Toroids
I've had good luck ordering transformers from Avel (or Plitron) directly. Friendly, fast service etc. Shipping is most certainly cheaper than PE. Somebody mentioned earlier that PE was out of stock on one particular model. Avel was out of stock of a pair that I ordered and gave me then next size up in power rating for the price of the original.
I've had good luck ordering transformers from Avel (or Plitron) directly. Friendly, fast service etc. Shipping is most certainly cheaper than PE. Somebody mentioned earlier that PE was out of stock on one particular model. Avel was out of stock of a pair that I ordered and gave me then next size up in power rating for the price of the original.
If you're orderring direct from avel, CALL THEM, they respond to their emails after half a week if they respond at all.
now here's a GC supply:
this supply was $1 -- of course it weighs 76 pounds -- I bought 3 of them from NASA, the big transformer is 6x5.25X4 inches -- they use metal bars to connect the transformer to the filter caps -- fully regulated with a fan blowing on the pass transistors -- all in the cost was about $100 for 3 supplies -- we are using them in a CNC application, not a GC application -- this is to demonstrate the point that you can get great stuff for no bucks by watching for high power linear supplies on EBay.:
this supply was $1 -- of course it weighs 76 pounds -- I bought 3 of them from NASA, the big transformer is 6x5.25X4 inches -- they use metal bars to connect the transformer to the filter caps -- fully regulated with a fan blowing on the pass transistors -- all in the cost was about $100 for 3 supplies -- we are using them in a CNC application, not a GC application -- this is to demonstrate the point that you can get great stuff for no bucks by watching for high power linear supplies on EBay.:
Attachments
There's a guy in the PassDIY gallery that made a very small but higher power Son of Zen . He water cooled it using the pond for his garden fountain. His power supply was a very compact switching supply. His claim was there are different levels of switching supplies. His was surplus from a cell phone relay station. He said that it is a whole different animal than the crappy stuff in computers and recommended that these high end supplies be considered for audio use. Of course they are extremely expensive new, but surplus can be very cheap. I just don't know how to recognize them. One clue is they often are made to slide into a rack mount mother ship.
Re: Toroids
Check the Plitron site again. They have dramatically increased prices recently. Avel is now cheaper at PE!
Oh well. I also got a superb deal on a tape wound toroid at www.coilws.com. $38 for a 235VA. 6 week turn around 🙁 and still waiting. I recently went back to look around,and the same transformer is $50! Makes me wonder if someone didn;t have a SNAFU on the web site!
RKH said:
Check the Plitron site again. They have dramatically increased prices recently. Avel is now cheaper at PE!
Oh well. I also got a superb deal on a tape wound toroid at www.coilws.com. $38 for a 235VA. 6 week turn around 🙁 and still waiting. I recently went back to look around,and the same transformer is $50! Makes me wonder if someone didn;t have a SNAFU on the web site!
Re: Re: Toroids
Component parts are up pretty sharply -- seems that the inventory belching is done.
MantramAudio said:I recently went back to look around,and the same transformer is $50! Makes me wonder if someone didn;t have a SNAFU on the web site!
Component parts are up pretty sharply -- seems that the inventory belching is done.
FS Gainclone toroids 50Vct 250Va
While cleaning up in my warehouse due to fire department
wanting bigger aisles found some 50Vct 250Va toroids made
for a definitive technology amp. They are priced at $25.00ea
p/n 15-0066. these are not on the website.
Steve @ Apex Jr
818 248-0416 Voice
steve.apexjr@prodigy.net
While cleaning up in my warehouse due to fire department
wanting bigger aisles found some 50Vct 250Va toroids made
for a definitive technology amp. They are priced at $25.00ea
p/n 15-0066. these are not on the website.
Steve @ Apex Jr
818 248-0416 Voice
steve.apexjr@prodigy.net
www.coilws.com has tape wound toroids at great volume prices. The price break is at 50, so if anyone wanted to do a group buy, I'd be willing to host it. I'm thinking about this anyway, so if anyone is interested, 18VCT 325VA 's will be around $36 if we bought 50.
Lead time is 4-6 weeks, and I have one ordered that should arrive any day now. I'll hook it up, measure it, and report my findings.
