A bit of new info
I just found out the internet fraud addy for the FBI. Maybe if enough victims complain to them, it'll get Dave Lucas's attention, or "Handwound Transformers" out of business!! www.ifccfbi.gov is the site to contact, supposedly. I'm going to try. What's there to lose? Anyone with me?
I just found out the internet fraud addy for the FBI. Maybe if enough victims complain to them, it'll get Dave Lucas's attention, or "Handwound Transformers" out of business!! www.ifccfbi.gov is the site to contact, supposedly. I'm going to try. What's there to lose? Anyone with me?
I could be wrong, but I believe if the perpetrator is located in this country, the FBI will look into it. You've nothing to lose by filing a complaint. At very least- the more witnesses to the fact that Handwound Transformers is ripping people off on the web, the better our chances of getting some action. Thanx for your interest- Al
Is Handwound t i t s u p?
I just tried to access www.handwoundtransformers.com and do not get connected to the infamous Dave Lucas' website. It has been two years since hat thief took my money for a output xfmer order and has given me nothing but false email promises that I would see my product.
I just tried to access www.handwoundtransformers.com and do not get connected to the infamous Dave Lucas' website. It has been two years since hat thief took my money for a output xfmer order and has given me nothing but false email promises that I would see my product.
rcavictim:
Sorry to see that you got ripped off by Dave. The really bad part is that his 10K 25W SE transformers actually work pretty good. I got a pair of these a few years ago. I used them in several amplifier prototypes before they found a permanent home in my 845SE amplifier. They are good from 28 Hz to 30Khz (3DB) with 80 Ma flowing through them. They sound pretty good too.
There was another thread that also involved Handwound. Below is the comment that I left there.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=28636&highlight=
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:
quote:
Due to a backlog of orders, we will NOT be accepting new orders until we have shipped all pending orders.
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.
Sorry to see that you got ripped off by Dave. The really bad part is that his 10K 25W SE transformers actually work pretty good. I got a pair of these a few years ago. I used them in several amplifier prototypes before they found a permanent home in my 845SE amplifier. They are good from 28 Hz to 30Khz (3DB) with 80 Ma flowing through them. They sound pretty good too.
There was another thread that also involved Handwound. Below is the comment that I left there.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=28636&highlight=
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:
quote:
Due to a backlog of orders, we will NOT be accepting new orders until we have shipped all pending orders.
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.
I only WISH I had been lucky enough to have gotten my x-formers AT ALL!! I paid $356.00 via Paypal for a ST-70 output pair, power trans and choke. Got nothing but empty promises, excuses and lies. By the time I realized I'd gotten screwed: My Paypal and credit card dispute options had expired. If I'm ever in Pennsylvania: I WILL pay him a visit!!
I ordered ST50 transformers over a year ago, paid and still nothing.
He answered my first email, then "dave is out of the office and will get back to you", then "we have your details, stop contacting us" and now nothing!
I have a long memory and one day I'll holiday in the States and pay him a visit!
On a positive note it forced me to teach myself about opt's and make my own!
Expensive lesson!
He answered my first email, then "dave is out of the office and will get back to you", then "we have your details, stop contacting us" and now nothing!
I have a long memory and one day I'll holiday in the States and pay him a visit!
On a positive note it forced me to teach myself about opt's and make my own!
Expensive lesson!
I just surfed to the Handwound transformers website and it appears that the domain registration has expired.. There is nothing at all on that website about audio transformers, now it is some sort of fairly generic portal they put on parked pages..
See http://www.handwoundtransformers.com/
See http://www.handwoundtransformers.com/
Got questions
Hi all,
There is no doubt that I don't have the 'ear' for much of the sonic details your talking.
But it got me thinking about this sub standard transformer dealer.
Seems like a good way to make a living.
My question is just how difficult is it to make parts like this?
Ive taken apart a few power transformers and don't find them all that complicated.
What am I missing here.
How difficult is this task to do? To your spec level?
Answer when you can.
Thanks in advance
Jack Crow in Kuwait
Hi all,
There is no doubt that I don't have the 'ear' for much of the sonic details your talking.
But it got me thinking about this sub standard transformer dealer.
Seems like a good way to make a living.
My question is just how difficult is it to make parts like this?
Ive taken apart a few power transformers and don't find them all that complicated.
What am I missing here.
How difficult is this task to do? To your spec level?
Answer when you can.
