'54 5e3 restoration

[maxkracht]

I've got an original 5e3 in for repairs. Any advice or opinions are appreciated, I don't work on tweed era fendrs very often... The speaker isn't original, tweed was mostly removed, needs a new handle/hardware, and I don't know what is currently working, will get to it in a few days... Going to keep everything looking as original as possible, but this will be a player, so erring on the side of functional. It has had a few repairs, but all of the original caps are in place, one was left floating inside the chassis. I plan to stuff the electrolytics and I have some spare yellow astrons if one is bad.

No idea what the best practice is for dealing with the asbestos. Lacquer? Remove? Lacquer then cover with shielding tape or some galvanized steel window screen?

Anyone know what the "bily" tape is about?

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[ampdan]

"Lily" wired the amp. She wired my 1955 Champ too.
That loose capacitor is one of the power supply caps. Other than that, the speaker, and an additional cathode resistor it looks all original.

[maxkracht]

Wasn't sure if it was the builder or the original owner. Looked like there was pen indentation to make a "b" but lily makes more sense. Can't remember seeing that kind of signature with tape before.

There are a couple of other tacked-on resistors and a poorly installed grounded plug, but relatively clean for its age.

[xtian]

Don't mess with the asbestos. It's in a stable, "non friable" state, so it won't broadcast fibers.

[bepone]

I've got an original 5e3 in for repairs. Any advice or opinions are appreciated, I don't work on tweed era fendrs very often...

1. ALL REMOVE - the best is to remove all and rebuilt all on existing board with modern carbon comp resistors and orange drop caps.. electrolytics from axials available
2. PARTIAL REMOVE - to preserve little bit the orig tone, measure all carbon comps and see which one is heavilly driften, you will see all of them, but maybe ypu can keep some,
New coupling caps (Orange drops 6PS or 225's) to the output tubes only, other leave inside and measure which one is leaking DC (after, in running)
New axial electrolytics everywhere

In both cases, new sockets apsolutelly everywhere, potentimeters how you want (maybe they are noisy, scratchy)

[Stephen1966]

Is the owner looking for a "restoration" of the original sound, or do they like the way it plays now.

It's a relatively simple circuit with minimal components so if this was on my bench I would recommend a full check up. If you have an LCR meter you can measure those caps in circuit - after you've drained them and with the power off of course. The moulded yellow Astrons are likely to be okay from what I've seen of other vintage restorations. 69 year old electrolytics though I think those are likely to be way off. The spring steel in the older jacks/sockets seemed better quality than current production Switchcraft so unless you see any obvious damage to them, and they have retained good continuity, I would leave them. Pots, are likely to have drifted as well being mechanical in nature, you might try replacing just the traces on their phenolic (?) wafer, but keeping the rest as original - not sure if current production CTS pots are the same design as from pots decades old, but you might be in luck there. CC resistors, being hugely hygroscopic may very well have drifted 30, 40, 50% or more and most builders/techs would probably just bin them and replace with modern alternatives. There is a way to restore CC resistors I heard about (though never tried) which is described here: https://www.diyaudio.com/community/thre ... ps.224511/ The tacked on resistors you speak of - especially if in parallel with existing resistors may indicate which of the originals have been drifting upwards. Regarding the intentions of the owner however, unless they are real bacon sizzlers, you might elect to leave them as they are. Looks like the death cap has gone, and reflowing the solder from the updated three core mains cable with a hotter iron should clean those connections up. Labels, other identifying marks, you want to preserve so be very careful if you go cleaning with IPA.

The asbestos should really be sent for hazardous waste management and disposal along with the entire back panel. If the amp is going to have it's Tweed replaced, there are ageing techniques which will give it the impression of an aged patina and that would be a good excuse to bin that back panel properly, cut and re-cover a new one. You really don't want asbestos anywhere near an amp that is going to get taken out and played, thrown around, and be as portable as any other amp. If it's going to be a museum piece or the owner is looking to this as some kind of financial investment where provenance and originality are at a premium then you need to tread a little more carefully and find real, actual expert conservationists - specialists in museum departments might be approached - or archaeology departments in universities and the like (it isn't all about dinosaur bones!). First stop though, might be to contact Fender and ask what they recommend. I'll echo xtian's advice though - don't mess with it.

Less is more, is true, and also - it might not be completely possible to do this - but try to make any fixes you make reversible. This is a very interesting job you've been landed with and I for one, would be very interested to see how it progresses. Best of luck.

PS. the letters 'GE' on the tube chart refer to May, 1957. https://sixstringacoustic.com/fender-amp-serial-number. The 5E3 wasn't produced before 1955 as I understand it, even so, a '57 5E3 makes it one of the earliest.

One further thought - maybe check the fibre board for conductivity as well - these are also hygroscopic and can provide shorts as they deteriorate.

