Lyle would have cleaned the board 😉😉😉

Thanks for the video.

Can you help me with my hacker, the bass has seemed to have dropped do you know what it could be ?

can't wait to see what it sounds like!

Another goodie! Thanks Martin!

That tremolo was a separate unit that had to be retro-fitted. Colby amps made a boutique version of this a few years ago, very interesting, dying to see how you bring this back to life Martyn!.

This is the amp Paul McCartney has used since 1959, he took it to Hamburg with him and he still has it in use in the studio today!. They don't make 'em like this no more!. It's not a guitar amp btw, it's for amplifying a record player.

Great amp its distributed loaded ..for a guitar amp rare and almost hi fi..loads of work there..gotta get a signal..argh. Extension cab for it when its up n running Not quite £650 yet😊

In 1961 when I was 12, I remember seeing a group of four young women who were doing what I can only describe as ' barbershop' close harmony singing . They had a pair of Reslo mics attached to a single stand and they in turn, were plugged into a Elpico which actually sounded quite impressive .. It looked brand new and I'm sure it would have been an AC55 model. Looking forward to seeing this one returned to it's former glory.

I don't know anything about those amps or the add-on tremolo units, but it would be nice to see it restored and listen to how it sounds. I can't imagine the tone would be that great thru that elliptical speaker. There is a YT video about the History of the Beatles Amplifiers, and I believe Paul McCartney's first amp was an Elpico, before he switched to playing bass guitar.

Beware of resistors that appear to have kind of an end cap on them where the component leads attach, because those are more likely to become intermittent than resistors where the lead passes right through the insulated body and into the resistor.

At 20:00, those with sharp eyes may notice that the pots are mounted to the preamp PCB, not to the front face plate, and there are aluminum shafts that extend the pot shafts out through the chassis so that the knobs can be used to turn the controls. This technique was fairly commonly used in hifi equipment of the 1960s through the 80s, and it's a good way to keep the signal path short and eliminate a lot of extraneous wiring that has to be done by hand, but for some reason it is rarely done in guitar amplifiers, which could certainly benefit from shorter, more concise signal paths because it allows fewer opportunities for RF energy and radiated hum fields to modulate the signal. The disadvantage, however, is that an amplifier that gets gigged and transported a lot runs the risk of a hard hit to one of the knobs actually cracking the circuit board. [Edit; closer examination reveals that these aren't separate "extension" shafts but instead the potentiometers have integral, built-in, extra long shafts, which of course exponentially increases their cost and the difficulty of replacing them].

Martyn, a note of caution about amplifiers with dual chassis that are connected by a signal-carrying RCA cable: I've seen amplifiers where the shield of the RCA cable is also the return ground for the B+ that feeds the tubes in the top-mounted preamp (Danelectro/Sears Silvertone amps in particular). Unplugging the RCA jack while the amp is turned on can cause your body to become the ground return between the two chassis. I got zapped hard by a Danelectro amp once and have remembered that lesson ever since. (I added a ground wire between the two chassis to make the amp electrically safe, and lifted the shield of the RCA cable at one end to prevent a ground loop).

Whoaa! Martyn, you’ve just inadvertently taken me right down memory lane. Stand by for a right old saga. August 1962, I was 10 years old and like every other kid at the time I was chipping away at my Dad to get me an electric guitar. Well, he came home from work one day and someone who worked with him had sold him an acoustic for 5 Quid. As you can imagine, it wasn’t up to much: odd tuners odd strings and rough old frets. It came with some sort of musical tutor stuffed into the sound hole, and my father tossed it to me with the promise of an electric guitar for Christmas, if I could play a tune by that time. Well, by September I’d mastered “Old Black Joe”, and was furiously working on “Railroad Blues”. My father now realized how rash his statement had been and was going to cost him dearly. So the ‘‘deal’’ had to be modified, he would forward 50 per cent, the other 50 per cent was my problem. So, I stepped up the paper rounds from just mornings to evenings as well plus the Saturday Football news (Pink ‘un and Green ‘un) By Christmas I’d Nailed 4 tunes, there was no escape route for my dad, a deal was a Deal! So off down to Hardy Smiths in Mansfield to get my dream guitar, A Watkins Rapier 33 in bright red (The colour of rebellion) It was Hardy Smith senior (Not Rob.) and a quick discussion revealed a suitable guitar teacher in Mansfield called Frank Wooley who live just off Baums lane. Now Frank played Bass in a local Ballroom dance band and he had the exact same ELPICO amp , in green as you rightly said. Now he used this amp into a homemade, ¾ inch ply, front ported cab with an 18 inch Fane speaker. I don’t think his had a trem unit fitted. I got to play through the elliptical speaker only, but it got me started on my journey. 72 now, and still slappin’ the plank. You were spot on with the time frame as well as the original colour. I hope you get to restore it to it’s former glory. Steve (Bangkok)

ive got a couple of selmer PAs , ''the reverberation 100'' ( that one uses the same valve that you find in a copicat ,ive forgetten the name ) and the ''tv pa100'' . i think theyre great for guitar but tend to be on the bassy side.i actually find it hard to keep it clean enough for rocknroll sometimes. im interested to see how you go.

