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curious symptom old Fisher stereo amp, inputs strange

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Tim R
Guest

Mon May 18, 2015 3:05 pm   



I have an old Fisher amplifier, looks like this model

https://www.google.com/search?q=fisher+amplifier&biw=1366&bih=588&tbm=isch&imgil=QIHAkgR3TJHJ9M%253A%253Bx3bT_GyZ4ziaKM%253Bhttp%25253A%25252F%25252Fwww.icollector.com%25252FFisher-Integrated-Stereo-Amplifier_i13728010&source=iu&pf=m&fir=QIHAkgR3TJHJ9M%253A%252Cx3bT_GyZ4ziaKM%252C_&usg=__rKhDSvzeFYPjP0ZG43GdOgOEcds%3D&ved=0CCcQyjc&ei=jd5ZVeuIL4ajgwSB7IHIDg#imgrc=QIHAkgR3TJHJ9M%253A%3Bx3bT_GyZ4ziaKM%3Bhttp%253A%252F%252Fmedia.liveauctiongroup.net%252Fi%252F13488%252F13728010_1.jpg%253Fv%253D8CF479980774DC0%3Bhttp%253A%252F%252Fwww.icollector.com%252FFisher-Integrated-Stereo-Amplifier_i13728010%3B640%3B480

that I used for amplifying the laptop until it started acting funny and I replaced it with an Onkyo. It's been so long I'd forgotten what was wrong.

It's reasonably powerful, small and portable, and so I dug it out of the junk pile and used it this weekend for a harpsichord at church.

It has the usual choice of inputs (phono, cd/aux, tape in) but the only input that would work was Tape Out. It did not matter if monitor was on or off, or any mode selected.

Is that a common mode of failure? Seemed strange to me. This thing is not worth fixing, I'm sure I got it for $3 at a yard sale, but I'm curious.

John-Del
Guest

Mon May 18, 2015 4:04 pm   



On Monday, May 18, 2015 at 9:05:16 AM UTC-4, Tim R wrote:
Quote:
I have an old Fisher amplifier, looks like this model

https://www.google.com/search?q=fisher+amplifier&biw=1366&bih=588&tbm=isch&imgil=QIHAkgR3TJHJ9M%253A%253Bx3bT_GyZ4ziaKM%253Bhttp%25253A%25252F%25252Fwww.icollector.com%25252FFisher-Integrated-Stereo-Amplifier_i13728010&source=iu&pf=m&fir=QIHAkgR3TJHJ9M%253A%252Cx3bT_GyZ4ziaKM%252C_&usg=__rKhDSvzeFYPjP0ZG43GdOgOEcds%3D&ved=0CCcQyjc&ei=jd5ZVeuIL4ajgwSB7IHIDg#imgrc=QIHAkgR3TJHJ9M%253A%3Bx3bT_GyZ4ziaKM%3Bhttp%253A%252F%252Fmedia.liveauctiongroup.net%252Fi%252F13488%252F13728010_1.jpg%253Fv%253D8CF479980774DC0%3Bhttp%253A%252F%252Fwww.icollector.com%252FFisher-Integrated-Stereo-Amplifier_i13728010%3B640%3B480

that I used for amplifying the laptop until it started acting funny and I replaced it with an Onkyo. It's been so long I'd forgotten what was wrong..

It's reasonably powerful, small and portable, and so I dug it out of the junk pile and used it this weekend for a harpsichord at church.

It has the usual choice of inputs (phono, cd/aux, tape in) but the only input that would work was Tape Out. It did not matter if monitor was on or off, or any mode selected.

Is that a common mode of failure? Seemed strange to me. This thing is not worth fixing, I'm sure I got it for $3 at a yard sale, but I'm curious.


Not sure if you're describing this right as tape out is not an input. If that's the way it works, you definitely have a problem there. Try posting a model number. In any case, make sure it doesn't use pre amp in and pre amp out jumpers (look like chrome horseshoes) that might be missing.

