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Magnatone 260 - What to recap and what to leave alone
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Mr. Pumpkin



Joined: 05 Dec 2008
Posts: 1414
Location: Richmond, VA

PostPosted: Fri Apr 08, 2016 9:00 pm    Post subject: Magnatone 260 - What to recap and what to leave alone Reply with quote

Hey guys, it's been a long time since I checked in and I've had a lot going on. A couple of new builds, and other things that I'll be posting but now to the question at hand:

I had the good fortune to pick up a vintage Magnatone 260 amp for a mere $200 off CL. I took a gamble since it wan't working at the time, since the power cord was missing and it looked in pretty rough shape cosmetically. But I knew the reputation of these amps, and how much they can be worth when functioning.

So to my surprise, after doing some cleanup, installing a new 3 prong cord, and firing it up it came to life rather nicely with one exception: that famous pitch shifting vibrato isn't working. So I've checked online and gather from most resources that it's most likely the caps in that part of the circuit.

My question is this: outside of the lack of vibrato, this thing is good and LOUD and quiet as a mouse as far as hum goes. And of course being a vintage amp, it has a couple of the big multi-cap cans on board. So how far should I go as far as replacing the other electrolytic caps in the circuit? I'm thinking I'd be better off leaving the cans as is, and just go for all the other ones in the circuit. I don't want to change the character of the amp too much, because it does sing nicely otherwise.

So opinions?

Also BTW, this thing is going to need to be recovered. The grill is still passable , but the "tolex" as it were is in sad shape. It's not tolex in the traditional sense, more fabric like. I have to replace it with something, so should I just go with something close, or keep trying to find something more original?
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tangelolemon



Joined: 26 Jan 2009
Posts: 2691
Location: Brooklyn, NY

PostPosted: Sat Apr 09, 2016 4:42 pm    Post subject: Reply with quote

Great amps. I love mine.

Before you go replacing caps to troubleshoot the vibrato, have you tried changing the 6CG7s?
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Mr. Pumpkin



Joined: 05 Dec 2008
Posts: 1414
Location: Richmond, VA

PostPosted: Sat Apr 09, 2016 8:43 pm    Post subject: Reply with quote

No haven't tried that yet. You think that would be the best first move in this case? Probably cheaper and easier for sure. BTW, mine only has the one 6CG7, since it's the mono version, not stereo.

BTW, figured you would be the best resource for this one. Didn't know you had one too. What year is yours? Mine appears to be the '59 model. It has the Jensen Special Design speakers in it
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tangelolemon



Joined: 26 Jan 2009
Posts: 2691
Location: Brooklyn, NY

PostPosted: Sun Apr 10, 2016 6:13 am    Post subject: Reply with quote

Your mono version should still have 2 6CG7s. Maybe this is part of your problem! Cool

And yes, that would be move #1, to get the two 6CG7s sorted.

Mine is a '59 also. I got it as just a chassis... had a repro cab made by Vibroworld (RIP), and the speakers are Webers.
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tangelolemon



Joined: 26 Jan 2009
Posts: 2691
Location: Brooklyn, NY

PostPosted: Sun Apr 10, 2016 6:15 am    Post subject: Reply with quote

here's a schematic with a tube diagram on the bottom so you can see where the TWO 6CG7s go! Cool



Here's a bigger version, but sans tube chart:

http://elektrotanya.com/PREVIEWS/63463243/23432455/magnatone/magnatone_260-a.pdf_1.png
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Mr. Pumpkin



Joined: 05 Dec 2008
Posts: 1414
Location: Richmond, VA

PostPosted: Mon Apr 11, 2016 1:18 am    Post subject: Reply with quote

Well dayum! That would be a problem wouldn't it! Sure enough they have a 12ax7 in that spot, which ain't right obviously. Never saw the tube chart before and didn't catch that in the schematic.

BTW, those little "diver down" flag symbols are the varistors in the circuit, right?
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Old Black



Joined: 18 Jan 2006
Posts: 1977
Location: Minneapolis

PostPosted: Mon Apr 11, 2016 10:04 am    Post subject: Reply with quote

I have two old Maggies - a 410 "Dana" and a '59 280. FWIW, I had the 280 rebuilt by Savage amps - new multi-cap can filter caps, 3-prong plug, NOS tubes and I had the Oxford 12s reconed. I asked them to keep the blue (Mallory?) caps unless they showed obvious leakage. I wanted it to be a reliable player - and it is - absolutely dead quiet and the vibrato circuit is so swimmy that you almost get sea-sick.

I wonder how these old Maggies compare with the new versions?
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Mr. Pumpkin



Joined: 05 Dec 2008
Posts: 1414
Location: Richmond, VA

PostPosted: Mon Apr 11, 2016 3:38 pm    Post subject: Reply with quote

OK, 2 new 6CG7's ordered from Tubes and More. We'll see what happens when they get here, fingers crossed! Cool
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tangelolemon



Joined: 26 Jan 2009
Posts: 2691
Location: Brooklyn, NY

PostPosted: Tue Apr 12, 2016 5:42 am    Post subject: Reply with quote

Mr. Pumpkin wrote:

BTW, those little "diver down" flag symbols are the varistors in the circuit, right?


Yep! Good luck with the amp. Hopefully the tube swap is all that's needed!
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Mr. Pumpkin



Joined: 05 Dec 2008
Posts: 1414
Location: Richmond, VA

PostPosted: Tue Apr 12, 2016 3:33 pm    Post subject: Reply with quote

I hope so too. Mine does have some of the blue Mallory caps in it, but a lot of the electrolytics aren't. But since it is so dead quiet now, even with the old caps, my fingers are crossed that the tube will fix the issue.

Then it's just a matter of recovering the poor thing. It's seen it's share of abuse, and needs a couple of pieces of the case replaced too. The back cover is completely missing, but I'm pretty sure I can fabricate that. The original covering on mine appears to be that sort of duck canvas material, not a tweed, but not tolex either. My wife, the seamstress, thinks she's found something similar online in an outdoor fabric, which would probably be good for an amp, and she's really sure she could help me make the pattern and cover it.

It's nice to have 2 crafty people in this relationship! Smile But she is getting a little jealous about the fact that I can use her embroidery machine better than she can. I can't help it, it's a CNC machine after all!
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WildIowa



Joined: 06 Mar 2004
Posts: 490
Location: Henderson IA

PostPosted: Wed Apr 13, 2016 7:18 am    Post subject: Reply with quote

What an excellent find. Some believe you should only replace caps if there is a problem with hum etc. Also, no matter how trashed the exterior is, consider the option of leaving it as-is versus a new covering sometimes the greatest value remains with the old original stuff no matter how bad or beat up it is. You might clik the link here and find a guy they call Mr. Valco (Terry Dobbs) from southern Indiana...he does old Valcos but an invaluable resource for info and advice on these old amps....he likes to recap everything, by the way...another tech near me leaves them original unless they hum....good luck. Terry's site also has an interesting story on him running on to a room full of stolen Stevie Ray Vaughn equipment and info on how he modded his amps etc.

http://www.valcoamp.com/
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Mr. Pumpkin



Joined: 05 Dec 2008
Posts: 1414
Location: Richmond, VA

PostPosted: Thu Apr 14, 2016 9:42 pm    Post subject: Reply with quote

Got the new tubes in today and installed them in the right spots... No joy!
Crying or Very sad

So a couple of questions before I grab the soldering iron:

From the schematic and what I would assume based on the labeling and the panel, the vibrato is only on channel 1, and always engaged unless the foot switch shunts the circuit to ground. Correct? I was using a switch from my Mesa Boogie TA15 to test it, which is just the single switch, 1/4 inch non-TRS cable, but played around without it as well.

Also, if I'm gong to start replacing caps, I think I'm going to concentrate on only the ones in the vibrato circuit and leave everything else alone. In a house where any single coil pup hums like a bee hive with almost every other amp, this thing is still near dead quiet even with a single coil attached to it. Wise idea?
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Mr. Pumpkin



Joined: 05 Dec 2008
Posts: 1414
Location: Richmond, VA

PostPosted: Thu Apr 14, 2016 10:04 pm    Post subject: Reply with quote

Also, on the subject of recovering the cab, here are some pics of what it currently looks like. There are some nice cigarette burns in the top, which add some mojo for sure, but the one side is especially bad. Luckily the grill cloth is in pretty good shape. Also note the custom handle Very Happy













Based on this, what does the group think about recovering it?
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Bootsypratt



Joined: 01 Dec 2006
Posts: 1236
Location: Columbia, SC

PostPosted: Fri Apr 15, 2016 7:31 am    Post subject: Reply with quote

I totally leave it as is. I would find a new handle, maybe a new old handle, and just maintain the tolex that is left and stop any more from coming off.
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marksound



Joined: 15 Aug 2005
Posts: 16669
Location: OKUSA

PostPosted: Fri Apr 15, 2016 8:15 am    Post subject: Reply with quote

I don't see nearly enough duct tape on that thing. Cool
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