Single ended guitar amp w/ oddball tubes

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Chrome Dinette
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Single ended guitar amp w/ oddball tubes

Post by Chrome Dinette » Fri Sep 19, 2008 4:58 pm

Actually the tubes aren't that exotic, just not often used in guitar amps.

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It can use 6sk7's or 6sj7's in the first socket, 6sl7's or 6sn7's in the second.

I am somewhat baffled that it only puts out about 6 watts. Based on my voltages and what the 807 data sheets say, I should be getting at least 10, but I will figure it out eventually.

zerosum
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Post by zerosum » Fri Sep 19, 2008 9:19 pm

Cool post! :sb: As always!

I like the housing!

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Moog$FooL$
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Post by Moog$FooL$ » Fri Sep 19, 2008 10:17 pm

ew! ew! ew!! :sb: :sb: :sb:

super nice post again!! i really like your stuff, do you have a blog or some sorta homepage with your projects on it??

i'm assuming this one is similar to an old film projector amp; with those type of tubes in it anyways??
i've never even heard of the 807. :eek:

is that a 5u4 rectifier??

i've got an Ampro projector amp down in the basement waiting to be rebuilt but i'm sure it wont come close to this craftsmanship. :waah:

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Kent
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Post by Kent » Sat Sep 20, 2008 12:46 am

Wow! You've been on a building rampage the past year. Kewl stuff! Congrats! Now get those sound files up! :hihi:

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Chrome Dinette
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Post by Chrome Dinette » Sat Sep 20, 2008 6:47 am

I bought the housing on Ebay for super cheap, which is nice, because buying a chassis is one of the most heartbreakingly expensive parts of building an amp.

The rectifier is a 5ar4, the circuit is not really based on anything, but I am still tweaking it, though it already sounds pretty great, especially with a GGG May Queen in front of it.

I probably need to start up a blog, though currently anything synth related gets posted at Deviant Synth.

807's aren't too uncommon. They are actually similar to 6L6's, but with a plate cap. I just happened to find some at a flea market and they have a Flash Gordon/Frankenstein visual appeal. One has to use caution with them as the B+ is present at the plate cap. I installed a bleeder resistor on one pole of the power switch to drain the filter caps when the amp is off.

I need to post clips of some stuff somewhere, though all of the stuff I have built in the past year will end up on the next (((microwaves))) record in some form.

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Moog$FooL$
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Post by Moog$FooL$ » Sat Sep 20, 2008 1:18 pm

hey.

thanx for the reply. :coffee:

you seem to know much about valves, any advice for one looking for further education?? what have you done to educate yourself? i guess you are designing these circuits on your own.

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Chrome Dinette
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Post by Chrome Dinette » Sat Sep 20, 2008 5:33 pm

There is a ton of stuff out there to read. Some of the tube amp books geared toward guitar players have questionable info, like the Aspen Pittman book. That book is full of great schematics, though. I actually found the Gerald Weber books more helpful when I was just getting started, though the "good old boy" tone they are written in gets old after a while.

This site has downloads of US Navy electronics training manuals that can be quite helpful. Volume 6 is tubes. All of these are good for learning about electronics. If the tube volume seems too advanced, go back and read the basic stuff.
http://wiki.4hv.org/index.php/NEETS

another site with lots of good info:

http://www.pmillett.com/

Eric Barbour turned me on to this neon lamp text, that has cool ideas:

http://www.tech-systems-labs.com/books/GE-lamps.pdf

Look at schematics of different gear and see how they compare to each other.

I have only recently got to the point where I am confident enough to not totally copy things. I learned by modifying existing amps, building a kit and then building from scratch. I still have much to learn.

I built some synth modules from Eric Barbour's schematics at the CGS Synth website, and later built some preamps using his ideas with other circuitry and features added on.
Last edited by Chrome Dinette on Sun Sep 21, 2008 7:45 pm, edited 1 time in total.

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Chrome Dinette
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Post by Chrome Dinette » Sat Sep 20, 2008 5:38 pm

Also, it's expensive, but back issues of Vacuum Tube Valley have a lot of good information, and schematics, geared more toward HiFi, but helpful nonetheless.

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Moog$FooL$
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Post by Moog$FooL$ » Sun Sep 21, 2008 3:55 am

ok.

great & useful links their!! 8)

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