[PatOMalley]

Are you saying that the CDs that cause clipping are the compressed overamped ones?

Let me know what CD and track. I will fetch one just to have a listen.

I have Amy Whinehouse ~ Back to Black; that has to be a candidate.

Quote:

Originally Posted by adriaan243 /img/forum/go_quote.gif "No change! I do not agree to change to solve problem from 'wrong' record. Clipping is not problem from dac but from records with too high basal output. We spent all week to study this problem. We made final decision, we decide to keep out design and its sound charactristic. Some records will hear clipping, we give up." It seems Valab made an "artistic" decision! They made a choice for what is in their opinion better sound. But from a technical point of view they are wrong, no decent CD player or DA converter will clip before the 100% level. Clipping should only occur in a real overload situation, the 0 level. In classical music and jazz this does not happen very often and most mastering engineers avoid the 100% level, but -3db and even -2 and minus 1db are quite normal and in some cases like rock and pop engineers push the CD level to the maximum and in these cases clipping noises may occur in this DAC. So actually hearing clipping or not may depend on your musical taste. The choice is simple: 330 ohm for those who have clipping problems and 390 ohm for those who seem to prefer the sound with the 390 ohm resistor.

 

[adriaan243]

Quote:

Originally Posted by PatOMalley /img/forum/go_quote.gif Are you saying that the CDs that cause clipping are the compressed overamped ones? Let me know what CD and track. I will fetch one just to have a listen. I have Amy Whinehouse ~ Back to Black; that has to be a candidate.

No, that is not correct.
In general CD's are not the problem, Valab is the problem.
During mastering the maximum levels are kept lower then let's say -0.3db and many engineers choose even slightly lower levels for safety, but there is nothing wrong with a CD that has been pushed near this maximum level, that is allowed.
In pop there is a tendency to produce CD's with a very high level and there can be happening a lot between -3db and -0.3db.
Anything between -3db and -0.3db may sound bad on a Valab with the 390ohm resistor.
The German DDDAC 1543 uses a 270ohm resistor as a best compromise, this is an older design and as we know now a wise decision.
I did not notice the problem on the music I play at homemost of the time, but measuring it made it clear, Valab was clipping at -3db and after modification it was clean, the cause is not the CD, but Valab.

 

[mbd2884]

Quote:

Originally Posted by darwinshardhat /img/forum/go_quote.gif I can fix my DAC and save money on Viagra all in the same thread? WHAT A DEAL! Forums really do have all the answers. Thanks for the extra description on how to solder. That is how I envisioned it. I don't think I need to do the mod as I am not hearing any clipping... at least none being caused by the DAC. Crap recordings however, do cause me no end of frustration.

From this and based on the latest postings, sounds like incompetence to me. And blaming the recording seems like a poor excuse since other audio gear aren't suffering the same problem.

 

[tubes]

You know guys I'm not trying to defend this dac, if it has a problem and it can be fixed then great. The thing is you guys have honed in on this distortion issue even going so far as calling it incompetence. You all know about the fix which is very easy to do especially the paralelling of resistors. What gets me is the condemnation of the dac by some of you, maybe you would be happier with some oversampling dacs, talk about induced distortions, phase and time problems so pick your poison. It seems most users using a CD player as a transport have no desire to change the resistors, on the other hand PC users seem to have problems with the distortion, could it be that using a PC with incompatible software exacerbates the problem? Try putting a Single Ended Triode amp on a scope and see what you get, they measure like sh!!, then listen to it, beautiful, sure there are trade offs with SET's but those that have them swear by them worts and all. My point is, don't get hung up on measurements, if it sounds bad to you then there are plenty of other choices.

 

[Lornecherry]

I agree with Tubes, $%@* measurements ...it is the end sound that counts. What I would like to know: if soldering in those resistors changes the sound overall??

 

[adriaan243]

Quote:

Originally Posted by tubes /img/forum/go_quote.gif You know guys I'm not trying to defend this dac, if it has a problem and it can be fixed then great. The thing is you guys have honed in on this distortion issue even going so far as calling it incompetence. You all know about the fix which very easy to do especially the paralelling of resistors. What gets me is the condemnation of the dac by some of you, maybe you would be happier with some oversampling dacs, talk about induced distortions, phase and time problems so pick your poison. It seems most users using a CD player as a transport have no desire to change the resistors, on the other hand PC users seem to have problems with the distortion, could it be that using a PC with incompatible software exacerbates the problem? Try putting a Single Ended Triode amp on a scope and see what you get, they measure like sh!!, then listen to it, beautiful, sure there are trade offs with SET's but those that have them swear by them worts and all. My point is, don't get hung up on measurements, if it sounds bad to you then there are plenty of other choices.

I have tried to explain the problem.
To be honest I agree with Tubes:
I am very happy with this DAC, the sound quality is quite impressive considering the very modest investment and I would call it a bargain.
This is not a Sony product but made by what might be called "cottage industry" and for that reason relatively cheap.
The manufacturer gave a solution and even seems to offer a full refund, what more can they do?

