You know you've been watching too many amp repair videos when you've never repaired an amp in your life, and in all honestly... you're not even a very good guitar player... but a few minutes into this video you're hootin' and hollerin' "Bad output transformer!!"
That tube board was made to be installed once when the amp was built and to never be removed. I guess ole Hartley decided that serviceability just wasn't a thing any more.
The boards were a mess James Brown said the 5150 was born tweaking the Peavey VTM. In general they never properly re-made or did a new board layout for the amp except where necessary (like adding another tube to the preamp)
Yikes. Thats no good. Removing that board the way you had to is bogus to get to the other side of that board. Glad i have not had to work on one of these. You have serious patience :-)
There is tons of room for improvements on those 5150 and getting a new (and definitely better) Output Tranny is one the things so I would consider it as an upgrade, not a failure
First tube amp project I ever did was to swap a Jet City amp with a custom PCB. I had the wires on the transformer swapped so I got the horrific full volume squeal. Thank god I only had a farty old 10 inch cabinet hooked up. Startled me. I had to do some head scratching to realize I needed to change over the wires. Amp worked find after that.
I had a similar issue when I put in a new OT on my 20 watt Jet City amp. The manufacturer of the OT actually colored the primaries backwards, so I got the squeal of death too. Luckily a quick swap and all was good
A mosquito got in the house and literally flew in my face just as I was reading retreads' comment.....it seems that sometimes you're the bug, and sometimes you're the bloodbank donor! (The little blighters frigging love me; like my father I am one of those people who seems to get bit when no one else does; but I have to wonder if the blood thinners I am on will kill the skeeter shortly afterwards 🤔).
When I get the riveted ones in and there's an issue there, I drill out the rivets and replace them with machine screws + keps nuts. It's a _gigantic_ pain, but it's better than wrecking a pad.
I’ve done it before. But it’s a lot better to do it from the inside of the chassis. And you have to do some kind of captive nut to make the whole setup work.
@@PsionicAudio , I haven't done it with tube sockets (and it probably wouldn't work longterm because of the heat) but on rare occasion I have epoxy glued a nut into place in a tight corner so I don't have to get in there with my stubby fingers, needle nose pliers, socket wrench or a telescoping magnet in order to reinstall a nut in a tight spot. Unfortunately, most of us don't have a spot welder, but it would be really nice if we could spot weld nuts to the underside of the holes in the flanges on the tube sockets.....
@@PsionicAudio you could do it on this amp ... maybe. IF there's enough clearance so that the nuts don't contact anything on the printed board, you could spot-weld or solder nuts to the flanges of the tube sockets, then use machine screws of the correct length, through the chassis. Not sure if the flanges are so flimsy that they'd bend due to the torque when tightening, though.
It would be better to just design a new board with Beltons, sane connections, better heat management, and a new heater connection for the octals. But then I’d have to redo the crappy preamp PCB board. And the shitty pots/jacks. And the shitty layout. And the shitty, well, everything. Cheaper to just buy a real Soldano.
I removed that board on a 6505 USA without any unsoldering by unscrewing he tube sockets. Maybe it was un upgrade on the latest amps. The problem was the same, screen grid resistor caput!
Somewhat off topic, but in case any of you electronics nerds like myself don't subscribe to the Curious Marc channel on UA-cam he posted a video yesterday of an interview with 2 guys who have published a gorgeous coffee-table book of cross-sectional micro-photography of electronic components such as resistors, capacitors, transistors, IC's, displays, and yes, tubes, including small CRT's. You can watch them slice components in half and polish the cut faces and then photograph them them. Its very cool!
Bruh just unplug the connectors from the board and carefully drill the 8 rivets out, then rivet the board back on again once complete, it’s actually less fiddly than dealing with tiny nuts and bolts. You don’t need to unsolder all the sockets.
@@TheCyberMantis Yeah mine popped a resistor when it was fairly new. I think it might have been a bias resistor. Someone else fixed it for me. I didn't want to deal with it, I was in my metal gat player phase, not into the electronics at that time. I did record a Black Metal demo tape with it while in that state, the demo sounded pretty good, but the amp lacked guts when turned up for live work,
@@TheCyberMantismy block popped the long blue resistor in 2012, and the only other thing I've had to do is clean the FX loop Jack's... I have a second block.. Don't think it's ever been repaired. Both were toured. One by Daisy Berkowitz of Marilyn Manson... The one with the blown resistor. Filter caps still good too. Yeah.. Idk.. They're beasts in my book... Still in 2023.
