| Posted by Bill | February 09, 2011 - 10:17 pm |
| I thought I noticed the tie between the resistors before but wasn't sure. It makes perfect sense now. Thanks |
| Posted by David Gillespie | February 09, 2011 - 07:20 pm |
| Hi Bill -- You got it correct in your last post. I tried to maintain the original Dynaco color code with the modification, so in the pic with the 5 ohm resistors, the green wire on the left goes to the cathodes of the left channel, the red wire on the right goes to the cathodes of the right channel, and the red wire in the middle goes to the output of the EFB regulator. In the pic of the filter cap wiring, the old cathode bypass cap is the terminal at 11:00, and has three wires connected to it: a red wire identified as "to EFB output" which comes from the 337 regulator, a black wire which goes to the two hum balance controls, and an additional red wire which is the red wire coming up between the two 5 ohm resistors. It is not easy to see, but careful inspection will show that the two center terminals where the 5 ohm resistors are mounted are tied together to make for a common connection to both resistors at that point. I apologize for the confusion, and hope this helps! Dave |
| Posted by Bill | February 08, 2011 - 07:37 pm |
| Or is the middle pink wire common for both resistors (coming from the output of the EFB) and you used green for one channel and pink for the other maybe? This would make sense, but hung me up for a while. Or maybe I'm getting too old! |
| Posted by Bill | February 08, 2011 - 06:28 pm |
| I have been studying the EFB mod and am wondering if there is a wire missing on one of the 5 ohm resistors going to the cathodes of the output tubes. I'm assuming that the pink wires are EFB output, but I don't see a second green wire going to the cathodes of the other channel. Or am I missing something maybe? |
| Posted by Bill | February 04, 2011 - 11:04 pm |
| Thanks Dave |
| Posted by David Gillespie | February 04, 2011 - 09:34 pm |
| Hi Bill -- Thanks for the interest! My installation was in an SCA35 of course, but I have communicated rather extensively through personal email with a fellow over on the diytube site who has installed the EFB modification in his ST35. Throughout that correspondence, he sent pictures of his work, which looked to be outstanding. If you check on the ST35 forum at diytube under the thread "Improved Performance for SCA/ST35 Amplifiers", go to nearly the bottom of page 4, and you will see his user name as "paart". If you contact him through that forum, I'm sure he will be happy to share his photos with you, and the forum for that matter. If you are unable to reach him, let me know here and I will contact his personal email to obtain permission to share his pictures with you. Thanks again for the interest! Dave |