Re: [Harp-L] Harp amp mods: Weber

[Rick Davis <bluesharpamps@xxxxxxxxx>]

I published a series of articles about a Fender Pro Jr harp amp project.
 You can find them at the Blues Harp Amps blog beginning here:

http://bluesharpamps.blogspot.com/2008/08/harp-amp-project-fender-pro-junior.html

The project did not include the mods suggested in the Weber article.  The
only circuit change was removal of the negative feedback circuit.  The rest
was just tubes and speakers.

Still, the results were quite good.  While nothing you do to the Pro Jr can
overcome its EL84 sound, the mods did improve its tone.

-- 
-Rick Davis
The Blues Harp Amps Blog
http://www.bluesharpamps.blogspot.com/



On Thu, Jun 23, 2011 at 11:59 AM, Robert Hale <robert@xxxxxxxxxxxxxx> wrote:

> I play a Fender Pro Junior and like it live, with line out to the PA.
> Gerald Weber's article here:
> http://www.harpamps.com/weber/Guitar51.htm
> comments on amp mods for harp generally, so I'm interested in what I
> can do with my Pro Junior.
>
> Your experience?
>
> *increase the value of the power supply dropping resistor that feeds
> the plate resistor of the preamp tubes
>
> *Larger than normal coupling caps: .1 uf  best for harmonica
>
> * self-balancing paraphase inverters rather than fixed
>
> *High idle plate current in the output stage
>
> Stay well
> Play well
>
> Robert Hale is the DUKE of WAIL
> Distance Learning via Webcam
> http://www.dukeofwail.com
> Gilbert AZ (Phoenix)
>
>