View Full Version : 80's style DIY Build
02-01-2011, 10:18 PM
I am almost done building this for my son who took this clip. Just need to put the loop in and it will be done:
02-01-2011, 10:32 PM
Great job man! Sounds like a fun amp!
02-01-2011, 10:57 PM
Nice tones---- built in the garage, i love it !!!!..............gldtp99
02-02-2011, 05:41 AM
Most excellent dude! Nice looking and sounding build.
02-02-2011, 11:23 AM
I like .. well done.
02-02-2011, 11:28 PM
The power section is straight out of an old JMP2204 schematic. The only difference is that I'm pushing 475 volts on the plates of the EL34's. I used the 100K NFB into a 5K pot for Prescence. BTW, all the pots are PEC's
I am using 100uf on the plates, 50uf on the PI, 50uf on stages 3-4, and sharing 50uf on stages 1-2. I am using a 20K power resistor between B2+ and B3+(PI), 10K Between B3+, B4+, and B5+.
The preamp is almost exactly as a 2203MV pre, but there is an added gain stage in front which is straight out of the O'Conner TUT2 book which influenced Roccaforte and Splawn. The slope resistor and tonestack values are straight out of the 2204 schematic, but I got rid of the cathode follower and am using a plate fed design. This is what gives it the more "raw", "angry" tone that I like in this design. There is nothing "secret" or "special" in this amp other than me playing with the layout to make it quiet and stable for the long hall. I am using JJ pre's. I gold pin in V1 and standards in V2, V3. I am using the new JJ 6CA7 for power. The trannies are from Antique Electronics, just their standard JCM800 replacements. The filter caps are F&T's, Coupling and tone stack caps are Sozo's with three NOS mustards in there (my last ones). The chassis is a Callaham trainwreck express clone, the headshell was made by Pacwood (65 amps, Two Rock, JBL, etc...) The loop is the Metro loss-less loop.
What I have noticed when I build amps is that they get better sounding after a good 12-20 hours on them. My son will be driving my wife crazy with this little beast....
02-03-2011, 09:43 AM
Is good. I like.
02-03-2011, 10:18 PM
The amp is finished and is quiet and stable, but rocks with the best of them. The Metro loop is awesome. No tone coloration at all. Here are some pics:
It is now in my son's bedroom. It sounds a lot better than I thought it would...
02-05-2011, 01:35 PM
Wish I had a father like you growing up!! Great job!
02-08-2011, 09:00 PM
Hey hey, from theampgarage. DIY tube amp can-do central!
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