Pop-riveting the tube sockets to the chassis was a cheapskate move on Peavey's part. I would be tempted to drill out the rivets and find another way to bolt those sockets to the chassis while they're already soldered to the PC board, perhaps some kind of speed clip or Tinnerman nut that clips over the holes in the flanged ends of the tube sockets, to provide threads; or replacing the tube sockets with some that have tapped threads for mounting, instead of holes. Customer's budget permitting of course, but it probably doesn't matter in this case unless the guy wants to both spring for a new transformer and make future service easier .....
Riveting is better than using nuts on things that are going to be exposed to vibration. It’s not that hard to drill rivets out and replace them. Just annoying if you don’t already have a rivet gun and a drill press (hand drilling is more risky as it’s harder to create an effective depth stop).
@@Jonathan_Doe_ , Drilling out pop-rivets when you don't have access to the underside of the rivet can be a pain because often-times the rivet starts to spin in the chassis hole before your drill bit has removed all of the mushroom-head of the rivet. This might necessitate having to take out the Dremel tool and grind the rest of the rivet head off (assuming you have sufficient space to get in there with the tool), which means you have to mask off the chassis of the amplifier with tape around the rivet(s) so that you don't leave big gouges and scratches all over it. A drill press may or may not help you drill out the rivets if any of them are close enough to a transformer that the drill chuck might graze the transformer; you might have to drill at an angle or use an extra long drill bit. Although sometimes you can knock the remainder of a rivet out of the chassis with a hammer and punch if you have drilled most of the head off of it first, this risks damaging tha circuit board that the socket is soldered to. In short, drilling out 8 pop rivets on an amp chassis is something that you really want to do only once for any given amplifier.! If you can devise another way of reinstalling it that will make it easier to remove next time, do it.
Bugera used octal sockets with threads which allow the board to be installed inside the amp and the socket screws go in afterwards from the outside. I dont have a clue where they got them from, maybe custom produced by them.
These things sold for $700 new back in 1992. I bought one in 1994. Played with it for 1 day, then took it back to the music store. I thought it sounded like crap. It was super loud, but sounded bad. I also had a Crate Stealth 50, which I thought sounded so much better. I kept the Crate. I still have it today. It sits in the closet. I play my Katana head now. I will probably never buy another tube amp. Prices are out of control, and the SS/digital stuff is really good now.
@@auntjenifer7774 They sounded bad through the Peavey cabinets with the Sheffield speakers. I nearly got put off them when I once tried one configured this way. But then I got my local music store to get one in on a trial basis and I tested it with my Marshall cab and it sounded awesome. I had a Marshall Valvestate 100 watt head, but I wanted to go all tube. I went with the 5150 because the single channel JCM900 master volume available at the time was pretty good, but just didn't have quite enough gain. I got a second Marshall cab at the same time.
@@xanataph Back then, I didn't know anything about "load boxes" or Boss SD-1. I could work with a 5150 today, but not back then. I was playing it in my house, through a Peavey 4x12 cab with Celestion G12K-85 speakers. If I turned it down far enough to stand being in the house with it, it sounded like crap. I kept the cab. I use the cab with my Boss Katana head now. It sounds great at any volume.
I once bought a non-functional Laney AOR50 for repair and while I'm no expert at 28, I also found the output transformer to be bad alongside bad EL34s. Was a bit of a chase and I had some help, but I was proud to find and confirm the defect myself. Any guesses on which caused which? Or may a mismatched output impedance cause both to give up the ghost? Same goes for the 5150s OT.
Can’t say for the Laney, but apparently the previous owner of this 5150 was using it with a load box. Not all load boxes are created equal, and some love to kill transformers.
i was playing my 1993 peavey 5150 on the channel 3 setting at bedroom level. and all of a sudden there was a big gain drop. there was still volume but the post gain was very off. could it be a power tube or a pre amp tube?
Most likely failure point besides guitar cables and such is a preamp tube. Like a specially if you tried in different channels and only one channel has the issue or there's a loss of gain and distortion
@@Crunchifyable2 the volume drop issue is gone. but now there’s an issue with my FX loop jacks on the back of the amp head. whenever i plug in effects to it, there’s a loud buzzing coming from it. but without anything in the fx loop, it’s quiet. any ideas what it could be?
