Late '68, early '69 restoration

Info for maintaining and tweaking your amp to perfection.

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Bainzy
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Post by Bainzy » Fri Jul 07, 2006 3:15 pm

Fantastic restoration job George - I'd like to feature this on PTPCircuits.com if you and the owner don't mind. Where did you get hold of the vintage style carbon films for the voltage dropper resistors?
"I want to know what happened to the plans they sent you"

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Post by Bunnest » Wed Aug 09, 2006 3:58 pm

Now I am actually excited to send my '69 super bass to George for a cap job. I think those old mustard caps are getting tired after almost 40 years of tone. do you recommend installing the NOS mustards or the new Sozo vintage plus. I understand that the NOS mustards are not holding charges like new caps, and it is best to install new ones. any thoughts on this??? Nos Mustards v. New Sozo +
68 Marshall JMP 100 Plexi
69 Marshall JMP 100 Plexi
71 Marshall JMP 100 Metalface
66 BF Fender Pro Reverb
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MacGaden
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Post by MacGaden » Wed Aug 09, 2006 5:24 pm

Doing a cap job means changing the big electrolytic caps, not the small mustard caps, unless one or two is defective. Some "Techs" change them, and charge you for it, to sell them...
They are getting very expensive. Don
MacG.

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Post by DaveFx » Fri Sep 22, 2006 7:02 am

Look at those pretty, shiny original mustards in there! Woohoo!
You're a true artisan, George!

Dave
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saborthw
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Post by saborthw » Thu Nov 30, 2006 10:14 pm

very nice work !!!!

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Post by BrownSound1 » Sat Dec 02, 2006 12:44 am

George, great job....you should think about working on amps for a living. :D
Why is it we can remember where all the wires go, but can never find a pick?

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Post by darrell » Wed Jan 17, 2007 8:00 pm

It's not NUDITY It's ART :wink:

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Post by neikeel » Fri Oct 26, 2007 1:12 pm

Flames1950 wrote:Jesus, that chassis looks like swiss cheese....how many different OT's have been on that thing??

I really appreciate that only six holes were added to my Super PA chassis now.
It is funnny but Ihave been studying this pending my early 68 superlead rebuild. It has the original OT (in the 'wrong' orientation) but is drilled for the later OT in the 'correct' orientation with grommet holes and everything, wierd :roll:
Neil

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Post by neikeel » Thu Jan 31, 2008 5:21 am

Progress is slow :cry: .

Can't get correct carbon films. Georges new PT fits a treat, but only half wired in. Waiting on decent front panel.

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Sorry about trailing wires. Will upload finished pics as soon as running.
Neil

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Post by beaulieu » Wed Apr 23, 2008 6:01 pm

I am trying to put another pt in my 69 i noticed on this amp the square rectifier has a wire going to the switch?? On my amp theres a black wire coming from the pt to this lug on the recifier ( the one at 110clock)
69 SuperBass Plexi
12000 Series Bulid
73 1987
68 Nos 50 build
2554 Combo
2550 Silver Jub stack
71 LesPaul Deluxe
68,71,73 4x12

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neikeel
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Post by neikeel » Thu Apr 24, 2008 4:02 am

It is an earth wire, not to the PT but earthed to a filter cap lug
Neil

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Post by beaulieu » Sat Apr 26, 2008 6:50 am

actually it was HT lead?? I cant remember what it was called exactly but on my new PT it used a grey and a blue wire that went to the square rectifier. at 110clock and 5 oclock. the red wire at 7 oclock jumped to the filtercap and the one at 1 oclock went to the grnd on another filter cap. I replaced to aftermarket PT from the 80's with a Marshall RI P.T. changed my voltages. Now I have right at 450 +/-! Amp seems to sound not quite as dull plus the hum is gone. I figured I use this PT for now untill I could find an original.
69 SuperBass Plexi
12000 Series Bulid
73 1987
68 Nos 50 build
2554 Combo
2550 Silver Jub stack
71 LesPaul Deluxe
68,71,73 4x12

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neikeel
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Post by neikeel » Mon Apr 28, 2008 10:03 am

beaulieu wrote:actually it was HT lead?? I cant remember what it was called exactly but on my new PT it used a grey and a blue wire that went to the square rectifier. at 110clock and 5 oclock. the red wire at 7 oclock jumped to the filtercap and the one at 1 oclock went to the grnd on another filter cap. I replaced to aftermarket PT from the 80's with a Marshall RI P.T. changed my voltages. Now I have right at 450 +/-! Amp seems to sound not quite as dull plus the hum is gone. I figured I use this PT for now untill I could find an original.
The grey and blue will be non-rectified HT ac (some amps used two light blue wires. The other end of the bridge is the rectified HT and will go to the fuse and the mains filtercaps (usually a red wire like yours). The opposite end of the rectifier bridge goes to earth by a black wire, usually to the earth lug on one of the PI mounting screws. I thought that this was the wire you were referring to!
Glad it sounds better!
Neil

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Post by beaulieu » Fri May 30, 2008 11:41 pm

this is called late 68 early 69 resto!! Was there any 68 100 watt amps with standup P.T.? I have a plexi paneled 100 watt and the serial # and insp tag are gone. It has an stand up pt so I figured it a 69. I guess its best to say its a 69? correct? I would suspect no 68's with a stand up PT. Also it has the filter caps up top!!
69 SuperBass Plexi
12000 Series Bulid
73 1987
68 Nos 50 build
2554 Combo
2550 Silver Jub stack
71 LesPaul Deluxe
68,71,73 4x12

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VelvetGeorge
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Post by VelvetGeorge » Fri May 30, 2008 11:44 pm

What's your serial number?

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