'64 JMI Vox AC30/6 | Part 4 : Rebuilding the Top Boost

[@nickparas7170]

Lyle, you are indeed a treasure. You need to write a book, or have a college kid transcribe your videos. Thanks so much for all you do. You are a wizard(?) of the magic that happens between guitar and tube amp.

[@richclayton5785]

I have Stephan’s book and have communicated with him. He’s fine fellow and the book is worth it.

[@75YBA]

For the longest time I thought Top Boost’s and Rangemaster’s were the same thing. Thanks for tearing this down and explaining it! Cheer Lyle!

[@BenState]

Show-off :) JJ, nice work man. Stephen's website has a 'corrections' page outlining specific references to the pages associated. Brad provided the link in the live stream the other day too.

[@Splattle101]

Nice call out for the book. And nice work on that TB module.

[@GScott50]

I ordered the book too, thanks for the link.

[@RaxFx]

"The Vox AC30 Guide" book makes a great Xmas present for your favourite tech... he/she/they will appreciate it that you not only knock their door when you're in trouble.

[@weschilton]

Stellar work on that top boost module! And thanks for the link to that book. I ordered a copy!

[@johnwilliamson467]

Bought the book . Thanks Lyle look like an interesting read.

[@JEmilioJNava]

nice, thanks for the info about the book ... just ordered a copy.

[@murrayguitarpickups9545]

Love you work Lyle

[@victorbeebe8372]

Aloha Lyle! Waiting for things to happen so I and my extended family can settle down. I'm interested in making small amps for around the house use. That book can come in handy. Mahalo

[@alexwoolridge94aw]

Thats a cool book. Im not an amp tech but kinda want a copy. My kinda reading material

[@mattjohnson6916]

That shielded wire looks great! I hope you can get some more in soon. I've been using RG188 from Pasternack for a while, but I'm interested in trying other types.

[@randysteffes97]

Should be rewarded 🎉

[@aquilarossa5191]

That unit looks like it would make a nice high voltage boost pedal. Top boost for any amp.

[@Satchmoeddie]

Those knobs look and sound super cheap too. I can hear them clicking together and tell it's super cheap styrene. Beautiful work on a micro sized Valco style tag board build, as per usual for amp master Lyle. I wish I could afford a Cheery Burl riveting machine to work on those old amps, so I could rivet the tag boards back in along with tube sockets and many many other things. Those tag boards were partly preassembled and then riveted in. My mother used to do that kind of work.

[@goodun2974]

Having drilled out numerous rivets in old tube gear, I hate them on principle (especially when they're also used as ground points) and would *never* consider re-riveting. As for the top boost circuit here, it strikes me that this is a case where a well laid out, high quality printed circuit board would be ideal, rather than having to build the circuit in layers on tag strips. If a designer got the layout right, then it would be almost impossible for somebody to screw it up, even as a kit.....

[@goodun2974]

Years ago I snail-mailed some of my own hand-drawn schematics and service notes for various oddball amps (Dickerson, Valco/Harmony etc) to Schematic Heaven, who scanned them and put them up online. That site is pretty much abandined, no longer updated or maintained; but I have more, similar, semi-unobtanium stuff to share which could be posted online. I don't have a computer and scanner, nor the digital skills to do so; is there a website I can snailmail to that'll post these schematics?

[@verifiedpersonae7332]

Wondering which shielded wire you were using here? I may have missed the section where you named it. Maybe someone can time stamp it for me

[@sgt.grinch3299]

Interesting

[@frankorobinson1540]

After watching your channel for a while now and in the market for a new amp but everything nice is 2500 and way up i have come to the conclusion that it might be better for me to just buy a quality amplifier kit and maybe just build my own jm 45 copy 😊would you have a suggestion for a company that possibly sells a kit with quality parts😊

[@jonnybeck6723]

Hope I'm not too off topic... Can an EZ81 tube perform rectifier duties in a 40-ish watt amp with no 5 volt tap, i.e. to convert later Fenders with diode rectification using the heater tap I'm guessing (?)

[@PsionicAudio]

No, and there is nothing wrong with a solid state rectification circuit.

[@jonnybeck6723]

@@PsionicAudio Thanx Lyle... you're a prince

[@richardlynch5632]

😎👍👍

[@roberthurless4615]

I have a small stash of the SM silver mica caps. So I was wondering which brand you prefer?

[@PsionicAudio]

Cornell Dubilier (CDE).

[@roberthurless4615]

@@PsionicAudio OK, thank you. I’ll check on Mouser.

[@PsionicAudio]

When you see the price you’ll understand half the reason I prefer Vishay 562R series ceramics.

[@nycLPplayer]

Source for the shielded wire please

[@PsionicAudio]

My vendor is out. :( When they have more and I get about 1000’ of it I’ll share.

[@cdr-sailor]

Does a similar book exist for Marshalls? I have a VS65R (Hey, it has a tube in it.); every schematic I've found online for my amp is mostly illegible.

[@mikewithers299]

I agree on a legible schematic for an old Marshall 2098. Can't find one out there. Must tube Marshall's I can find though.

[@goodun2974]

Back in the late 1980s I requested a schematic for my Marshall Lead 20 solid state combo amp, and Marshall sent me an entire book of schematics! I know I still have it around here somewhere......🤔

[@mikewithers299]

@goodun2974 if they are as good as Peavey about sharing info that would be awesome. I've not tried to ask them yet.

[@goodun2974]

​@@mikewithers299 , unfortunately, I suspect Marshall operates very differently now than they did back in the 1980's! As for Peavey, do they still provide service info and/or parts, now that they've shuttered all American manufacturing and everything is made in China?

[@mikewithers299]

@goodun2974 that's a good question. Back in the '80's and '90's they sent me all that but I need to see if they still do. I got more amps to fix.

[@goodun2974]

The fiddly nature of building that circuit onto a small metal bracket while attempting to maintain good physical isolation between signal and power supply makes me think that perhaps this add-on top boost should be done via a small high quality printed circuit board. If somebody was to design one and get the layout correct, then it would be highly repeatable and not prone to layout mistakes.

[@colbyjack7074]

At about :55 seconds in Lyle said "Into the bin they go". Hmmmm... very Aussie(?) I'm wondering if he's giving a nod to our Aussie friend at Brad's Gear Garage. 😄

[@murrayguitarpickups9545]

I picked up on that, Americans are "supposed" to say trash or garbage. I recently heard an American say "Toilet" and it really threw me off.

[@PsionicAudio]

Hadn’t thought of it but do I listen to a lot of history documentaries, a high percentage of which are either British or read by a Brit. Maybe it leaked out. If I start saying “aluminium” then I’ll need an intervention.

[@goodun2974]

​@@PsionicAudio, a pronunciation of "soul-durr" would definitely require an intervention! Which reminds me that a couple years ago, the auto-correct/predictive text program in my phone switched to British spellings after an automatic update, so that favor, flavor, color, behavior and aluminum automatically switched to "favour, flavour, colour, behavour, and aluminium". This annoyed me for months, and conversing with people online made them assume that I was British, and nobody at customer service even knew that there was, or how to access, the language selection program in the phone, until I chanced to meet somebody else with the same exact Samsung phone and he figured it out.

[@daveogarf]

"GROVE-venor"

[@johnbriggs3916]

GROVES-ner

[@PsionicAudio]

I don’t even know er…

[@Exploboy]

Top position (neutral) on potentiometer in passive EQ? Doesnt make any sense. Technically it's not 'flat'....

[@johnbriggs3916]

Grosvenor is pronounced Groves-ner.

[@PsionicAudio]

The only guy I knew with that last name pronounced it like I said, so apologies to Stephen if he says it differently.

[@johnbriggs3916]

@@PsionicAudio It's originally Norman-French, so it ought to be pronounced GRO-v'ner. The 's' shouldn't be pronounced, but in practice usually is, but by metathesis after the 'v' rather than before.

[@johnbriggs3916]

The names apparently means "fat huntsman" (yes, there's a legend behind that!)

[@goodun2974]

​@@johnbriggs3916, yes, in my experience the S should be silent....