[maxkracht]

I mean restoration as: maintaining the maximum number of original components, while maintaining the appearance of originality in replaced components, and maintaining the maximum functionality of the amp. Obviously, everyone has a different balance between those, but I have a decent amount of experience to know what I can and can’t get away with. Not my first old fender, but I appreciate the extra sets of eyes.



I have a method of stuffing cardboard electrolytics with modern caps that works very well. I do not believe in reforming old caps. I also have a supply of period correct resistors, jacks, tube sockets, etc., and some replacement yellow Astrons if necessary. I will, on occasion, hide new film caps under the board and keep the old ones for show, with written warning for future techs of course, but hopefully, it won't come to that... Haven't plugged it in yet, so fingers crossed.

It will have a grounded power cord and disconnected ground switch. Might add some, somewhat hidden, easily removable, fuses or backup diodes to protect the iron. Aside from that, the goal is looking original as possible at first glance. Mods and improvements are saved for new builds or less valuable old ones in rough shape.



There’s another local guy who does cabinet work who will handle most of that stuff and finding a correct speaker. Not sure if It will be re-tweeded or not. I like the bare wood, but understand the benefits of both ways. Local guy uses hide glue, so It should be fairly reversible.

PS. the letters 'GE' on the tube chart refer to May, 1957.




I’m an idiot, was looking at the D right below the GE. At least I was in the right decade…. Should have known the caps were later.


Don't mess with the asbestos. It's in a stable, "non friable" state, so it won't broadcast fibers.

Could you point me to any articles/information on how to determine this? It isn't the worst looking asbestos I've seen in old gear, but it's more cloth than tile and It's in a box that vibrates... Feels wrong just to leave it alone. Wouldn't adding lacquer bind the fibers more, reducing risk? I also don't see why taking it outside, ripping it off, triple bagging, then lacquering the remaining fibers to the board would be a bad move. Would a future owner be pissed that I removed the asbestos?

[xtian]

https://www.mesotheliomahub.com/mesothe ... -asbestos/

OK, I agree it should be disposed properly.

[maxkracht]

Not going to call a hazmat crew, not going to throw out the whole back panel, and don't really feel comfortable leaving it as is, but there should be a good middle way.

[Stephen1966]

Not going to call a hazmat crew, not going to throw out the whole back panel, and don't really feel comfortable leaving it as is, but there should be a good middle way.

Sure, I get what you're saying and it's perhaps deserving of a longer conversation with the owner to see how they feel about it. An original '57 Deluxe with 99% of its original parts is just about as good as it gets but if they don't want it to sound crap, which it most likely will, compromises have to be made. On the issue of reversibility I would be interested to see if you find any grounding issues. That "floating cap" (B+3) is normally in line with the other power caps on the board (tied to the same ground as the one it normally sits beside - B+2) and swinging it over to the chassis as it's been done, looks like an earlier tech was attempting to deal with a noise issue - perhaps by separating the power section from the preamp filters. That could be the board itself. In which case you have an even bigger set of compromises to consider. It's all a trade off as far as future purists and investors will see it though. As for stuffing the caps, I wouldn't, as that's destructive and as you suggest, wouldn't pass a serious inspection. Better in my eyes to replace any that need replacing straight out and preserve the old ones for future owners to decide what to do with. I mean, is the current owner going to be having the back off every five minutes to show off the internals to their buddies? If they are, I think you are right to feel uncomfortable. If you lacquer it though, you might have to do some digging to find some treatment that is going to be able to withstand the heat over a long period of time while remaining totally clear. May be more trouble than it's worth and it's worth quite a lot at this stage.

RobRobinette's page has some good photos of a '57/'59 in near original condition for reference: https://robrobinette.com/How_The_5E3_De ... uxe_Photos

Mmm! Getting ahead of myself now but do you think it might have been possible noise issues started to appear when the death cap and ground switch were modded?

[maxkracht]

That "floating cap" (B+3) is normally in line with the other power caps on the board (tied to the same ground as the one it normally sits beside - B+2) and swinging it over to the chassis as it's been done, looks like an earlier tech was attempting to deal with a noise issue

I meant “floating” as in it is not, intentionally, connected to anything. Just left there rattling around in the chassis. So, no grounding change. Notice the black resistor tacked in parallel to the first dropping resistor. The original resistor was cooked, likely from a tube failure, and someone put what they had on top. Decent chance that event is when the first filter cap was replaced.

As for stuffing the caps, I wouldn't, as that's destructive and as you suggest, wouldn't pass a serious inspection.



I don’t stuff caps all that often, but I do it well enough to pass a non expert inspection, even fairly close up. I understand the offense of cutting one open, but I do have extras pulled from less complete amps if a future owner came after me… Parts in a bag are much less interesting than old parts in an amp for aesthetic reasons. The originals will never be reused, they don’t work, so no reason to be precious. After the first time, it is easy to re-re-stuff caps as necessary. I have done a lot of work for the owner over the years and he appreciates this sort of thing when a job calls for it. Assuming the transformers are ok, I have functional period correct replacement parts for everything else if necessary. No such thing as functional period correct electrolytics in my opinion.



