We used to make their chassis’ and grills back when I was still a teenager. The grills were a flattened steel expanded 18 ga steel that when you sheared created razor sharp points on all 4 sides. Everyone who made that job still around all have nasty “SWR” scars (mine is on my left ankle from a pallet of them on the floor)
Absolutely love the opener about wearing pants the reflection in the hot solder line was really good I've watched so many of your videos maybe not every single one but almost everyone that's the funniest thing you've ever said and it makes me believe that you may actually have a sense of humor. Nice to know that you are human After All All joking aside you are my number one source for actual troubleshooting and repair information when it comes to amplifiers I'm thoroughly impressed with everything that you do your discipline and consistency in the way that you do things and have been the subscriber for quite a while now. Keep up the great work and make sure those pants stay on when you're shooting that video
I just repaired one of these. Ended up being a bad solder joint on the master volume. That wonderful lead free solder. Pulled the whole power section to check the final output transistors and drivers. Just a stupid broken solder joint in the end that I couldn’t see as it was covered up by push/pull limiter pot.
That’s the thing it’s hard to get clients to understand with amps like this. Just to diagnose a simple problem can require an almost complete disassembly/reassembly. This one could be one/multiple bad caps or it could just be one bad solder joint. Same symptoms. If I go farther in diagnostics and the owner declines the repair, odds are I would not get paid for the two hours diagnostics would take. So I stopped until I can speak with the owner.
Love the channel and i'm thinking of repairing, now vintage equipment again as a part time hobby (ears willing). Your channel helps motivate me to love the music again. Music is a universal language and quality sound should be preserved and taught. Top rate music equipment should be cared for and repaired to make that possible. I was a bench tech for audio and video in the 80s and 90s. Same pre-estimate game plan. Look, smell, feel and basic measurements. Things like further disassembly, service manual, and oscilloscope add time and money. Peavey CS-400 power amps stand out as successful and sometimes profitable repairs because they were tanks. I still have a Sansui 7070 stereo receiver service manual from the 1970s. My friend's brother wouldn't pay $75 for the service manual much less a rectifier or power transformer repair. Ahh the memories. Now those receivers are big dollars. Not many of us knew that and some succumbed to M 80 blasts or worse. Boredom breeds stupidity. Keep the music alive !
I had one of these for more than a decade. It was a great amp. Only issue I had with mine was the standby switch got sketchy. Sometimes I’d have to flip it on and off a couple times to get to work.
I had a pre fender sm900 and that was actually a tight little work of art. Easy to fix I still have trays of the Sanken 2sc3264’s. Never parting with them since there was a bad time when most you found were fakes.
I cut my chops on old Fender tube amps and knew little about solid state amps. Years ago a friend at work asked me to look at his broken Crown power amp and not knowing what I was doing cost me a nice Vintage 30 speaker.
Thanks Matt. No Darkglass yet. But all the Class D amps seem to be using ICE modules which have a fairly high failure rate (that said, replacements are fairly inexpensive). The real concerns are that the module used will either be in production for a long time or that the manufacturer will stock replacements for X many years. We’ll see.
I do have the same SWR 750X, my power board was destroyed and now I do have a very new one with new transitors. What I do not know, should I opwer on the amplifier totally unconsidered? Can I do a damage, if the bias is not adjusted? I can see the potentiometer but I do not know which values on which point to meassure... do you have an idea?
Eh, looks like a nice amp, but I prefer bass (and guitar amps, too) that aren't so feature laden. All that extra crap just adds to problems. I wish manufacturers would stop cramming so much stuff into amps and just give us simple circuits.
That does make a case for pedals, doesn't it? My main amp is a Katana, so I can't say I have followed that path in the past, but if I add to my amp collection, it is certainly a consideration.
Since that thing is 20 yrs old, I imagine there's hundreds, maybe thousands of amps out there by now that are simple. Go find one. 🤷 And considering you don't buy every amp on the market, that means there's more than enough to choose from. And that there's no reason for you to harp on this 20 yr old example 🤣🤣🤣 talking about "I wish they would stop packing options into amps...." as if that's the only way they come. Smdh. Come on.
@@J.C... Huh? I know that there are lots of simple amps out there. That said, a lot of the affordable options are loaded with unnecessary options . This is my observation; take your passive aggressive concern trolling somewhere else.
Sorry, dropped phone, I have a 73 twin that is 99% original and a 72 bassman 100 that has been massively modified seemingly to be a 50 watt 6g6b on the second channel and heaven only knows on the first channel, how does a guy go about getting an Amp to you for eval and repair? I'm a huge fan from Colorado and really would like some info? Curious?
