My version of Joe Bento's AA4 guitar amp
 

I built Joe Bento's guitar amp for my son a few days ago. It was a
simple project to put together. I did swap out the 35W4 tube with a
50DC4 so I did not have to put a dropping resistor for the filament.

This little amp works great, here it is in the raw. I was going to sand
and spray paint the chassis but I decided leave it as is.

Sal

My version of Joe Bento's AA4 guitar amp
 

Sal wrote:
I built Joe Bento's guitar amp for my son a few days ago. It was a
simple project to put together. I did swap out the 35W4 tube with a
50DC4 so I did not have to put a dropping resistor for the filament.

This little amp works great, here it is in the raw. I was going to sand
and spray paint the chassis but I decided leave it as is.

Sal

Nicely done, Sal.

-Bill

My version of Joe Bento's AA4 guitar amp
 

On 2009-06-05 06:04:53 -0600, Sal said:


I built Joe Bento's guitar amp for my son a few days ago. It was a
simple project to put together. I did swap out the 35W4 tube with a
50DC4 so I did not have to put a dropping resistor for the filament.

This little amp works great, here it is in the raw. I was going to sand
and spray paint the chassis but I decided leave it as is.

Sal


Very nice, Sal. Isn't it amazing just how loud 3 watts is when feeding
an efficient speaker? I'll have to remember the 50DC4. That resistor
is otherwise just a source of heat under the chassis.

I made another amp with a 12AX7 and 50L6. Did I post a photo? I don't
remember. Inserted again for your viewing pleasure. I havn't
transferred this one to a permanent chassis yet. In this one, the
primary of the transformer is wired for 240, giving 60V at the
secondary - perfect for the series string heaters. Plate voltage is
then derived through a solid state doubler. I alctually like the tone
of the 50L6 better.

I think I'll stick with alumunum for most future projects. The black
powdercoat chassis, while very nice, is much harder to work with than
aluminum.

My version of Joe Bento's AA4 guitar amp
 

Thanks Joe,
I wondered how you dropped the filament voltage, smart idea.

Maybe I have to build the 50L6 version... :-)

Sal

Joe Bento wrote:


Very nice, Sal. Isn't it amazing just how loud 3 watts is when feeding
an efficient speaker? I'll have to remember the 50DC4. That resistor
is otherwise just a source of heat under the chassis.

I made another amp with a 12AX7 and 50L6. Did I post a photo? I don't
remember. Inserted again for your viewing pleasure. I havn't
transferred this one to a permanent chassis yet. In this one, the
primary of the transformer is wired for 240, giving 60V at the secondary
- perfect for the series string heaters. Plate voltage is then derived
through a solid state doubler. I alctually like the tone of the 50L6
better.

I think I'll stick with alumunum for most future projects. The black
powdercoat chassis, while very nice, is much harder to work with than
aluminum.

------------------------------------------------------------------------

My version of Joe Bento's AA4 guitar amp
 

Bill M wrote:
Sal wrote:
I built Joe Bento's guitar amp for my son a few days ago. It was a
simple project to put together. I did swap out the 35W4 tube with a
50DC4 so I did not have to put a dropping resistor for the filament.

This little amp works great, here it is in the raw. I was going to
sand and spray paint the chassis but I decided leave it as is.

Sal

Nicely done, Sal.

-Bill

Thanks Bill.

Sal