 

[r8833]

I have the 09 version, this is a awesome dac . It beat a audiosector dac which is double the price. Do some of the tweaks that others have metioned and it will take this dac to another level..I am going to buy another one for my other system

 

[darwinshardhat]

Quote:

Originally Posted by mbd2884 /img/forum/go_quote.gif From this and based on the latest postings, sounds like incompetence to me. And blaming the recording seems like a poor excuse since other audio gear aren't suffering the same problem.

You misunderstand. I've narrowed down my issues to distortion on bad recordings, which shows up on playback through all of my systems and also the terrible audio processing on my work computer. My home setup with the VALAB is working perfect. I'd go as far as to call the audio quality stunning. I'm using it from my Mac though and I can control the output volume so I do not experience the clipping.

It is unfortunate that this DAC does not work well in certain configurations. Those of you that can't use the DAC for this reason absolutely should demand a refund if you aren't willing to modify it. You deserve to get what you paid for, a DAC that works well for your application.

 

[julius_the_cat]

Quote:

Originally Posted by r8833 /img/forum/go_quote.gif I have the 09 version, this is a awesome dac . It beat a audiosector dac which is double the price. Do some of the tweaks that others have metioned and it will take this dac to another level..I am going to buy another one for my other system

What differences did you find when you compared the Valab with the Audiosector?

 

[MikeW]

i dont' think it's a pc problem, I just think people who have PC's have more flexibility on what they playback, most of us don't have a CD full of pure tones laying around, but anyone with a laptop and foobar can easily play any pure tone in a matter of seconds. PC people just have the tools to show the problem readily available.

 

[dcolak]

So, the final response from Valab is that they will continue to produce the DAC that clips the music whenever it is louder than -3dB (S/PDIF or USB).

For the people that just got into this thread, the DAC is clipping when you use a CD with the song that has louder passages (> -3dB) or when you use it as any other DAC or soundcard - with volume on 100% in Windows or Mac.

Most people use their soundcards and DAC's by having windows/mac volume on 100% and using their pre/amps to control the volume.

That is not possible with Valab DAC, it must never be set to 100% on a PC/Mac.

With a CD player, users will not have the option to lower the volume, so, depending on the music, they will hear clipping more or less.

And... that's about it

Let's move on to some more serious DAC's that do not accept distorting music intentionally just to have "a special characteristic" in their sound.

 

[paara]

Quote:

Originally Posted by dcolak /img/forum/go_quote.gif So, the final response from Valab is that they will continue to produce the DAC that clips the music whenever it is louder than -3dB (S/PDIF or USB). For the people that just got into this thread, the DAC is clipping when you use a CD with the song that has louder passages (> -3dB) or when you use it as any other DAC or soundcard - with volume on 100% in Windows or Mac. Most people use their soundcards and DAC's by having windows/mac volume on 100% and using their pre/amps to control the volume. That is not possible with Valab DAC, it must never be set to 100% on a PC/Mac. With a CD player, users will not have the option to lower the volume, so, depending on the music, they will hear clipping more or less. And... that's about it Let's move on to some more serious DAC's that do not accept distorting music intentionally just to have "a special characteristic" in their sound.

I have to say I agee with you. It is strange that VALAB continues to operate the DAC so close to its max capacity that there is clipping in some songs.

But now you can ask for a "no clipping" version

Great options.

Maybe thay will add a version that hum or not as well

 

[tubes]

I don't know what you've been told but the Valab is now being shipped with the 330 ohm resistors, if you request a dac with 390R you can get it that way. As Dcolak says "it's time to move on" maybe you can find perfection in another $200.00 dac, I doubt it but good luck.

 

[paara]

Quote earlier post:

"No change! I do not agree to change to solve problem from 'wrong' record. Clipping is not problem from dac but from records with too high basal output.
We spent all week to study this problem. We made final decision, we decide to keep out (our?) design and its sound charactristic. Some records will hear clipping, we give up."

The VALAB is probably a great DAC, but I think it is strange that they choose to deliver a DAC that will clip under normal use.

I had planed on buying one, but after I mentioned the clipping issue in an E-mail, they stopped answering my mails. I am still tempted, it is an easy fix getting rid of the clipping.

What I am more concerned about is the posts here mentioning humming and non functional DACs, and problems getting in contact with VALAB.

 

[tubes]

Ealier post was wrong, who did they get their info from? The MFR is now making them with the 330 resistor. How often the dac clips is still not clear. There have been several requests to post the name of the tracks that clip but so far as I can tell there has been no mention of what music causes the clipping. Why these people continue to beat a dead horse is beyond me, there is a solution to the problem but not one of the winers has said they are going to replace resistors, they just continue to repeat the same old crap over and over again.