Allen 20 watt amp

Joined
Jun 12, 2010
Messages
2,492
Location
Willamette Valley
#1
Well.....I finally got motivated to start on the Allen 20 watt amps I have. I was considering modding the circiut but I've decided to give it ago stock for now. I've completed the recap on one at this time.


All caps were replaced save for one that goes to the extension socket. The carbon comp resistors were replaced with metal film 1% resistors. The red resistors were left for now as they are supposed to have "mojo" to them. Can cap was replaced with a 40uf + 40uf can on top and 10uf underneath.


Fired it up and it was nice and quiet. No red plating and no noise. Listening to 20 minutes or so of music and all is well.


It's been running now for about 40 minutes or so and no issues and it's not hot.


Time to get going on a second so I can hear these guys in stereo


Before:





After:





 
Joined
Jun 12, 2010
Messages
2,492
Location
Willamette Valley
#10
Just to update this a bit there was quite a bit of gain at the input with the pot so with the help of a friend I bypassed the first gain stage of the 12AY7 and sent the tip of the RCA jack to a .1uf cap then onto the second gain stage. This works much better with a pre amp. The other RCA is still usable with the potentiometer so it's the best of both worlds.... :)
 
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