dac chip vs analog stage as to sonic impact


when buying a cd player or dac, which has more impact on the sound of the component, the dac chip or the analog stage ?

to what extent can a tube analog stage "offset" the effects of a dac chip ?

if one were to assign a percentage contribution to the dac and analog stage as to the affect upon the overall sound, what might the numbers look like ?
mrtennis
Reference Audio Modifications (RAM) does a mod to the Behringer DEQ2496 where they use transformers connected directly to the AKM DACs, thereby eliminating all the analog circuitry. They say this is their top of the line mod, and it costs accordingly.
gentlemen:

my main concern is the possibility that a tube sensitive analog stage may be able to improve the over all sound of a cd player or d/a when the dac hip is of dubious sound quality.

i guess only experimentation will answer this questions.
Since APL appears to be the only modder that changes the DAC in a commercial player, perhaps one should view Alex Paychev's crediting 70% of total improvement to a DAC swap as relevant strictly to his own shop's choice of CDP and chosen regime of modifications. Certainly some DACs are better than others, but the gestalt of modded machine is a combination of many factors-- starting with a decent mule player. Allen Wright chose the SCD-1/777ES as its base platform because its transport & DAC sound great with a drop-in replacement analog stage & other mods. A Modwright 777ES with std. DAC is the player of choice in a cost-no-object Magico system recently reviewed by John Atkinson. Zanden builds a superlative DAC around an old Philips TDA-1541 chip. I've built a battery powered SCD-1 around the player's std. DAC; the sound of improved player barely ressembles the sound of the stock Sony. The improvement I gained is due about 30% to the replacement analog stage, 30% to transport mods, and 40% to power mods. So this question is likely reductio ad absurdum...

Dave
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Tvad...Checking the APL website I notice that the DACs which they use for the update are AKM. That's what I have in my Behringer DAC2496 which may be why it sounds good.
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By current standards the CAL products are very colored in their sound. Not unpleasant sounding, but not particularly accurate to the source material.
A DAC is an analog device. What do you think the "A" stands for. It is also a digital device, but the digital part is a go/nogo thing and not likely to affect sound quality. The analog output of a DAC chip is fast and accurate, but generally needs a buffering circuit to provide a low impedance signal for output to other parts of the audio system. I think that the question relates to the quality of this follow-on circuitry. In early CD players this is where manufacturers chose to cut corners, and many early CD players were significantly improved by replacement of this circuitry. This is still common practice by MOD shops, even going so far as to install tube stages. Few, if any, MODs involve new DAC chips.
Mrtennis - I would agree as I prefer non-os dac designs. Coming from the perspective that I primarily focus on analog (vinyl) as my primary medium, non-os dacs have given me the satisfaction of a sonic signature more synonymous of the analog sound I prefer. The added bonus is I don't have to open my checkbook to achieve this sonic signature.
hi alex. it seems to me that the better dacs are not 24/192. i have yet to hear a cd player or a d/a converter with such a chip regardless of mods sound anything but digital and forced.

the old cal aria and the old cal tempest were ideal products.
Mrtennis, that is exactly correct. Masking inferior digital design and DACs with tubed analog stage sounds really bad indeed, IMHO.

At the same time, carefully designed digital with an appropriate DAC can do miracles with just a few Op Amps and all solid state output buffer.

Of course, the "real deal" (for me) is superior digital/DAC design combined with fast and transparent tube output stage.

Regards,
Alex
hi alex, do you mean that a tube analog stage may not overcome the faults of a dac chip ?
"if one were to assign a percentage contribution to the dac and analog stage as to the affect upon the overall sound, what might the numbers look like?"

70% DAC

30% Analog stage

Regards,
Alex