Podcast alert: Tube amp repair

I've been listening to this since it started. It's pretty great but I do roll my eyes at Skip fairly often when he disparages pcbs or transistors. He reminds me too much of my father at times. Definitely recommend it though
 
I'll have to give it a listen, thanks for the link.
Psionic is a great tech, he knows his stuff.
 
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Psionic is one of the better amp techs posting on Youtube. He really does know his stuff, unlike quite a few others. (The Guitologist for one...) I like Uncle Doug as well - ponderous but good natured and yes, he knows his stuff too.

Amp techs can be a funny lot. SO opinionated! But I guess you get that way if all you do every day is poke around in mostly cheaply built PCB amplifiers mis-handled by guitar players. I think that a lot of the animus pointed at PCBs is not because PCBs are inherently inferior but that a lot of PCB amps are poorly designed. I like building amps on tagboard or turret board, but then I'm not building to a schedule or a price-point. As a tinkerer I like tagboard and turrets because I can swap parts around easily. And they look so cool!
 
Tube amps are a harsh environment. Lotsa heat, lotsa vibration. PC boards have a hard time standing up to the abuse. They need to be thick, they need to be epoxy-glass, they need plated-thru holes and they need to be securely mounted. And none of that surface-mount crap! Turret boards make a lot of sense mechanically because the long component leads relieve the stresses caused by temperature change and vibration. If a turrent loosens, it doesn't break a connection like a cracked trace would do.

"It is hard enough to remember my opinions without also remembering my reasons for them."
- Friedrich Nietzsche
 
TheSin said:
I’m about to dip into some amp building finally so I’ll check it out. I’ve been all over Lyle’s vids (Psionic Audio) on YouTube! Dude is awesome!
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Be careful, it’s just as addicting as building pedals and WAY more expensive! I picked up amp building last year when the lockdowns started and I’m now.. 8 builds in?
 
coltonius said:
Be careful, it’s just as addicting as building pedals and WAY more expensive! I picked up amp building last year when the lockdowns started and I’m now.. 8 builds in?
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What have you built so far and which are your favorites?
 
TheSin said:
What have you built so far and which are your favorites?
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Completed:
• 5F11 Vibrolux head
• 5E3 Deluxe head
(These two take turns sitting atop a 1x12 cab with an Eminence GA-SC59)
• 5F2-A Princeton w/ 10” speaker
• Mojotone 1w “Studio” (5E3 clean channel, JCM800 dirt channel)
• 5C3 octal Deluxe x2 (one for a friend)
• 1w Champ in a 1590DD enclosure
• BF Deluxe Reverb

In progress:
• 5F6-A Bassman
• BF Princeton Reverb

They all have varying degrees of mods to suit my taste, but I’d have to say the DR is pretty tough to beat right now! That could be because it’s my latest build though. The octal Deluxe is a fun one too, because it’s cleaner and not as ratty as the 5E3.
 
The 5F11 is a beauty, isn't it? I really like the 5E7/5F4 circuit too. If you build them with the right transformers they sound amazing with EL34s and a GZ34.

The best thing about building amps is that you can make them better than stock. Or at least suit yourself better than a stock amp would. And it is extremely addictive - and can get expensive!
 
coltonius said:
Completed:
• 5F11 Vibrolux head
• 5E3 Deluxe head
(These two take turns sitting atop a 1x12 cab with an Eminence GA-SC59)
• 5F2-A Princeton w/ 10” speaker
• Mojotone 1w “Studio” (5E3 clean channel, JCM800 dirt channel)
• 5C3 octal Deluxe x2 (one for a friend)
• 1w Champ in a 1590DD enclosure
• BF Deluxe Reverb

In progress:
• 5F6-A Bassman
• BF Princeton Reverb

They all have varying degrees of mods to suit my taste, but I’d have to say the DR is pretty tough to beat right now! That could be because it’s my latest build though. The octal Deluxe is a fun one too, because it’s cleaner and not as ratty as the 5E3.
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Nice list!
 
HamishR said:
The 5F11 is a beauty, isn't it? I really like the 5E7/5F4 circuit too. If you build them with the right transformers they sound amazing with EL34s and a GZ34.

The best thing about building amps is that you can make them better than stock. Or at least suit yourself better than a stock amp would. And it is extremely addictive - and can get expensive!
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Oh yes! The Vibrolux is an amazing amp, and the trem is just hypnotic.

I have Rob Robinette to thank for the crash course in amp modding. Once I got the hang of it, I realized it’s not too different from modding pedals; the same principles generally apply.. My 5E3 has the “Lead” channel and a 3-way NFB toggle, both of which make it infinitely more usable!

I’m currently building the Bassman with a fixed/cathode bias toggle and EL34 compatibility. It’ll probably go into a head so I can play with cab configurations.
 
Rob Robinette's pages are a fantastic resource. I've learnt a lot from him.

My all-time favourite mod for a 5F11 is a very simple one - disconnect the NFB. It really doesn't need to be there. Disconnect it and the amp opens up, is louder, fuller, everything good and nothing bad.

I'm not one for lists as a rule, but if I can remember them all I have built (often more than one each) the following:

5F4/5E7 as a 12+10 and as a single 12. My man gigging amp with a pair of KT77s
5F6-A Bassman
5E8-A Twin
5F8-A big box Twin - almost a 2x12 Superlead. Glorious sound and VERY LOUD
5F11 Vibrolux
5E3 Deluxe
5F2-A Princeton as a 1x10
1974 Marshall 18W trem 1x12 combo
18W Marshall TMB head
JTM45 head
1987 and 2204 50W Marshall heads and soon a 1987 in a 1x12 combo
A Supro with 6973 power tubes - can't remember the model - maybe Model 24? Not loud but a fabulous overdrive if you link the channels.
Ceriatone Trainwreck
Deluxe Reverb
And I have rebuilt a Deluxe Reverb RI, a Princeton Reverb RI with 6L6s and even a Super Reverb RI and always used the bias vary trem because it sounds incredible.

I'm sure I've forgotten something! As you can see it's very addictive.
 
That’s awesome. I’m queuing up parts for a 6G4-A brown Super build (which I’ll throw into a Deluxe Reverb chassis). After that, I think I’ll try something Voxy- leaning toward the Trinity TC15 with an EF86 “Matchless” channel.
 
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