Using a passive preamp with icepower 50asx2se?

[Gaspar74]

Hello folks, Pardon my noobish question. However Im building a icepower amp based on the 50asx2se. I would like to have volume control on the Amp but not sure what direction to go in. I was wondering if using a passive preamp such as the Nobsound NS-05p between my Dac a music fidelity V dac II and the power amp is a wise choice? Im told the input impedance of the icepower is low appx 8k. Now I have a few optins for volume control seeing I use Roon and can enable DSP volume to the Source but prefer not to. WHats my best option? My other option was I often run my Yamaha CA-1000 vintage integrated as a preamp as well. CUrrently using it with a TPA3255 Class D chip board in that manner. Is there an off the shelf input buffer board I can buy to install in the ice amp along with a volume pot? Or what of these mentioned options are the best for my situation?

 

[Gaspar74]

would this work as input buffer
https://www.aliexpress.com/item/3256803614905447.html?spm=a2g0o.cart.0.0.5f5738dafc1OcO&mp=1

could I power using the Aux of the Ice?

 

[ranshdow]

If you were to use a passive preamp like say the Schiit SYS which has a 10k volume pot in it, your worst-case load impedance on your source would be something like 8.1k at the midpoint of the volume knob (5k + (5k * 8k // 5k + 8k)). I think most modern sources with op-amp based outputs have output impedances of less than 600 ohms generally, so you should be good. (actually the load gets down to 4.1k at full volume).

 

[rayma]

The voltage gain is only about 20dB. This may be too low to reach maximum output
with normal sources and a passive volume control. But, depending on your speakers,
it might be enough for typical listening levels.

The preamp board mentioned should add enough gain (14dB). It should be able to work with
the 50asx2se aux supply, but only uses the positive DC voltage, not the negative.

 

[Decker]

I use 4 channels of the Icepower 50asx2se modules after a buffer preamp (no gain) into a Pass 6-24 crossover (slightly less than gain of 1). In my system there is plenty of gain.