This topic has been the bane of my existence for a few years now. I very frequently am using an integrated amplifier which does not have any pre-outs or subwoofer outputs. I want to use the volume control of the integrated amp as it has a high quality potentiometer rather than using the volume control in my DAC.
My system is as follows:
Main Speakers: GR Research NX-Treme's
Subwoofers: (2) triple OB subs and (2) Rythmik F15HP sealed subwoofers
Integrated Amp: Line Magnetic 845 Premium
DAC: Holo Audio Spring 3 KTE with Preamp module
Source: Bluesound Node 2i
Also have available a MiniDSP SHD unit which I currently have the subwoofers only hooked up to.
I'll explain my current setup. I have the Bluesound feeding into the Holo Spring then directly to my Line Magnetic amp. In addition, I'm using a 2nd digital output from the Bluesound to the MiniDSP, which is then providing signal to the subwoofers. However, this means I have 2 independent volume controls - the subs are controlled separately from the main volume which is certainly not ideal. I do like being able to put a crossover on the subs with the MiniDSP. I want to avoid passing the main signal through the MiniDSP to the Line Magnetic if possible.
One alternative would be to use the volume control on the Holo Spring for everything as I could use a digital output from the Spring to the MiniDSP. It at least has a potentiometer rather than a digital volume control, but I'm not sure exactly how quality the volume control is. However, it would be upstream from the Line Magnetic and MiniDSP and should be able to control both.
The other option would be to use line level inputs and get rid of the MiniDSP altogether - but my understanding is that the line level inputs may not be ideal with a tube amplifier? Also I would miss out on the benefits of the MiniDSP for bass control but I'm not married to keeping it.
Does anyone have an idea for the best way to physically connect the subwoofers to the system?