I usually err on the side of having a more functional tool, with very high quality modern components and techniques, than a historically accurate one. When it’s this close to complete, I like to give a reasonable attempt at looking original. I doubt the cover will be off regularly, but people do hear with their eyes to some extent. I do a LOT of things differently when building new 5E3s and it is hard to resist the urge to do things to this one like: install balanced heaters instead of the grounded by the tube socket kind, or add screen resistors, grid stopper, etc., but it worked once…. Can always go back and make adjustments if the owner wants.

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I think I am leaning toward: removing the asbestos as much as possible, as safely/responsibly as possible, covering any possible remaining fiber residue with lacquer/shellac/something removable, then adding some high quality aluminum shielding tape on top. (Not the regular duct stuff). I don’t think heat is as much of an issue as the asbestos would imply; plenty of similar amps have survived without it… The amp already has the tweed stripped, a layer of some kind of finish on top, a replacement speaker, etc. to scare away true purists. It isn't going in a museum. How many potential collectors actually want to see the asbestos and what monetary gain could be had by keeping it?

[Stephen1966]

I meant “floating” as in it is not, intentionally, connected to anything. Just left there rattling around in the chassis. So, no grounding change. Notice the black resistor tacked in parallel to the first dropping resistor. The original resistor was cooked, likely from a tube failure, and someone put what they had on top. Decent chance that event is when the first filter cap was replaced.

You also have that cement resistor for the power tubes tacked on as well, along with another, apparently the cathode resistor for the PI - the value doesn't make sense though. If that floating cap isn't connected there's no filter for the preamp, and B+ voltages for V1 and V2 are going to be off as well. The whole power section looks bad, and the Sprague Atom could indicate when the repair work (some of it at least) was performed. It looks early, don't know if you can get a date off it. Most of the preamp section of the board looks good but are those grey/white flecks mould or just grime? You're probably going to have to remove it and replace it if it's the former. A good opportunity at least to test all the components out of circuit.

When you get an object as beaten up and worked on like this the question is really if it would ever be worth going the full hog and doing a full faithful restoration. The cost-profit analysis sometimes indicates it just isn't worth it. I've seen some with modern replacement parts go for good money though. NOS parts as replacements, will get you a little closer but amps like these, are meant to be played not stuffed inside glass cases. If there isn't an imperative for Museum standard preservation then there is no harm in your approach. I think there is a greater value in restoring the vintage sound of the amp with all its saggy persnickety features.

Be safe.

[maxkracht]

If that floating cap isn't connected there's no filter for the preamp

Confirmation bias is a trip. I'm an idiot and counting to three is hard... My first impression was, extra cap that isn't attached was the original reservoir, not a severed preamp cap. Closer inspection, the positive side of the screen cap also broke off. 3rd amp I have worked on in the past week with a snapped filter cap lead, so you would think I would know better by now... Strain relief is good.

those grey/white flecks mould or just grime?

Just dirty. Will give it a once over with some compressed air and a vacuum, and I'm sure lots of cleaning with IPA in my future. Will try to actually get this project started today.

[Stephen1966]

Confirmation bias is a trip. I'm an idiot and counting to three is hard...

Haha! Welcome to MY world! Nah! You're missing an Astron MINIMITE cap - the one the Atom replaced - still want to go to the bother of stuffing them? The other big Minimite on the board doesn't look so clever either. I would definitely have that board out to work on it, unlikely there is any damage on the back with the hookup wires but considering the role gravity has played here, I wouldn't chance it. Maybe unhook the PT first and test it unloaded - it would be a shame if you fixed the board and then when you came to switch it on, the transformer was fried.

[maxkracht]

It lives... Still plenty of work to do, but there is a functional and decent sounding amp. One of the power tubes was leaky, the board is slightly conductive, and one or more of the coupling caps might be starting to go leaky, haven't tested out of circuit yet. The original bias resistor was a bit low, might order a nice enameled one that looks more the part. Installed larger dropping resistors. Pots are relatively clean, all of the remaining resistors were within like 3%. Not much hum. I think its a good start...

Cap stuffing went well, even if some of you find it distasteful. Can't really tell anything was changed without desoldering and looking at the cut on the bottom, unless you notice how shiny the new wires are, or that I didn't have the correct value cardboard tube for one of them. Hard to get a picture where you can see seams or drills. New Nichicons and Vishays are way lighter than the originals, so I'm not worried about things snapping again.

It's very hot, and very humid here, so worst time of year for fiberboards. I will spend some more time with IPA and see how much I can improve things. Hopefully, I can avoid pulling the board all the way.

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