Other web Sites
Harmonica Blues  Harmonica Amps
Harmonica Links Harmonica Pages
• Archives Home
• Years
 · 1992
 · 1993
 · 1994
 · 1995
 · 1996
 · 1997 		 · 1998
 · 1999
 · 2000
 · 2001
 · 2002
 · 2003
 
Web HarpL
Ebay Searches:
Amps:
Microphones:
Effects:
Harmonicas and Gear:
Harmonica Music and Instruction:

 

 

Harp-L Archives

[Previous Message] [Next Message]
[Next in Thread]
[Start of Thread] [End of Thread]

From: Mike_Diro~msmucker.com
Date: Sun, 19 Sep 1999 14:31:03 -0400
Subject: Bassman Stuff (No Harp)

I have been reading "A Desktop Reference of Hip Vintage Guitar Amps" by Gerald
Weber. In it he discusses several mods to "improve" your Bassman.

Here is one that requires no tools. When/if you look at a schematic, it makes
sense, but may not be obvious. "The way the volume controls on each channel are
connected, the one that you are not using actually affects the tone and volume
of the one your are using. Actually the one you are not using both increases
the grid resistance of the second gain stage as you turn it up and grounds out
some highs. You get maximum gain and bottom when it is about one third to one
half all the way up, depending upon the taper of the individual pot." It makes
a difference, fire up your amp and see for yourself.

Another mod I have seen discussed here on the list, but was reluctant to believe
until I read and tried, is patching the normal and bright channels. Plug your
harp mic into your input of choice, then use a 1/4" patch cord to connect the
remaining input to the number one input of the other channel. Adjust both
volume controls to suit your taste. According to Gerald, "This will strengthen
the signal that the power tubes get from the preamp." I have questions about
what is going on with the signal (i.e. splitting in half?, half volume per
channel?, increased/decreased current flow?), but can tell you it does make a
difference in the sound. Whether it helps get "the sound" or not, you'll have
to decide.

Another mod discussed that relates specifically to the RI Bassman is the speaker
connection. This is one I have not yet tried. On page 54 it states, "Also, if
you own a Fender re-issue, you will want to reverse the speaker wires on each
speaker so that the amp plays forward like an original." Weber discusses how
the original Jensens were not labeled for polarity according to "modern"
standards (the exact opposite of it). In a nutshell, this means your amp plays
backwards compared to an original. Weber states it will increase apparent low
end. Once you locate the positive speaker lead (by today's standard), it should
go to the sleeve of the plug and the negative terminal should go to the middle
of the plug.

I have to offer a disclaimer because I'm no Electrical Engineer, so try at your
own risk.

I would recommend Weber's book to anyone who wants to learn a little about tube
amps. I can't vouch for the technical integrity of the book, but I think I
learned a little.

Jelly