Sansui QRX 7500 question

I just picked up a QRX 7500. On inspection, the right front channel was out. I opened her up and found two blown bus fuses in the line out. After replacement, it's working, however, I have a question: on QS Synthesizer function, I can get all 4 channels, but the rear channel is much weaker than the front, in output and on VU meters. Is this normal? Excuse my ignorance, but I've never had a quad receiver before.

It may be entirely normal, depending on what you're playing. Depending on your source, there may not be a whole lot to send to the back. Synthesized quad depends on the phase differences in the front channels, and the more microphones used the more differences there are. On many classical recordings - even ones intended for quad - all you'll hear in the back is "hall sound". By contrast, on many rock albums there's lots of stuff in the back, but still at a lower level. Only with discrete 4 channel (R2R, 8 track, CD4) is there signal from the back that can equal the front.

Happy trails,
Larry B.

Thanks very much! I'm playing FM rock, and I noticed that on some songs the rear channel does have more power. It looks like the quad is working then!

So the regular matrix, phase matrix and CD 4 modes should only be used on authentic quad recordings?

Rey1 said:

Thanks very much! I'm playing FM rock, and I noticed that on some songs the rear channel does have more power. It looks like the quad is working then!

So the regular matrix, phase matrix and CD 4 modes should only be used on authentic quad recordings?

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Regular matrix will do a good job of extracting surround information from stereo recordings (with varying results, as I said). It will do a better job with QS encoded recordings.

Phase matrix should only be used with SQ-encoded LPs.

CD4 should only be used with CD4-encoded LPs.

Happy trails,
Larry B.

rear weak channels are normal - hence the availability to raise the volume between front and rear - i raise the rear until it seems in balance with the front.

qs synth - use it - its the best stereo to quad decoder available.

sansuigirl