Tuesday, July 20, 2010

One more mod


In addition to my DS1 having a variation of the Modern & JCM mods including the hifi mod that replaces almost all resistors & capacitors to higher quality components the distortion was still a little bit on the fuzzy side.Trying the AMZ fat mod I remember the distortion being much more defined and pleasing however, this comes with the cost of much less distortion on tap. This got me thinking, looking at the two resistor’s that bring the gain down from the fat mod its really only R-9 that sets the amount of available gain (R-6 set the proper working voltage of 4.5v with the fat mod). Even with all the mods to my DS1, I still had a lot of gain on tap so I thought I could sacrifice a little gain for some character of the fat mod.

The original fat mod replaces R-9 (22 ohm) with a 1k resistor, in the parts bin the smallest value of resistance I had was a 100 ohm so I gave it a shot & I got exactly what I wanted a touch of the fat mod tone & slightly more bass at the cost of just a little reduction in distortion. With the small change in value to R-9, R-6 did not require a change to re-bias the transistor. measuring the voltage on the collector of the transistor is 4.37v that is good enough the ideal voltage of 4.5v.

For more info on the AMZ DS1 Fat Mod & how it works click here:

With variations of all four mods, I now have a DS1 distortion pedal that’s more suited to my needs, of course, I always want a bit more bass but the overall tone is what I was looking for.

To finish the pedal off, a ‘Marshall JCM’ decal & new knobs.

Here's the final list of changes;

-D4 = 1N4148 Connected in Series to another 1N4148
-D5 = Square RED LED
-R13 =1k
-R17 =15k
-C8 = 1uF
-C9 = 1uF
-C5 = 1uF
-C2 = 1uF
-C3 = .033uF
-R9 = 100R

Best of luck on your DS1 mod adventures…

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1 comment:

  1. I don't see how you combined the modern mod and the JCM mod? The only change is the D5 LED and the R9 100R :) Or am i wrong?

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