curious symptom old Fisher stereo amp, inputs strange

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I have an old Fisher amplifier, looks like this model

https://www.google.com/search?q=fisher+amplifier&biw13%66&bih58%8&tbm
=isch&imgil=QIHAkgR3TJHJ9M%253A%253Bx3bT_GyZ4ziaKM%253Bhttp%25253A%2525
2F%25252Fwww.icollector.com%25252FFisher-Integrated-Stereo-Amplifier_i13728
010&source=iu&pf=m&fir=QIHAkgR3TJHJ9M%253A%252Cx3bT_GyZ4ziaKM%252C_&u
sg=__rKhDSvzeFYPjP0ZG43GdOgOEcds%3D&ved0C%CcQyjc&ei=jd5ZVeuIL4ajgwSB7
IHIDg#imgrc=QIHAkgR3TJHJ9M%253A%3Bx3bT_GyZ4ziaKM%3Bhttp%253A%252F%252Fmed
ia.liveauctiongroup.net%252Fi%252F13488%252F13728010_1.jpg%253Fv%253D8CF479
980774DC0%3Bhttp%253A%252F%252Fwww.icollector.com%252FFisher-Integrated-Ste
reo-Amplifier_i13728010%3B640%3B480

that I used for amplifying the laptop until it started acting funny and I r
eplaced 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 ju
nk 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 inp
ut that would work was Tape Out.  It did not matter if monitor was on or of
f, 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.  


Re: curious symptom old Fisher stereo amp, inputs strange
On Monday, May 18, 2015 at 9:05:16 AM UTC-4, Tim R wrote:
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bm=isch&imgil=QIHAkgR3TJHJ9M%253A%253Bx3bT_GyZ4ziaKM%253Bhttp%25253A%25
252F%25252Fwww.icollector.com%25252FFisher-Integrated-Stereo-Amplifier_i137
28010&source=iu&pf=m&fir=QIHAkgR3TJHJ9M%253A%252Cx3bT_GyZ4ziaKM%252C_
&usg=__rKhDSvzeFYPjP0ZG43GdOgOEcds%3D&ved0C%CcQyjc&ei=jd5ZVeuIL4ajgwS
B7IHIDg#imgrc=QIHAkgR3TJHJ9M%253A%3Bx3bT_GyZ4ziaKM%3Bhttp%253A%252F%252Fm
edia.liveauctiongroup.net%252Fi%252F13488%252F13728010_1.jpg%253Fv%253D8CF4
79980774DC0%3Bhttp%253A%252F%252Fwww.icollector.com%252FFisher-Integrated-S
tereo-Amplifier_i13728010%3B640%3B480
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 replaced it with an Onkyo.  It's been so long I'd forgotten what was wrong
.  
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junk pile and used it this weekend for a harpsichord at church.
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nput that would work was Tape Out.  It did not matter if monitor was on or  
off, or any mode selected.  
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ot 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 t
hat'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 a
mp out jumpers (look like chrome horseshoes) that might be missing.


Re: curious symptom old Fisher stereo amp, inputs strange
On Monday, May 18, 2015 at 10:04:50 AM UTC-4, John-Del wrote:
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 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 tri
ed the input into all of them, only REC OUT worked.  I know it's not an inp
ut, 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 ove
r 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.  

Re: curious symptom old Fisher stereo amp, inputs strange
Sounds like you have a problem with the preamp section. Throw us a model nu
mber.  

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

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 one
s out there. Believe it or not I might have one. I have a couple of old one
s that vintage. One is not coming apart becaause it only has the typica blo
wn 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 ex
actly the right way to do it but it works, though on some moels with some s
ources you get higher distortion because you are impressing the signal on a
n output. However, it shouldn't hurt anyrthing doing it that way.

Re: curious symptom old Fisher stereo amp, inputs strange
On Monday, May 18, 2015 at 11:31:54 AM UTC-4, snipped-for-privacy@gmail.com wrote:

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Never knew that, thanks.




Re: curious symptom old Fisher stereo amp, inputs strange
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 pro
bably a power supply problem and a 2SD613 might fix you up with a 12 volt r
egulator 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 o
rder.

