Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Misc Schematics and Layouts => Topic started by: jessetrbo on November 18, 2017, 04:52:42 pm

Title: In search of a schematic: Lesmann 500-P (Accordio-Organ amplifier)
Post by: jessetrbo on November 18, 2017, 04:52:42 pm

Greetings:

I recently purchased a Lesmann 500-P "Accordio-Organ" amplifier and am in search for a schematic.  It's a 3 channel combo amp with a 15" CTS speaker.  There are 4 12ax7s, and a lone 12au7. 

I am well aware that this is probably an impossible endeavor... I've searched this forum, the internet in general, and called a shop in Milwaukee that has some of these amps (but no techs in house) and I'm coming up empty.  Aside from my efforts, these amps aren't popular (or even known) so there doesn't seem to be much discussion anywhere.

The amp has been cared for... and serviced in the not too distant past.  It works, despite the power filter section being heavily modified (I've seen a pic of as similar Lesmann that had 5 caps and two resistors, as you might expect.  My amp has a resistor and two caps!).

I am hoping to learn more about it, hence my inquiry.  In the meantime, I will slowly try to draw the layout and try to make some analysis on my own.

Thanks for your time,

--Jesse

Title: Re: In search of a schematic: Lesmann 500-P (Accordio-Organ amplifier)
Post by: sluckey on November 18, 2017, 05:07:38 pm

Quote

There are 4 12ax7s, and a lone 12au7.

Surely there are more tubes.

Quote

I will slowly try to draw the layout

Drawing a schematic will be 1000x more useful than drawing a layout.

Posting some high rez pics would be helpful too.

Title: Re: In search of a schematic: Lesmann 500-P (Accordio-Organ amplifier)
Post by: rafe on December 04, 2024, 08:11:43 am

did you ever find a schematic?