DUMBLE dumblenotes free download

File name dumblenotes.pdf

file:///C|/Documents%20and%20Settings/Larry/My%20Documents/My%20Webs/Schem/rumbleamps/rumble.htm The following is a transcript of an anonymous conversation dealing with the construction of a Dumb Bell amp. (Edits have been made to the original transcript to ensure anonimity...) I built the Dumb Bell clone, and put the Dumb-Bell-ator in the chassis with it. The thing sounds great in a combo with a Weber-reconed D130 JBL. My friend with a recent Dumb Bell OD 100 has agreed to let me see and measure inside next week. It has the Skyline EQ and the Precision Power Amp sections. I will not be allowed to cross the "goop boundary". I don't have a digital camera, but intend to shoot some photos. I'm only going to have a few hours with this thing, but I can get a lot done, I think. This amp has the multiple trim pots inside, and I hope the owner will let me fiddle with them. He is a touring guitarist/guitar tech and has it set up for himself, but he's a great guy and hopefully won't mind. Just a taste: S/N higher than 200! EL34 output tubes (must be rare) All teflon 20ga mil-spec solid core wire Has a choke file:///C|/Documents%20and%20Settings/Larry/My...ocuments/My%20Webs/Schem/rumbleamps/rumble.htm (1 of 7) [1/21/2002 7:39:38 PM] file:///C|/Documents%20and%20Settings/Larry/My%20Documents/My%20Webs/Schem/rumbleamps/rumble.htm Late '97 model (date codes from transformers/choke) Here's more Transformer codes: Output: TF-170 1052 9716 Mains: TF-130 1052 9716 Choke: TF-155 1052 9640 The TF-130 transformer can be had from Triode Electronics and I understand it costs like $200+ or so..." "By the way the Dumb Bell transformers are right here in my Magic Parts catalogue: TF170, Marshall 100w output transformer, 4, 8, 16 ohm, 4 x EL34, 4 x 6550 Primary 1730 ohms, 20-20K HZ, $65. TF130 Fender Twin Reverb, Showman, Dual Showman, Quad Reverb, Bassman 100, power transformer 4 x 6L6 $58.50. TF155, Choke, Super Reverb, Twin Reverb, etc. 3 Henries, 90 ohms dc resistance, $9.75." Volume=1megA Treble=B250kA Middle=250kA Bass=500kA with a 105k disc across the top and bottom lugs(is this 1microfarad?)I used 0.01ufd with good results. Master=1megA with a 47pfd in a "brite" type arrangement(wiper to top) Pre-PI: OD tone trim pot on top the goo: Treble=250k Mid=20k Bass=1meg OD drive=250kA OD level=1megA (couldn't get to the input trim) Voltages: file:///C|/Documents%20and%20Settings/Larry/My...ocuments/My%20Webs/Schem/rumbleamps/rumble.htm (2 of 7) [1/21/2002 7:39:38 PM] file:///C|/Documents%20and%20Settings/Larry/My%20Documents/My%20Webs/Schem/rumbleamps/rumble.htm V1pins 1=209.6 3=1.716 6=206.0 8=1.788 V2pins 1=229 3=2.03 6=227.5 8=2.03