Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Leevi on April 26, 2011, 02:07:28 pm
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What is the relation between these amps?
Is CBS a copy of Bogen CHA-20?
/Leevi
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The Carolina Blues Special is a completely gutted Bogen CHA-20 that I rewired. I simply kept the chassis, PT, OT & sockets. I added a reverb trannie and an additional 12ax7 socket. I have a bunch of photos of several conversions.
The wiring was a real mess but the amp was dead quiet at idle anyway.
I rewired three different Bogens into CBS amps. They all sounded great to me. It's a warm cleaner tone amp. I thought the amp sounded somewhat like HotBluePlates 5E3 but cleaner and with reverb. (he was over to jam and brought his 5E3) I still have some recordings done with those amps.
Later, I made two more CBS amps from scratch & those were built into 18w type tweed chassis.
With respect, Tubenit
I think I did this recording with the Bogen head in the picture below (all the guitar work is this amp) :
http://www.soundclick.com/player/single_player.cfm?songid=6775767&q=hi&newref=1
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I'm trying to find a schematic for an acoustic amp and based on one earlier track the
CBS could be suitable for that purpose?
/Leevi
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The following remarks are regarding acoustic guitars with K&K Western pickups. However, I've used an acoustic with a piezo also and got somewhat similar results.
The Carolina Blues Special with a Jensen re-issue C12Q sounds excellent with an acoustic guitar! My son-in-law is a superb acoustic player & I've heard both nice Martin and Larrivee guitars played thru his CBS and I thought they sounded really wonderful.
Having said that, I use the clean channel of my Tweed BluezMeister with the PAB and mid-boost off & the volume set on "3" to play with my band when an acoustic is needed. I'm using a Emminence Red,White and Blues but honestly I think a cleaner tone speaker that allows better highs would work better. Something like the Weber 12F150 would be a good choice I think. I have a Larrivee also.
I think the main thing is to get the preamp plate voltages somewhat high such as 180v-230v for an acoustic.
With respect, Tubenit