ShortScale Forum Index www.shortscale.org
Head 'n Neck Above
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
UploaderUploader   ShortScale WikiBuilder

Peavey Stereo Chorus 400 - Volume Issue

 
Post new topic   Reply to topic    ShortScale Forum Index -> Effects, Amps & Gear, Pedal Building
View previous topic :: View next topic  
Author Message
Fran
The Curmudgeon


Joined: 20 Apr 2006
Posts: 21032
Location: Nottingham, Englandshire.

PostPosted: Sun May 03, 2015 5:22 pm    Post subject: Peavey Stereo Chorus 400 - Volume Issue Reply with quote

I picked this Amp up as something I could leave in rehearsal rooms, as it didnt cost me much and is supposedly a very loud Amp, 130w RMS.

The Amp works but even turned up full its nowhere near as loud as my Marshall MG15w and not usable for rehearsals. Tried everything I can think of but no joy.

The two Scorpion speakers are reading just under 4 ohms which is right, although the back panel states 4 ohm minimum. The Power Amp ins appear to do nothing, no signal.
I took it apart today and cleaned all the pots, they were gunked up and it has improved their functionality but its still very quiet. There appears to be some staining? down one edge of the PCB, I assume the previous owner spilled something on it. He hasnt used it for two years but said it worked fine when he last tried it.

Pics...
Hidden: 






Anyone got any ideas what the volume issue could be?
_________________
dezb1 wrote:
Stop fucking about and get an SD-1

robroe wrote:
I got a stomach ache. Anyone got any heroin? Or like a gun or something?

brandonwinmill wrote:
Maybe i'll sell my internet. It's lost its fun since i already beat it twice.
Back to top
View user's profile Send private message
paul_
.
.


Joined: 27 Jul 2006
Posts: 9091

PostPosted: Sun May 03, 2015 10:02 pm    Post subject: Reply with quote

That brown stuff is solder flux, probably not a spill by previous owner. It's likely that the board was made that way at Peavey (note that it's mostly around the same components, board-mounted pots), though I suppose someone else could've done the pots at some point so it wouldn't hurt to make sure they're the right values.
_________________
Aug wrote:
which one of you bastards sent me an ebay question asking if you can get teh kurdtz with that 64 mustang? Mad

robertOG wrote:
fran & paul are some of the original gangstas of the JS days when you'd have to say "phuck"
Back to top
View user's profile Send private message
NickS
.
.


Joined: 14 Jan 2008
Posts: 9458
Location: Nr. Basinggrad, UK

PostPosted: Mon May 04, 2015 12:19 pm    Post subject: Reply with quote

I agree with Paul on the flux residue. Possibly someone's already had the pots off once and cleaned them. The Power Amp Ins will be line-level inputs so you'll need the pre-amp out/mixer/out/slave/out (possibly FX out will do depending on the level) from another amp to drive them. Vice versa, to test the pre-amp section, do you have another amp you can feed it into? I haven't tracked down the circuit diagram for this beast yet.
Back to top
View user's profile Send private message
Fran
The Curmudgeon


Joined: 20 Apr 2006
Posts: 21032
Location: Nottingham, Englandshire.

PostPosted: Mon May 04, 2015 2:04 pm    Post subject: Reply with quote

Thanks Paul and Nick.

I'll try it into the Marshall.
Incidentally, I tried it through the 16 ohm Orange cab using one of the speaker output jacks and it was louder than it is through it's own speakers.
_________________
dezb1 wrote:
Stop fucking about and get an SD-1

robroe wrote:
I got a stomach ache. Anyone got any heroin? Or like a gun or something?

brandonwinmill wrote:
Maybe i'll sell my internet. It's lost its fun since i already beat it twice.
Back to top
View user's profile Send private message
NickS
.
.


Joined: 14 Jan 2008
Posts: 9458
Location: Nr. Basinggrad, UK

PostPosted: Tue May 05, 2015 3:36 pm    Post subject: Reply with quote

OK, I found the circuit diagram. The reason you're getting nothing from the power amp input is because (I didn't realise) the preamp output is on the tip and the power amp input on the ring of a TRP jack.
Back to top
View user's profile Send private message
Fran
The Curmudgeon


Joined: 20 Apr 2006
Posts: 21032
Location: Nottingham, Englandshire.

PostPosted: Tue May 05, 2015 6:42 pm    Post subject: Reply with quote

What does that mean Nick, is there a problem with the power in Jack sockets?
_________________
dezb1 wrote:
Stop fucking about and get an SD-1

robroe wrote:
I got a stomach ache. Anyone got any heroin? Or like a gun or something?

brandonwinmill wrote:
Maybe i'll sell my internet. It's lost its fun since i already beat it twice.
Back to top
View user's profile Send private message
NickS
.
.


Joined: 14 Jan 2008
Posts: 9458
Location: Nr. Basinggrad, UK

PostPosted: Tue May 05, 2015 9:49 pm    Post subject: Reply with quote

No, it just means that to connect to the power amp ins you need to use stereo jack plugs and connect to the ring and sleeve instead of the tip and sleeve of a mono plug. For the preamp out you can use a standard mono lead. Sleeve is always ground.

You could probably also do this by pushing the plug only part of the way in so that the tip touches the ring contact on the socket.
Back to top
View user's profile Send private message
Fran
The Curmudgeon


Joined: 20 Apr 2006
Posts: 21032
Location: Nottingham, Englandshire.

PostPosted: Sat May 09, 2015 3:08 pm    Post subject: Reply with quote

The Power Out works fine into another amp Nick, seems loud.

Does this mean anything? Confused
_________________
dezb1 wrote:
Stop fucking about and get an SD-1

robroe wrote:
I got a stomach ache. Anyone got any heroin? Or like a gun or something?

brandonwinmill wrote:
Maybe i'll sell my internet. It's lost its fun since i already beat it twice.
Back to top
View user's profile Send private message
NickS
.
.


Joined: 14 Jan 2008
Posts: 9458
Location: Nr. Basinggrad, UK

PostPosted: Sat May 09, 2015 10:18 pm    Post subject: Reply with quote

Could even be crappy jack sockets..
Back to top
View user's profile Send private message
NickS
.
.


Joined: 14 Jan 2008
Posts: 9458
Location: Nr. Basinggrad, UK

PostPosted: Tue May 12, 2015 10:17 pm    Post subject: Reply with quote

Seriously, take a stereo jack plug, wire the tip and ring together and stick it in the preamp out/power amp in. Maybe bad contacts are not your problem, but that is the reason I got a JTM60 for silly money and I've been running it for several years with a jumper cable in the effects loop sockets.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    ShortScale Forum Index -> Effects, Amps & Gear, Pedal Building All times are GMT
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB 2001, 2002 phpBB Group

Anti Bot Question MOD - phpBB MOD against Spam Bots
Blocked registrations / posts: 622321 / 0

Guitars at Musician's Friend

Help support this site by clicking the above link!