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Peavey Studio Chorus 210

Posted: Tue Jul 05, 2022 1:49 pm
by GnLguy
I have a Peavey Studio Chorus 210 that belonged to my late brother in law.

Amp works really well except I can't get the chorus effect to work. I have the correct foot switch

Are there any known issues with this amp or circuit that would prevent it from working? Is the chorus on these amps typically really deep like we could get from a pedal?


Many thanks in advance
Keith

Re: Peavey Studio Chorus 210

Posted: Tue Jul 05, 2022 3:51 pm
by JamesPaul
I do/have not owned one, but until someone stops by who has you could try a couple general things.

Several Peavey amps require certain switch settings on the control panel, for the footswitch to operate properly. The manual appears to still be available here:

https://secure.peavey.com/manual-search ... S#archived

You could confirm all switches are set correctly. There may also be some helpful hints on the Chorus effect in the manual. No offense intended if you have already done this.

The other is to get some Deoxit, spray your footswitch plug, and plug/unplug it from the amp a few times. You may as well get a 1/4" plug, spray it, and plug/unplug it from every input and output jack on the amp. Spray the plug before exercising each jack. There may be some switching jacks on the amp also. The same applies to switches on the control panel, but they may or may not be easy to access without removing the amp chassis. The idea here is some dust or corrosion may be preventing some signal paths from activating.

I remember the amp being discussed on here before, so someone with more specific knowledge should be along.

Hopefully it will be something easy instead of failed parts.

Re: Peavey Studio Chorus 210

Posted: Tue Jul 05, 2022 8:07 pm
by Enzo
Do you have the 1988 version or the 1990 version??

Look at the footswitch connection, and see if the base of Q8 or Q10 is being controlled. Those transistorsare in the two versions.

Re: Peavey Studio Chorus 210

Posted: Tue Jul 05, 2022 9:23 pm
by GnLguy
JamesPaul wrote:
Tue Jul 05, 2022 3:51 pm
I do/have not owned one, but until someone stops by who has you could try a couple general things.

Several Peavey amps require certain switch settings on the control panel, for the footswitch to operate properly. The manual appears to still be available here:

https://secure.peavey.com/manual-search ... S#archived

You could confirm all switches are set correctly. There may also be some helpful hints on the Chorus effect in the manual. No offense intended if you have already done this.

The other is to get some Deoxit, spray your footswitch plug, and plug/unplug it from the amp a few times. You may as well get a 1/4" plug, spray it, and plug/unplug it from every input and output jack on the amp. Spray the plug before exercising each jack. There may be some switching jacks on the amp also. The same applies to switches on the control panel, but they may or may not be easy to access without removing the amp chassis. The idea here is some dust or corrosion may be preventing some signal paths from activating.

I remember the amp being discussed on here before, so someone with more specific knowledge should be along.

Hopefully it will be something easy instead of failed parts.
Thanks for your response and no offense taken. Reminding someone is never a bad thing

I've looked thru the manual quite a bit and I didn't see anything that should have to be set a certain way for the chorus to work. Not to say that I may have overlooked it.

I'll try spraying the footswitch plug, the pots on this amp were terrible so it's not out of reason that the footswitch plug could be gunked up; it's either a 7 or 9 pin DIN plug & those connectors can easily get corroded

I sent an email to Peavey's support desk and they are usually good to get back with advice.

Re: Peavey Studio Chorus 210

Posted: Tue Jul 05, 2022 9:26 pm
by GnLguy
Enzo wrote:
Tue Jul 05, 2022 8:07 pm
Do you have the 1988 version or the 1990 version??

Look at the footswitch connection, and see if the base of Q8 or Q10 is being controlled. Those transistorsare in the two versions.
Likely the 1990 version, it's a teal stripe amp

I suppose that those transistors that you mentioned are on the main circuit board of the amp and I would venture a guess that those transistors latch that circuit either ON or OFF

And what would that tell me if the base of those xsistors are being controlled - other than maybe checking them if they might be defective?

Re: Peavey Studio Chorus 210

Posted: Wed Jul 06, 2022 10:54 am
by Enzo
I don't know from colors, I leave that to the fans, but it should say on the serial number tag either Studio Chorus 210 or Studio Chorus 210 "90

It is just a switching circuit, so start at the footswitch, measure DC voltage across the chorus switch. One side of the switch is ground, the other at some voltage, Does clicking the switch make that voltage alternately appear and disappear? It should. Now follow schematic over to the transistor, that same voltage change should appear on the base leg. More important, does the collector of that transistor toggle between +15v and -15v?

I am looking at Q8 on the 1990 drawing.

Re: Peavey Studio Chorus 210

Posted: Thu Jul 07, 2022 9:14 am
by GnLguy
Can you post the schematic? I've not found it online

Re: Peavey Studio Chorus 210

Posted: Thu Jul 07, 2022 11:22 am
by Enzo
You don't find a lot of them online because Peavey customer service freely provides them when you ask, but here:
PV Studio Chorus 210 1990.pdf
(1.84 MiB) Downloaded 179 times

PV Studio Chorus 210 1988.pdf
(1 MiB) Downloaded 174 times

Re: Peavey Studio Chorus 210

Posted: Thu Jul 07, 2022 6:21 pm
by dak
Enzo wrote:
Thu Jul 07, 2022 11:22 am
You don't find a lot of them online because Peavey customer service freely provides them when you ask,
In my experience, that makes it more likely for them to end up somewhere online, but often on pages that want something in return.

