1/2 watt tube guitar amp

[rcavictim]

I once made a "pintsize" amp with a 1U4 tube..Little OPT from an old TV,and a camera flash circuit for the power supply!
It worked nicely,and could drive a little 1-inch speaker(similar to whats in headphones) pretty loudly..
The camera flash made a nice little power supply,running from 1 'D' cell,and another for the filament.

Hey DJ,

That was very innovative of you! What kind of camera flash unit did you use and what kind of plate voltage and current could it support on the valve? I have a whack of disposable flash camreas which you can get free from film development shops as trash after they remove the exposed fim to process. The little HV power supply is nifty but I never imagined to use one as a vacuum tube plate supply for a portable amp.

 

[DigitalJunkie]

My camera flash circuit came from a disposable camera also.(those HV caps are useful in tube circuits! )

I've no idea of the voltage/current.. I think I could get it up to about 400V,if I let it sit and charge the cap for a bit,but it would of course dip down a fair ways with a load...(Mind the voltage! most of the caps appear to be 330V/350V types.)
They don't seem to be able to support a very current-hungry load,but it was okay for a small "flea" amp.

Maybe you could parallel two camera flash circuits for more current?
Perhaps a flash from a "real" camera would be a bit "beefier" ?
Or maybe you could get a bit more power if you ran it from a higher voltage? (3V instead of 1.5?)

I remember playing with 1U4's and 3S4's(?) on the bench with that circuit..that little amp was pretty impressive,for a hacked-together experiment I did just for fun.

The OPT I used was the audio OPT from an old B+W Solid State TV.

Hum,thats about all I remember.

Let me know if anyone tries it,i'm interested to see how it turns out!

 

[ThSpeakerDude88]

Testlab:

thats ok, thanks!

 

[yamhill]

looking for "niteglow" guitar amp schematic - low power guitar amp

I'm looking for a low power guitar amp hopefully like the one described below. I'm very late to this thread, and the link is dead.

Thanks

Sounds like you have almost exactly the same requirements as I had some time ago. I ended up making my own design using affordable parts. It is a single tube amp using the ECL82 and no controls.
The ECL86 could be even better. It would be nice to try if it could be a drop-in replacement.

Here is some more info about my "Niteglow" amp:
http://www.angelfire.com/music6/thomas_s/

-thomas

 

[thomsva]

Hello, Yamhill.

I made a new version of the amp and also made a new website: http://www.freewebs.com/niteglow/

 

[Brett]

Hello, Yamhill.

I made a new version of the amp and also made a new website: http://www.freewebs.com/niteglow/

Cute. I've done something similar in a tube pre for bass with the intent of getting a more tube poweramp tone from a tube pre, SS power combo.

 

[unclejed613]

if you use submini tubes powered with a 12V gel-cell, you could make a tube output "pignose" style amp. some of those submini beam pentodes are rated at 3W, and you could get the required plate voltage (about 100V) with a simple DC-DC converter.