[hebrer]

What is your opinion on including a dedicated DAC to feed signal into an integrated tube amp?

Isn't tube amp going to smooth out signal from internal DAC (e.g. Onkyo receiver) more or less the same way as a signal from dedicated DAC (e.g. non-oversampling DAC http://dhost.info/mhdtlab/cons.htm or http://www.sigtone.net/shekd2.html)

I use Yarland FV-34-C tube amp (http://www.ornec.com/Yarland_FV_34_C_III_QQC100156C) with single-driver speakers Fostex FE127eN (http://www.planet10-hifi.com/FE12xeN.html) and I wonder if a separate non-oversampling DAC is going to make a worthwhile difference.

Any opinions are much appreciated...

[bunnyma357]

I know I heard an improvement going from the internal DAC on my Squeezebox 3 to using an external Zero DAC, going into an Onix SP3 integrated tube amp. The DAC sounds a little less harsh, with a better sense of space - it is easiest to hear on the decay of a cymbal hit, it is smoother and present longer with the external DAC.

The difference is definitely subtle, but there. I guess a lot of the performance/value equation depends on which DAC you choose.


Jim C

[K Shep]

Sometimes.

[Quiet Earth]

Isn't tube amp going to smooth out signal from internal DAC (e.g. Onkyo receiver) more or less the same way as a signal from dedicated DAC (e.g. non-oversampling DAC

No, not if I understand what you are trying to say correctly. Let's see if I do.......

If you are saying that an integrated tube amp will smooth out a bad sounding DAC (like one inside a cheap cd player) then I would say no. A tube amp will amplify the bad CD player much the same as a similar quality solid state amp would. Bad sound in, bad sound out.

If you are saying that a non-oversampling DAC will generally "smooth out" digital sound, so sending it to a tube amp will make it too smooth, then I would also say no. A good NOS DAC should actually give you more detail where the detail matters. That would be where the music lives.  So use a nos DAC with your favorite tube amp! 

My only concern with some of the low price NOS DACs going into an integrated amp would be the output voltage level. Make sure it's at least two volts or make sure that your integrated amp has plenty of gain. (The Constantine is probably close enough. I have one and it works pretty well.)

[hebrer]

Quiet Earth - thanks for your comments, this is exactly what I was curious about. The comment about the voltage level is very useful also.

[JLM]

Didn't know any Onkyo receivers had an inboard DAC.  My guess is that it provides a step up from PC soundcards.  I'm sure the Constantine will make a very nice improvement.  I like the idea that you're not going with a tubed DAC as too many different tubes can layer too many tube "favorings" into the overall sound.  And as all those different tubes age differently the sound keeps changing slightly to confuse things even more.

I recently added a modded Behringer DEQ2496 to my Oppo to replace it's internal DAC and add EQ.  The Behringer's stock DAC is pretty rough according to all the reports (I'd never tried it because it only as professional XLR analog outputs).  Once I got the unit back with digital cable and XLR/RCA interconnects from Scott Endler (good guy) I tried the DAC first.  Even now after 200 - 300 hours I'm finding much more resolution (detail and imaging).  I've found cymbals "inside" snare drums and more focus within the soundstage.  Keep in mind that the Oppo was Sterephile class C rated, so its no slouch.

But frankly the biggest advantage was the EQ that provided room EQ "polishing" (on top of room treatments) and replaced the baffle step/zobel circuit in my single driver speakers (Bob Brines FTA-2000).  Keep in mind that I have a dedicated listening room with nearfield setup ala Cardas so things are already "ordinary guy ideal".  Flattening out the overall frequency response really helps "make sense" of the whole presentation, but the biggest advantage was to extend the frequency response on both ends.  The somewhat "soft" high end is gone and the bass (which is by far the best I've ever heard from a single driver design) is way deeper/tighter.  There is no need for a sub (these speakers "out bass" the Hsu VTF-2 sub in my A/V system).  It's like going from crummy tires to racing treads.

The total cost of a modded Behringer DEQ2496 through Scott would be about $800 plus modding time, probably more than you had in mind, but a significant step up, especially for a single driver speaker application.

[hebrer]

Thought I would report back about which road I took in the upgrade.
I ended up buying a used Rotel RCD 855 player with TDA1541A DAC chip /actually two of them/. Needless to say, the improvement over Onkyo receiver is very much noticeable. When I find the courage to try the non-oversampling mod /reportedly should not be difficult/, I expect to hear even more of the NOS DAC bliss
Thank you for your inputs above.

[hebrer]

And, btw, the old Rotel RCD 855 player cost 35 GBP plus shipping from ebay. As a low-cost way to try out quality TDA1541A chip, this I hope to think was not bad.