I have a 550x that has the Clip LED always on from the moment the amp is turned on. I've never un-muted the amp while this clip is on to know much more. Anyone with initial thoughts what could cause the clip LED to just be full ON? Caps? Other transistor failure may not allow it to even turn on. Checked the tube and visually looked it over, nothing too noticeable. Sad to send this one to E-waste but I am not set up to do a bunch of a measurements beyond a using a multimeter.
Man, I bought the 550x in 2005 for $999 (before tax). I always had it paired with an Ampeg 410hlf. I didn't "gig" with it. Warm but dynamic and crisp. A slight "natural" compression from the tube pre. I miss it. Now using preamp pedals into class D power amps. Far more affordable this way. But I truely think something is lost to the lightweight successors. These days I'm way to paranoid to spend that kind of money on an amp head to have it fail eventually. In my opinoin, something that cost that much should last a very long time. Even if it fails within warranty its usually a PITA to deal with.
If you take a preamp-tube out of the circuit, there's going to be one or more, open-end, high-impedance signal-trail-points, which will simply increase the hum. Every other technician would have plugged a non-faulty 12ax7 before turning it back on. The lid is also part of the hum-shielding - so....really ?
@PsionicAudio Say I found on if these, and took it to a great Amp tech and was willing to spend money. Could they make it better as in reliability? Finding issues before they happen and adding better parts?
We used to make their chassis’ and grills back when I was still a teenager. The grills were a flattened steel expanded 18 ga steel that when you sheared created razor sharp points on all 4 sides. Everyone who made that job still around all have nasty “SWR” scars (mine is on my left ankle from a pallet of them on the floor)
Absolutely love the opener about wearing pants the reflection in the hot solder line was really good I've watched so many of your videos maybe not every single one but almost everyone that's the funniest thing you've ever said and it makes me believe that you may actually have a sense of humor. Nice to know that you are human After All
All joking aside you are my number one source for actual troubleshooting and repair information when it comes to amplifiers I'm thoroughly impressed with everything that you do your discipline and consistency in the way that you do things and have been the subscriber for quite a while now. Keep up the great work and make sure those pants stay on when you're shooting that video
I had this with a Henry 8x8. Such a killer amp. It over powered everything else on stage.
I just repaired one of these. Ended up being a bad solder joint on the master volume. That wonderful lead free solder. Pulled the whole power section to check the final output transistors and drivers. Just a stupid broken solder joint in the end that I couldn’t see as it was covered up by push/pull limiter pot.
That’s the thing it’s hard to get clients to understand with amps like this. Just to diagnose a simple problem can require an almost complete disassembly/reassembly.
This one could be one/multiple bad caps or it could just be one bad solder joint. Same symptoms.
If I go farther in diagnostics and the owner declines the repair, odds are I would not get paid for the two hours diagnostics would take.
So I stopped until I can speak with the owner.
Love the channel and i'm thinking of repairing, now vintage equipment again as a part time hobby (ears willing). Your channel helps motivate me to love the music again. Music is a universal language and quality sound should be preserved and taught. Top rate music equipment should be cared for and repaired to make that possible. I was a bench tech for audio and video in the 80s and 90s. Same pre-estimate game plan. Look, smell, feel and basic measurements. Things like further disassembly, service manual, and oscilloscope add time and money. Peavey CS-400 power amps stand out as successful and sometimes profitable repairs because they were tanks. I still have a Sansui 7070 stereo receiver service manual from the 1970s. My friend's brother wouldn't pay $75 for the service manual much less a rectifier or power transformer repair. Ahh the memories. Now those receivers are big dollars. Not many of us knew that and some succumbed to M 80 blasts or worse. Boredom breeds stupidity. Keep the music alive !
I have the SWR Bass 350. Really great amp, especially the tubes.
I had one of these for more than a decade. It was a great amp. Only issue I had with mine was the standby switch got sketchy. Sometimes I’d have to flip it on and off a couple times to get to work.
"...that and hot solder". 🤣 We appreciate the good sense and decorum. Not necessarily in that order. 😬
I had the pleasure of listening to Doug Wimbish at some point in the 1990s demonstrating gear. Warwick bass, but Trace Elliot amps. Wonderful sound.
I had a pre fender sm900 and that was actually a tight little work of art. Easy to fix I still have trays of the Sanken 2sc3264’s. Never parting with them since there was a bad time when most you found were fakes.
Sanken output transistors, good stuff. Might not be easily available nowadays.
I cut my chops on old Fender tube amps and knew little about solid state amps. Years ago a friend at work asked me to look at his broken Crown power amp and not knowing what I was doing cost me a nice Vintage 30 speaker.
