Speaker Terminals on Old Fisher Receivers?

[Avogadro33]

Question For Fisher Receiver Gurus . . .

For every tube receiver I had heretofore seen, speaker hookup has been the same:

One of the two conductor wires to the receiver terminal “C” (common), the other conductor to one of three impedance terminals: 4-ohm, 8-ohm or 16-ohm. Simple enough.

Now, my new (to me) Fisher 800 (TA-800) is different (and similar to the Fisher 600 (TA-600)) in terms of the speaker terminals on the rear of the receiver, and corresponding the instructions in the owner’s manual:

The Fisher Owner’s Manual states:

---- Channel A (the left speaker): one conductor wire to terminal “C” (common), the other conductor to one of three impedance terminals: 4-ohm, 8-ohm or 16-ohm. As expected. HOWEVER,

---- Channel B (the right speaker): Regardless of the impedance of the speaker, connect the wire conductors between Channel B terminals “G” and “X”. In addition, connect a jumper wire between Channel B terminal “P” and the other Channel B conductor wire to the Channel B 4-ohm, 8-ohm or 16-ohm terminal.

Can someone explain what this (perhaps obsolete) speaker terminal set-up is all about?

Thank you.

 

[gadget73]

Its for the phase reverse switch. On the TA-600 its on the back corner if I remember right. Basically it inverts speaker + and - without having to un-hook the speaker. Apparently in the days of simulcast stereo, a phase inversion was fairly common and being able to just throw the switch to fix it was convenient. The 600 has a flying lead to get this done though, it doesn't need a jumper wire installed.

I usually wire around these things. On my 600 I run both speaker - to the "C" terminal and the two + leads to whatever the appropriate impedance tap is.

 

[Avogadro33]

Thank you, gadget73.

As a bottom line, do you mean that I can operate my new (to me) Fisher 800 (TA-800) by connecting the "Channel B" speaker wires to the speaker terminals in the "ordinary" manner, i.e.,: to the "G" terminal and to the "8-ohm" terminal, without the "P" terminal and the jumper wire? That would make life easy --- actually, I thought of try that but was afraid that in doing so I might soon see smoke from the transformer!

Thanks again.

 

[gadget73]

not sure if its marked G or C or 0, but whatever the ground/common/0 ohm tap is can serve as negative for both speakers, and the impedance tap on each channel can be connected to the + speaker lead.

I use my Fisher TA-600 and my Sherwood 5500-II that way. The switch in the 600 is a bit flaky and it was easier to wire around it than take it apart and polish the contacts. Cleaner didn't sort it and I wasn't motivated to put more work into it.

 

[Avogadro33]

gadget73 ---

Your last message is interesting. My Fisher 800 (TA-800) has just been fully restored yet I get nothing from the Fisher-chassis-designated "B Channel".

1) I followed the Owner's Manual for connecting a jumper wire between the "P" and "8-Ohm" terminals and connecting the B channel speaker wires to the B channel "X" and "G" terminals. No Sound from the B channel.

2) I followed your earlier message to by-pass the jumper wire rig and instead to connect the B Channel speaker wires to the B Channel "8-ohm" terminal and the "G" terminal. No sound from the speaker connected to the B channel.

If I understand your latest message, you suggest that for the B channel speaker I instead connect the speaker wires to the B channel 8-Ohm terminal and to the A channel G (common) terminal.

Ok, I'll try that.

Thank you,

Howard