New project

[BERENO]

I dont know too much about amplifiers, so I decided to take on a new project. I dont know where else to post this... if it is in the wrong section, mods please move to the correct one

Ok, so my boss was getting rid of an old JVC JA-S44 amplifier and I decided to take it off his hands for him.

A little bit of background - it is a European model amp (so I am told) that was made in the late 1970's, and it was supposed to deliver around 100WPC and was a top of the line amp (once again so I am told).

The amp is no longer working, but I guess it was working a while ago (whatever that means) I see that it has a blown fuse, and am going to replace that here soon. If that is the only problem (which I doubt) then I guess my project will be short lived. If it is not, then I am asking if I can commission some of the fellows on here to help me out with the restoration of an old amp, or even if I should attempt such a project.

Comments are welcome, but please just dont say negative things. This is a project based on these intents:

Fun
Learning
possibly a good sounding amp

below are some pics of it AFTER i cleaned it up a bit. It was a horrible mess before i busted out the clorox and simple green.












Thanks in advance everybody

[lineup]

Hello BERENO

Cleaning is done. Good.

There are several fuses in amp.
When a fuse blow there is a reason, a problem, that is the cause.
This cause can be temporary, by wrong handling.
But can also be that some component is defect.
You should do visual inspection. Are there any areas on circuit board that looks like burnt. After high heat.
If not, maybe was only a temporary shortcut of the output terminals that made the fuse go.

In an old amplifier, from 70-ies, power supply capacitors may be dried out.
Like car batteries, they have liquid stuff inside.
You should most probably change them for new ones.
They help to filter away hum and keeps the supply give amplifier clean powering.
Main big electrolytic caps are those two big black cans next to the heatsink.
They have a 'metal band' around them to fix their position.

[ostripper]

I am JVC fan (owned many)..
From what I see from your transformer/caps/ OP chips you have
a 50-80w/ch early model IC amp (STR-xxx.. one of the first)
If you post the number off chip I will tell you exactly.
The old STR chips are harder to find but possibly still obtainable.
If it blows fuses
again one of the chips fried. (thermal grease dries out),as
those older chips didnt have any protections built in.
OS

[BERENO]

Ok so I will look into testing the caps and whatnot in a week or so because it is Finals week, so I am starved for time to study. I will update this thread then. thanks for your responses