I misspoke about the reverb driver tube in the old standalone reverb units. I said 6L6. Meant 6K6, with later ones using 6V6 or EL84. Just a slip while I was thinking about ten things at once. L, K, V. Easy to do but important differences. Sorry about that.
And oh man did the comment section nail that home lol! I got here a little later and saw this comment first. Then I proceeded to read through the comments and noticed how almost every other commenter felt the need to correct you! Lol! You have a lot of patience!
I just ran into the same problem on an old Twin Reverb. Had new TungSols in V1 and V2, and started getting bleed. I could hear the guitar in the speaker with the amp volume all the way down. Swapped in some new JJs and the problem went away. When I first heard the bleed, I remembered seeing this video several months ago. So I watched it again and turns out to be the same problem. Thanks for saving me countless hours chasing noise.
Very interesting and really like the way you troubleshoot. I'd love to know more about repairing tube amps so your video was super enjoyable to watch. I know some basics, like checking/measuring with a meter continuity, ohms, Caps, etc, but really don't know how these circuits work. Love to learn for sure, especially since I have two tube amps... Actually, I have 3 tube amps. I have a really old Premier Amp my dad got me around 1967 (It was used, so the amp is older then 1967 as it was pretty beat up when I got it). It is the type amp where the Head and Speaker Cab are wedged shaped and fold together for into a box shape for transporting it. I'd love to troubleshoot it as it doesn't work anymore, but I really would need to learn a lot more to fix it. Again, love the way you troubleshoot and you explain what you're doing with a lot of detail. Thanks...gave a Sub. Phil NYC Area
Glad to see you back at it all refreshed. Hope you can take some regularly scheduled breaks from time to time, good for your soul. I just became aware of your reference to black panel amps in an article I read. I have adopted the same
Both of those tubes flash blue after you swapped them. Watch it closely. The right tube starts flashing after the swap with the left tube. The right tube also flashed after you reflowed the connections? one last time and didn't flash the 2nd and 3rd time you turned it on after reflowing.
Hi Lyle, love your channel, been a subscriber for quite some time now. Your coverage on these old black panel fenders has been awesome! I always look forward to these fine videos. I have a 67 Fender Super Reverb black panel in absolute mint original condition. One owner amp, before me that is. My question is, it was I played for the past 15 years and stored in a closet. Is this good for the electronics? I heard you say in your latest live video that you should play your amp at least 4 hours a month to keep the electronics “juicy”. Should I be worried. It’s got lots of use since I’ve owned it this past 4 months. Thanks. Jason
And yet remains the question why some brand preamp tubes "bleed" by parasitic oscilation in this tube and some don't. While in another amp it's the other brand that bleeds... How to prevent this? Just curious...
The channel bleed that was occurring inside the preamp tubes was causing not only intermodulation distortion but also lowering the gain because the signal outputting from any given gain stage is inherently out of phase with the gain stage before or after it. In essence, way too much local negative feedback!
The stand alone reverbs pre CBS 6G15s from the 1961 to 67 used a 6K6GT not a 6V6GT. 6K6, 6W6 and 6V6 powerbeam pentodes are all similar but the 6K6GT is not rated for as much plate wattage (heat dissipation and flashover) as the 6V6G /GT. 6W6s are also a lower wattage octal same pin out, yada yada different plate resistance etc. Rebais a 6V6 amp and you can occasionally swap those tubes around with each other. 6W6GTs are only designed for 300 Volts plate and 315 Volts plate for the 6K6GT. They will usually handle 20-33% more. I have stand alone reverbs powered or driven by 6973s and by 6DR7s too. The 6DR7 units are NOT Dick Dale type reverb. Those tanks are tiny shoe box tanks. Cheesy reverb! Gibbs made those tanks, obviously to a VERY low price point.
I find it maddening that JJ & New Sensor cannot make basic full wave rectifiers that are consistent and of at least semi-decent quality. Their 5AR4s are a joke. Shuguang was doing okay with them, until they weren't doing anything at all. I heard rumors of late 2021. Finger's crossed!
When Adding two 1N4007 In-series on the HV High Voltage to the Rectifier, isn't the diodes rectifying the HV High Voltage BEFORE it gets applied to the Rectifier? So it Semi Solid State Rectification & Tube Rectification. For the Bleed Preamp Issue was caused by the preamp tube brands because of the Grid to Cathode Leakage issues I think you were mentioning something about certain preamp tube brands cause grid leakage which causes bleeding of the amplifier channels.
The bridging happens through the tube. You still get the voltage drop and "sag" from the tube. The diodes just help out and keep some of the strain off the tube. It's an inaudible change that prolongs rectifier tube life.
Seems that you prefer the Super over the Pro Reverb. Pricing is all over the place currently. What would you consider a fair price for a cosmetically flawed SR. Never gonna leave the house.
