'54 5e3 restoration

[Stephen1966]

Actually! I'm curious, what tubes does it have in there? I saw the RCA rectifier and the black bottle (Russian?) 6V6s but what preamp tubes? 12AY7 and 12AX7? The RCA looks original... what about the others? What do you think?

[maxkracht]

The red astron isn't that far off...
How far? Should be possible to calculate the cutoff.

Don't remember numbers, but was close enough that I didn't really care or notice any loss of high end if there was any. Already back in the hands of its owner so too late for me to experiment unless it comes back.

Of course, there's no reason other than authenticity to go with a Jenson P12

I believe the guy doing cabinet work has an old P12 for him.

Actually! I'm curious, what tubes does it have in there? I saw the RCA rectifier and the black bottle (Russian?) 6V6s but what preamp tubes? 12AY7 and 12AX7? The RCA looks original... what about the others? What do you think?

Original rectifier. Came with RCA 6v6s, one tested really weak and was leaking heater to cathode, other was also sorta weak. Those were just generic soviet tubes. They are fine, nothing special but perfectly fine. Got a bunch of them pretty cheap a year or so ago and I have been using them as testers and seeing what abuse they can take. It had a CBS 12ax7 and a Sulvania au7 if I remember correctly. I was doing all of my testing with an old rca 12ay7 in place of the au. I just recommended the owner put in a new tube in v1 and whatever 6v6s he likes. He was going to experiment with things anyway, but he generally likes rca 6v6gt.

[Stephen1966]

Great work, I'm sure it is going to sound great. Some improvements could have been made, sure, but installing diodes on the tubes was a good call, without compromising the tonal heritage.

Let's hope it's not too long before we see this old lady again.

Any final thoughts...?

[maxkracht]

In case anyone else needs to de-aspestos a tweed amp; little bit of water in a spray bottle helps loosen the glue under the asbestos and keeps the fibers from getting in the air. Careful work with a razorblade and I could scrape almost all of it off fairly quickly without scratching the wood too much. Just a bit left in the tweed around the edges that can be re-covered with something less carcinogenic. I'm sure there are better ways to do that, but worked fine...

Will post a link if the owner puts up a demo video.

[angelodp]

Great work Max, I built a Mission 5E3 as well, and one for my nephew. I got a cool mod tip from Henry Heistl for mine and its sounds great. The Mod involved a dual gang pot.

[maxkracht]

Thanks. Interesting, Is that the type of pot with one knob or two? Separate master volume? I think I have rebuilt my mission kit 4-5 times over the years trying way too many mods...

[angelodp]

It's a one knobber. Were you on the forum when Henry was here. Super amp builder.

Best A

[maxkracht]

Were you on the forum when Henry was here. Super amp builder.

Not sure, I lurked for a long time, so maybe? Took a while to get rid of enough ego to be openly dumb in front of a bunch of smart people…

I worked on something recently that had a similar, control the preamp and a later stage at the same time setup. I want to say it was a pevey or something... Interesting idea to play with.

[angelodp]

Yeah, ego smeego, you are good people. Henry is Redplate, I have one, nice amp.

[drew]

In case anyone else needs to de-aspestos a tweed amp; little bit of water in a spray bottle helps loosen the glue under the asbestos and keeps the fibers from getting in the air. Careful work with a razorblade and I could scrape almost all of it off fairly quickly without scratching the wood too much. Just a bit left in the tweed around the edges that can be re-covered with something less carcinogenic. I'm sure there are better ways to do that, but worked fine...

It’s an extraordinarily bad idea to do this. You’re fooling yourself if you think you can make asbestos safe to disturb simply by spraying water on it. There is a reason that asbestos abatement workers wear full personal protection suits with air supplies. There is no safe level of exposure to asbestos. It makes zero sense to risk your or anyone else’s health for the sake of an easily replaceable piece of wood with tweed cloth on it.

[maxkracht]

Fair enough. I understand the risk and took adequate precautions in relation to my comfort level. I don't think anyone should take this lightly, and in no way do I claim to be an expert. Everyone should do their own research and do what they think is best.

I did the work outside, away from people, wearing PPE. All material was disposed of in multiple layers of sealed plastic bags and the back panel was taped off and stored in plastic bags until It could be covered in lacquer. I don't think water magically makes it safe, but I do think it makes a slight improvement, even if it is only to speed up the job.

My assessment was: The owner wasn't going to get rid of the back panel, wouldn't have known about the asbestos if I didn't tell him, and might have been fine keeping it in place. So, ultimately there is a short period of exposure under somewhat controlled settings instead of long exposure in his house and music venues across the state under uncontrolled settings in a vibrating box that pumps air.

There is asbestos in old stuff, more than most people think. Zero exposure is unlikely, especially if you work around old electronics, old houses, old anything really...

You are absolutely correct that throwing it away is the safest option. It wasn't mine to throw away, and I believe it is currently safer than it was.