Tim R
Guest

Mon May 18, 2015 5:07 pm   



On Monday, May 18, 2015 at 10:04:50 AM UTC-4, John-Del wrote:
Quote:

Not sure if you're describing this right as tape out is not an input. If that's the way it works, you definitely have a problem there.


I'll look for the model tonight.

There are four sets of RCA sockets. REC IN, REC OUT, CD/AUX, Phono. I tried the input into all of them, only REC OUT worked. I know it's not an input, at least I think it's not supposed to be. My vague memory says it used to work on CD/AUX and when one channel stopped working I just moved it over one set. Both channels worked on REC OUT.

While it's not worth a lot of effort to me, it is still the most convenient size amp I have when I need to carry it somewhere.


Guest

Mon May 18, 2015 5:31 pm   



Sounds like you have a problem with the preamp section. Throw us a model number.

In that Google search, it looks like the one on the upper left ? Black front ?

If it is what I think it is, it uses a TC91XX type IC for input selection, that coulsd be bad which would be bad because you know there are no new ones out there. Believe it or not I might have one. I have a couple of old ones that vintage. One is not coming apart becaause it only has the typica blown channel, but there is another one might have it that is scrap.

It frequently does work to backfeed it through the tape output. It's not exactly the right way to do it but it works, though on some moels with some sources you get higher distortion because you are impressing the signal on an output. However, it shouldn't hurt anyrthing doing it that way.

Tim R
Guest

Mon May 18, 2015 6:09 pm   



On Monday, May 18, 2015 at 11:31:54 AM UTC-4, jurb...@gmail.com wrote:

Quote:

It frequently does work to backfeed it through the tape output. It's not exactly the right way to do it but it works, though on some moels with some sources you get higher distortion because you are impressing the signal on an output.


Never knew that, thanks.


Guest

Mon May 18, 2015 9:53 pm   



So, that amp, it has tact switches and lights that tell you what source it is on ?

If they are mechanical switches, actually that is good. that means likely a simple problem. If it is electronic, you might neeed that chip.

If it is tact (not mechanical) switches, do the lights light up to indicate the selected source ? If so that is bad. If they don't light up irt is probably a power supply problem and a 2SD613 might fix you up with a 12 volt regulator or something. If the chip, WELLLLLLLL, there are solutions of one cannot be had.

Still, get that model number in here and we'll know all about it in short order.

Leif Neland
Guest

Tue May 19, 2015 2:11 am   



Tim R udtrykte præcist:
Quote:
I have an old Fisher amplifier, looks like this model

https://www.google.com/search?q=fisher+amplifier&biw=1366&bih=588&tbm=isch&imgil=QIHAkgR3TJHJ9M%253A%253Bx3bT_GyZ4ziaKM%253Bhttp%25253A%25252F%25252Fwww.icollector.com%25252FFisher-Integrated-Stereo-Amplifier_i13728010&source=iu&pf=m&fir=QIHAkgR3TJHJ9M%253A%252Cx3bT_GyZ4ziaKM%252C_&usg=__rKhDSvzeFYPjP0ZG43GdOgOEcds%3D&ved=0CCcQyjc&ei=jd5ZVeuIL4ajgwSB7IHIDg#imgrc=QIHAkgR3TJHJ9M%253A%3Bx3bT_GyZ4ziaKM%3Bhttp%253A%252F%252Fmedia.liveauctiongroup.net%252Fi%252F13488%252F13728010_1.jpg%253Fv%253D8CF479980774DC0%3Bhttp%253A%252F%252Fwww.icollector.com%252FFisher-Integrated-Stereo-Amplifier_i13728010%3B640%3B480

that I used for amplifying the laptop until it started acting funny and I
replaced it with an Onkyo. It's been so long I'd forgotten what was wrong.

It's reasonably powerful, small and portable, and so I dug it out of the junk
pile and used it this weekend for a harpsichord at church.

