You're right, Bus, I very much remember all of the provisions on that Maple SHC-8 for the tuner, as well as a special plug on the amp for it. This player has none of those things, except an AC outlet on the preamp, which is way on the front underside of the unit. That alone led me to speculate that there could have been some aftermarket accessory that would require internal mounting. I didn't look at the schematic yet but I don't believe it has a tuner on it. The fact that the selector has "AM-FM" on it is also a clue that what would normally just say "tuner" or "aux" was meant for something specific. Of course, it's just speculation and it is definitely not something obvious, like on the earlier units. I would also speculate that if there was a tuner for this, be it internal or otherwise, it MIGHT one of those phase-inverted mono units.

I am betting this is not an out of phase cart and reason is the out of phase set up was only done so you could select either mono or stereo playback. I am 99% sure the PS-16 is a stereo ONLY unit thus there would be no need for the out of phase cart.

UNLESS RCA used the out of phase cart to utilize that center bass channel, like send each separate out of phase signal to opposite outer channels then combine those two otp signals back in phase for a mono signal to the third center bass channel.

How exactly the 3 channel system takes the stereo signal and splits it up will be very interesting to see and read about. Try and get that schematic posted and hopefully DVC can give us a run down of the tricks it uses.

Good discussion!

Brain,
It sounds like you have issues with the center channel. It should be kicking out enough bass to shake the floor joists.

This amp is not as abstract as the simulated push pull amp that used the out of phase stereo cartridge. The cartridge looks the same in this model but it’s a standard in-phase cartridge.

It is a real three channel amplifier with three independent audio channels, three sets of output tubes and three output transformers. It doesn’t use any phase tricks to simulate anything. Lesser models only have a two channel amplifier and combine the signals for the bass speaker with a third output transformer. The cheapest versions only have two output transformers and combine the signals through inductors at the output transformer secondarys for the center bass channel.

These three channel amps take advantage of the fact that low frequency is not very directional in the first place. The recorded bass signal is combined as a mono signal to allow the stylus to track a stereo record better. Out of phase bass signals could pinch a stylus right out of the groove.

The bass amp has less to do. It only has to reproduce low frequencies. The same for the right and left amplifiers, they only have to deal with the mids and highs. Like a good old fashioned mono bi-amp system, it has lower intermodulation distortion and gives the impression that the system has more power output that it actually does. Push-pull 6BQ5 outputs are good for about 14-watts. This amp has three sets of outputs totaling 42-watts. Performance should sound more like a 25-watt per channel, two channel amp.

The system also takes up less real estate than a six foot console or twin 30-inch cabinets. The side satellite booster rockets take up very little space and can be easily positioned for the stereo effect. There was a certain amount of space savings involved with out sacrificing good "big speaker" bass response.

Love your explanations, Doug. To the point, with all interesting details intact, lol. So BB is right, this is more of a conventional 3-channel amp. Power output sounds impressive for a small console, I can't wait to get that third channel going. Will have to keep my eyes peeled for a nice RCA external tube tuner...

Charlie, since your selector switch says AM-FM, I suspect there was an optional internal tuner for this set, very similar to the tuner in my SHF-4. RCA likely made another model number of this set that included the tuner from the factory.

Wow, this is a pretty potent system, almost as good as a Mark I.

Hey guys!

SO I just bought this same unit... mine is in a little bit more worn condition. I'm working to get it back on it's feet.

Can you guys take a look at the amp and tell me exactly what I need to get it working... I have the original manual believe it or not... but it doesn't do much in the way of replacement parts.

I had a jukebox when I was a kid and I just had to have this when I saw it... it's so beautiful and it was like it called me over to it!

Anyway any help would be amazing! Thanks!

irdaryl@gmail.com

dc

Well, for starters, you will need a minimum of 5 6BQ5 tubes and four 6CG7 tubes for the amp...that is what's missing in your photo. You may also need 2 more 6CG7 tubes for the preamp---you didn't post a pic of that. Then, after you determine whether or not the power transformer is good, at minimum you will need to replace all of the paper and electrolytic capacitors, and possibly some resistors. Once you get the amp going, you will need to service the record changer, which will need disassembly and relubrication.

Hopefully, you got the satellite booster rockets with it....they are what make it unique. Post more pics if you can.

Brain:

I replaced one of the 6FQ7 preamp tubes in my RCA console with an ECC85/6AQ8, and the boost in sensitivity is AMAZING!
I get the same volume level at "2" that I used to get at "3 1/2"
This change also effects the loudness contour intensity - increasing "punch".
I also notice a substantial decrease in background noise.

6FQ7 = mu 20
ECC85 = mu 58

I finally got around to getting this console working. When I got it, sound was crappy and the bass channel was very low. After replacing caps and lubing the TT, all I can say is WOW! This thing sounds better than my SHF-2. I love that middle bass channel...this is the first such unit I've ever owned, and I love the "novelty" of it. All of my other Stereo-Orthophonics sound great, but this one has a a really tight punch on the bass and a more powerful higher end that I can only describe as a more "confident" sound than the earlier units. Separation, which is a really important factor for me, is excellent.

And the cartridge is one of those newer non-reverse-phased units that has a spring metal bridge for the needle instead of the usual hardened rubber. The turntable is a beauty...and I had almost forgotten that they made turntables without four separate turrets! I have it tracking at about 5 grams, which is an improvement over my other stereo units, too. I'm loving it!