Rebuilding multi-section can capacitors

[Default]

Nice how-to here.

 

[capnjuan]

Thanks Steve; also nice to know that if you don't want to take on the job, there's somebody out there who will for about the cost of a new part ... if you could find it. J

 

[ce blues]

howdy,

I'm in the process of sending out (2x) 2-stage 8uF/8uF @ 450vdc cap cans for a very old Masco PA unit (MC17) for use as a harp amplifier (Little Walter had the same rig). It was a little tone monster when we first got it....but my harper wasn't savvy enough to let me reform the caps with my variac before he started blasting through it.....boy did it sound sweet before it failed! neat thread, hope more folk contribute to this one

ce blue

 

[Default]

You could try these if you aren't wedded to the cans or you could gut the old cans and glue them inside.
http://www.tubesandmore.com/scripts/fox ... -EM8-8-450

 

[ce blues]

part of the problem is that I AM wedded to the look of the vintage cans....this is a 1937 MASCO amp. now, inside the chassis I'm am happily going with all new sprague caps...but the visible ones just gotta look vintage (hence the rebuild on the two multi-stage cans because they sit on the chassis' top side). On an old Magnatone M197 (1947) rebuild, I had the room to install new caps under the chassis after cutting the old 4-stage can from the loop; but with the MASCO I just don't have that option.

blue

 

[capnjuan]

... in the process of sending out (2x) 2-stage 8uF/8uF @ 450vdc cap cans for a very old Masco PA unit (MC17) for use as a harp amplifier (Little Walter had the same rig) ...

Hi CEB; cheap fix Here at Antique Electronics.

 

[Default]

<bows to the master>

 

[ce blues]

thanks Capn'......I know they would work....they just wouldn't look correct (know what I mean?). I'm sure we're being really anal about the whole thing

ce

 

[capnjuan]

thanks Capn'......I know they would work....they just wouldn't look correct (know what I mean?). I'm sure we're being really anal about the whole thing

Yes; I know exactly what you mean. Another BBer and I spent a couple of months going back and forth with a Chicago molding company ... they own the old Dakaware molds for amp knobs and other bits and pieces ... best after-market match left, authentic on the right ... my knob-partner owns the amp .. :wink:

 

[ce blues]

ah, a man after me own heart.....you know exactly what I mean about the look of an old amplifier. thankfully, all of the old control features (even the painted surfaces) are completely intact on the MC17.
blue
the amp on the left? the knob is plastic after market?

 

[capnjuan]

... the amp on the left? the knob is plastic after market?

Yes; actually same amp; L pic with aftermarket knob the chassis is out of cabinet, R pic it's in the cabinet with an original knob. The knob on the left posta be 'oxblood' ... but what's 'oxblood' turns out to be largely a matter of opinion. I tried two sets of brown and oxblood from Weber ... no match there either. So ... got hosed on eBay buying what you see in the pic on the right and more from the next generation; without the swirly compressed grain, just solid 'oxblood' ... pure dark brown but found a yellow paint stick in an arts and crafts store to replenish the pointer stripe ... like the ones below on a Gibson GA20T Ranger ... there's really no good substitute.

 

[ce blues]

man, don't I know the truth of that....try finding vintage parts or adequate substitutes. and as for being hosed on flea-bay, let's not even go there! nice looking amp, Cap'n! I love old Gibbies. my main amp is an GA-30......sweet thick sounds for my guilds and 335's. (you may have guessed that I'm a humbucker-fiend? In fact I bought my very first Stratocaster only a year ago and I've been playing 50 years!)
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[capnjuan]

Thanks; if you click the GA20T link in my siggie, you can read more than you'd ever want to know about the amp in the pic and another GA20T. There are more electronic equivalents/upgrades than there are cosmetic ones; ... like the Gibson amp handles and grill badges ... if you want one, get ready to bend over ...

Yes, I'm a big Gibson fan too - the older models produce a very pleasant tone and, with attention, can be refurbished to run another 55 years. But, as with older guitars, there's the dilemma of what can/should be changed/upgraded and what shouldn't. So much depends on physical condition.

 

[ce blues]

very cool project....I've read the first three pages but now I'm getting dirty looks from my boss and need to do a minimum of work to put the smile back on his face. nice amps. I'm well acquainted with pentodes in the preamp; both the 1947 M197 Magnatone and the '37 MASCO MC17 utilize a pentode in the pre. gotta run....I'll get back to reading about your 1/2 GA40 project (since there are two GA20's....doesn't that equal a whole GA40?).
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[capnjuan]

very cool project.... (since there are two GA20's....doesn't that equal a whole GA40?).

Well ... maybe if I could scotch-tape them together.... I'll never know how close they are .... but they're going to have similar tone ... I think the GA40s, thanks to the larger OT and choke, would have more headroom.

 

[ce blues]

... I think the GA40s, thanks to the larger OT and choke, would have more headroom.[/quote]

without a doubt, Cap'n....however, we both also know that the scotch tape would seriously detract from that vintage vibe.....unless, of course, you could scrounge a roll (that still had its sticky) from the 1950s :roll:

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