Hello,
I've recently bought a DAC from ebay for a friend of mine who sent it back a couple of days later, citing distorted audio coming out of both headphone and line out.
I can indeed confirm his claims and searching the forum left me somewhat baffled. Regarding some other DAC, audio indeed results in distortion and it's been suggested to set the main volume slider in Windows to not more than 65%.
However, the question remains: what does the volume slider control? By looking at the block diagram of the CS4398, I can't really decide myself (I'm no expert by any means). If it's a digital volume control, the assumption is there that it's "crushing bits", as in out of those 24bits I'm getting less, once the volume slider moves down from 100%. If it's analog, then I assume it's all fine, and all 24bits are retained?
Could somebody please clarify how volume control works in this chip?
Thanks,
Takeshi
I've recently bought a DAC from ebay for a friend of mine who sent it back a couple of days later, citing distorted audio coming out of both headphone and line out.
I can indeed confirm his claims and searching the forum left me somewhat baffled. Regarding some other DAC, audio indeed results in distortion and it's been suggested to set the main volume slider in Windows to not more than 65%.
However, the question remains: what does the volume slider control? By looking at the block diagram of the CS4398, I can't really decide myself (I'm no expert by any means). If it's a digital volume control, the assumption is there that it's "crushing bits", as in out of those 24bits I'm getting less, once the volume slider moves down from 100%. If it's analog, then I assume it's all fine, and all 24bits are retained?
Could somebody please clarify how volume control works in this chip?
Thanks,
Takeshi
It says "non-decimating" in the datasheet for the CS4396, meaning that resolution is maintained down to a low level. Its performed by the same block as the interpolation, so it's digital. There is no analogue audio on the chip until the last stage.
You don't say AFAICS whether the volume control has any effect on the distortion for your DAC.
Some description of the type of distortion may help. Do you have a scope?
Does the DAC have any kind of reputation? I would expect if it is faulty by design, it would have.
I'm definitely not an expert, just interested in the question.
You don't say AFAICS whether the volume control has any effect on the distortion for your DAC.
Some description of the type of distortion may help. Do you have a scope?
Does the DAC have any kind of reputation? I would expect if it is faulty by design, it would have.
I'm definitely not an expert, just interested in the question.
It sounds like "classic" analog distortion to me and definitely not digital clipping. I have a cheap Chinese digital scope, will try to post some screenshots.
If you turn the volume down to about say 50%, distortion is gone. As for the reputation of the device, I don't really have a clue. Friend selected it, and I helped him getting it.
If you turn the volume down to about say 50%, distortion is gone. As for the reputation of the device, I don't really have a clue. Friend selected it, and I helped him getting it.
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