I can see deeper into the music" .... Who said that? A little more power as well, whatever that means, like when Horowitz bangs away at Liszt.

So we went from 512 to 128 and that's better?!?
Well, we went all the way back to 16 bit non-os and that's better.

I remember when we first did the mod - detail was the benefit. This is not the first time detail has been a red herring. Same thing happened to me with Teflon caps. Tons of sparkly smooth detail when I used them to bypass my Jupiters. What a fool, huh? Cryo'd or not I love the topend on the Jupiters. The Obbligatos too for that matter.

"One day this wars going to end." - Apocalypse Now.

 

[Bill Allen]

Pat,

... [snip} You're really are paying attention to the details. Gold Star.

The reason I never did the FS mod on my main DAC (#3) was I wanted to eventually get around to trying the reclocker board. I have a reclock board still sitting on my bench untouched. Some day.

Interesting results by Rhodes, perhaps the FS mod was not the best idea afterall. Lets see what else his scope uncovers.

 

[rhodes54]

Quote:

Originally Posted by Bill Allen /img/forum/go_quote.gif Interesting results by Rhodes, perhaps the FS mod was not the best idea afterall. Lets see what else his scope uncovers.

The distortion we saw on the scope was only in the analog domain. To clarify my post a bit: They are harmonics from harmonics on higher frequencies (above 20 khz) because the brickwall filter is missing. My modded DAC has the DIR9001 mod, my stock DAC doesn't. The results with the SSOM were the same on both dacs so the DIR9001 mod has no influence on that.
We measured the amount of jitter too on the incoming signal and after the DIR9001. The DIR9001 mod indeed gives the lowest amount of jitter. I can't remember the measurement details but it is worth keeping the DIR9001 mod.
If Pat liked what he heard when he removed the DIR9001 mod it's probably because the highs get less tight and start smearing a bit more (more jitter). I experienced that when your highs get masked (by a tube amp or speakercable for example) your system might sound wider and deeper. But is that really thru?
Pat, I am curious what you experience if you listen to your DAC for a few weeks and then switch back to the DIR9001 mod again.

 

[donunus]

I have a question about the 2009 dac. Do I have to change any jumper settings inside to get the best sound from USB? I notice there is a spdif or i2s jumper setting?