@@PsionicAudio The pop rivets have the heads on the opposite side of the frame. they are designed to be attached from the outside. That is how the amplifier was originally built. The board was built, and soldered with the tube sockets in place and then the entire assembly was attached to the frame with pop rivets. Drilling out 8 pop rivets is much easier than desoldering 32 pins.
Seems like a choice of stupids then. I can't see riveting with the board in place giving a good even connection. And I should not have to buy a riveting tool to change a screen grid resistor.
@@PsionicAudio It seems that you have never used a pop rivet tool. They provide very stable mounting and have the advantage that the rivets can be mounted from one side of the structure. I have had to purchase tools that seemed ridiculously expensive to perform proper service work. A $10 Pop riveter and a few dollars of the correct length rivets is not a great expense for doing a job in a more efficient manner.
@@PsionicAudio No, the board does not have to be removed from the tube sockets. A pop rivet provides the ability to put the rivets in from the other side of the chassis. That is how the amplifier was assembled. The tube sockets, resistors, capacitors,etc. were assembled onto the board, the board was flow soldered and then installed in one piece to the chassis with pop rivets. By drilling out the rivets, the board can be removed from the chassis in 5 minutes, and re assembled as quickly, if not faster.
Every peavey amp I've ever seen opened up has had the worst design with no foresight for repairs. It's either arrogance or stupidity 🤷 Maybe a combination of the two.
I watched Brad's Guitar Garage rebuild and improve a Peavey Classic 30 a couple of weeks ago. The mechanical design of that thing is stupid beyond belief.
@@dangitdan9938 , I've seen that type of construction inside lots of audio- video home-theater receivers as well. Which is one reason why the audio shop I work for has decided not to repair them any more.
Does anybody know how the standby switch works in this circuit? I have been wracking my brain looking at the schematic trying to figure it out. It looks like the screen supply and plate supply are coming straight from the B+ regardless if the switch is closed or open. I cant figure out how the switch causes the signal to cut out when it’s open. Any help would be appreciated
It’s just a really poorly drawn schematic. Plate goes to filter cap and OT CT and dropping resistor. Other side of resistor to SB switch then to screen node and on from there.
@@PsionicAudio ya I see that much. I just dont see how the SB switch has any effect. Maybe the screen supply is coming from the B+ through the OT CT only. Then I guess it makes sense. Thanks, I’ll try to trace it tonight rather than rely on the schematic. Love your videos btw!!!
is it worth fixing ???? in my world peavey was always JUNK and after they screwed over all their american workers i wrote them off .... they did make a classic 50 and 30 watt tube amps i heard were pretty good ....
You know you've been watching too many amp repair videos when you've never repaired an amp in your life, and in all honestly... you're not even a very good guitar player... but a few minutes into this video you're hootin' and hollerin' "Bad output transformer!!"
😂I use that Blazing Saddles quote all the time at work
Oh Dem Blazing 5150 SADDLES!!!!
So glad I have a old one
That tube board was made to be installed once when the amp was built and to never be removed. I guess ole Hartley decided that serviceability just wasn't a thing any more.
The boards were a mess James Brown said the 5150 was born tweaking the Peavey VTM. In general they never properly re-made or did a new board layout for the amp except where necessary (like adding another tube to the preamp)
Yikes. Thats no good. Removing that board the way you had to is bogus to get to the other side of that board. Glad i have not had to work on one of these. You have serious patience :-)
Blood for the blood God!
"The blood is the life!" Renfrew, in "Dracula" (the original literary version).
I was on pins and needles waiting to hear if the plates were hooked up right! 😂 WORST sound EVER!!
You never forget your first Oscillation Overthruster moment! A Flux Capacitor discharge cannot begin to compare.
There is tons of room for improvements on those 5150 and getting a new (and definitely better) Output Tranny is one the things so I would consider it as an upgrade, not a failure
Oooof, when the clip changed to the temped in OT I knew this wasn't a fun job
First tube amp project I ever did was to swap a Jet City amp with a custom PCB. I had the wires on the transformer swapped so I got the horrific full volume squeal. Thank god I only had a farty old 10 inch cabinet hooked up. Startled me. I had to do some head scratching to realize I needed to change over the wires. Amp worked find after that.
