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Grateful Dead Music Forum

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 #110233  by guitarcats
 Wed Feb 29, 2012 4:57 am
I have done a bit of searching but so far have had no luck. I have a 65 Fender DRRI that I want to modify so its close to getting a Jerry like tone. Since I just dropped a wad on getting my Phiga Wolf, is there any mods that I can do to my amp without breaking the bank? Thanks in advance!!
 #110237  by SarnoMusicSolutions
 Wed Feb 29, 2012 7:27 am
Sure... plenty.

You should visit Waldo's site:

www.wald-electronics.com


He's got a lot of preamp info. The Deluxe Reverb Reissue does a good job of sticking with the classic circuit. That circuit is very nearly the same as the Twin Reverb except instead of a midrange knob/pot, it's just a 6.8k fixed resistor.

But you can start by replacing the 100k plate resistors on the main preamp tubes with the Dale RN70 100k types. You can change the two tone-stack capacitors (.1uf and .047uF) for a pair of .022uF SBE Orange Drop 225p types. You can change the treble cap (250pf) to silver mica type. You can change the 22uf cathode bypass capacitors to Sprague 150d mil-spec tantalum types. And also there are other film cap's in the signal path that can be upgraded to the 225p Orange Drop types. Waldo's marked up schematic should help. There are more little places to tweak, but these are some good main places to make the amp more Jerry-like.


B
 #110266  by jeager
 Wed Feb 29, 2012 12:49 pm
You might let people know where you are and ask who in your area they have used for amp work etc... In case your not sure about a good tech in your neck of the woods.
 #110280  by guitarcats
 Wed Feb 29, 2012 4:56 pm
jeager wrote:You might let people know where you are and ask who in your area they have used for amp work etc... In case your not sure about a good tech in your neck of the woods.
I live in MN and already have a place. Its Savage Audio who makes the Savage guitar amps.
 #110308  by guitarcats
 Wed Feb 29, 2012 10:16 pm
Bobbyg wrote:Maybe you've already done this, but putting a JBL K-120 really helps too!
I installed a cannabis rex in last year and really like it so far. My plan is to start small with mods to the preamp and then sometime next year have it made into a head and get a 2x12 cabinet with the jbl's.
 #110511  by JonnyBoy
 Sun Mar 04, 2012 3:16 pm
I did some reissue mods and found the tone stack (tone controls) and the plate resistors (Dale metal film) really made it sing. BE CAREFUL soldering on the board. You can burn the board easily without using proper soldering technique/skill. The good thing about the PCB is that the components are clearly marked within the circuit for weekend warrior amp techs to find easily.