![]() The other amp with the bigger xfmrs was from 1963. I don't remember if I specified the ages, this one was built in 1966. I have another 4 channel Leslie amp that has the larger transformers on all channels, I guess the bean counters got involved with the designers to cut costs by the time this one was made. That's the original, as weird as it looks. lolYep, T2 was the one that went south- bummer. It looks like too nice an amp to risk trannies on, much less vintage 7189's! =)Įdit: Assuming now, that the tranny you're replacing is T2 (second from left in the DSCN1400 pic), that would explain the size difference, but the construction difference in that OT still 'grabs my attention' for whatever reason. I'd definitely be wondering about that segment of the circuit given the above.Īlso have to agree with replacing all the electrolytics in that puppy. Color is close, but construction made me wonder since is was so different from the other 3 OTs and also the PT. Yeah first glance at pic DSCN1400.JPG had me wondering if the one OT had been replaced. I removed the bell ends, everything looks great inside- it just doesn't work right. I ended up replacing all that stuff with discrete parts, and will clip the contacts on the cap cans to leave them in the sockets (for good looks). I really need to get a Variac- what a great tool. ![]() A second visit from one of them helped find the root of the trouble, and I will do the rest of the repair myself. #SPECIFICATIONS JENSEN C15L HOW TO#Either of them could have identified the problem more quickly, but they took the time to explain to me what needed to happen, why, what to expect, and how to deal with things that didn't turn out as they should have. It feels great to have finally had some hands-on direction from good guys who know their stuff. ![]() The new transformer weighs 3.3 lbs, the original weighs 2lb., 5 oz. Running that into a 16ohm load should double the primary to 8.5k, which should be acceptable for the 7189 output tubes. I'm going to replace it with a Fender OPT for a Hot Rod Deluxe.The old xfmr was rated primary 9.3k/16ohms, the replacement rated 4250k/8ohms. Naturally, the OPT that went bad is the larger one, for the bass- go figure. Once I took the bad channel out of the circuit, the other three seem to be holding. It will be tight, but I think I will be able to get it mounted on the chassis (may have to move one of the smaller ones over a bit, or some such minor modification), but the turns ratio and power handling capacity look to be a good fit. I eventually fund a transformer that should be an upgrade, via CE Dist. Once again, it was time to study and grow. Trying to obtain a replacement OPT from another Leslie has proven to be an exercise in futility. Eventually, we found one of the output transformers was showing a resistance. Still had a short in there as soon as the amps got hooked into the newly rebuilt power supply. I replaced the diodes, resistors, and electrolytics myself. I have now learned a great deal, and finally have a better handle on why things are as they are in there. The three of us worked together for five hours checking and measuring everything in the amp. When push came to shove, two of my friends (both serious electronics guys) came by to help me out. ![]() As things turned out, I had lots of work in diagnosing it. ![]()
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