Hold the Horses!!!
Were talking apples and Oranges here...
I was refering to ONLY Output Transformers in my last post, since that relates to the original thread....
As for input transformers and the core materials they use is a whole different animal....
There are no "special" C-cores.... unless they measue the C-cores they recieve and only keep the top of the lot...similair to measureing and matching tubes....
The advantage of C-Core is that all the grain is oriented in the same direction...since it is made from thin strip of M6, ..... How you angle the cut for the gap is important also, since you change the amount of surface area in the gap which affects fringing ... WIth EI lamintaions the E and I are perpindicular in grain orientation..but the EI lamination can have some advantages...
As for a Dynaco ST-70 UL output transformers...they were low end bugdet stuff .....very colorized and not what I refer to as Hi End..
I wouldn't spend a whole lotta $$$ on something like that, since those outputs were quick and dirty design..... Hammond should be fine for matching that lower level of quality....
Chris
Were talking apples and Oranges here...
I was refering to ONLY Output Transformers in my last post, since that relates to the original thread....
As for input transformers and the core materials they use is a whole different animal....
There are no "special" C-cores.... unless they measue the C-cores they recieve and only keep the top of the lot...similair to measureing and matching tubes....
The advantage of C-Core is that all the grain is oriented in the same direction...since it is made from thin strip of M6, ..... How you angle the cut for the gap is important also, since you change the amount of surface area in the gap which affects fringing ... WIth EI lamintaions the E and I are perpindicular in grain orientation..but the EI lamination can have some advantages...
As for a Dynaco ST-70 UL output transformers...they were low end bugdet stuff .....very colorized and not what I refer to as Hi End..
I wouldn't spend a whole lotta $$$ on something like that, since those outputs were quick and dirty design..... Hammond should be fine for matching that lower level of quality....
Chris
Nobody has mentioned Bud Purvine at O-netics. I've just bought some OPTs from him based on the fact that he gets good press from Lynn Olsen, and that means something in my book, since Lynn uses/used to use Lundahl. He's a bit of a cult figure, and I have no idea of the waiting list - I waited a few weeks. He's a really nice guy and good to do business with.
HPurvine@aol.com should get him. I'd be interested in any experiences with his transformers - I haven't wired mine up yet. Andy
HPurvine@aol.com should get him. I'd be interested in any experiences with his transformers - I haven't wired mine up yet. Andy
cerrem said:
Hi,
I am not a transformer manufacturer, so I can't know all aspects of question.
I know only that Lundhal in their datasheets tells about a "Special" audio C-core, of their OWN production. See: http://www.lundahl.se/pdfs/datash/1620_3_7_9202.pdf
They also insist on their can and cores machine pruduction:
http://www.lundahl.se/pdfs/papers/design_philosophies.pdf
It is true special C-core? I don't know...
BTW speaking about MC stepup transormers was only a way to make an example of different philosophy between lundhal and sowter...not to speak about apples and oranges.
Examining all different products of a company sometime is useful to learn more about them...
get money back from Handwound transformers
I ordered a pair of 300B SE output transformers from Handwound Transformer operated by Dave Lucas and paid immediately through Paypal in May 2004. After the term that I expected to receive them, I started to e-mail him. I have written many e-mails to Dave Lucas between Sep. 2004 to May 2005. He always uses excuses such as ¡§ It¡¦s almost finished. It has been sent. They were shipped 2 weeks ago. It is in process now¡¨ to cheat.
Finally I asked him to refund, but the replies were the same - "The check has been sent". After a survey through internet I found that Dave Lucas has cheated many customers through internet for many years. Many customers were helpless to get money back, especially those who lived far away from Pennsylvania.
Some of Dave Lucas¡¦s internet frauds were appeared in diyAudio Forums and Tube DIY Asylum.
I decied to take action to get my money back. Tracking from the phone number that he left on paypal I found that Handwound Transformer was located in Erie, PA. His address was also found.
Thanks to diyAudio Forums and Tube Diy Asylum, I provided these information and a complaint letter to the Erie Regional Office of the Bureau of Consumer Protection. I got a reply from the office soon with a copy of Lucas's letter indicated that he will refund me immediately. I knew that this was the same old trick. After a few weeks, I wrote another complaint letter and mentioned that Lucas might also try to cheat. Final the clever attorney was able to force him refund me money.
I would like to thank the Bureau of Consumer Protection and would like to share my experience of getting money back. I hope that my experience can be helpful to stop internet frauds.
I ordered a pair of 300B SE output transformers from Handwound Transformer operated by Dave Lucas and paid immediately through Paypal in May 2004. After the term that I expected to receive them, I started to e-mail him. I have written many e-mails to Dave Lucas between Sep. 2004 to May 2005. He always uses excuses such as ¡§ It¡¦s almost finished. It has been sent. They were shipped 2 weeks ago. It is in process now¡¨ to cheat.
Finally I asked him to refund, but the replies were the same - "The check has been sent". After a survey through internet I found that Dave Lucas has cheated many customers through internet for many years. Many customers were helpless to get money back, especially those who lived far away from Pennsylvania.
Some of Dave Lucas¡¦s internet frauds were appeared in diyAudio Forums and Tube DIY Asylum.
I decied to take action to get my money back. Tracking from the phone number that he left on paypal I found that Handwound Transformer was located in Erie, PA. His address was also found.
