Ceriatone Forum

Hello,

I have been building pedals and undertaken some pretty large projects such for quite a while. The only experience I have with high voltage is than in my large custom built multiFX board (Pete Cornish style) I wired 120vac into a transformer which has about 14 windings from 12-24Vac which supply a bunch of individual power supplies which in turn power each effect board.

So, nothing high voltage, but some Very complex builds.

Being a Gilmour nut (hence the Cornish board) I am very interested in the DR504. However, of course, I am a bit worried about the high voltage warnings. I have studied the DR103 pictures against the layout for hours, and have done a pretty good job figuring out how it all works. I understand all the wiring and layout, etc. Its amazing what you can learn by comparing pics to the drawing.

It is my understanding that the danger lies in the fact that even after you have cut the power off, these large electrolytic caps still store enough energy to kill you, so you have to know how to discharge them. Other than that, and the fact that you should never touch ANYTHING while the power there is a cord plugged into the wall....where are the other dangers? I have never had professional training.

I very much want to complete one of these kits! I know I could just order it built, but being a DIY guy with not so much $$, I'd really love to do it myself. Is there any reason Not to start out with the DR504?

Also, how hard is it to bias amp once complete? Any special equipment needed? Thanks!!!!

Stephen

The warnings are there for a reason, BUT, the fact that you are being cautious to begin with means you won't be ignorant of the risks. Therefore you will be fine, don't delve into an ON amp, use your meter to check voltages to see how long they take to decay, if too long make yourself a discharge device (resistor and croc clips, effectively). I found with my OTS there was never any residual voltage after even only a few minutes.

Biasing is just a multimeter, twiddle the pot!! Plenty of material on the web to read about how to do it, or ask here nearer the time. One thing I did with my oTS, since I had way less electronics experience than you was to take it to an amp tech after completion for him to power it up and test all the voltages, then insert the vavles and bias it and fully test it. He only charged me £40, worth every penny for the piece of mind.

Go ahead, you'll enjoy it and the satisfaction will be immense.