Hey! Thanks for the video! Do you have a video on how to fix the volume and treble pots noise when turning the knos up? I get a very high hiss noise when turning the treble or volume knob.
90 percent of the components have been replaced in that amp. I understand this with an amp that's still being gigged regularly but I also lament the loss of so much originality. Meanwhile...I recently acquired a '79 Pro Reverb that is absolutely factory original to the tiniest detail. Even all the tubes are date code matched, Fender orange label, factory installed tubes of the correct date range. Yes it needs caps in the doghouse. Otherwise it's in perfect running shape and all the tubes still read strong like new.
@@PsionicAudio , an alternative to 6V6 or 6K6 would be 6AQ5/6005, basically a mini 7-pin 6V6 (takes up less space, needs less heater current). I've got about (60) 6005W, the ruggedized milspec version....but if somebody insists on using a preamp tube as a reverb driver, a 6CG7 or 12BH7 would have been a better choice than a 12AT7, although the pinouts are different. Big plates, tall bottles, higher dissipation.
I somtimes go in your video archives when working on a similar amp, for reference. You've left a bunch of gems out here on TH-cam, and I really appreciate the knowledge you've released into the world! I noticed on this particular '67 that the previous tech added 100 ohm artificial center tap resistors, even though the heater center tap is soldered to chassis. Obviously want to do one or the other. I only spotted it here as the amp I'm working on has the exact same scenario. Would you typically go with the resistors or keep it as is with the center tap to chassis? Cheers, Lyle
Not necessary with a GZ34. But switching the 5V rectifier filament supply would involve the most current and a slow change to playing mode. The best standby option is to switch the HT secondaries, as found on some Marshalls. But no standby is needed in a Super Reverb with tube rectification.
@@PsionicAudio That is why I said preference. I use 6cl3 damper diodes (tube ) with 11second warm up with high current on the heaters but low unit cost . Does a very nice soft slope up and 250 ma all night long . While not used in in your application it just more of a design thought than a real world application for your use. A design vs repair exercise . Enjoy the videos.
I'm a tube noob but I read once that some tubes have unused pins wired as internal conections. Sometimes people use those as a terminal strip for amp wiring. I'm sure its not the case but it could happen right? Thanks for the video.
It depends on who you buy your tubes from a lot of vendors will try to pass off there’s nothing bad to thank you and you’re some idiot that won’t know any better I have it happens a lot when I was buying tubes from China and after I sent them back a few times I would end up with some really good power tubes from my old plexi Marshall
@@PsionicAudio I had never seen one with EL84 ... just the silver panel ones with one extra 12AX7 that don't sound as good, but now I wanna try that and listen ... as always this channel is informative and inspirational.
Well, the OT is very nice, as is the chassis and cab. And the 10" CTS alnicos are fantastic. I'm not the one who removed all the blue Ajax caps. And I could restore this but it's outside the client's budget. But it sounds very very good as-is. And there is no "new amp" available that sounds like this at any price like he paid for this old SR about 10 years ago. So.
There's a guy on Facebook with the same name, with a pic of a bench containing a guitar, amp, and soldering iron. Probably just a disgruntled wannabe tech.
@@stevencraig there's a creeper on here with the same name as Steven Craig that tries to be witty but just fails miserably nothing more than an nut gobbler
I misspoke about the reverb driver tube in the old standalone reverb units. I said 6L6. Meant 6K6, with later ones using 6V6 or EL84.
Just a slip while I was thinking about ten things at once. L, K, V. Easy to do but important differences. Sorry about that.
And oh man did the comment section nail that home lol! I got here a little later and saw this comment first. Then I proceeded to read through the comments and noticed how almost every other commenter felt the need to correct you! Lol! You have a lot of patience!
I just ran into the same problem on an old Twin Reverb. Had new TungSols in V1 and V2, and started getting bleed. I could hear the guitar in the speaker with the amp volume all the way down. Swapped in some new JJs and the problem went away. When I first heard the bleed, I remembered seeing this video several months ago. So I watched it again and turns out to be the same problem. Thanks for saving me countless hours chasing noise.
Taking notes from your detailed process has helped me get the funk out my amp. Appreciate all of it.
As Skip Simmons says... before putting a car on the alignment rack, first check the tire pressure in all four tires. Excellent troubleshooting!
There's something about old FENDERS. Paradise is not a destination. It is your state of mind when playing a old FENDER.
Great to see you back in action.
It was definitely not one of my original suspicions. Thanks for taking us along for the ride.
Very interesting and really like the way you troubleshoot.
I'd love to know more about repairing tube amps so your video was super enjoyable to watch. I know some basics, like checking/measuring with a meter continuity, ohms, Caps, etc, but really don't know how these circuits work. Love to learn for sure, especially since I have two tube amps...