Thanks to diyAudio Forums and Tube Diy Asylum, I provided these information and a complaint letter to the Erie Regional Office of the Bureau of Consumer Protection. I got a reply from the office soon with a copy of Lucas's letter indicated that he will refund me immediately. I knew that this was the same old trick. After a few weeks, I wrote another complaint letter and mentioned that Lucas might also try to cheat. Final the clever attorney was able to force him refund me money.
I would like to thank the Bureau of Consumer Protection and would like to share my experience of getting money back. I hope that my experience can be helpful to stop internet frauds.
Hey-Hey!!!,
I would recomend the 5k/100W Hammond 1650. 'R' is its designation I think. Either way, the spec is enough to differentiate it from the other 5k a-a Hammond offerings.
I have heard it in a few good circuits and it is really good. You can get it in a potted version for a bit more. Flat kicks even the Mk.iii output Iron.
I think both the A431 and A470 winds are available from Heyboer in Michigan. Both substantially less than $100 each too. The Dynaco Iron is not the only stuff that Heyboer can wind too. Another nice featue of dealing with Heyboer is that the bill comes with the Iron, not before it.
cheers,
Douglas
I would recomend the 5k/100W Hammond 1650. 'R' is its designation I think. Either way, the spec is enough to differentiate it from the other 5k a-a Hammond offerings.
I have heard it in a few good circuits and it is really good. You can get it in a potted version for a bit more. Flat kicks even the Mk.iii output Iron.
I think both the A431 and A470 winds are available from Heyboer in Michigan. Both substantially less than $100 each too. The Dynaco Iron is not the only stuff that Heyboer can wind too. Another nice featue of dealing with Heyboer is that the bill comes with the Iron, not before it.
cheers,
Douglas
Hey-Hey!!!,
I don't have any experience with the SE. If Hammond has changed from the two winding secondary on the 5k/100W I'd want to re-evaluate it.
I have a bit of experience with the Dynaco stuff, and it is *NOT* all that great. They're not bad, but I wouldn't put them into the $150 each category by any means. Half that perhaps...
cheers,
Douglas
I don't have any experience with the SE. If Hammond has changed from the two winding secondary on the 5k/100W I'd want to re-evaluate it.
I have a bit of experience with the Dynaco stuff, and it is *NOT* all that great. They're not bad, but I wouldn't put them into the $150 each category by any means. Half that perhaps...
cheers,
Douglas
I just read this thread with the comments about handwound transformers. It is pretty obvious now that this guy is a rip off artist. His web page has had a note claiming:
This has been there for about 6 months.
I won two "845SE transformers" from him cheap (about $110 for the pair) on Ebay when he just started his transformer operation. It took 6 months, and several emails, countless excuses, but I got the transformers. They actually worked pretty good and are still in the 845SE amp.
I later won a pair of 100 watt P-P transformers on Ebay (really cheap $55 for the pair). It took a 4 month excuse story again, and I got the transformers only after getting in touch with their ISP and explianing that one of their clients was perpetuating a fraud. The transformers do actually work reasonably good.
I was stupid enough to bid again, only to find that I had been blocked from all of his auctions. I emailed him and he replied that he blocked all of the Ebay customers that he did not make any profit on! I forwarded his reply to Ebay.
Friends that actually got any transformers from him later on all said that they were junk. Too bad, If he could have managed his business, he would have done well.
On a more positive note, I just received two transformers from Edcor today. The transformers look impressive, and were shipped bolted to a piece of plywood. I will report the results after I test them, in the associated thread.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=72654
This has been there for about 6 months.
I won two "845SE transformers" from him cheap (about $110 for the pair) on Ebay when he just started his transformer operation. It took 6 months, and several emails, countless excuses, but I got the transformers. They actually worked pretty good and are still in the 845SE amp.
I later won a pair of 100 watt P-P transformers on Ebay (really cheap $55 for the pair). It took a 4 month excuse story again, and I got the transformers only after getting in touch with their ISP and explianing that one of their clients was perpetuating a fraud. The transformers do actually work reasonably good.
I was stupid enough to bid again, only to find that I had been blocked from all of his auctions. I emailed him and he replied that he blocked all of the Ebay customers that he did not make any profit on! I forwarded his reply to Ebay.
Friends that actually got any transformers from him later on all said that they were junk. Too bad, If he could have managed his business, he would have done well.
On a more positive note, I just received two transformers from Edcor today. The transformers look impressive, and were shipped bolted to a piece of plywood. I will report the results after I test them, in the associated thread.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=72654
I am far from being convinced on this ....really I can't see what's in it on hand-made transformers....all I find is alot of inconsistencies and the occassional stamping wrongly inserted... as one might expect
Machine wound is far more reliable and the leakage L's & C's more predictable.
Can someone tell me what there is "special" is about hand- made ?
richj
Machine wound is far more reliable and the leakage L's & C's more predictable.
Can someone tell me what there is "special" is about hand- made ?
richj
Thee is a difference between 'made by hand' and being a 'Handwound' brand transformer.
On the other stuff I agree, I have employed a winder to produce some custom modifications to an old Peerless design and it is done with a machine winder and stacker, and of course the price is a quarter of the 'wound by hand' winder.
cheers,
Douglas
On the other stuff I agree, I have employed a winder to produce some custom modifications to an old Peerless design and it is done with a machine winder and stacker, and of course the price is a quarter of the 'wound by hand' winder.
cheers,
Douglas
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