Amp chassis & transformer bell rust

[ggizzy]

BuzzK- You are right about someone buying amps based on visual condition. Those amps look good. Very well done. I do quite a bit of metalworking myself. And I have rebuilt amps onto new chassis before. I have a lot of other stuff to work on and so I don't want to go to the trouble of bending and drilling a whole new chassis. It has been my experience that metal fabricating is 80% of the work on building these simpler tube amps Also, this one isn't eaten through anywhere- very superficial. The pictures do it no justice.

Maxhifi- This is where I got essentially and have already oiled the spots. The amp is an emi std-373. (See ad). It has a really nice three band, three inductor freq correction feedback network of some sort. (See image) I haven't sorted the amp in total. But I have diagrammed a big portion of the schematic.

Leland- possibly what im looking for! I wonder if dremmel sells attachments that would work. Haven't fired that guy up in a while...

Of all the suggestions, maybe leaving it in ratty condition is a better option. New house is in a safe neighborhood though and at 125 lbs apiece, someone would need to be pretty quick on their feet to get it out- maybe with a hernia!

 

[BuzzK]

I had several runs of custom chassis made and I used to sell them, because I couldn't find what I liked commercially. I finally quit making and selling them, because fewer and fewer people want to build from scratch, and I probably have only about 1/2 dozen more amps I'd like to build before I quit.

Here is an example of my rebuild of the classic Acrosound II. I didn't care for the dc-choke-inside-the-mains-transformer idea, so I'm taking a different approach. Would two original Acros be worth more than my best effort? Most likely. But I wouldn't be having as much fun, for sure.

I'd love to see some more amp porn. Can you share a full frontal and rear shot of your amp?




Buzz

 

[maxhifi]

Amp looks interesting, I assume you have a pair?

Were it mine I would remove loose rust, oil the rusty spots, then make it work. But I like "patina", and hate painting.

To make it look new, it looks like a good candidate for sandblasting, priming, and painting. I would say goodbye to those old decals and reproduce as well as possible
If you have a friend or contact who can get you a bit of time with a sandblasting booth.

Trying to spot repair and match old paint sounds extremely tedious and fiddly, with a high potential to look worse than it does now. I would be very wary of that option.

I wouldn't do it though, too much work for too little reward.

 

[ggizzy]

Here are two pictures. The entire cab/amp is the EMI DLS-1, a studio designed predecessor to the famous DLS-529, Dangerous Loudspeaker." Pretty massive transformers, and yes, I have the pair. They are very similar to Abbey Rd REDD.36C monitors which would have likely had a Leak TL/25+ instead of the STd/373. I've read they are better, but I now have both that I can test. . The drivers are the same in both units, and there is another post I did awhile back about the White Elephant speaker which also utilised these same drivers.

I Will probably leave them as-is, at least until after New Year, when I get moved into the new place. I'll probably strip all the components for now and box everything up.

Thanks for all the help, I will start a new thread when I finish.

 

[maxhifi]

Wow

Given how the amp isn't visible, I see absolutely no motivation to repaint it. I have no idea how you found these, but nice find!

 

[Dandy]

I faced a similar leave or strip and rebuild issue with a nice 50s stereo Mullard 5-10 amp recently. I opted for a complete strip down and rebuild on the grounds that this is the only way to ensure reliability and to stop any further corrosion.

In my experience an amp in that condition will have component aging issues that should not be left if it is to be used regularly.

 

[maxhifi]

I faced a similar leave or strip and rebuild issue with a nice 50s stereo Mullard 5-10 amp recently. I opted for a complete strip down and rebuild on the grounds that this is the only way to ensure reliability and to stop any further corrosion.

In my experience an amp in that condition will have component aging issues that should not be left if it is to be used regularly.

How do Brits look at American equipment? When I see something like this, or a Quad, or a Leak, or your 5-10, I definitely wish I would run I to that sort of thing locally! On the other hand, I can't imagine you run into a lot of Klipsch or Altec speakers, for example.

 

[Dandy]

Most of my amps are American, because I got them more cheaply here in the U.K. I have almost never seen US speakers here. Klipsch or Altec are exotic unknowns to me.