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Quad 8 track output? - tab10672 - 01-17-2018

Hello, been a while since I posted anything, havnt done to much with tubes for a while but thought maybe someone with a better electronics background could help out with a problem. Anyway,

I have always used a componant type 8 track deck with pre amp/line outs connected to a solid state amp. I want to replace it with a realistic quadraphonic player that only has amplified/speaker outs (has a 2 channel stereo option). Can I connect the deck via a voltage divider to drop the signal to line level without any damage to the output transistors, since it wouldnt have the 8 ohm speaker load? or would it be better to tap into the preamp portion of the circuit? Im hoping i can connect it without modifing the deck itself. 

Any input would be greatly appriciated, Thanks, Todd

RE: Quad 8 track output? - Arran - 01-18-2018

So the Radio Shack deck doesn't have a line level output for the 8 track player? I have a quad eight track/tuner/amplifier in storage, but it's a cheapish unit, it probably uses op amps or TO package transistors for the output. Do you need the quadraphonic function or just the standard stereo output? My inclination would be just to pick up a stand alone component style 8 track player, with a line level output, it's not like they are hard to find. To modify the Radio Shack unit is something you would need a schematic to do.
Regards
Arran

RE: Quad 8 track output? - tab10672 - 01-18-2018

I have a few stand alone 8t decks but i would like to install this one to play my 8 tracks and quad tapes, as you say, 8 track decks are everywhere but stand alone quad decks like this one, not so much.

RE: Quad 8 track output? - Ron Ramirez - 01-18-2018

I think the best way to go would be to make new line outputs just before the standalone's volume controls, and then disconnect B+ from the preamp and output amp transistors, in effect killing the amplifier section. Otherwise you would need to have a load across your speaker terminals all the time, a waste of power. You would end up with a tape deck without the amplifier, which I believe is your goal. As Arran noted, however, you'll need a schematic.

RE: Quad 8 track output? - Stall-U-Rated - 01-18-2018

What would a quad 8 with line level outputs go for these days?

Steve

RE: Quad 8 track output? - Arran - 01-19-2018

Probably for whatever any two people were willing to pay, if anything, for an as is unit. I believe that there were some car stereos of the era that had quad sound, FoMoCo offered it in some of their cars, I'm not too sure about G.M or Chrysler though. Quadraphonic sound was an interesting idea, but in the end it really amounted to no more then a fad, the number of quad cartridges that I have run across I can count on one hand so not many people were buying them obviously. I have one and what it has is right and left channels like a normal stereo tape, but then it has a pair of right and left rear channels which was just the music with no lyrics, so basically it's an 8 track with half the programing of a regular 8 track. Like AM stereo it was one of those things where nobody got around to establishing an industry made standard.
Regards
Arran

RE: Quad 8 track output? - jerryhawthorne - 01-19-2018

Arran, a quad was installed after market in a 1970 911 I purchased in 1985. It had several tapes with it and frankly I couldn't tell much about the four channel in that little car and doubted it even had enough speaker to handle four channels! In general standard tapes were not bad but in that car the sound of music was not special, the sound of the motor was sweeter!

RE: Quad 8 track output? - tab10672 - 01-20-2018

"then it has a pair of right and left rear channels which was just the music with no lyrics,"


Some, like what you are describing were called "discrete surround" while others were true surround, like Pink Floyd Dark Side of the Moon, one song (on the run I think) when the guy is running and breathing hard, he runs a circle around you on the quad which is pretty cool, another "true surround" i have is ccr gold but 90% are as you said just music minus the vocals on the rear speakers.