Well, here's another one I'm asking for help with. I've had this little amp for God knows how long now. I only use it on rare occasions in the bedroom, with tonight being one of those times. The left channel is dead. Absolutely 0 anything from it. I've pulled it and a cursory look reveals nothing amiss. Could have been the speaker itself, but I didn't check yet.
Anyway, my model is here:
https://www.radiomuseum.org/r/lafayette ... eo_10.html
And you can get a glimpse of the amp itself I'm this video: https://youtu.be/DQcu7F239DQ
The 10A has the same main amplifier section and volume volume controls, it just has more input options.
It won't be hard to trace, but i figured if I had a schematic, it'd be a bit easier to track down the issue.
Thanks.
Lafayette Stereo-10 Amplifier
Lafayette Stereo-10 Amplifier
Hey, what do I know?
Re: Lafayette Stereo-10 Amplifier
First guess would be output transistor. Next, an aging volume potentiometer.
Let us know what you find!
Let us know what you find!
WA2RBA
Re: Lafayette Stereo-10 Amplifier
The good thing is that I have 1 good working channel and it's so minimal that it'll be easy to check back and forth with a multimeter. I just need the elusive thing called time.
If you have a chance to look at that video I linked, you'll see how minimal it is.
If you have a chance to look at that video I linked, you'll see how minimal it is.
Hey, what do I know?
- Janitor Tzap
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Re: Lafayette Stereo-10 Amplifier
Do you have an actual model number on the amplifier?
I've been digging through Sams PhotoFacts and not finding it.
I agree with it possibly being fried output transistor(s).
But, I would think tracing the signal path from the Inputs,
all the way though to the last stage to the speakers shouldn't be that hard.
At the Left & Right Input Jacks, inject a 1Khz signal.
Then with a Signal Tracer, track the 1Khz signal through the circuit till you loose it.
Then at that point where you lose the signal, is where the problem lies.
I hope the output transistors are fine.
Some of those old transistors are getting hard to find, or even find a equivalent cross as a replacement.
Signed: Janitor Tzap
Re: Lafayette Stereo-10 Amplifier
That is all that they have on the amp. I know there's a 10-A and a 10-B, not sure if there are any others. I'll look when I get back home.
Hey, what do I know?
Re: Lafayette Stereo-10 Amplifier
Well, I put it on the bench and had a spare speaker hooked up. With the 1/8" stereo plug to RCA's plugged into the Phono stage, I did the finger noise test, switching the speaker positive back and forth. Both sides worked. So I cleaned the pots and switches, put it back together and hooked the regular speakers back up. That's when I found one of the ancient speaker wire splices was the culprit.
You'd be surprised at how good an old itty-bitty amp like this when paired with decent speakers (Fisher DS-153) can sound. And Bump. Was listening to this live: https://youtu.be/IGPiTuAVNQw and it was clean at full throttle. Kinda diggin it.
You'd be surprised at how good an old itty-bitty amp like this when paired with decent speakers (Fisher DS-153) can sound. And Bump. Was listening to this live: https://youtu.be/IGPiTuAVNQw and it was clean at full throttle. Kinda diggin it.
Hey, what do I know?
- Janitor Tzap
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Re: Lafayette Stereo-10 Amplifier
Cool.
Nice to know it was something simple.
Some of these early transistor designed amplifiers can be really well made.
Thus, they can out perform a lot of crappy cheap amps that die within a few years.
Just have to remember to give it a bit of a cleaning, once every few years.
Signed: Janitor Tzap
Nice to know it was something simple.
Some of these early transistor designed amplifiers can be really well made.
Thus, they can out perform a lot of crappy cheap amps that die within a few years.
Just have to remember to give it a bit of a cleaning, once every few years.
Signed: Janitor Tzap
- dacflyer
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Re: Lafayette Stereo-10 Amplifier
I had a radio kick my butt before.. everything checked out,,but sound never came out of the unit..headphones worked fine.. come to find out the headphone jack was the issue..there's 2 switches inside that thing. 5 connections.. one side wasn't making connections.. did some fiddling around and cleaning contacts, finally got it going..
Re: Lafayette Stereo-10 Amplifier
Well, the thing is over 50 years old and that was probably the first time it was cleaned. o_OJanitor Tzap wrote: ↑Sun Mar 07, 2021 7:13 am Cool.
Nice to know it was something simple.
Some of these early transistor designed amplifiers can be really well made.
Thus, they can out perform a lot of crappy cheap amps that die within a few years.
Just have to remember to give it a bit of a cleaning, once every few years.
Signed: Janitor Tzap
Hey, what do I know?
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