seti Posted June 19, 2006 Share Posted June 19, 2006 I asked many people in Hope this question but didn't get an answer. The question came to me while we were listening to Coytee's wonderful MC30 macintosch amps. The transformers are potted on these. I am having some webster electric / allen 90 organ amps worked on and I noticed that the allen 90's have potted transformers while the same amp labeled webster electric does not have any transformers potted. What do they acheive by potting the transformer? What is the end result? Any info much appreciated. Quote Link to comment Share on other sites More sharing options...
Guest " " Posted June 19, 2006 Share Posted June 19, 2006 I asked many people in Hope this question but didn't get an answer. The question came to me while we were listening to Coytee's wonderful MC30 macintosch amps. The transformers are potted on these. I am having some webster electric / allen 90 organ amps worked on and I noticed that the allen 90's have potted transformers while the same amp labeled webster electric does not have any transformers potted. What do they acheive by potting the transformer? What is the end result? Any info much appreciated. Is this helpful? went to a few sites and found this to have broaded comments than most. //////////////////// The airtight case for encapsulated transformers. For more than 25 years, our encapsulated, or potted, transformers have proven so superior in meeting customer requirements that we no longer offer open-frame transformers. Potted transformers are highly protected from environmental dangers. They provide: Moisture Resistance: The potting compound guards the transformer in damp and humid environments, including wave soldering processes and wash rinses. Mechanical Strength: The potting compound protects the wire and complete winding from accidental cutting, dirt entrapment, and other hazards, so potted transformers are perfectly suited for industrial environments Shock and Vibration Resistance: The potting compound strengthens the grip of the pins, so the transformer requires no additional clamping on the PC board. All bobbins have up to 20 pin placement options. When applications require extreme shock and vibration resistance, we can add pins to further improve PC board adhesion. Increased Heat Transfer: The potting compound conducts heat more efficiently than air in an open-frame transformer, which results in a higher power/volume ratio In addition to these mechanical advantages, potted transformers offer an important electrical advantage over open frame transformers. Enhanced Insulation System: Our potting process is performed under vacuum, eliminating any air gaps or pockets in the potting compound. Accordingly, testing agencies consider the potting compound an insulator. This reduces spacing requirements, resulting in smaller packages with better insulation. //////////////////////////// Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted June 19, 2006 Share Posted June 19, 2006 Could you guys help me out with the term "potted"? I think you are referring to the transformers which have something that looks like an enclosure which contains the transformer. Is this enclosure have a fill material to pack the transformer in the enclosure? Quote Link to comment Share on other sites More sharing options...
Guest " " Posted June 19, 2006 Share Posted June 19, 2006 Could you guys help me out with the term "potted"? I think you are referring to the transformers which have something that looks like an enclosure which contains the transformer. Is this enclosure have a fill material to pack the transformer in the enclosure? seems like newer technology encloses and seals in epoxy, whereas older flavors used a thick tar substance. I think I have seen wax even used. /////////////////////////////////////////////////////////////////////////////// Key Features: Designed for push-pull tube output circuits. Enclosed in a drawn steel case, the transformer is completely potted in epoxy. Frequency response 30 Hz. to 30 Khz. at full rated power (+/- 1 db max. ref. 1 Khz) minimum. Lead connection is via 10 bottom mounted lugs. All units include 40% screen taps for Ultra-Linear operation (if desired). Typical applications - Push-Pull: triode, Ultra-Linear pentode, pentode and tetrode connected audio output. Cat. No. Audio Watts Quote Link to comment Share on other sites More sharing options...
BEC Posted June 19, 2006 Share Posted June 19, 2006 We crossover rebuilders are happy that Klipsch did not pot their crossovers like EV did. Bob Crites Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted June 19, 2006 Share Posted June 19, 2006 yuk! Those EV crossovers are downright icky. Quote Link to comment Share on other sites More sharing options...
garyrc Posted June 19, 2006 Share Posted June 19, 2006 Potted Transformers "Moisture Resistance: The potting compound guards the transformer in damp and humid environments" One McIntosh MC30 and one MC40 tube amp (which had gigantic, potted, power and output transformers) were taken in trade by Berkeley Custom back in the '60s. They had been on the floor in somebody's basement, and a higher level swimming pool leaked (big time) inundating the basement. The amplifiers sat under water -- chlorinated water -- for quite some time (I think it was a summer home, and nobody was around). Berkeley Custom hung them on hooks in the backroom, first one way, then another, so the remaining, now filthy, water could drain out, then toweled them off, and replaced some tubes. I think they replaced a very few soggy capacitors, and that's all. The beautiful chrome finish of the "deck" of the amps was totally corroded, and could not be remedied. Now this is going to sound like an urban legend, but I saw them, and I heard them through Klipschorns. Not only did they sound great, but they sounded much better, warmer, airier, than the Marantz 80 wt/ch RMS solid state amp they had in the store. Quote Link to comment Share on other sites More sharing options...
seti Posted June 20, 2006 Author Share Posted June 20, 2006 Thanks for the info guys I'm going to pot my transformers and sink them in a pool ; ) Quote Link to comment Share on other sites More sharing options...
Marvel Posted June 20, 2006 Share Posted June 20, 2006 They are usually designed to be potted or not. It can change the electrical characteristics, and definitely will hold the heat in (can be good or bad-- would depend on the design) Quote Link to comment Share on other sites More sharing options...
Guest " " Posted June 20, 2006 Share Posted June 20, 2006 They are usually designed to be potted or not. It can change the electrical characteristics, and definitely will hold the heat in (can be good or bad-- would depend on the design) Hold the heat in - intresting comment. Not knowing from experience, I would have assumed the potting material would help in heat transfer. Quote Link to comment Share on other sites More sharing options...
Guest " " Posted June 20, 2006 Share Posted June 20, 2006 They are usually designed to be potted or not. It can change the electrical characteristics, and definitely will hold the heat in (can be good or bad-- would depend on the design) Hold the heat in - intresting comment. Not knowing from experience, I would have assumed the potting material would help in heat transfer. Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted June 21, 2006 Share Posted June 21, 2006 That's an heat transfer is an interesting issue. I suppose some materials would conduct heat better than others. My first thought is that it would serve as an insulator and hold the heat in. But I am blissfully ignorant. Quote Link to comment Share on other sites More sharing options...
Guest " " Posted June 21, 2006 Share Posted June 21, 2006 That's an heat transfer is an interesting issue. I suppose some materials would conduct heat better than others. My first thought is that it would serve as an insulator and hold the heat in. But I am blissfully ignorant. i really don't know. Thats why I said it was an intresting view. Open to new ideas though. I assumed (maybe incorrectly) that unpotted xformers had air gaps that were less conductive of heat than xformers with out air gaps due to the use of potting material. Quote Link to comment Share on other sites More sharing options...
Mark Hardy Posted June 23, 2006 Share Posted June 23, 2006 I actually thought one of the major reasons for potting transformers was to lessen the mechanical hum (buzz) of the laminations. Interesting question, isn't it? Quote Link to comment Share on other sites More sharing options...
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