Actually, I have 3 tube amps. I have a really old Premier Amp my dad got me around 1967 (It was used, so the amp is older then 1967 as it was pretty beat up when I got it). It is the type amp where the Head and Speaker Cab are wedged shaped and fold together for into a box shape for transporting it.
I'd love to troubleshoot it as it doesn't work anymore, but I really would need to learn a lot more to fix it. Again, love the way you troubleshoot and you explain what you're doing with a lot of detail. Thanks...gave a Sub.
Phil
NYC Area
Glad to see you back at it all refreshed. Hope you can take some regularly scheduled breaks from time to time, good for your soul.
I just became aware of your reference to black panel amps in an article I read. I have adopted the same
I am your newest subscriber. Wow, really well done! I really like your style. Thanks.
That was some epic tube jockey'in!
super reverb black face is my favorite amp ever.
Really like the green lamp mod…
Both of those tubes flash blue after you swapped them. Watch it closely. The right tube starts flashing after the swap with the left tube. The right tube also flashed after you reflowed the connections? one last time and didn't flash the 2nd and 3rd time you turned it on after reflowing.
Hmmm, my Silverface Super is suspiciously quite, I'm going to try this. Thanks!
Hi Lyle, love your channel, been a subscriber for quite some time now. Your coverage on these old black panel fenders has been awesome! I always look forward to these fine videos.
I have a 67 Fender Super Reverb black panel in absolute mint original condition. One owner amp, before me that is. My question is, it was I played for the past 15 years and stored in a closet. Is this good for the electronics? I heard you say in your latest live video that you should play your amp at least 4 hours a month to keep the electronics “juicy”. Should I be worried. It’s got lots of use since I’ve owned it this past 4 months.
Thanks.
Jason
The mighty mighty blackface super
And yet remains the question why some brand preamp tubes "bleed" by parasitic oscilation in this tube and some don't. While in another amp it's the other brand that bleeds...
How to prevent this? Just curious...
I caught it at 1:11, the vibrato channels volume pot has a cracked wafer inside the pot. needs to be replaced.
The channel bleed that was occurring inside the preamp tubes was causing not only intermodulation distortion but also lowering the gain because the signal outputting from any given gain stage is inherently out of phase with the gain stage before or after it. In essence, way too much local negative feedback!
Yup
The stand alone reverbs pre CBS 6G15s from the 1961 to 67 used a 6K6GT not a 6V6GT. 6K6, 6W6 and 6V6 powerbeam pentodes are all similar but the 6K6GT is not rated for as much plate wattage (heat dissipation and flashover) as the 6V6G /GT. 6W6s are also a lower wattage octal same pin out, yada yada different plate resistance etc. Rebais a 6V6 amp and you can occasionally swap those tubes around with each other. 6W6GTs are only designed for 300 Volts plate and 315 Volts plate for the 6K6GT. They will usually handle 20-33% more. I have stand alone reverbs powered or driven by 6973s and by 6DR7s too. The 6DR7 units are NOT Dick Dale type reverb. Those tanks are tiny shoe box tanks. Cheesy reverb! Gibbs made those tanks, obviously to a VERY low price point.
I find it maddening that JJ & New Sensor cannot make basic full wave rectifiers that are consistent and of at least semi-decent quality. Their 5AR4s are a joke. Shuguang was doing okay with them, until they weren't doing anything at all. I heard rumors of late 2021. Finger's crossed!
When Adding two 1N4007 In-series on the HV High Voltage to the Rectifier, isn't the diodes rectifying the HV High Voltage BEFORE it gets applied to the Rectifier? So it Semi Solid State Rectification & Tube Rectification. For the Bleed Preamp Issue was caused by the preamp tube brands because of the Grid to Cathode Leakage issues I think you were mentioning something about certain preamp tube brands cause grid leakage which causes bleeding of the amplifier channels.
The bridging happens through the tube. You still get the voltage drop and "sag" from the tube. The diodes just help out and keep some of the strain off the tube. It's an inaudible change that prolongs rectifier tube life.
Seems that you prefer the Super over the Pro Reverb. Pricing is all over the place currently. What would you consider a fair price for a cosmetically flawed SR. Never gonna leave the house.
Hey! Thanks for the video!
Do you have a video on how to fix the volume and treble pots noise when turning the knos up?
I get a very high hiss noise when turning the treble or volume knob.
90 percent of the components have been replaced in that amp. I understand this with an amp that's still being gigged regularly but I also lament the loss of so much originality. Meanwhile...I recently acquired a '79 Pro Reverb that is absolutely factory original to the tiniest detail. Even all the tubes are date code matched, Fender orange label, factory installed tubes of the correct date range. Yes it needs caps in the doghouse. Otherwise it's in perfect running shape and all the tubes still read strong like new.