I had a similar issue when I put in a new OT on my 20 watt Jet City amp. The manufacturer of the OT actually colored the primaries backwards, so I got the squeal of death too. Luckily a quick swap and all was good
What even causes that squeal? Is that a grounding issue?
Sometimes you're the windshield, sometimes you're the bug.
I’m Batman
A mosquito got in the house and literally flew in my face just as I was reading retreads' comment.....it seems that sometimes you're the bug, and sometimes you're the bloodbank donor! (The little blighters frigging love me; like my father I am one of those people who seems to get bit when no one else does; but I have to wonder if the blood thinners I am on will kill the skeeter shortly afterwards 🤔).
Mark Knopfler?
Wow what a pain almost as bad as a Mesa.
Well at least you can repair it. I'm sure the amp is worth it.
When I get the riveted ones in and there's an issue there, I drill out the rivets and replace them with machine screws + keps nuts. It's a _gigantic_ pain, but it's better than wrecking a pad.
I’ve done it before. But it’s a lot better to do it from the inside of the chassis. And you have to do some kind of captive nut to make the whole setup work.
@@PsionicAudio , I haven't done it with tube sockets (and it probably wouldn't work longterm because of the heat) but on rare occasion I have epoxy glued a nut into place in a tight corner so I don't have to get in there with my stubby fingers, needle nose pliers, socket wrench or a telescoping magnet in order to reinstall a nut in a tight spot. Unfortunately, most of us don't have a spot welder, but it would be really nice if we could spot weld nuts to the underside of the holes in the flanges on the tube sockets.....
@@PsionicAudio you could do it on this amp ... maybe. IF there's enough clearance so that the nuts don't contact anything on the printed board, you could spot-weld or solder nuts to the flanges of the tube sockets, then use machine screws of the correct length, through the chassis. Not sure if the flanges are so flimsy that they'd bend due to the torque when tightening, though.
It would be better to just design a new board with Beltons, sane connections, better heat management, and a new heater connection for the octals.
But then I’d have to redo the crappy preamp PCB board. And the shitty pots/jacks. And the shitty layout. And the shitty, well, everything.
Cheaper to just buy a real Soldano.
@@PsionicAudio I've done the whole power amp board as point to point before. That worked reasonably well, but it's not exactly time efficient.
I removed that board on a 6505 USA without any unsoldering by unscrewing he tube sockets. Maybe it was un upgrade on the latest amps. The problem was the same, screen grid resistor caput!
What an absolute nightmare!
Was that a Blazing Saddles reference? 😭😭😭😂Jk🤘
Somewhat off topic, but in case any of you electronics nerds like myself don't subscribe to the Curious Marc channel on UA-cam he posted a video yesterday of an interview with 2 guys who have published a gorgeous coffee-table book of cross-sectional micro-photography of electronic components such as resistors, capacitors, transistors, IC's, displays, and yes, tubes, including small CRT's. You can watch them slice components in half and polish the cut faces and then photograph them them. Its very cool!
Bruh just unplug the connectors from the board and carefully drill the 8 rivets out, then rivet the board back on again once complete, it’s actually less fiddly than dealing with tiny nuts and bolts. You don’t need to unsolder all the sockets.
Came here for this comment. Yeah, I was wondering why not go that route, too
I had one of these amps for years and I put a lot of hours on it without issue. For such a cheaply built amp, mine was a trooper.
You got lucky.
@@TheCyberMantis Yeah mine popped a resistor when it was fairly new. I think it might have been a bias resistor. Someone else fixed it for me. I didn't want to deal with it, I was in my metal gat player phase, not into the electronics at that time. I did record a Black Metal demo tape with it while in that state, the demo sounded pretty good, but the amp lacked guts when turned up for live work,
@@TheCyberMantismy block popped the long blue resistor in 2012, and the only other thing I've had to do is clean the FX loop Jack's... I have a second block.. Don't think it's ever been repaired.
Both were toured. One by Daisy Berkowitz of Marilyn Manson... The one with the blown resistor.
Filter caps still good too.
Yeah.. Idk.. They're beasts in my book... Still in 2023.
Oh my god!
Did I see that correctly? Peavey pop riveted the output tube sockets directly to the chassis?
Nothing like having to do a bunch of desoldering in order to assemble something.
Did you swap the 100 ohm to 490ohm for 6l6?
