Older AV receiver to replace pair of SPEC-4 power amps in my quad system

[Gimme 4]

Had one of my Pioneer SPEC-4 power amplifiers in my quad system fail this morning. POP and no front channels. Smell of burning. Took out multiple resistors and transistors in the R channel. Luckily I had hoarded away enough parts from my heyday working for Pioneer that I got it going. But I pretty much used up all the semiconductors I had. One channel fried, 3 to go! Keeping my fingers crossed they go another 31 years!

Anyway was thinking it should be relatively cheap to pick up an older AV receiver with substantial power in 4 channel mode. I recall reviews in S&V several years ago some of the Onkyos had pretty good power almost equal to the 150 wpc of my SPEC-4s. . Asking for any suggestions here. It will serve as a 4 ch power amplifier only in an old quad system, so DSP, video processing etc are all irrelevant. Thanks for any input!

 

[0tto]

if receiver has discrete RCA analog multi channel in, by default upon switching to, signal, you feed to receiver,
bypassed all processing and goes directly to amplification only. in such case receiver works like power amplifier.

 

[Gimme 4]

Thanks much for the reply. I was thinking the audio still went through the room equalizer-processing stages even in an auxillary multichannel input. I guess (but don't know for sure) what I am looking for is a multichannel receiver with pre-out main-in connections that I could bypass all ahead of the power amp stage. Probably pretty scarce.

In the meantime, I have the failed Spec 4 on my bench, fixed and running. About a half-dozen resistors and that many transistors including one shorted final output transistor in the R channel. Fortunately this time I had all the original parts needed, but if it happens again I'm screwed, will have to track down substitute parts. Found many dry cracked-looking solder connections on all boards which I suspect was the cause of the failure. I am now in the process of going through both amplifiers replacing a few electrolytic capacitors and resoldering every connection I see that is questionable.

 

[0tto]

Thanks much for the reply. I was thinking the audio still went through the room equalizer-processing stages even in an auxillary multichannel input. I guess (but don't know for sure) what I am looking for is a multichannel receiver with pre-out main-in connections that I could bypass all ahead of the power amp stage. Probably pretty scarce.

no. just straight to amplification.
pre-out on receivers isn't really rare. at least mine present Yamaha and two previous receivers
have 7.1 in and 7.1 pre-out.

honestly i don't understand obsession with old gears. it's fun and exciting but they don't hold even
close to modern amplification.

 

[Gimme 4]

no. just straight to amplification.
pre-out on receivers isn't really rare. at least mine present Yamaha and two previous receivers
have 7.1 in and 7.1 pre-out.

None have main amp inputs?

honestly i don't understand obsession with old gears. it's fun and exciting but they don't hold even
close to modern amplification.

??? You are on a Quadraphonic forum primarily about 1970's technology 4 channel sound, and you don't understand? That I don't understand!

Thanks for the replies though!

 

[0tto]

None have main amp inputs?

none of other connections is active upon switching to "mch in". it's kind of doing shorter circuit
in which incoming signal bypassed everything and goes directly to amplification section. that's standart.
there also many receivers has an option "pure audio/pure direct" in which receiver processes only
digital to analog and sends it to amplification without additional processing thru DSP.
in "pure" all connections remains active but if one is uses receiver to pass video through, there don't be
video on "out" because receiver will turn off video processing and even the illumination of it's own display.

??? You are on a Quadraphonic forum primarily about 1970's technology 4 channel sound, and you don't understand? That I don't understand!

Thanks for the replies though!

hey, i have two quad receivers, quad R2R deck and bunch of quad LPs
i didn't said about processing of obsolete surround formats. only about amplification
actually now working on issue how to hook up multiple multichannel analog devices,
including one quad receiver, to sole "mch in" on receiver