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Re: dirtbox gain increase and bypass Q

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4/18/2000 6:16 AM

Re: dirtbox gain increase and bypass Q

I'm building the HotBox and had some problems with oscilation until last night. I lowerd the anod voltage from 245V to 150V and then it stoped oscilate, But when I switch it in bypass mode (I have made it with a thrue bypass) it's starts to whistle. I think it's because I don't connect the input for the first gain stage to ground when it's in bypass mode. I will rewired it to night and se what happend. When you removed the 220K resistor you increased the gain and you got the pedal to oscilate. If you change the bypass switch to a 3PDT and rewired it so it will connect the input for the pedal to ground when it's in bypass mode I think it will work.

Lars

4/18/2000 7:33 PM
Ricky	did you build your hotbox just like the schematic? I'd like to know if you have done any alterations to the original circuit and what there effects are. I'm basically trying to give mine a high-gain option so it's a little more versitle. BTW, if you want me to do any voltage readings on mine, its no problem at all. let me know. -Ricky

4/19/2000 6:50 AM
Lars	The only mod I have done is a true bypass switch, the switch between clean- and Dist- channel are still there. I lowerd the anod voltage to 150v and then it stoped oscillate. Can you se what the voltage is in your hotbox. Lars

4/20/2000 11:56 AM

Lars,

Did you build it on a PCB? I'm trying to figure out how best to build one of these. I posted a preliminary layout that might work on turret board or maybe terminal strips. I don't know if this is the best way to do it. I figured unless the tube sockets are PCB mount, there would be so much off-board wiring it wouldn't do much good to have a PCB. Trouble is with my layout, it looks like it's going to take a fairly good sized enclosure to stuff it into (like rack mount, maybe). Anybody have any ideas or comments?

http://tinpan.fortunecity.com/solidgold/29/hotboxpl.gif

JD

4/25/2000 10:07 AM
Lars	I did mine on a board that messaured 4´ long and 2.1´ wide. I did fit the tubes on the board. The R and C for the high voltage did I mount on a separate board that was 1.5´ long and 2.4´ wide. Lars

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