Amp/Preamp Asylum

Posted by shambrick on October 17, 2005 at 12:37:45

Hello all.

I have vintage Pioneer SX-1250 receiver that sounds great on its own, but I was also was thinking of using it’s pre-amp outputs to drive a tube amplifier – an integrated amp with it’s own volume control and two signal imputs.

The amp is a Mexing/Mingda MC-34B push-pull. I have two options to drive it; 1) using one of the 1250’s tape outs, or 2) using the 1250’s pre-amp out.

The advantage of #1 is that output level is set, and I can use the MC-34B’s volume knob to control the output.

The advantage of #2 is that I get the use of the 4 tone controls (50Hz, 100Hz, 10kHz, 20kHz) of the 1250 which I really like - yeah I know audiophiles are supposed to listen to the music “flat” but…

With option 2, the question is, where should I set the volume controls of the 1250 and amp? It seems that the most logical thing to do would be to adjust the volume control of the 1250 to a certain average voltage output, leave it there, then use the volume control on the tube amp to set the output. If this is the way to go, what should the 1250 output voltage be, and what kind of signal should I use to determine it. I have a scope that I can use to measure.

Or is this whole idea just crazy.

Thanks in advance.