Elpico AC55 Part Two Full Restoration Making it Sound Great For Guitar
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- Опубликовано: 12 сен 2024
- A full restoration on a Elpico AC55 amplifier. In part one we saw just how dilapidated this amplifier was. So, in this video we are going restore it. We are also going to make some mods to this amp. This isn't really a guitar amplifier but it's quite easy to turn it in to one. We also spend some time making this amp safe to use. The chassis grounds on this amp, or lack them leave make this amp a little dangerous.
Hi Martyn, great work as usual, another amp saved! I rebuilt one of these last year. The tremolo resistors and caps were originally housed in small shielded metal box riveted to the bottom of the enclosure. Mine had failed so had to pull it apart and build something on strip board. I have photos if you're interested in seeing the guts of the original tremolo unit, it was a new old stock item but hadn't survived the passage of time... even siting dormant on a shelf somewhere in it's original box. It was an after-market / upgrade item. Anyway, smashing work again - really enjoy your vids!
Hello Justin, thank you. Yes, I would love to see the photos. Drop me an email. Thank you take care.
First class workmanship Martyn.. Well worth the effort, time and outlay on replacing most of the worn-out parts. Sounds really great even through the elliptical speaker.
Hello Pete. I was surprised how good that speaker sounded. Take care.
I have one Swedish late 50's tube radio which I converted to amplifier many years ago. It has a patented Rola alnico (?) speaker which is so utmost extremely ellicptical speaker that it is almost ridiculous, but it sounds great!
BTW U.S. PAT. NO. of that Rola is 2,820,527 and technical details can be found easily, just using a Google search. 🤓
Great Stuff Martyn, I was hoping you'd get the go ahead and do a full renovation.
Hello Steve. It should last a good few years now. Take care mate.
Nice video Martyn. Just a shame about the 50htz mains hum. 👍👍👍
Hello John, thank you. Yes, it's really bugging me. It does sound great though. Take care John.
Long live Elpico!
Hello Steve. Let's hope so. Take care mate.
Im impressed with tremelo as an add on unit..
Good plan to make a guitar input mod changing resistor and capacitor ..your guitar was sounding great along with butthole surfers..it was in background
Cheers Martyn
Hello Paul. I noticed that when II was editing the video. Are you working on anything at the moment?
Been putting two decca deccallian 88s back working and a decca deccalian 4
Next i found a simms watts ge100..solid state pre amps with 100 watt u/l power ..
A 7189 or 7189A is closer electrically to the EL84 but is good up to 400 volts and 14 watts. The characteristics of 6BW6 are closer to a 6V6 than to an EL84
That's good info. I never thought to check 6BW6 against a 6V6. Take care.
Those pots have the longest shafts I've seen. Are they even available today if one had to be replaced?
Maybe some high end Hi-Fi company does them?.
Probably have to scavenge them from old radios as I believe that's exactly what those in the Elpico are.
You'd have to use couplers and extension shafts (cut the shafts off of any existing pots that are defective and use them as extension shafts) should any of those pots needed to be replaced.
Hello Michael. That's a good question. Thankfully they were all okay. Take care Michael.
Hello Keiran. What a nightmare that would be. Luckily they are all okay. Take care mate.
Hello. Thank the Lord they all work okay. Take care mate.
Since EZ80 can't supply as much current as an EZ81, and cant tolerate as much 1st stage capacitance, it's probsbly a good idea to put diodes inbetween the transformer's B+ secondary and the plates of the rectifier. Youll still get the desired volage drop, but youll extend the life of the EZ80.
Hello. That sounds like a good idea. I will check that one out for next time. The Mullard tubes a re quite tough though. I reckon it will be fine. It was a bit of a juggle to get the voltage to match those 6BW6 tubes but they sound great. Take care.
Sounds brilliant. Do you think the new output valves made much difference to the actual sound? Bugger originality, I’d be doing something about moving the mains switch closer to the power input.
Hello Mark. Yes, I think they do. Email me and I will give you some details on them. Take care mark.
The only thing you can do with this switch configuration is to run it through a shielded cable (only has the shield, nothing else).
Hello David. That's a good idea. I have another amp I need to finish off, a Wem Westminster with the same problem. I will give that a go. Thanks David. Take care.