I've been really enjoying your content, was wondering if you've had any experience/opinions with the newer Class D bass amps particularly darkglass
Thanks Matt. No Darkglass yet. But all the Class D amps seem to be using ICE modules which have a fairly high failure rate (that said, replacements are fairly inexpensive). The real concerns are that the module used will either be in production for a long time or that the manufacturer will stock replacements for X many years. We’ll see.
maybe it's just the misaligned knob
Too funny!! 😂
Just another old $400 head. Prolly worth chucking if repair is too much. Thanks for doing bass amp videos
Get the the schematic from Fender. They bought SWR around 2000 or so.I worked there from 1988 till mid 1997.
Don Butler! It’s the best of West Coast and Mid South Amp tech gathering if the tribes!
why do I miss the preamp tube on the right side? Socket is empty... minute 9:27
Because I took out to see if it was the source of the hum.
@@PsionicAudio ah, okay, I see...
Cheers Lyle!
I do have the same SWR 750X, my power board was destroyed and now I do have a very new one with new transitors. What I do not know, should I opwer on the amplifier totally unconsidered? Can I do a damage, if the bias is not adjusted? I can see the potentiometer but I do not know which values on which point to meassure... do you have an idea?
Take it to a tech.
Eh, looks like a nice amp, but I prefer bass (and guitar amps, too) that aren't so feature laden. All that extra crap just adds to problems. I wish manufacturers would stop cramming so much stuff into amps and just give us simple circuits.
Hard to beat simple.
That does make a case for pedals, doesn't it? My main amp is a Katana, so I can't say I have followed that path in the past, but if I add to my amp collection, it is certainly a consideration.
Since that thing is 20 yrs old, I imagine there's hundreds, maybe thousands of amps out there by now that are simple. Go find one. 🤷
And considering you don't buy every amp on the market, that means there's more than enough to choose from. And that there's no reason for you to harp on this 20 yr old example 🤣🤣🤣 talking about "I wish they would stop packing options into amps...." as if that's the only way they come. Smdh. Come on.
@@J.C... Huh? I know that there are lots of simple amps out there. That said, a lot of the affordable options are loaded with unnecessary options . This is my observation; take your passive aggressive concern trolling somewhere else.
An excellent reason to wear pants , that I've never considered . LOL thanks for that .
Was SWR bought out by Fender? Their site forwards you to Fender site.
A long while ago
Sorry, dropped phone, I have a 73 twin that is 99% original and a 72 bassman 100 that has been massively modified seemingly to be a 50 watt 6g6b on the second channel and heaven only knows on the first channel, how does a guy go about getting an Amp to you for eval and repair? I'm a huge fan from Colorado and really would like some info? Curious?
His email is in the description of every video. Start with contacting him that way.
Love Mc Eschers art...
I have a 550x that has the Clip LED always on from the moment the amp is turned on.
I've never un-muted the amp while this clip is on to know much more.
Anyone with initial thoughts what could cause the clip LED to just be full ON? Caps?
Other transistor failure may not allow it to even turn on. Checked the tube and visually looked it over, nothing too noticeable.
Sad to send this one to E-waste but I am not set up to do a bunch of a measurements beyond a using a multimeter.
Man, I bought the 550x in 2005 for $999 (before tax). I always had it paired with an Ampeg 410hlf. I didn't "gig" with it. Warm but dynamic and crisp. A slight "natural" compression from the tube pre. I miss it. Now using preamp pedals into class D power amps. Far more affordable this way. But I truely think something is lost to the lightweight successors. These days I'm way to paranoid to spend that kind of money on an amp head to have it fail eventually. In my opinoin, something that cost that much should last a very long time. Even if it fails within warranty its usually a PITA to deal with.
Escher...😎👍😃
Personal favorite 😎👍
😎👍❤🖖
And what did the owner say? The cliffhanger!
If you take a preamp-tube out of the circuit, there's going to be one or more, open-end, high-impedance signal-trail-points, which will simply increase the hum. Every other technician would have plugged a non-faulty 12ax7 before turning it back on. The lid is also part of the hum-shielding - so....really ?
I have a 73 silverface twin all original and
I’ll never forget what the Dali Lama told me : Always…no no
Never solder naked
It doesnt look bad. Pitty it isnt worth repairing.
It's very much worth repairing. Just not an inexpensive repair. I opened it up anyway hoping for some minor obvious thing to be wrong.
Ahh the amplifier is worth, its just the costumer's budget. Got it.
@PsionicAudio Say I found on if these, and took it to a great Amp tech and was willing to spend money. Could they make it better as in reliability? Finding issues before they happen and adding better parts?
Sounds expensive to me. Better not let Brandon work on it.