I never turned my 65 RI past 3
I thought the original Fender Reverb Unit used a 6K6 reverb-driver tube?!
Yeah. Later ones used 6V6s and EL84s. Point being they used to use actual output tubes to drive the transformer.
@@PsionicAudio , an alternative to 6V6 or 6K6 would be 6AQ5/6005, basically a mini 7-pin 6V6 (takes up less space, needs less heater current). I've got about (60) 6005W, the ruggedized milspec version....but if somebody insists on using a preamp tube as a reverb driver, a 6CG7 or 12BH7 would have been a better choice than a 12AT7, although the pinouts are different. Big plates, tall bottles, higher dissipation.
I somtimes go in your video archives when working on a similar amp, for reference. You've left a bunch of gems out here on TH-cam, and I really appreciate the knowledge you've released into the world! I noticed on this particular '67 that the previous tech added 100 ohm artificial center tap resistors, even though the heater center tap is soldered to chassis. Obviously want to do one or the other. I only spotted it here as the amp I'm working on has the exact same scenario. Would you typically go with the resistors or keep it as is with the center tap to chassis? Cheers, Lyle
Thanks Steve. Artificial is better as the resistors will act as fuses and save the PT in case of a heater fault.
PS the Super Reverb PT doesn’t have a physical CT wire on the heater secondary. Only HT CT and sometimes a shield wire to chassis.
How much are these worth when about the only original parts left are the transformers and the cabinet? Just curious.
I bought a 68 SUoer reverb because my ac30 is having that issue I have lost half my volume …
The standby switch I fell would be better if it switched the rectifier heater on and of ramping the voltage up and down softer. Just my thoughts.
Not necessary with a GZ34.
But switching the 5V rectifier filament supply would involve the most current and a slow change to playing mode.
The best standby option is to switch the HT secondaries, as found on some Marshalls.
But no standby is needed in a Super Reverb with tube rectification.
@@PsionicAudio That is why I said preference. I use 6cl3 damper diodes (tube ) with 11second warm up with high current on the heaters but low unit cost . Does a very nice soft slope up and 250 ma all night long . While not used in in your application it just more of a design thought than a real world application for your use. A design vs repair exercise . Enjoy the videos.
on my super i remove V1 and it sounds better that way. I never use the normal channel anyway
Lol a Super Reverb on “4” should be damned loud.
looks like nearly every component in the amp has been replaced
Yeah, sadly. Not by me.
Every part in that amp has been replaced? Did some one just make that Amp from parts?
That all happened before my tenure. Except for the PI outs in AB165 Bassmen I almost never find bad blue Ajax caps.
Ah Shits n' giggles & Pink Floyd lick....
I'm a tube noob but I read once that some tubes have unused pins wired as internal conections. Sometimes people use those as a terminal strip for amp wiring. I'm sure its not the case but it could happen right? Thanks for the video.
That's always something to consider. Not an issue in this case though.
Those “ceramic” tube sockets are not to be trusted. Compare the thickness of their petal parts to a belton and you’ll see what I mean
I didn’t put them in. I prefer Belton and another phenolic type I like for octals in Fenders. But these ceramics are still OK.
It depends on who you buy your tubes from a lot of vendors will try to pass off there’s nothing bad to thank you and you’re some idiot that won’t know any better I have it happens a lot when I was buying tubes from China and after I sent them back a few times I would end up with some really good power tubes from my old plexi Marshall
Sad to see how gutted this amp is from the previous tech. Be careful who you take your vintage amp to folks.
Fender '63 Reverb uses 6K6GT/6V6GT for reverb driver ... just for the record.
Yes, and later ones used 6V6 and EL84s.
@@PsionicAudio I had never seen one with EL84 ... just the silver panel ones with one extra 12AX7 that don't sound as good, but now I wanna try that and listen ... as always this channel is informative and inspirational.
So what is left of the original amp? the choke and output tranny? Just get a new amp dude.
Well, the OT is very nice, as is the chassis and cab. And the 10" CTS alnicos are fantastic.
I'm not the one who removed all the blue Ajax caps. And I could restore this but it's outside the client's budget. But it sounds very very good as-is.
And there is no "new amp" available that sounds like this at any price like he paid for this old SR about 10 years ago. So.
Jo Park-You are clueless dude. Obviously you don’t know squat about building/repairing tube amps.
Creating the world's most sterile amps one amp at a time
How many of my amps have you played, Vance?
There's a guy on Facebook with the same name, with a pic of a bench containing a guitar, amp, and soldering iron. Probably just a disgruntled wannabe tech.
👏🤡
@@PsionicAudio wasn't referring to one of your designs or builds. Be glad to check one out I'm sure they are top quality
@@stevencraig there's a creeper on here with the same name as Steven Craig that tries to be witty but just fails miserably nothing more than an nut gobbler