Need help getting modern Dolby surround thru 80's Kenwood amps

[M.O. Deloofs]

Audiokarma gurus,

I've got what seems to be an uncommon problem based on my research. Here is my problem: I want to be able to us my Kenwood C2 control amp, M2 power amp, and SS-79 surround processor to do both stereo music listening and Dolby 5.1 surround sound. The SS-79 is too old to decode modern 5.1 Dolby. I am willing and able to add an AV receiver with the required connections to achieve these capabilities. I am not particularly concerned about the specs of the video audio. In my research I found the Kenwood VR-6070 AV receiver. This unit decodes Dolby 5.1, has preamp out for each surround channel, has acceptable specs, is affordable, and matches the width and general aesthetic of my other Kenwood gear. I'm looking for a way to achieve this system capability without having to rely on some kind of complicated switch gear at the speaker wires.

Here's my favorite option so far: Starting with the AV receiver connect the front channel pre-out to the control amp Aux 1 input. Connect the AV receiver rear channel pre-out to the control amp Tape A "play" input (not sure how these work or if I need "play" or "rec"). Connect the center channel line out directly to the center channel speaker (my music-listening setup does not use center channel so I can go from AV receiver directly to the speaker). Connect the control amp "output" to the M2 power amp "input." Connect the control amp "Tape A Rec" (again not sure if I need "play" or "rec") to the surround processor "in." Connect power amp output to the front channel speakers. Connect surround amp output to the rear channel speakers.

To listen to music with the surround processor I would set the control amp input to whatever source I want (phono usually), then set the tape loop to "source." I would then set the surround processor to "hall" mode for the reverb effect that I like. I hope that this would allow the surround processor to use the front channel signal.

To listen to movie audio I would set the control amp input to "Aux 1" and set the tape loop to "Play A." I hope that this would allow the AV receiver rear channel signal to pass straight through the control amp to the surround amp. I would set the volume levels on the AV receiver balance so that I could simply max the volume on the control amp and use the AV receiver volume controls for the whole system. I believe the surround amp's volume control would be bypassed entirely and just use the AV receiver's volume setting.

Would this work? Would the rear channel volume adjust through the tape loop? See attached drawing for connections. All sources are omitted for clarity.

 

[swechsler]

I doubt that will do what you want in call cases. For one thing, if you want to use the surround amp's "hall" effect, you won't have volume control over the rear channels; you'd have to control the volume separately with the control amp (front) and the surround amp (rear), since, no, tape record outputs are fixed, not variable. You need to feed the surround amp using the control amp's preamp outputs, and then of course you can't use it for the rear channels for Dolby Digital.

IMO, the easiest solution would be to forget about the obsolete surround amp, and find a 5.1 receiver with preamp outputs that has a similar surround program.

 

[M.O. Deloofs]

Okay I understand. The VR-6070 that I'm looking at has stereo surround features and preamp out for every channel so I think that will be perfect. It looks like I can connect the control amp output to the AV receiver CD input with a wye/splitter, connect the AV receiver rear line level output to my rear speakers, and front channel pre-out to the control amp Aux 1 input.

I think that will let me send stereo music audio from control amp to the front channel speakers AND the AV receiver then to the rear channel speakers. I think it was ALSO let me send Dolby 5.1 movie audio from the AV receiver into the control amp and out to the speakers and also from the AV receiver directly to the rear speakers.

See drawing for connections.

 

[hjames]

Get a newer AVR with the Dolby-Surround effect you want to hear.
Trying to fake the effect with 80s gear will never really do what you want.

I had an HK AVR-7300 with discrete level preamp outs - so - I ran the front MAIN preamp to the audio amp I used with my good speakers,
and used the AVRs internal amps to feed the center speaker, side surrounds and rear surrounds.
Worked great for movies and TV, and I have the audiophile sound for albums and CDs ...

 

[swechsler]

While you're at it, you may as well compare the AVR's built-in preamp to that of the C2 (if possible, have a friend do the rewiring while you listen without knowing what you're listening to, so it's a "blind" test). You may find that there's no benefit to using the C2 at all, and that the AVR performs perfectly as an A/V preamp for all your needs.

 

[plugto]

So much used gear on Craigslist, and Ebay. Get a decent power like 100watts, make sure there is HDMI connections, and for the future if needed pre-outs. Cheapest and easiest way to get what you want. Put the system you have now in a dedicated 2 channel analog use. I got a Denon for my daughter and it was 100$. Clean and loud. HDMI for the display.
Nice try to save the old stuff but just aint gonna happen with the gear you have.

 

[M.O. Deloofs]

Okay I bought a Kenwood VR-6070 for $100 on Ebay. It has good specs and every Dolby/THX format I could ever want, preamp out for every channel, and the stereo surround effects I like. I'll try a few things out and see what sticks. Honestly I'm more interested in the hifi stereo stuff than surround sound and movies. Maybe I'll just throw the old SS-79 surround amp in the stack for the aesthetic

Thanks for the advice!

 

[plugto]

Try some Binaural music. You will be blown away. If you like 2 channel than this is the holy grail. Headphones, no room effects like reflections, gain, decay, or any standing waves.
Imaging will scare you. There really is good surround sound music though.