Peavey booster schematic request

[catalin gramada]

Hello All
I just bought an old Peavey 400 booster amplifier made in 1977 which is not in quite proper condition. It is a 400 series H. I can fix the little problems which it have but in the same time I prefer to do a general maintenance.
Please if you can help me with a schematic for this model or for a similar which use the same (or almost) power pak. Thank you.
Best Regards
Catalin

[doctor]

Hello All
I just bought an old Peavey 400 booster amplifier made in 1977 which is not in quite proper condition. It is a 400 series H. I can fix the little problems which it have but in the same time I prefer to do a general maintenance.
Please if you can help me with a schematic for this model or for a similar which use the same (or almost) power pak. Thank you.
Best Regards
Catalin

This is the most vintage I have.

[catalin gramada]

Thank You Doctor
It is not quite the same model as mine didn.t use op amps but maybe it helps. Seems, like enzo wrote somewhere in this forum, series 400H it is a later design, but didn.t found it. just variation 400B, 400R, and all bass amps from that era seems to use almost the same design for power section.
grt.
Catalin

[Jazz P Bass]

Your best bet is to contact Peavey.
Ask for the schematic.

[J M Fahey]

Then yours is the earlier one , all discrete and +/- 40V rails.
I have it somewhere, it might also be in MEF somewhere.

[catalin gramada]

Then yours is the earlier one , all discrete and +/- 40V rails.
I have it somewhere, it might also be in MEF somewhere.

Hello
seems you have damn right as time the filter caps are rated for no more than 50v. Thanks
grtz
Catalin

[J M Fahey]

Try this one:

[catalin gramada]

Thank you ,I will check. someone tryed to fix it and some components was replaced and don.t know this was conform with original. It is a simply amp, it is not hard to do to work it but I want to fix it as original it was
Catalin

[Jazz P Bass]

You will need this to cross the transistors.

[catalin gramada]

Thanks for support Jazz. I allready had sent a request to Peavey. maybe they will be kind to help me with schematic aso. As well I intend to change all electrolithycs from circuit as they worked under high surge current due to the low voltage supply-supose, they are not to much usable over 35 working years. I remeber 20 years ago this generation Peavey amps sound pretty good. I wonder now when I see on some forums users which buy a second hand one and they are pretty dissapointed- suppose again due to used components -capacitors / electrolithyc in principal I think....
Catalin

[TomCarlos]

I am trying to open the schematic posted by JPB (400booster.pdf) but it will not open. I think that happens with old posts and pdf files. I wrote to him asking if he has it. I will repost if he does. Anyone else? Do you have a copy of the "Input" module? I already have the power amp.

Thanks !!

[Jazz P Bass]

Sorry, but I looked through my files and cannot come up with the schematic that I posted.

[g1]

I have a feeling that was the spec. sheet from peavey, which is available online and is a match for title and 128.7kb file size.

[TomCarlos]

Thanks G1 -

Yep, I have the spec sheet. I will try to find the schematic. It might be similar to the Super Festival 800 Booster, except for the output.

[dmeek]

Here is the 800 Booster

Peavey 800 Booster.pdf