RPI to USB DAC to Power AMP (no integrated, no pre-amp)?

Hi All

I have a USB DAC (Khadas Toneboard), and RPI. I am upgrading my ancient integrated amp to a power amp.

Forgive the basic question, but can I plug the RCA out from my DAC straight into RCA of a power amp?

I assume I would need to be careful with setting the volume to a low level first in Roon, but otherwise this is possible?


Your not going to get the best quality out of this. Not sure the Kardas has any digital volume controls but if it does it won’t be as good as a pre and will reduce sq. If not your using Roons DSP volume which again is far from stellar and you use lossless. Spend some money and either get a good quality DAC that can also offers itself as a preamp such as the RME ADI 2 or buy a preamp.

The Khadas DAC has no volume control. Are you saying I would lose lossless using volume control from Roon?

I guess I can’t see how introducing another box into the chain, in this case a preamp, can only but add complexity and another opportunity for the signal to degrade

You can use DSP for volume control. While Roon will no longer label it as lossless, it doesn’t affect the SQ.

Forgive my ignorance, but are you referring to the volume slider within Roon ( and control app) ? Bit confused by the reference to DSP, which I understand to be a lot more than volume control

I’m told that a bigger problem is the reliance on software for volume control. A software glitch can send speaker-wrecking sound out through your amp. I’d put at least a passive attenuator in line between the DAC and the amp.


I am afraid it does when I have used it.

You need to use DSP volume as the DAC has no volume to control. It’s in device settings under Volume control make sure you put in some safety levels for it not to pump out at max. So it uses Roons DSP engine to allow control of volume digitally. I for one would not go down that route and as Bill says I wouldn’t trust software to control anything like this. Roons already sent my Naim endpoint to 100%more than twice. Also you might find the Kardas really does not have the control to run power amps. Your choice of course but this is my option you asked the forum for opinion. Mine is stick with preamp you have or buy a new one or a DAC designed to be a pre.

1 Like

I use DSP volume control in one situation and it does not affect SQ. YMMV. I did have a device jump to 100 percent volume a couple times when set on device volume. I no longer use that setting.

1 Like

Ok guys, it appears that buying a simple preamp ( perhaps a headphone amp / pre amp combo, as I don’t have a headphone amp yet) and running that between my DAC and power amp is the way to go.

CrystalGypsy, what do you mean by the Khadas doesn’t have the control to run power amps? I assume adding a pre amp removes this “control” issue? Again, forgive my lack of understanding, I’m learning here

In a similar situation, I’ve used this -


Have my eye on this Topping A30, assume will do the same thing


Yeah, the unit I referenced isn’t an amp.

It’s just a passive volume control that would go between your DAC and any passive amp you might buy.

If you want a headphone amp, that’s different.

1 Like

You could look at the Schiit Magni 3 and Heresy amps they are both headamps with a preout to.

1 Like

@Fin you could also look at Rothwell attenuators to reduce level going in to the power amp. Then you’ll be sure full level from your DAC will not destroy your speakers (or shock you …) These attenuators are more transparent than any cheap preamp. Worth looking at if you still would like to go directly to a power amp.

1 Like