After five years of trying to get this #102 style build to sound real. It was ok but not good
I did use a PPS but other than that stock Fender Twin Code 606 transformers date 1971
no matter what did to the circuit it never delivered the goods. It did the feedback city thing.
No magic I used the resistors and Sprague 6PS capacitors that Dumble used on the real #102
Still no avail. Then I scored a set of NOS Thordarsen-Meissner EIA code 238-9608 Twin set transformers.
What a difference it sounds real now with only one hour of play time on the NOS transformer set.
I'm not sure what brand of transformers is in the real #102 anybody in the know please chime in.
Best regards, Steve.
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67plexi wrote:After five years of trying to get this #102 style build to sound real. It was ok but not good
I did use a PPS but other than that stock Fender Twin Code 606 transformers date 1971
no matter what did to the circuit it never delivered the goods. It did the feedback city thing.
No magic I used the resistors and Sprague 6PS capacitors that Dumble used on the real #102
Still no avail. Then I scored a set of NOS Thordarsen-Meissner EIA code 238-9608 Twin set transformers.
What a difference it sounds real now with only one hour of play time on the NOS transformer set.
I'm not sure what brand of transformers is in the real #102 anybody in the know please chime in.
67plexi wrote:After five years of trying to get this #102 style build to sound real. It was ok but not good
I did use a PPS but other than that stock Fender Twin Code 606 transformers date 1971
no matter what did to the circuit it never delivered the goods. It did the feedback city thing.
No magic I used the resistors and Sprague 6PS capacitors that Dumble used on the real #102
Still no avail. Then I scored a set of NOS Thordarsen-Meissner EIA code 238-9608 Twin set transformers.
What a difference it sounds real now with only one hour of play time on the NOS transformer set.
I'm not sure what brand of transformers is in the real #102 anybody in the know please chime in.
Best regards, Steve.
Another note, the power tranny in 102 has multi taps, MAY have been say trainwrecked,( like the dumble modded marshall i`ve seen in pics) he`s using a multi tap primary , so lower voltages could be in order, ya never know! If you havent been in it firsthand, anything could be possible....a tech could easily change that for outa country use..
Thank you Max. I understand the layout claims that Woodward-Schumacker transformers were used. It may be fact.
On my low Plate classic ODS-100 I did use a 606-142 OPT with 4 and 8 ohm taps PT 606-6937 PT wonderful sounding amp.
I have a suspicion that MR Dumble tested the frequency response on all the OPT he used http://personalpages.manchester.ac.uk/s ... 124020.jpg
I went through OPT hell with the Tweedle Dee Deluxe built the first one in 4 hours using a 606-905
1959 OPT 4 and 8 ohm taps. Then trying to build a back up amp #2 400+ hours later 4 different PT
3 Different OPT then found one more 1959 OPT 4 and 8 ohm taps both were NOS that did it.
All I can say is in 1959 Woodward-Schumacher OPT were very consistent in their transformer windings. The early TF-135 and New Sensor were
Thordarsen-Meissner not now.
Charlie, Fender did offer a special order 4 and 8 ohm secondary's
on the Showman amps. I got my 606-142 OPT from a Carvin X-100
1981. I have serviced just a few of the Showman amps with dual 4 and 8 ohm secondary's they do exist but are rare.
Steve, that is interesting. I really don't care for the sound of the 4 ohm to 8 ohm mismatch. So the only thing that would get me to go through the trouble of replacing the Mojo Twin Heybor I have now is to find a transformer with an 8 ohm tap or a 4 and 8 but I don't think that is going happen in the near future. You know I was thinking about your experience with your 102 amp and I guess you can play with resistors and caps and even tubes but if the transformer isn't right it will be in vain or at least you only get part of the way there. I have purchased many vintage Schumacher transformers for Fender amp repairs and they all aren't good. In fact some were dogs. I am kind of at the place with my Low Plate Classic were I have become very critical of the sound. One day it sounds pretty good and the next day not so much. It has this hard high end that I can't seem to tame and I am at the point were I am second guessing everything. I guess this is just part of the process of amp building especially these circuits.
CW
What speakers are you running this through? I have a coffee-can SRO that works well for an an amp that was a little harsh on the top end. No fun to carry but that's another issue. FWIW, sh
Darin, The Thordarsen-Meissner PT is 12.5 volts higher under load B+ 477.5 v than the Fender Iron 465 v
My best sounding Amp so far has 500v B+1 under load.
Adjusting the dropping string I don't think it matters.
