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Website, Store / General / fuse size?
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on: September 22, 2009, 01:06:55 PM
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I am having a difficult time finding the correct size fuse. anyone have this problem? 5mm x 20mm is to small, not long enough. I am thinking 6mm x 25mm would be correct?
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British Style / Plexi Lead, Bass, Superlead / Re: Microphonics on 1987 with PPIMV ??
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on: September 14, 2008, 05:29:03 PM
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I'm enjoying my new Ceriatone 50W Plexi. However, I'm really struggling with both microphonics and general background noise.
I'm sure it's not the tubes. I have a load of good pre's and the amp acts the same with all of them.
First, the microphonics. With the PPIMV on 10, I cannot get the channel volumes even to 3 without uncontrollabelle high squeeling. Sounds like a microphonic pre, but can all my pre's (the JJ's it came with, 3 NOS Blackburn Mullards, a long plate GE, and an RFT) all be microphonic, surely not. With the PPIMV down at about 4 or 5, I can play fine - no microphonics. But as the PPIMV goes up - back comes the squeeling.
So that's the microphonic problem. Then there's the general background noise.
With the channel volumes anywhere below about 7 its' acceptable. But above that there's too much unacceptable noise.
So this is all fine if I play with the channel volumes below 7 and have the PPIMV at half way or below, but I don't want to be restricted to that.
Could any other folks with the Ceriatone 1987 WITH a PPIMV comment to let me know if they have experienced anything like the same problem with their amps.
Is it possible that the PPIMV circuit could be responsible for these problems. I have read that different PPIMV circuits can really behave very differently.
is the amp in a head box? do you have shielding under the chassis? |
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British Style / Plexi Lead, Bass, Superlead / Re: New Amp - Brown 100
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on: September 14, 2008, 05:11:29 PM
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Filtering is lowered to 32x32 cans which was more like Ed's 68 Plexi. 100pf cap on the phase inverter section istead of the 47pf. .1uf coupling caps in that section as well, instead of the 0.022's. Ed's amp had 820k Carbon Comp resistors at V1 and V1B which had drifted in value to 1K, that's what is in the Brown amp, and V1 Cathode .68 cap changed to 330uf like what wa found in Ed's amp. here's where the info was found for making this amp. I think Nik was trying to create this version. Ceriatones Super Lead is based on the 69 Circuit where as Ed's amp was a 67/68 which is different from a 69.
1) By Mark Cameron by pictures taken in the early 80'S.
There ARE small tone altering and/or gain altering mods.
...the cap on v2(330uf) cathode.
...its a 2.7k/.68 and the resistor looks like the stock part(but I don't think it is)but the cap is one of those yellow square type from the 70' Marshall's. From the circuit card It looks like it came stock with this arrangement. The post that is pressed in looks stock too witch tells me more than anyone could.In the pics the serial # is 12301.
(2) By ******. 1980.
To try to wrap up is ED thing...
His head was a 67/68 and he had the first stage valve with BOTH cathodes tied together sharing the same 820 ohm resistor that was bypassed with a 330uF blue cap...
His treble cap was a round shaped ceramic that was a 250pF that said MURATA ... With 56K on the tone circuit feed..
One of the 470K mixer resistors was bypassed with a round hollow tubular MURATA cap 500pF... If memory serves me right on the value, or it was a 330pF..I will check my notes....
The real kicker, his phase-inverter "get-rid-of-the-FIZZIES" cap was a 100pF instead of the normal 47pF ....and this my friends is how the "brown sound" with that added compression happens..
Oh, BTW those 820 ohm resistors were carbon-comp and drifted in value up about 1.1K and make the amp much more gainy and warmer, since these re-bias the 12AX7 valves in a bit more non-linear region..
I am pretty sure the feedback resistor was a 47K ...I will have to check my notes...
The filter cap in the center of the board was a dual 16uF gray RS cap...
The screen filtering was 2 DALY 32uF light-blue caps in series... The voltage doubler were 2 100uF DALY royal-blue caps...
Rear cap on top of chassis was a royal-blue HUNTS 32uF or 16uF...need to check notes..
The value of the coupling cap between V1 and V2a....022uF.
At least that was what it was in 1980...
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Community / Classifieds / FS ; Ceriatone Marshall 100 Watt Super Lead w/PPIVM Master Volume
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on: May 25, 2008, 02:59:30 PM
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Here is my Marshall 100 Watt Super Lead Clone made by Nik at Ceriatone.com it has a master volume on it, and some sozo caps as well. all hand wired point to point. Power tubes are JJ EL34's and 3 12AX7's it has less then 10 hours of playing time on it. If you were to order one from Nik, and then have him install the master, get the head box from mojotone and Marshall logo, it would cost you about 1400. here's your chance to get it for only $1250. Kicks ass over any Marshall made today. this is a clone of a 1969 Marshall Super Lead. sounds great and not a scratch on it. I need to sell because I have too many of them. see pictures here. http://denver.craigslist.org/msg/693815802.html |
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to keep the forums alive.