Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: billcreller on November 07, 2012, 10:05:25 pm
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I have this Rickenbacher steel guitar from the mid 30s, in for some ( a lot) work. Someone has wired a .005 cap in series with the hot wire from the volume pot to the hot side of the pickup. My question is, how is the signal supposed to get past that ? The guitar did work with that in there, but output was barely audible with the amp on about 7 on a scale of 10.
Anyone ever heard of a so-called mod like this ?
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AC passes through caps.
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Yes, but this cap is so small that it probably blocks all of a guitar's fundamental frequencies. Is proper vol restored with the cap bypassed?
If yes, then probably someone: a) installed a tone cap in the wrong spot; AND b) missed a decimal space. I.e., .047 = .05, but mistakenly used .005
Do not let this person work on the space shuttle! :icon_biggrin:
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Well, the guy did have a tone cap in there. The tone control is gonna get removed anyway. The guitar didn't have one originally, & the owner sez lose it. TIG welded the hole shut for the tone pot.
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TIG welded the hole shut for the tone pot.
One of the frying pan Ricks with a metal bodie?
Brad :icon_biggrin:
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Yeah, a mid-30s frypan. I've refurbished 6 of those in recent years. This one had cracks near the headstock, and had to cut some metal out at the cracks, for welding etc. It got dropped at some point, and broke one of the horseshoe magnets, as well as causing cracks. Over the years, people drill holes in these, for whatever reason, and I just get them welded shut.
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Measure the pickups dc resistance and you'll get an idea of the strength of signal to expect plus should help to troubleshoot if the magnet wire/windings are suspect. By the sound of things, old stuff has can easily decay and short or corrode creating high resistance enough to lower output signal strength too. I agree on the removing the cap or at least make it a 0.1 minimum. Maybe someone thought the thing had too much low end and did that?
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The DC resistance of these old Rick frypan and bakelite pickups from the 30s runs anywhere from 1200 ohms to just over 2000 ohms. Nothing like modern windings. And they were wound with #36 or 38 wire. And the original volume pots are 100 K ohms. Most folks believe the pickups were not wound to any particular resistance or number of turns, but to.... "that looks like enough wire" ..type thinking. I record the DC ohms of the ones I work on.
When I get a pickups made for the horseshoe magnet type, I have them made to about 1800 ohms, by Jason Lollar. And he has the horseshoe magnets now also.
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Jason Lollar knows his stuff.
I've read 3 or 4 interviews with him in Tone Quest Report Mag. over the years.
Brad :icon_biggrin:
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I have the guitar finished now, with the welding done, the welds blended in, and the whole body polished. And it doesn't have the volume of a modern pickup, but sounds great. It belongs to one of my Hawaiian friends, who is a prominent player there.
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I bet it has low output on purpose so that it plays nice and clean as a Hawaiian guitar should? Especially with those old amps that would break up fairly quickly and this was their remedy de jeur. Did you take any pictures of it?
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Yeah, I took some pics today. I'll have put them on my photobucket site in order to post some.
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I had to get Jason Lollar to build a new pickup. The one on this guitar is really dead. We'll see if it's the answer to the output problem :dontknow:
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The new pickup is in it now, and it really sings !! :icon_biggrin:
Couldn't get the pics to upload for some reason....
(http://i561.photobucket.com/albums/ss52/steelybill/steel%20guitars%20and%20amps/Rickenbacher%20Steel/P1011154.jpg)
This is what I started with...
(http://i561.photobucket.com/albums/ss52/steelybill/steel%20guitars%20and%20amps/Rickenbacher%20Steel/P1011212.jpg)
finished..
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The new pickup is in it now, and it really sings !! :icon_biggrin:
Nice!
Brad :icon_biggrin:
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WoooWeee!
Bill, that sure cleaned up nice...amazing.
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I played through an old Rick amp a few years ago. It was a metal cabinet model from the 30s, with black wrinkle paint on it. I believe the speaker was not very good in it at the time....and old Rola if I remember correctly.
They do sound great through my National clones though.
Her's a pic of the bottom of the guitar after I stripped the crappy paint off of it. I needed a lot of sanding to get it smooth enough to polish. That's when I discovered all the cracks in the head stock
(http://i561.photobucket.com/albums/ss52/steelybill/steel%20guitars%20and%20amps/Rickenbacher%20Steel/P1011160.jpg)
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I posted a schematic of a rick M-8e on the Prowess website, I believe it is mislabeled as a M-83.
Its a sweet sounding amp, three tubes. I gave my M-8e to a guitar player so I could borrow his equipment.
M-8e to me is to be an "M 80"??? M80 fireworks are a type of big firecracker that is quite notorious in the world of pyrotechnics. Sometimes called “salutes,” these large firecrackers were originally made in the early 1900s by the US Military to simulate battlefield noises and conditions for soldiers in training. However, because of a high rate of property damage and personal injury caused by them, they have been outlawed for quite some time being for sale and use as a consumer firework.
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M-8e to me is to be an "M 80"???
You're confusing the M-8e with the M-8t. :wink: