PS Audio DAC output


I have a PS Audio DLIII DAC (with Cullen stage IV mods) which I think has a bit "hard", agressive and fatiguing sound...

 According a review, its output is around 2,8V. I plug the DAC at the "Direct Input" of my integrated amp (bypassing pre), which sensitivity is 1V/5kohm (1kHz). Is ok?

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Bad idea!  The DL III does not have a volume control.  If you plug this into an input without volume control you will send full voltage to your speakers.  This would be the same as turning the volume all the way up on the integrated.  Do you think your speakers (or maybe even the integrated) will survive this?  Absolutely use the built-in pre.  As for the hard sound of the DL III (non-modified), it’s been a long time since I had one but I don’t recall it sounded hard at all.  Perhaps something else in your system is the cause of this?
As soon as I posted this I had a thought about your integrated.  Does the “Direct Input” completely bypass the preamp section as your post says, or does it bypass tone controls?  If you don’t know look at your manual, but if you are already using the “Direct Input” and the volume control still functions then you are just bypassing the tone controls.
Hi. The direct input is the shortest path on my integrated, the signal goes to an exclusive volume pot, then straight to the power amp (Yes, I still have volume control!). The whole preamp section is bypassed, even the normal volume pot, cause the pots are not the same.

What source is driving the DAC?  USB?  S/PDIF coax?

The source can easily be at fault.

Steve N.

Empirical Audio

Dear, Steve.

As a transport, I have two options:

1) An Asus notebook connected to DAC via USB.
2) I also have a Squeezebox Touch, via S/PDIF coax.

Between them, I prefer the notebook via USB. The Squeezebox+S/PDIF sounds a bit lean...

I Only hear redbook files.
What is the make and model of your integrated amp? What happens when you don't bypass the pre--is the sound still "aggressive and fatiguing"?
Hi. My integrated is a Sansui AU alpha 707MR

Yes, sound is also fatiguing if I use the preamp inputs.
Missak, glad to hear my second response was the correct one.  I followed the link but the writeup seemed like a sloppy translation from Japanese so I couldn’t make a lot of sense of it.  I’m not familiar at all with Sansui equipment so I can’t really offer help on that. Not sure what speakers you are using, but I still think the issue is with something other than the DL III.  Too many unknowns for me to offer any help, sorry.
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I think I figured it out. I changed the sampling rate from 96khz to 192khz and the sound became smooth and "liquid". Since it is now late at night, I have heard in very, very low volume, so tomorrow I will check in a comfortable level. Still, it seemed to make a good difference. I hope I'm not mistaken.

Dear, pmotz. Do not worry, I appreciate your help. If you want to look at the schematic, the service manual is here:

My (adorable) speakers are Harbeth Super HL5 Plus.
Solved! The problem was in AC power...

Fixed and sounding fantastic now. Running Squeezebox Touch as transport > Oyaide coax cable > PS Audio DLIII DAC. Smooth, full, articulated, zero fatigue. Goosebumps! Just amazing. Thanks.
The USB input on the DLIII is the weak link. I used a USB?SPDIF converter with the one I owned.
The USB input on the DLIII is the weak link. I used a USB?SPDIF converter with the one I owned.

Agreed. Now, with everything tidy, surely the SBT + S/PDIF + DAC configuration excels with mastery.
When there was the problem with the amp AC line, the SBT/coax sounded lean and with over-tight and hidden bass. In a way, the USB input seemed to come out better (less worse), although it was not good either.