Nik
Lead time is 4-6 weeks, and I have one ordered that should arrive any day now. I'll hook it up, measure it, and report my findings.
Nik
Peter Daniel said:
Yes, 18-0-18. They are made to order overseas and imported by this company.
Let me get mine and test it and I'll publish results. The only bad part is with only one I wont be able to test the consistency of it, but I'll have a good idea about the quality.
Other than quiescent current, what other tests should I run? I have access to a scope and RMS meters.
They'll make any size, but I figure we could standardize maybe 2-3 sizes and have a good offering for the DIYers.
Maybe:
160VA 18VCT for the true dual monoblockers.
235 VA 18VCT for the average budget shared PSU.
400VA 18VCT for the over the top shared PSU.
Of course these are aimed at Chip Amps, and I picked one that suits LM1875-ers and LM3875-ers.
Peter you strike on a point not made here before. Any tranformer that is CT and not DUAL secondary is not really suitable for GC as the star ground is compromized. So a tranformer should read "Dual 18 VAC secondaries" instead of all these deals that say 36 VCT and similar. That is of you are an orthodox GC builder and want the better performance of you PSU.
UrSv:
I have a question:
You mention dual secondaries, to me that means 4 wire
output whereas a center-tap will only have a 3 wire output
Why would you need the extra wire.?
Steve @ Apex Jr
I have a question:
You mention dual secondaries, to me that means 4 wire
output whereas a center-tap will only have a 3 wire output
Why would you need the extra wire.?
Steve @ Apex Jr
Apex Jr said:
Because the orthodox GC building calls for a perfect separation of return currents and a perfect star ground in order to achieve the best performance. Can't be done with a CT transformer AFAIK.
I suspect that center tap business is some old US tradition as I never see this in Europe where we, or at least I, do not see CT anywhere for toroids and I cannot see why on earth you would not have dual secondaries on a modern transformer when CT only imposes limitations and problems and AFAIK has no benefits. Different issue though.
I did some comparisons and two separate bridges sound better than a single one possible with center tapped windings. There is no really any difference in transformers having dual secondaries and the center tapped. The only difference is that for CT the wires are connected under the wrapping and have a common wire on the outside. I found this not to be a big problem and so far I didn't encountered a transformer I couldn't convert to 4 wires (from centertapped 3 wire setup).
But when you order custom transformers always ask for dual secondaries and dual primaries (in case you want to use it in 230V areas).
But when you order custom transformers always ask for dual secondaries and dual primaries (in case you want to use it in 230V areas).
one of the small probs with CT's
is that they are not necessarily tapped at the exact center. this becomes a potential problem in high efficiency switching designs.
i really can't see how it is problematic at all in a linear power supply design, in fact, I am wont to call this more of the audio urban mythology.
is that they are not necessarily tapped at the exact center. this becomes a potential problem in high efficiency switching designs.
i really can't see how it is problematic at all in a linear power supply design, in fact, I am wont to call this more of the audio urban mythology.
Sedlbauer transformers
Hi!
I recently found at Distrelec a 2x18V 150VA transformer by Sedlbauer AG (Germany). The brochure may be found here . These transformers feature an integrated thermostat, switching off at 125 °C. This product costs in Italy about Eur 28; it is 5 Euros cheaper than the 160VA Talema (RS) and 10 Euros cheaper than the 160VA Avel-Lindberg (Farnell). I don't know if they have a reseller in USA.
Ciao,
Massimo
(this is not an aureole; it's a toroid!)
Hi!
I recently found at Distrelec a 2x18V 150VA transformer by Sedlbauer AG (Germany). The brochure may be found here . These transformers feature an integrated thermostat, switching off at 125 °C. This product costs in Italy about Eur 28; it is 5 Euros cheaper than the 160VA Talema (RS) and 10 Euros cheaper than the 160VA Avel-Lindberg (Farnell). I don't know if they have a reseller in USA.
Ciao,
Massimo
(this is not an aureole; it's a toroid!)
Massimo, I like the anatomical reference
are your torroids pink ?
(this is heading nose-first into the Sin Bin!)
are your torroids pink ?
(this is heading nose-first into the Sin Bin!)
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