Fisher 500B - how to convert "Tape Mon" jacks to another aux input

[1rebmem]

I wanted to have 3 Aux inputs on my 500B so this thread shows how to convert the "Tape Mon" jacks on the rear of the unit to an Aux input when the selector switch is placed to "Tape".

Here is my prior thread on converting the "Tape Head" jacks to an Aux input:
http://audiokarma.org/forums/index....onverting-500b-tape-head-input-to-aux.845623/


For the Tape Mon conversion, we will solder in two jumper wires and snip and lift two resistors.
Everything is located alongside the selector switch, close to the front of the unit.

The red arrows point to the two 560K resistors, R26 and R28.
The yellow arrows point to 330K resistors, R24 and R25.
The pink arrows point to C17 and C18.



We have to solder a jumper across the parallel R26/C17 and another jumper soldered across R28/C18.
The pink arrows point to the added added jumpers (brown wires).
The aqua arrows point to the snipped ends of the 330K resistors. I will shrink tube insulate the floating ends and leave them. That way it would be easy to un-do the mod.


This is all you need to do to convert the Tape Mon jacks to an Aux input having the same sensitivity as the factory Fisher Aux input. This mod is actually easier to do than the Tape Head input conversion.

Jef

 

[AlphaEcho35]

Thanks for writing this up!

 

[thornev]

Go Jef !

 

[Catmanboo]

why butcher it up when all you need is a switch box? Thats the solution around here, I'm always scouting out more of 'em. But that's just me...

 

[1rebmem]

why butcher it up

Hmmmmm.....I don't see how this is butchering. Is adding IBAM or EFB butchering?

 

[Catmanboo]

maybe wrong choice of words. No offense. As i have tape decks I must not eliminate that function, but longevity mods, now that's a different story!

 

[Hannes123]

I wanted to have 3 Aux inputs on my 500B so this thread shows how to convert the "Tape Mon" jacks on the rear of the unit to an Aux input when the selector switch is placed to "Tape".

Here is my prior thread on converting the "Tape Head" jacks to an Aux input:
http://audiokarma.org/forums/index....onverting-500b-tape-head-input-to-aux.845623/


For the Tape Mon conversion, we will solder in two jumper wires and snip and lift two resistors.
Everything is located alongside the selector switch, close to the front of the unit.

The red arrows point to the two 560K resistors, R26 and R28.
The yellow arrows point to 330K resistors, R24 and R25.
The pink arrows point to C17 and C18.
View attachment 1344371


We have to solder a jumper across the parallel R26/C17 and another jumper soldered across R28/C18.
The pink arrows point to the added added jumpers (brown wires).
The aqua arrows point to the snipped ends of the 330K resistors. I will shrink tube insulate the floating ends and leave them. That way it would be easy to un-do the mod.
View attachment 1344382

This is all you need to do to convert the Tape Mon jacks to an Aux input having the same sensitivity as the factory Fisher Aux input. This mod is actually easier to do than the Tape Head input conversion.

Jef

is this also doable with the 500c??? Would be really cool if so

 

[ic-racer]

Looks reversible. I did something similar to one of my integrated amps. Guess what, five years later I reversed it when I got some other gear and re-configured my system.

 

[petehall347]

you could have switched tape monitor switch the other way . its always worked on any amp i have tried that way .

 

[notdigital]

is this also doable with the 500c??? Would be really cool if so

This help?

Improving the Fisher 400

With Dave G's instruction, I implemented that mod in my 500c:

Fisher 400 high level inputs

 

[gadget73]

The tape head jacks can be re-purposed into a line level input, or to a second phono input if you want. Phono is probably easier but it depends what you're really after. The problem is that it involves poking around on the selector switch, and sometimes physical access is a real chore.

but yeah, I wouldn't do this with the tape monitor jacks. They already are line level, just have to flip the monitor switch.

 

[Hannes123]

yes! i thought, a conversion is needed to bring the tape monitor to the same level like the normal AUX. But the tape head is perfectly fine also
just don´t wanna use a switch/selector box

 

[Hannes123]

This help?

Improving the Fisher 400

With Dave G's instruction, I implemented that mod in my 500c:

Fisher 400 high level inputs

perfect, thanks!