Great guitar amp now Martyn,excellent job,intuitively done.

Looks like a '74. Yes?

Another great 'silverface' go-through, thank you! At around 26:00, what is the brand of meter, please?

The Vibrolux Reverb is a wonderful amp. I picked one up in Jan 2024. The cabinet had been chopped in half, reverb tank missing, several knobs missing, front baffle and Fender logo missing, several preamp tube shields missing, etc. I recapped the amp, re-built the bias supply, fixed the cabinet, replaced the missing bits, etc. I had some leftover Fender grill cloth from a previous project to cover a new front baffle. All I have left to do is add a bias adjustment pot to the bias balance pot. It really doesn't make much sense to keep a 1970's Fender amp "as original as possible", as they don't have any inherent collector's value, and should be fully serviced and played. But I understand some customers don't understand this, or don't want to spend the extra money for a tech to complete the job.

The bias filter cap might be the most important cap in the amp, and those white Mallory caps are a known failure point.

Caps on the 6L6 sockets were factory installed to prevent parasitic oscillation which was sometimes caused by poor lead dress when these amps were built. The amps usually sound better with these removed, and if it oscillates then you need to fix the lead dress.

Back in the 1990's a local guitarist asked if I could look at his 1974 Fender Twin Reverb. Doghouse caps were gone so replaced them, but like you, couldn't find a problem anywhere else apart from the amp had very low output. No internet back then and other amp techs would never give anything away without cash changing hands, so I admitted defeat . A few weeks later it dawned on me what was causing the problem, but I never took on the job as it was way above my paygrade at the time. The owner found a tech 300 miles away to do the work and it cost him more than the amp was worth back then to get it done.

Willow Valve sold rebranded tubes from 70s to the 90s. They were based in Reading. They were bought out around 2000 by Connect Distribution in Birmingham and moved there. I don't know what happened to them after that.

Wow, that is the cleanest silver panel Fender I have ever seen. The green heater wires are still bright green, and the white wires aren’t green with corrosion GUMPTION! I’ve had luck reducing DC leakage on the volume and tone pots by removing the just wax on the board between the bypass cap eyelets. Heat gun, shop towels and alcohol work pretty well. Not too much effort. Or just leave the volume control alone while you play. Sound great!

Hi these amps sound amazing. What other amp do you think they sound most comparable too?

You're right about those old boards. Most people just keep replacing caps, resistors, and tubes and never resolve the underlying problem. I'll be rebuilding one once the snow starts falling as the alcohol washes haven't made much difference.

Love watching these...great player too!

Oh boy. Can it do Skynyrd?

Good sound indeed.

Can you go from dirty to clean by just rolling off the guitar's volume control a little bit? Because an amp that will work like that and not need it's controls touched during a gig would be about as good as it could get for most players.

Cute amplifier!! I found your channel today, good job dude!!

Nice job, Martyn, sounds damn good!

Great job! Awesome playing, especially the blues licks. Thanks for bringing us along.

It's sounding so good mate. What a difference you've made to it, that's exactly the kind of drive tone I was hoping for and you've nailed it!. Really exceptional work, thank you. Talk soon.

That's turned into an amp for all seasons and styles. Great work Martyn..

Thank you for putting out some great content. It's so hot over here in the U.S. I've had to put my projects on hold plus I've had covid so that's that. Take care my friend.

Nice video with some good playing by you. Good !

What happened to the rest of the series of this amp, I was looking forward to watching what you come up with and how it sounds?

Glad I found this, think I’ve got the intermittent problem in the 2nd channel so will check out the footswitch

I posted some examination and reviews of soldering equipment and accessories on my channel recently; probably very little info that you don't already know, but perhaps some of your viewers who are learning about DIY electronics repair or kit building may find the videos helpful.

Great sounding amp - I firmly believe that musicians / guitarists are being totally rippod off by boutique amp builders charging astronomical prices for a neat well built amp that doesnt sound half as good as this home project

Great work as usual! Nice one!

that drive channel sounds like a plexi. clean channel like a deluxe reverb. Damn Laney is slept on amps.

you are a damned fine guitar player

Sounds great !!! Any tips on having an option to reduce output volume ? Such as pentode/triode switch or unplugging a speaker or ?

I've had one of those for 10-12 years now... I was just thinking of changing the output tubes and google linked to your vid. Great playing! I enjoyed your video.

I have one of these amps and when it gets warm I start getting audio cutout and static for some time even after it is turned off - it was suggested it could be a bad EL-84 - (or was that EL-34 - I'll doubecheck) - is it a ton of pain to replace these? I don't know much about biasing - I do know nwough to like leave it unplugged for a month before working on it - LOL

Sounds great and really nice playing!

Hi Martyn, another dog’s breakfast cleaned up nicely. Chris, guitaramptech from Sydney just recently posted a video on an early ‘70s version of one of these amps. It’s worth a watch to hear his opinions on the grounding scheme that Marshall used.

So you've got your probe on the output jack in order to chopstick around and find issiues? I've recently got a scope to try and find oscilations etc. But haven't gotten. I to using it yet.