Re: curious symptom old Fisher stereo amp, inputs strange
John-Del:  

On a lot of receivers/amps(esp. older ones),  
'Tape Out' does mean 'coming from' the  
tape/cassette deck, and 'Tape In' means
what is going out of the receiver/amp to  
the record deck.

From my own experience.

Re: curious symptom old Fisher stereo amp, inputs strange
On Tuesday, January 8, 2019 at 5:34:00 PM UTC-5, snipped-for-privacy@gmail.com wrote:
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You have those backwards.  On the receiver, the tape in "comes from" the tape.

The tape out comes from the pre-amp section prior to the volume control.

Re: curious symptom old Fisher stereo amp, inputs strange
5:36 snipped-for-privacy@yahoo.com wrote:  
"You have those backwards.  On A RECENT receiver, the tape in  
"comes from" the tape.  
The tape out comes from the pre-amp section prior to the  
volume control. "

See my edit(caps) above.

On older gear, pre-1980, the routing of  
those ins and outs as I described them  
stands.  How do I know?  Because I  
assumed the same thing you stated  
above, and got no audio!  Once I  
flipped both RCA pairs around, Voila,  
everything was fine.

Re: curious symptom old Fisher stereo amp, inputs strange
On Tuesday, January 8, 2019 at 6:07:32 PM UTC-5, snipped-for-privacy@gmail.com wrote:
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I won't argue your results, but with 35 years of repairing audio gear, I ha
ve not seen one yet that has that property.  The in/out label on any gear i
s usually for that particular unit.  The same exists on tape machines.  The
re are input and output jacks there as well.  The "output" jack on the tape
 should be activated when the tape is in play mode, thus is an output.

Re: curious symptom old Fisher stereo amp, inputs strange
:
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e:
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have not seen one yet that has that property.  The in/out label on any gear
 is usually for that particular unit.  The same exists on tape machines.  T
here are input and output jacks there as well.  The "output" jack on the ta
pe should be activated when the tape is in play mode, thus is an output.

Same here.

I'm old enough and have seen enough to know I'll never see or know everythi
ng, but I've never seen a tape monitor setup where the tape out is an input
. I've got 45 years as a professional audio/video tech and have worked on m
any stereos, and this includes many vintage vacuum tube Scotts, Fishers, Ei
cos etc. from the 60s through the current HT surround receivers.  But I'll  
never say never.


Re: curious symptom old Fisher stereo amp, inputs strange
On Tue, 8 Jan 2019 16:35:58 -0800 (PST), snipped-for-privacy@yahoo.com
wrote:

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Me either. Audio-video tech for 30+ years.

Re: curious symptom old Fisher stereo amp, inputs strange
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have not seen one yet that has that property.  The in/out label on any gear
 is usually for that particular unit.  The same exists on tape machines.  T
here are input and output jacks there as well.  The "output" jack on the ta
pe should be activated when the tape is in play mode, thus is an output. "

That has not been my experience. In most amps the tape output is pretty muc
h at the output of the input selector, or in the case of a Yamaha for examp
le, form another separate selector. As such it can be backfed.  

If it is buffered or even resistor isolated that will not work so well, but
 it seems the engineers decided that the low output impedance as worth it t
o keep the noise down. As such, not only can it be backfed, it can also be  
shorted by the wrong thing connected and cause no output. I got this DCD Pr
o CD player, commercial, like DJ model. I had it temporarily hooked up wron
g because I couldn't really see in the back, it was going IN to the tape OU
T. Well when the CD player was shut off it apparently shorts the outputs an
d that resulted in no sound from any source.  

In another case I had a VHS HIFI, a Sanyo VCR-7200 that when turned off got
 non linear at the record INPUTS. It caused severe distortion unless it was
 turned on. It is easy to figure out why, the input stage was probably diod
e protected against overvoltage and when the power supply dropped, the shun
ting was to zero volts.  

It is a piece of wire, the "current" can go both ways.  

