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ChristoMephisto
Platinum Member
Canada
1288 Posts |
 Posted - 02/28/2010 : 16:29:11
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Was playing with my OD1 clone and decided to remove the six way rotary for the clippers, seeing as I prefer the stock asymmetrical diodes better. Also modded it to older specs with more .1 caps and at C2/R4 removed the .0047/100k for .047/10k. Now it has more gain and bass, despite the hipass of 338Hz.
Supposedly this will get you 90% of the original sound of the early OD1s. In some other post someone quoted the 3403 was just two 4558s.
So this got me wondering, could Q5/Q6 on the SD1 be rewired though a 4558.
Sure enough it can
Remove Q5,Q6,R3,R15
From the Base through the Ve+(3,5)
Ve-(2,6) shorted to the Output(1,7) which goes to the Emitter
Vcc+(8) to one of the removed Collector
Vcc-(4) to Ground (R3 and R15 ground)
http://eu11.stripper.jp/pulcino/blog/archives/cat_boss_od1.html
http://www.godiksennet.com/images/sch/SD1PG2.JPG
Would this work or has anyone seen this done?
Or was this a waste of time in calculations n doodles? |
Edited by - ChristoMephisto on 02/28/2010 16:31:16 |
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cctsim
Silver Member
United Kingdom
418 Posts |
Posted - 02/28/2010 : 18:15:36
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In theory, it should work. You are basically replacing the bjt based emitter followers with opamp based voltage followers.
I haven't tried it myself, but I've read that opamps in this function sound a bit colder, whatever that means.
"From the Base through the Ve+(3,5)"
I guess here you mean base of Q5 to opamp pin 3 and base of Q6 to opamp pin 5.
You should be careful not to mix-up the opamp pins, e.g. pins 1,2,3 should replace the functionality of Q5 and 5,6,7 to replace Q6. |
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ChristoMephisto
Platinum Member
Canada
1288 Posts |
Posted - 02/28/2010 : 18:47:24
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quote:
Originally posted by cctsim
"From the Base through the Ve+(3,5)"
I guess here you mean base of Q5 to opamp pin 3 and base of Q6 to opamp pin 5.
You should be careful not to mix-up the opamp pins, e.g. pins 1,2,3 should replace the functionality of Q5 and 5,6,7 to replace Q6.
Exactly what i meant, no fear of mixing them up, got it all mapped out.
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cctsim
Silver Member
United Kingdom
418 Posts |
Posted - 02/28/2010 : 18:50:09
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| Let us know how it sounds once implemented. |
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ChristoMephisto
Platinum Member
Canada
1288 Posts |
Posted - 03/02/2010 : 10:50:50
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Well, pretty easy to wire up.
Now i have this high pitched whine come from it
Guess I'll go back to stock.
Nothing ventured, nothing gained |
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SD1>OD1 the faux Quadamp