Pop-riveting the tube sockets to the chassis was a cheapskate move on Peavey's part. I would be tempted to drill out the rivets and find another way to bolt those sockets to the chassis while they're already soldered to the PC board, perhaps some kind of speed clip or Tinnerman nut that clips over the holes in the flanged ends of the tube sockets, to provide threads; or replacing the tube sockets with some that have tapped threads for mounting, instead of holes. Customer's budget permitting of course, but it probably doesn't matter in this case unless the guy wants to both spring for a new transformer and make future service easier .....
Yeah, just drill out the 8 pop rivets. Rivet it back together after the repair.
@@TheCyberMantis Yeah, drilling eight rivets seems easier than de-soldering and cleaning up 32 tag terminals!
Riveting is better than using nuts on things that are going to be exposed to vibration. It’s not that hard to drill rivets out and replace them. Just annoying if you don’t already have a rivet gun and a drill press (hand drilling is more risky as it’s harder to create an effective depth stop).
@@Jonathan_Doe_ , Drilling out pop-rivets when you don't have access to the underside of the rivet can be a pain because often-times the rivet starts to spin in the chassis hole before your drill bit has removed all of the mushroom-head of the rivet. This might necessitate having to take out the Dremel tool and grind the rest of the rivet head off (assuming you have sufficient space to get in there with the tool), which means you have to mask off the chassis of the amplifier with tape around the rivet(s) so that you don't leave big gouges and scratches all over it. A drill press may or may not help you drill out the rivets if any of them are close enough to a transformer that the drill chuck might graze the transformer; you might have to drill at an angle or use an extra long drill bit. Although sometimes you can knock the remainder of a rivet out of the chassis with a hammer and punch if you have drilled most of the head off of it first, this risks damaging tha circuit board that the socket is soldered to. In short, drilling out 8 pop rivets on an amp chassis is something that you really want to do only once for any given amplifier.! If you can devise another way of reinstalling it that will make it easier to remove next time, do it.
Bugera used octal sockets with threads which allow the board to be installed inside the amp and the socket screws go in afterwards from the outside. I dont have a clue where they got them from, maybe custom produced by them.
These things sold for $700 new back in 1992. I bought one in 1994. Played with it for 1 day, then took it back to the music store. I thought it sounded like crap. It was super loud, but sounded bad. I also had a Crate Stealth 50, which I thought sounded so much better. I kept the Crate. I still have it today. It sits in the closet. I play my Katana head now. I will probably never buy another tube amp. Prices are out of control, and the SS/digital stuff is really good now.
That's bad luck! Do you think this one's in the video sounds good !? I think it sounds good.
@@auntjenifer7774 They sounded bad through the Peavey cabinets with the Sheffield speakers. I nearly got put off them when I once tried one configured this way. But then I got my local music store to get one in on a trial basis and I tested it with my Marshall cab and it sounded awesome. I had a Marshall Valvestate 100 watt head, but I wanted to go all tube. I went with the 5150 because the single channel JCM900 master volume available at the time was pretty good, but just didn't have quite enough gain. I got a second Marshall cab at the same time.
@@xanataph Back then, I didn't know anything about "load boxes" or Boss SD-1. I could work with a 5150 today, but not back then. I was playing it in my house, through a Peavey 4x12 cab with Celestion G12K-85 speakers. If I turned it down far enough to stand being in the house with it, it sounded like crap. I kept the cab. I use the cab with my Boss Katana head now. It sounds great at any volume.
My 5150 paired with my Marshall 1960 cab sounds awesome
I always hated the sound of these 5150 amps, too. I love The Mighty Van Halen, but these amps are junk. Noisy as hell. 🤷♂️
I once bought a non-functional Laney AOR50 for repair and while I'm no expert at 28, I also found the output transformer to be bad alongside bad EL34s. Was a bit of a chase and I had some help, but I was proud to find and confirm the defect myself. Any guesses on which caused which? Or may a mismatched output impedance cause both to give up the ghost? Same goes for the 5150s OT.
Can’t say for the Laney, but apparently the previous owner of this 5150 was using it with a load box. Not all load boxes are created equal, and some love to kill transformers.
@@PsionicAudio this is good info. What should someone look for to not buy amp destroying garbage?
_I get no kick from champagne,_
_Mere alchohol doesn't thrill me at all._
_So tell me why should it be true,_
_That I get a belt out of youuuu?__
So if it needed a new transformer, why did it have nice full volume on the clean channel !?
