Replacing transformer

[Bearitone]

I want to replace the transformer in my old Ampeg Vh140c solid state combo amp. Problem is I have no clue how to even tell what transformer I have, and which one to replace it with. I don’t even know if it’s a power transformer or output transformer.

All I see is this stamped on it:
94-605-02
EIA 831-8915
831-B3

It has 5 wires coming out and i have a multimeter i cause to measure resistance across each one to do some investigating if that helps.

Can anyone help me with this?
Mercury already said they can’t help me because they don’t do any solidstate amps, only tube amps.

 

[mnemonic]

Won’t have an output transformer, it will be the power transformer.

Is there anything wrong with that transformer? If not, I would leave it be. All it does is supply the amp with the correct voltages.

Resistience of the windings wont tell you much of anything. You can either plug it in to the mains and measure the AC voltage out of each secondary tap (probably not high given its a solidstate amp, but still don’t electrocute yourself), or you could check the schematic and see what voltages it calls for and where.

There may also be specs for the transformer in the schematic or service manual. It’s available online, just google.

Then once you have that info you can look for a transformer with the right voltages, or have someone custom wind one for you.

 

[Bearitone]

Won’t have an output transformer, it will be the power transformer.

Is there anything wrong with that transformer? If not, I would leave it be. All it does is supply the amp with the correct voltages.

Resistience of the windings wont tell you much of anything. You can either plug it in to the mains and measure the AC voltage out of each secondary tap (probably not high given its a solidstate amp, but still don’t electrocute yourself), or you could check the schematic and see what voltages it calls for and where.

There may also be specs for the transformer in the schematic or service manual. It’s available online, just google.

Then once you have that info you can look for a transformer with the right voltages, or have someone custom wind one for you.

It’s just all rusty and dirty like someone left the thing outside.

How were you able to tell it was a PT and not an OT?

And I just printed out the schematic so i’ll give it a look.

Thank you!

 

[mnemonic]

Transistor output solidstate power amps have no output transformer

Old transformers tend to get rusty, you can just brush off any loose flakes and revarnish it. Don’t sand it though.

There’s lots of articles online about transformer restoration.

 

[Bearitone]

Transistor output solidstate power amps have no output transformer

Old transformers tend to get rusty, you can just brush off any loose flakes and revarnish it. Don’t sand it though.

There’s lots of articles online about transformer restoration.

Alright so i did some research on transformer restoration (read through forums and such) and i now understand i CANNOT sand, scrape, or do anything to the enamel/lacquer covered plates.



But, would i be hurting anything if i brushed the black caps on either side clean then, painted them white? Was also thinking of wrapping the enamel covered plates in black gaffers tape to at least cover the dirt/grime/rust

Edit:
Never mind i dug deeper and found a great video. For those interested you can just remove the clam shells and clean them.

Everyone online makes the transformer sound super fragile so i was scared to even attempt this.

 

[wakjob]

I'd carefully remove any scale or chips,
then hit the whole thing with a rattle can of black enamel.

 

[Bearitone]

I'd carefully remove any scale or chips,
then hit the whole thing with a rattle can of black enamel.

Primer first yeah?

 

[Necky379]

What would happen if someone was to sand or wire brush a transformer? What effect does rust and flaky enamel have, is it more than cosmetic? Thank Lemmy I never got it in my head to take on a project like this. I would have that transformer down to bare metal and rattle canned without even considering I was doing any kind of damage.