It has the usual choice of inputs (phono, cd/aux, tape in) but the only input
that would work was Tape Out. It did not matter if monitor was on or off, or
any mode selected.

Is that a common mode of failure? Seemed strange to me. This thing is not
worth fixing, I'm sure I got it for $3 at a yard sale, but I'm curious.


If the switch was a mecanical rotary switch, the inputs would go to the
separate pins on the switch, and the selected input would then be
connected to the viper and the tape out, and further through the volume
and tone controls to the output stage.

So the switch, whether mecanical or electronic, is dead, and you are
feeding the signal directly into the volume/tone controls.

If you don't need the other inputs, I would just cut my losses and the
connection to the switch, and just feed into the tape out, obviously
the tape out is not buffered, otherwise you would be trying to feed
signal backwards into an amplifier, which would not work.

A HiFi-nut would probably replace the switch with goldplated reed
relays anyway :-)

Leif

--
https://www.paradiss.dk
Ting til konen eller kæresten.
Eller begge.


Guest

Tue May 19, 2015 2:21 am   



On some receivers/amps, the "Tape Out" RCAs were where you
connected the output FROM the cassette/tape deck - to hear
it back. Counter-intuitive, and took me time to figger out! Smile

Tim R
Guest

Tue May 19, 2015 4:13 am   



On Monday, May 18, 2015 at 8:21:43 PM UTC-4, thekma...@gmail.com wrote:
Quote:
On some receivers/amps, the "Tape Out" RCAs were where you
connected the output FROM the cassette/tape deck - to hear
it back. Counter-intuitive, and took me time to figger out! Smile


Okay, this is a Fisher CA-400.

It has 5 sets of L and R RCAs on the back. They are marked Phono, Tuner, CD-Aux, REC OUT Tape, P.B. Tape. The only one that seems to work is REC OUT..

On the front there are 4 pushbuttons, for Phono, Tuner, CD-Aux, and Tape Monitor. All the buttons push in and lock, but no indicator lights of any kind appear anywhere. The power indicator light does come on.

It says 250 Watts on the back. It's a compact unit, the sound was not too bad out of it, even driving some home entertainment speakers. It would be nice if it worked. But if repair is more than a parts swap it will be beyond me. In my youth I held an Amateur Extra Class (NX9L) and I did some projects, but those days are far behind.


Guest

Wed May 20, 2015 5:12 pm   



I can't seem to get a print for that unit but from what you wrote I owuld bet you have a 12 volt regulator out.

If it has mechanical switches, you say the "lock" in, then it does not use that unobtainium IC. It might use some 4066 type CMOS switches but those are easy to get. But the fact there are lights not lighting means likely a supply is missing.

Tim R
Guest

Wed May 20, 2015 5:35 pm   



On Wednesday, May 20, 2015 at 11:12:36 AM UTC-4, jurb...@gmail.com wrote:
Quote:
I can't seem to get a print for that unit but from what you wrote I owuld bet you have a 12 volt regulator out.

If it has mechanical switches, you say the "lock" in, then it does not use that unobtainium IC. It might use some 4066 type CMOS switches but those are easy to get. But the fact there are lights not lighting means likely a supply is missing.


There are also a couple of weird outlets near the speaker terminals that appear to supply voltage to components.

I was going to throw this thing away. But if you think it's safe to use putting the input into the output sockets, maybe it is useful as is. (I mean safe as in not failing when I need it most in public.)

My memory is not reliable but I think I used it as a home stereo amplifying my laptop and feeding a couple of regular stereo speakers. And when one channel stopped working I moved the inputs over one, not realizing I was using an output, and it worked again.


