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Accuphase CDP Owners - Straight to Power Amp??

I've got an Accuphase DP500 hooked to a Plinius 9200 integrated. Recently out of curiosity I bypassed the preamp section of the 9200 and connected the DP500 direct to the power amp section. I thought the sound would take a dive given the built-in freebie volume control on the Accuphase may be inferior compared to the 9200's preamp. Well the result was quite positive, I would not necessarily say better as the presentation is a little different, but definitely not sonically inferior.

To Accuphase CDP owners I was wondering if you are running it straight to a power amp or do you prefer to use a preamp and if yes why?
noelpastor
amfibius
282 posts
 
If it is digital then I am surprised that you did not notice a performance hit. Digital volume control discards bits before analogue conversion, so you lose resolution and puts the signal closer to the noise floor.

Also, most CDP's only implement volume control as an afterthought, so - (1) the output impedance of the CDP is not low enough, (2) it is not engineered to drive long runs of interconnect, (3) output voltage may not be high enough so you'll have difficulty driving low sensitivity power amps, and so on.

Perhaps your Accuphase has a really good implementation but i'll have to check the specs before further comment :) Good on you for trying, and thanks for reporting.
noelpastor OP
65 posts
 
After a couple of days listening with the preamp bypassed I did start to notice a little bit of annoying harshness on a couple of CDs (Chicago and Ambrosia collection CDs) - CDs which I normally enjoy when going through the pre. I posted this also on AA and someone there gave this link to an interesting Accuphase Q&A w/c I think sort of explains what i'm hearing.

http://www.dagogo.com/Spotlight/AccuphaseCulture.html

I also thought the noise floor without the pre to be slightly less blacker, at the same time ironically I also noticed subtly increased resolution and detail. Right now I can still go either way. It is quite possible that while the built in digital volume attenuator in the Accuphase may not be the best, the built-in preamp on the 9200 may also be less than stellar. Would really love to hear someone who has compared the Accuphase DP500 volume control with a dedicated quality preamp.
plutos
224 posts
 
I had similar quest a couple of years ago and finally ended up using TVC as volume control. Digital volume control usually gives better results than mediocre preamp because eliminating a lot of cheap and unnecessary components in signal path. The problem with digital volume is that the lower the volume the worser the sound. You don`t hear much details if listening in low volumes. That also applies somewhat to resistive based preamps. One most astonishing virtue of TVC is the similarity of sound in lower volume settings. You get an incredible details and soundstage in silent listening.
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