Thanks in advance
Jack Crow in Kuwait
Quite a lot actually. There is a very large difference between power transformer design and good audio transformer design whether it be input, output or interstage. Things like leakage inductance, interwinding capacitance, not to mention sizing a core for good linearity and power handling in audio power applications are not trivial. Making all the right tradeoffs between required primary inductance, leakage inductance, and stray capacitance not to mention core losses, take a lot of experience to get just right.
I have several friends who wind audio transformers for their own amplifiers and none of them are satisfied with the results of the first couple of passes and often end up rewinding them multiple times to get the best possible performance.
The higher the primary impedance or required power handling is in general the worse the problems become. SE output transformers have the additional complication of sizing the gap correctly for the desired target inductance and permissable flux density, and because they run with a large dc flux present in the core they must be sized much larger for a given power level which exacerbates both leakage inductance and interwinding capacitances.
Interleaving primary and secondary windings may reduce leakage inductance at the expense of increased capacitance. Winding technique also plays a great role in optimizing these issues. Even the order in which the various windings are interconnected has a serious effect on high frequency resonances in the transformer pass band and perhaps no less importantly above it, particularly if NFB is employed from the secondary.
The art is in making or knowing how to make the right tradeoffs in the initial design. The real experts have spent many years experimenting and learning to understand how to balance the many tradeoffs - there is no such thing as a perfect transformer, but some come close enough in practice to attain legendary status. (Some of the Bartolucci, Tango, MQ, and Tamura Amorphous Core types qualify.)
Note that I am not intrepid enough to even attempt to wind my own transformers, although I have designed quite a few power transformers and consulted on the construction of output transformers on several occasions, and by no means would I consider myself any sort of expert on the subject. My comments while many should be regarded as topical in nature..
I have several friends who wind audio transformers for their own amplifiers and none of them are satisfied with the results of the first couple of passes and often end up rewinding them multiple times to get the best possible performance.
The higher the primary impedance or required power handling is in general the worse the problems become. SE output transformers have the additional complication of sizing the gap correctly for the desired target inductance and permissable flux density, and because they run with a large dc flux present in the core they must be sized much larger for a given power level which exacerbates both leakage inductance and interwinding capacitances.
Interleaving primary and secondary windings may reduce leakage inductance at the expense of increased capacitance. Winding technique also plays a great role in optimizing these issues. Even the order in which the various windings are interconnected has a serious effect on high frequency resonances in the transformer pass band and perhaps no less importantly above it, particularly if NFB is employed from the secondary.
The art is in making or knowing how to make the right tradeoffs in the initial design. The real experts have spent many years experimenting and learning to understand how to balance the many tradeoffs - there is no such thing as a perfect transformer, but some come close enough in practice to attain legendary status. (Some of the Bartolucci, Tango, MQ, and Tamura Amorphous Core types qualify.)
Note that I am not intrepid enough to even attempt to wind my own transformers, although I have designed quite a few power transformers and consulted on the construction of output transformers on several occasions, and by no means would I consider myself any sort of expert on the subject. My comments while many should be regarded as topical in nature..
Kevin is right.
I cannot speak for all types of transformers. But the kind of pro balancing (step-up) transformers Telefunken did half a century ago are wound 30,000 turns, using a magnetic wire 1/4 the size of a human hair into a three chamber bobbin with only a few percentage tolerance. The wire is over a mile long, or close to two kilometres.
Of course, this is an extreme example and refers to step-up transformers. I just wanted to stress that the cost is likely to come down to labour, not material.
I cannot speak for all types of transformers. But the kind of pro balancing (step-up) transformers Telefunken did half a century ago are wound 30,000 turns, using a magnetic wire 1/4 the size of a human hair into a three chamber bobbin with only a few percentage tolerance. The wire is over a mile long, or close to two kilometres.
Of course, this is an extreme example and refers to step-up transformers. I just wanted to stress that the cost is likely to come down to labour, not material.
Thanks guys
Wow,
That was educational.
Guess that's not a future line of work for me. Sounds like very fancy test gear to make some of these measurments and a skill set I clearly don't own, and may not be able to develop any time soon.
Then again if it was easy, everybody would be turning wire.
Thanks for the education
Jack Crow TDY in Kuwait
Wow,
That was educational.
Guess that's not a future line of work for me. Sounds like very fancy test gear to make some of these measurments and a skill set I clearly don't own, and may not be able to develop any time soon.
Then again if it was easy, everybody would be turning wire.
Thanks for the education
Jack Crow TDY in Kuwait
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