Guest

Thu May 21, 2015 4:03 am   



Yes, the perhiperahls ere not stand alone. Some called these rak suystems, I called them frack systems for "fake rack". But the amps did have juice. Whatever of these are left, the perips are usually gone but the amp remaians, maininly because it was nevr bat on propoerly, overheated ad fried out. Fisher did alot of shitty shit back then. Some units were OK though, for example my garage stereo is a CA-885. Don't borher looking it upo there is almost zero info on it. It is close to 200 WPC and just doesn't care. In fact it puts out over 200 WPC bu I havn't tried to measure it accurately. All I know is it ran the lathe off the speaker wires just fine. (JK)

Those outlets are usually aboiut 12 V AC or so. Yuo DO NOT have to use their particular perips, anything that pliugs in the wall wil work as long as you got cables to hook up thre audio signal. You can ru that amop with amnything, it is just the juk they sold with it is dependent upon that amp for a power source. It does not work both ways.

Bnottom linee, I bet you smack that thing hard on the fround it works. And I bet you find bad connections on a three terminal device that says someting like "7812" on it.

Tim R
Guest

Thu May 21, 2015 5:37 pm   



On Thursday, May 21, 2015 at 11:05:30 AM UTC-4, Evan Platt wrote:

Quote:

Tape out is an output, not an input. I have an older unit. It's for
putting the output to a tape recorder.
--


Evan,
Here is my setup. My HP laptop feeds an M-Audio Fast Track external sound card/USB interface. RCA cables out of the M-Audio feed the Tape Out of the Fisher amplifier. Plenty of loud sound comes out of the speakers.

I have also tried this with the Fast Track feeding an Input on a Pioneer amplifier. Loud sound comes out of the speakers this way too.

Very clearly, the RCA sockets marked Output on the Fisher are functioning as an input. Also clearly, the sockets marked Inputs on the Fisher don't do anything.

Something is broken. Or, maybe outputs always work as inputs and I just never tried, I dunno.

Evan Platt
Guest

Thu May 21, 2015 9:05 pm   



On Mon, 18 May 2015 06:05:13 -0700 (PDT), Tim R <timothy42b_at_aol.com>
wrote:

Quote:
I have an old Fisher amplifier, looks like this model

https://www.google.com/search?q=fisher+amplifier&biw=1366&bih=588&tbm=isch&imgil=QIHAkgR3TJHJ9M%253A%253Bx3bT_GyZ4ziaKM%253Bhttp%25253A%25252F%25252Fwww.icollector.com%25252FFisher-Integrated-Stereo-Amplifier_i13728010&source=iu&pf=m&fir=QIHAkgR3TJHJ9M%253A%252Cx3bT_GyZ4ziaKM%252C_&usg=__rKhDSvzeFYPjP0ZG43GdOgOEcds%3D&ved=0CCcQyjc&ei=jd5ZVeuIL4ajgwSB7IHIDg#imgrc=QIHAkgR3TJHJ9M%253A%3Bx3bT_GyZ4ziaKM%3Bhttp%253A%252F%252Fmedia.liveauctiongroup.net%252Fi%252F13488%252F13728010_1.jpg%253Fv%253D8CF479980774DC0%3Bhttp%253A%252F%252Fwww.icollector.com%252FFisher-Integrated-Stereo-Amplifier_i13728010%3B640%3B480

that I used for amplifying the laptop until it started acting funny and I replaced it with an Onkyo. It's been so long I'd forgotten what was wrong.

It's reasonably powerful, small and portable, and so I dug it out of the junk pile and used it this weekend for a harpsichord at church.

It has the usual choice of inputs (phono, cd/aux, tape in) but the only input that would work was Tape Out. It did not matter if monitor was on or off, or any mode selected.

Is that a common mode of failure? Seemed strange to me. This thing is not worth fixing, I'm sure I got it for $3 at a yard sale, but I'm curious.


Tape out is an output, not an input. I have an older unit. It's for
putting the output to a tape recorder.
--
To reply via e-mail, remove The Obvious and .invalid from my e-mail address.


Guest

Fri May 22, 2015 1:20 am   



The tape out jack is essentially a fixed level audio out that comes from the switching IC. If the IC is defective, you are likely backfeeding the IC from the output into the amp. Replace the switching IC. This is likely to be a TC9163 or an LAxxxx (I don't recall the number).

Dan

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