Polytone 215-700 Custom Bass Amp SCHEMATIC NEEDED please

[mikelazich]

The amp is a large 2x15" 2 channel solid state bass amp from the early 1970's or late 60's when Polytone was founded is my best guess.

The two channels have no effects. They simply have the standard volume, treble and bass controls.

I'm guessing by the model number that it's about a 70 watt RMS amp.

Polytone Company is of no help, nor is the "pay for the schematics" web sites either.

I can't seem to find any similar amp configurations for really old Polytones made in this period as I would guess the company may have used basically the same amp in some form.

Any help would be appreciated.

Thank you.

 

[JMFahey]

All Polytones use the same preamps, some have passable reverb and a horrible distortion added (but it's still always the same stuff) coupled to 2 or 3 (no more) power amps: a fully discrete one, an LM391 driver based one and a 3rd which is a vatiation of the first.
So if you download a couple Polytone schematics which are dancing around, you'll be fine.
Like a Mc D hamburger, they may offer 37 "different" versions, but all can be built with the same 6 basic ingredients, which you'll find in those schematics.
The exact same chassis may power anything from a single 8" + Piezo to single 12", 2 x 10", 1 x 15" and even 1x15" + 2x8" , 4 x 10" or your 2 x 15".
But you'll find no big surprises..
First thing is to check which power amp you have, the rest is easy.
Good luck.

EDIT: as of power, you might be surprised.
You might very well have 2x 15" 4 ohms each, for total 2 ohms and over 120W RMS.

 

[mikelazich]

Thanks for your input.

As to Polytone schematics, what I've found searching are the later Polytones from the later 1980's with more controls on them, rather than the basic 3 knobs per channel.

I've not been able to find Polytone schematics from the late 1960's or early 1970's. Any suggestions for links?

Again, thank you for your input. It's appreciated.

 

[Enzo]

What about it are you trying to repair?

 

[mikelazich]

Looking for Schematic for circa early 70's Polytone 215-700 bass amp with two 15's

As to what I'm trying to repair. The symptoms are: 1. It has no volume to speak of or power at all; and 2. It sounds distorted, muttled or like s**t.

I need some type of schematics at I am not doing the repair myself, so I need to provide some guidance to the person who will be doing the work.

I can't find on the web schematics from late 60's to early 70's Polytones, which at least the repair person could get some notion of the circuits involved.