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Anyone hear from Paul lately? I asked him about transformer manufacturer suggestions for the TDR-21 but he has not responded in several days.
I think I am going to get a 250va 25vdc primaries transformer, either Avel Lindberg or Plitron toroidal, unless someone can steer me to a better choice. A bit overspeced, but I think that may yield some benefits, as a bit stiffer power supply is never a bad thing :)
Parts Connexion in Canada have some nice Hammond toroids, I've used them before and they're very quiet.
I think Paul's philosophy concerning transformers for top rate DC power supplies, is that they need to be specialy designed to prevent inrush currents at switch-on causing saturation of the core. He offers his own very specially wound transformer which unfortunately is very heavy. I considered getting one but the postage to OZ was about the same as the cost of the tranny.
Mike
So what transformer did you go with?
Martin,
I have used AVELs and never had a noise issue so far, like the transformer humming.
Pete
Hi Pete,
At the current time I am still trying to decide what path to take.
At the moment I am still using a KAB would you believe; but I have changed the DC connection point to bypass the rectifier bridge, increased the size of the input cap on the PCB (effectively across the incoming DC line that ) and doubled the size of C3, the main 21V DC cap. This has provided me with what I consider to be a moderately decent PS. However I really must bite the bullet and build a much impoved supply if I can locate a local quality torroidal transfomer. The problem as Paul indicated some time ago, a lot of these components although they may be indicated as being of high quality local manufacture, actually come from that large country next to Taiwan
I should also mention that I have replaced the KAB connection lead with far more substantial quality wiring and a better plug/socket.
Hi Pete,
Sorry for the tardy reply. I am very busy at present catching up will all the production delays through December into the New Year for various weather issues (no transit of incoming or outgoing goods and loss of mains power during gales up to hurricane force), holidays and the occasional virus attack (yes we get them out here too). Aside from all the catch up effort my e-mail inbox is overflowing with a much larger than usual influx of enquiries both technical and sales, oh and the trading figures for the end of January Tax assessment have taken a few days to deal with. Expect delays with everything for a while.
A 250VA 25vac transformer will work.
Re the transformer I use, these are a special build and custom made in small quantities to my specification for each application. Sorry this is costly but there is no way around this for high quality transformers in a relatively small market. I would not have these transformers made if there were no benefits to sound quality. Added to the transformer cost is the high cost of overseas insured and tracked shipping via fast air services.
I have not used AVEL transformers for a long time or Plitron transformers at all so cannot comment on their abilities.
Regards
Paul
Sorry :oQuote:
Originally Posted by Paul Hynes
No need to be sorry Martin, most of the e-mail is from abroad and nothing to do with Technics power supplies.
Regards
Paul
I'm knee-deep in the phase 3 regulator upgrades. More later...
Fantastic. Once again, cant wait for your update.Quote:
Originally Posted by MartinT