Need to order my faceplate and drill the head cabinet.
The K60 power supply is a good design but it is double stacked.
Which was not possible in this build so I decided to get the filter caps right on the tone board.
Made a new layout for the B+1 and B+2 caps. There was just enough room to get it done too Separate out the bias board as well.
I did a lot of pencil drawings on paper before I settled for this layout.
This amp is so quiet it's hard to tell it is even on, I wish I could get all my amps to idle like that.
Mark do you build these from the Astroid schematics? I finished mine up today and have some odd voltages and although it sounds good It's no where near as loud as my Express. On V1 my pin 1 is 282 and pin 6 is 366... On V3 pin 1 and pin 6 are 461 and 444 resp. Pin 2 and pin 7 are 3.44 and pin 3 and pin 8 are 9.02 ... All my other voltages are in line with Allyns K60 voltages and she biased up and played. I guess I'm just curious if there is an error in the package I followed. My B+'s are 484, 482, 475, 439, 408
Yes I got my info from Bnwitt 3 years ago and used that to build the K60.
I also use the layout and schematic to figure out the new board where I moved the filter caps to the tone board since running cap stack in a Fender chassis is a no go.
You really need to follow carefully that filter cap board layout it's tricky and I am wondering about that on yours. Others have built amps off the information as well.
M Fowler wrote:Yes I got my info from Bnwitt 3 years ago and used that to build the K60.
I also use the layout and schematic to figure out the new board where I moved the filter caps to the tone board since running cap stack in a Fender chassis is a no go.
You really need to follow carefully that filter cap board layout it's tricky and I am wondering about that on yours. Others have built amps off the information as well.
This is a loud amp.
Mark
I will double check that board, thanks. I suspect something around the presence control as apparently my phase splitter is not drawing like it should. My gradual/fast switch is acting up as well and those two areas could affect my voltages at those points. The phase splitter not working properly would certainly affect my gain and could be my biggest problem as I can get decent crunch and overdrive, just not loud volume. Thanks.
Found it...
I had the 470 ohm and 10k ohm phase splitter bias resistors reversed. Voltages are all spot on now and I'm looking for an opportunity to terrorize the neighborhood
Yes much better now. Went and got a matched set of 6ca7's and blew my B+ fuse. I noticed one is pulling down 200 to 300 ma's under playing conditions. I bumped the fuse up to a 1 amp fast blow and all is fine so far. Gonna have to find a field to play this thing in it's so loud.
I finished up a cabinet for this thing today and got a chance to run her up to the 2 o'clock position in gradual mode...WOW. The touch sensitivity on this thing and the chime and harmonics are unreal. You don't even have to touch the volume knob to clean up. I flipped it into fast mode and found I had to back it off to around 12 o'clock to cut down on the audible hiss and ...DOUBLE WOW, hang on baby. Everything nice about gradual mode, times 10. Fast mode tells on you immediately and no hiding it either. Your either warmed up and ready or not... I can see why the metal dudes like larger amps now. The bottom is just "there" with this amp solid, deep and clear, not one drop of mudd and balls to spare. I tried my Express afterwards and while still a great amp it doesn't add up to the K60 and it shouldn't. I feel this amp is the Express, Liverpool and Rocket all rolled into one...leave your volume knob untouched... just change your attack.
Separate out the bias board as well.
On V3 pin 1 and pin 6 are 461 and 444 resp. Pin 2 and pin 7 are 3.44 and pin 3 and pin 8 are 9.02 ... 
