Monday, August 4, 2014

My latest acquisition.

Friday, July 25, 2014

Vibro Champ Update

The chassis prep is nearly complete. I have pots nearly all selected. I am adding push-pull pots to enable switching for tone stack and feedback loop. I've settled on a PS design with the help of the PSU design software from Duncan Amps. This allowed me to make use of a 4-part electrolytic capacitor. I had hope to use a 5.5H choke I pulled from a Knight-Kit, but an over zealous drill operator (guess who) over penetrated while drilling pot holes, and wrecked the choke. Import stuff: pilot light will be green. The 7C5 tube base had to be move from bottom mount to top mount. This 7C5 will be wired in parallel with the 6V6, which will allow "either/or" operation. Hope to have chassis fully loaded by end of August. If you get this update as an email remember to go to the blog to see full size photos.

Thursday, April 10, 2014

Vibro Champ Clone

I've decided to postpone the Frankenstein amp (Conn 6020) and pursue a Vibro Champ (AA764) clone. Like the Frankenamp I have all of the parts that I need, but I believe the Vibro champ will be easier. With the other projects I have going I think it is a better fit. I have two solid state amps that will get attention soon. I will say this for the benefit of those who wanted to know how I was going to convert the Conn 6020, I am looking at the Ampeg Portoflex SB12 as a basis. As far as the Vibro Champ, I have one thing to resolve: the power supply. I have been rendering some old Knight Kits and one old Conar kit for parts. I hope to use a pre-Stancor Chicago Standard transformer and a 6X4 rectifier taken from a Knight-Kit O-scope.

Sunday, January 19, 2014

Carmen Ghia Goof

It turns out that the problem I've had with this amp hasn't been a bad component but my error.  When I converted the Hammond AO-35 using the Phoenix schematic, I failed to ground a resistor that was tied to the terminal strip on the side of the chassis.  Grounding this resistor solved all of my problems.  My Dad found this problem while we were trouble-shooting this by phone.  Thanks Dad.  Click on the image to see it enlarged.