The only manufacturer I've seen so far that just puts up schematics online themselves was Mackie. That still feels somewhat weird to me. But it certainly is convenient (and for me a definite criterion for buying decisions) if schematics are readily available in one form or another.

I mean, let's not fool ourselves: cloning audio hardware requires quite a bit more than the schematics or you end up with a hum fest. So I don't really think schematics are much of a revenue killer, except of course that they allow you to keep old gear going rather than buying new.

Re: Peavey Studio Chorus 210

Posted: Thu Jul 07, 2022 10:08 pm
by JamesPaul
dak wrote:
Thu Jul 07, 2022 6:21 pm
Enzo wrote:
Thu Jul 07, 2022 11:22 am
You don't find a lot of them online because Peavey customer service freely provides them when you ask,
In my experience, that makes it more likely for them to end up somewhere online, but often on pages that want something in return.

The only manufacturer I've seen so far that just puts up schematics online themselves was Mackie. That still feels somewhat weird to me. But it certainly is convenient (and for me a definite criterion for buying decisions) if schematics are readily available in one form or another.

I mean, let's not fool ourselves: cloning audio hardware requires quite a bit more than the schematics or you end up with a hum fest. So I don't really think schematics are much of a revenue killer, except of course that they allow you to keep old gear going rather than buying new.
It is typically Intellectual Property that keeps manufacturers from distributing schematics. Still, I agree that having schematics is not enough to clone audio hardware.

Re: Peavey Studio Chorus 210

Posted: Fri Jul 08, 2022 2:19 am
by dak
JamesPaul wrote:
Thu Jul 07, 2022 10:08 pm
It is typically Intellectual Property that keeps manufacturers from distributing schematics. Still, I agree that having schematics is not enough to clone audio hardware.
What "Intellectual Property" would that be? Can't be patents since that just covers actual devices, not the schematics. Can't be trademarks, really. And I have a hard time understanding how copyright could block releasing the schematics of an in-house development.

The only thing vaguely making sense is trade secrets, and they don't make a lot of sense for something that is straightforward to reverse engineer if you are into commercial competition.

"Intellectual Property" here (like all too often) seems more of a shorthand for "this would require someone to authorize it and nobody here has enough of a clue or wants the responsibility" than anything else.

When I was young, electronics intended for import/sales into the U.S. were required to come with schematics, usually in a pouch inside or stuck or glued somewhere. Somehow that didn't cause much of a problem. The pouches in a color TV set were pretty thorough, including color calibration instructions and oscillogram sketches at various points in the circuits.

Re: Peavey Studio Chorus 210

Posted: Fri Jul 08, 2022 4:02 am
by JamesPaul
dak wrote:
Fri Jul 08, 2022 2:19 am
JamesPaul wrote:
Thu Jul 07, 2022 10:08 pm
It is typically Intellectual Property that keeps manufacturers from distributing schematics. Still, I agree that having schematics is not enough to clone audio hardware.
What "Intellectual Property" would that be? Can't be patents since that just covers actual devices, not the schematics. Can't be trademarks, really. And I have a hard time understanding how copyright could block releasing the schematics of an in-house development.

The only thing vaguely making sense is trade secrets, and they don't make a lot of sense for something that is straightforward to reverse engineer if you are into commercial competition.

"Intellectual Property" here (like all too often) seems more of a shorthand for "this would require someone to authorize it and nobody here has enough of a clue or wants the responsibility" than anything else.

When I was young, electronics intended for import/sales into the U.S. were required to come with schematics, usually in a pouch inside or stuck or glued somewhere. Somehow that didn't cause much of a problem. The pouches in a color TV set were pretty thorough, including color calibration instructions and oscillogram sketches at various points in the circuits.
Steady my friend....steady.

Re: Peavey Studio Chorus 210

Posted: Fri Jul 08, 2022 4:13 am
by JamesPaul
Invective schematic?

Re: Peavey Studio Chorus 210

Posted: Fri Jul 08, 2022 11:30 am
by Enzo
In my experience, that makes it more likely for them to end up somewhere online,
OK, then where are they? For decades as a Peavy authorized repair center, I encountered many people wanting Peavey schematics. I directed them to the factory, who were happy to provide them. If someone wanted a Fender schematic, I usually linked them to some web site. I almost never directed a Peavey request to some web site.
What "Intellectual Property" would that be? Can't be patents since that just covers actual devices, not the schematics. Can't be trademarks, really. And I have a hard time understanding how copyright could block releasing the schematics of an in-house development.
It isn't a conspiracy or a mystery. It is the design and documentation. It doesn't matter if someone else can figure it out. There isn't a Fender amp out there that I couldn't just take one apart and trace out the schematic if I wanted. That doesn't make their schematic any less their intellectual property. Some companies freely distribute intellectual properties, some do not. Copyright doesn't prevent a company from passing out drawings, but they may include protection of their copyrighted material as a reason not to.

Liability is also a concern. If I send your son a schematic for an amp I made, courts can (and have) argued that that is tacit approval for him to work in the amp. And if he electrocutes himself doing it, I can be in the liability loop. Some companies like to take no risk, others do not see this risk as substantial. But it is part of their decision.

Re: Peavey Studio Chorus 210

Posted: Fri Jul 08, 2022 12:56 pm
by dak
I was responding to "It is typically Intellectual Property that keeps manufacturers from distributing schematics.". That makes it sound like manufacturers are compelled not to hand out schematics. They aren't compelled to hand out spec sheets and catalogs, either. The question is just why they wouldn't do that if they want to convince people that it's a good idea to buy their equipment.