It did not. The output was less than that of a Champ.
i was playing my 1993 peavey 5150 on the channel 3 setting at bedroom level. and all of a sudden there was a big gain drop. there was still volume but the post gain was very off. could it be a power tube or a pre amp tube?
Most likely failure point besides guitar cables and such is a preamp tube. Like a specially if you tried in different channels and only one channel has the issue or there's a loss of gain and distortion
@@Crunchifyable2 the volume drop issue is gone. but now there’s an issue with my FX loop jacks on the back of the amp head. whenever i plug in effects to it, there’s a loud buzzing coming from it. but without anything in the fx loop, it’s quiet. any ideas what it could be?
Would rather pop out the 8 rivets than unsolder and resolder 32 pins.
And then what? You can’t install nuts and screws with the board in the way.
@@PsionicAudio sure can't. Hence the rivets.... So rivet it back on.
Just drill rivets and then re-rivet MUCH easier!
That would not work mechanically without removing the board from the sockets. So…
You should have gave that amp a number 6
Perhaps give it *three* sixes 😳, or the "deep six" as a boat anchor!
You could have drilled out the pop rivets on the tube sockets and pulled the board without desoldering.
And then? Hard to re-rivet them properly without removing, you guessed it, the board.
@@PsionicAudio The pop rivets have the heads on the opposite side of the frame. they are designed to be attached from the outside. That is how the amplifier was originally built. The board was built, and soldered with the tube sockets in place and then the entire assembly was attached to the frame with pop rivets.
Drilling out 8 pop rivets is much easier than desoldering 32 pins.
Seems like a choice of stupids then. I can't see riveting with the board in place giving a good even connection. And I should not have to buy a riveting tool to change a screen grid resistor.
@@PsionicAudio It seems that you have never used a pop rivet tool. They provide very stable mounting and have the advantage that the rivets can be mounted from one side of the structure.
I have had to purchase tools that seemed ridiculously expensive to perform proper service work. A $10 Pop riveter and a few dollars of the correct length rivets is not a great expense for doing a job in a more efficient manner.
@@PsionicAudio No, the board does not have to be removed from the tube sockets. A pop rivet provides the ability to put the rivets in from the other side of the chassis. That is how the amplifier was assembled. The tube sockets, resistors, capacitors,etc. were assembled onto the board, the board was flow soldered and then installed in one piece to the chassis with pop rivets.
By drilling out the rivets, the board can be removed from the chassis in 5 minutes, and re assembled as quickly, if not faster.
Why didn't they solder those output tubes directly to the PCB? They would have saved the cost of tube sockets! 🤔
Ssshhh, don't give the Chinese PCB manufacturers/assemblers any ideas....
All of these cheaply made AMPS make me cringe.. Handwired or DEATH..
THEY LAST A LIFETIME (properly maintained) cheers !
ua-cam.com/video/cjnFk-lZV9I/v-deo.html
Every peavey amp I've ever seen opened up has had the worst design with no foresight for repairs. It's either arrogance or stupidity 🤷
Maybe a combination of the two.
I watched Brad's Guitar Garage rebuild and improve a Peavey Classic 30 a couple of weeks ago. The mechanical design of that thing is stupid beyond belief.
@@goodun2974 the U shaped PCB is beyond stupid. It's like they don't want techs to fix them.
@@dangitdan9938 , I've seen that type of construction inside lots of audio- video home-theater receivers as well. Which is one reason why the audio shop I work for has decided not to repair them any more.
Peavey must have been one of the pioneers in electronics 'planned obsolesence'.
Does anybody know how the standby switch works in this circuit? I have been wracking my brain looking at the schematic trying to figure it out. It looks like the screen supply and plate supply are coming straight from the B+ regardless if the switch is closed or open. I cant figure out how the switch causes the signal to cut out when it’s open. Any help would be appreciated
It’s just a really poorly drawn schematic. Plate goes to filter cap and OT CT and dropping resistor. Other side of resistor to SB switch then to screen node and on from there.
@@PsionicAudio ya I see that much. I just dont see how the SB switch has any effect. Maybe the screen supply is coming from the B+ through the OT CT only. Then I guess it makes sense. Thanks, I’ll try to trace it tonight rather than rely on the schematic. Love your videos btw!!!
is it worth fixing ???? in my world peavey was always JUNK and after they screwed over all their american workers i wrote them off .... they did make a classic 50 and 30 watt tube amps i heard were pretty good ....