This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.
Topics - markorock37
« on: May 06, 2013, 01:04:08 PM »
I am working on a Fender Bassman 400 ss bass head, its is blowing voltage regulators to bits. I replaced the 7815 and 7915 regulators and it blew 'em again. I have now replaced them once more along with all the diodes nearby. Instead of lifting one leg to test each I just went ahead and replaced all D100-111. Q102 was also blown and replaced. Ready to start it up on the limiter, anything else I should check beforehand?
« on: March 02, 2013, 12:05:37 AM »
I have a Peavey M2600 power amp on the bench right now with low output. Guessing the main caps are shot. They are 5000uf 55v. Having trouble finding these but I do have some 6800uf 80v will those be okay? Thanks.
« on: June 04, 2012, 08:23:11 PM »
Building a solid state guitar amp, everything is ready to go except my rail power is too high. I'm running 52 volts and would like to get around 25-30 volts. I'm using a 36 volt power supply w center tap into a full wave rectifier and two 2200uf 50v caps. What's my best solution? Thanks
« on: March 30, 2012, 03:00:25 PM »
Building a chipamp based on a LM1875. I'm using 2200uF caps in the amp circuit and a 34.5vac transformer. Really the only question I have is what size filter caps to use after the rectifier.
« on: March 09, 2012, 02:38:52 PM »
The only place I found any IRF230's in stock they are $13.49 a piece, any better sources out there? I need 4 for a Megabass head.
« on: February 09, 2012, 07:30:31 AM »
I am trying to repair a DOA Line 6 Spider II 210, amp powers up, I can hear the speakers have power, so the power amp section is working. However, none of the lights are coming on and when I tested the cable connector goint to the preamp board no power was present. Transformer checks out fine, and all resistors on the power supply board are good. Bridge rectifier is conducting one way only like its suppossed too. The only thing I question is the little ST 2N 5401 transistor being good on that board. Anyone have this issue with these amps and what should I be looking for?
« on: December 20, 2011, 11:19:34 AM »
Picked up a Sunn stage lead for next to nothing. Has power but no sound. Found an open 680K resistor which I replaced. When I powered it up it fried one of the power resistors on the board. I couldn't find a schematic for it anywhere so anyone had any luck with these?