I didn't mention it before I think, but some of those units used a TC9164 o
r something as a selector chip and those did go bad. I had to change a bunc
h of them back when. That was how they were - the tape output was the only  
"input" that would work.  

What I don't remember is if those chips fed a CMOS switch set or had it onb
oard. Like 4066s, or the cheaper one, 4016 ? Whatever.  

I could probably find a print and find out but why don't you just to it ? R
ight from Google you got Electrotanya, and then there is hifiengine and hif
imanuals. You need a membership to the latter two but they don't charge, th
ey don't spam or any of that. I got nothing but good to say about those sit
es.  

If you need the TC9164 they are out there. I have just Googled it and it se
ems they do have the actual switches onboard.  

I know that amp is considered BFC by audiophiles but that series of amps is
 not bad. The circutry is fine, low distortion, all that. Anything the audi
ophools don't hear in it is their own problem. The only problem is they are
 underbuilt, for someone like me. I mean I will work it into 2.3 ohms n shi
t, they don't like that, they get too hot. That's why I don't use one, but  
for normal human beings the are OK.  


Re: curious symptom old Fisher stereo amp, inputs strange
On Tuesday, January 8, 2019 at 4:34:00 PM UTC-6, snipped-for-privacy@gmail.com wrote:
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Agreed --- my vintage Sansui receiver works exactly that way.

Re: curious symptom old Fisher stereo amp, inputs strange
On Tuesday, January 8, 2019 at 8:11:28 PM UTC-5, Terry Schwartz wrote:
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I have a 70s Sansewer receiver in my dungeon, I'll see how that one is configured.  But I'm wondering if the tape mon connections are simply labelled "in" and "out", or if they're preceded by "connect to"...


Re: curious symptom old Fisher stereo amp, inputs strange
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I can't stand shit like that. Just say it, output or input, not what you connect it to.  

Re: curious symptom old Fisher stereo amp, inputs strange
On Tuesday, 8 January 2019 22:34:00 UTC, snipped-for-privacy@gmail.com  wrote:
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Other way round. Confusion can come from the fact that on a lot of amps the
 selected input is connected directly to the tape output*, thus one can alw
ays use 'tape output' as an unswitched input. I say always... some amps won
't work this way since there are buffers in the way, and they don't pass si
gnal backwards.

*Phono inputs are of course preamplified first.


NT

Re: curious symptom old Fisher stereo amp, inputs strange
snipped-for-privacy@gmail.com wrote: "Other way round."

Nope.  I hooked the thing up via literal interpretation, and  
got no playback audio from tapes, and nothing recorded  
to blanks.

Once I reversed them, like I said, everything worked as it  
was expected to.

And as can be seen from Terry's testimony some posts back,  
I'm not the only one experiencing gear labeled counterintuitively  
to how it was supposed to be hooked up.

You weren't there in either of our cases, so you can't refute  
either of our experiences.

Re: curious symptom old Fisher stereo amp, inputs strange
On Wednesday, January 9, 2019 at 3:30:16 PM UTC-5, snipped-for-privacy@gmail.com wrot
e:
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No one is calling you a liar, but after nearly 50 years repairing consumer  
electronics as a career, I've never seen one wired like that. To me, this m
eans the examples you cite are aberrations or at least a very small percent
age of the units in service.  They could have been wired that way intention
ally or maybe the jacks or TM switch were miswired.   It's also possible th
e rear panel was simply silk-screened incorrectly or a revised version was  
released with the previous version's back panel.

As I pointed out above, the other possibility is that the INs and OUTs were
 prefaced by "connect to", which changes the context entirely.  I recall so
me low end packaged component systems that did not use universal nomenclatu
re, but had connection "instructions" on the back panel (ie: connect to tap
e deck output).


Re: curious symptom old Fisher stereo amp, inputs strange
MIDI in and out confuses me though.

I've never been able to get it to work except by trying it both ways.  

Weird thing on this Fisher amp.  Putting in headphones (and it's a 1/4 inch jack) disconnects speakers automatically.  There's no way to have both room sound and headphone sound.  Still it's nice to have this working again.  

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