It seems that SE transformers are either the lower end ones (Hammond 125ESE/Edcors) or those that are greater than $100 each. Does anyone know of a vendor who sell a decent one in the $50-70 range? I would think that there would be a good size market for these medium priced units.
Any vendors come to mind? If there are any from overseas, hopefully the shipping would be reasonable.
Any vendors come to mind? If there are any from overseas, hopefully the shipping would be reasonable.
I wouldn't use anything less than Lundahl. Building a good sounding amp is a lot of work and anything cheaper than that is a waste of time and money. Sure, there are a lot of guys who say they use Hammond or Edcor and it sounds "good" to them, but I've heard those OPT's and they are pretty poor next to a James, Magnequest, or a good Japanese make.
John
John
I've bought transformers from this guy and was very pleased. The quality was considerably better than Hammond or One Electron. I bought a pair of the 600 ohm ones for $150 shipped. Looks like there is a few different impedance values available too. The only thing is that from the time they shipped till the time they got to my house was about 4 months. If your in a rush to get them, paying extra for quicker shipping may be a good idea.
http://search.ebay.com/_W0QQsassZbiglawhkQQhtZ-1
http://search.ebay.com/_W0QQsassZbiglawhkQQhtZ-1
You didn't mention impedance or power level, but at 5K, 10 watts and <$150 pair you can't go wrong with the James 6115HS. Finding a place to buy them however might be a challenge.
http://euphoniaaudio.netfirms.com/e...d=142&osCsid=9754bf3a20a369cbd9bdf346fbcd8bf3
http://euphoniaaudio.netfirms.com/e...d=142&osCsid=9754bf3a20a369cbd9bdf346fbcd8bf3
I have a fair stock of output transformers, to try in circuit, that I am going to settle in my own mind whether the expensive ones are any better than the 'budgets' its going to be interesting to say the least.
hammond, james and magnequest, and cheap chinese inc.
I tried both of those ebay ones, I wasn't keen on the chrome ones, but I thought the eastern audio rather good, esp for the price, they were very small tho'.
They are both finished to a very nice standard.
From my search so far in terms of weight, for a 300b tx, there seem to be around 3 types, cheap ones are 2kg or less in weight, the optimum seems to be around 3kg/6lb, and the big ones, around 10lbs plus.
Once you get over a certain size, the hifreq. starts to suffer, so its really a balance of either low freq, or hi freq, the japanese certainly seem to thing hi freq is important, and when you realise that even 3db down at 100khz actually may begin rolling off around 10khz, that's why its sometimes important, also, phase extends way down into the audible band, too.
Another problem is the low freq. there are at least 2 ways of describiing this, and most specs. give the small signal lo freq. which almost always is less than 12hz. And that's what you see on the plots.
A much more accurate one is the large signal, which they don't quote, as most small transformers attain around 40-50 hz with this, that's why they don't quote it.
I am sure there is an optimum winding configuration for each size to maximise hi freq regardless of core size, but havne't the knowledge to determine that theoretically, and I am not sure about what is tha max core size b4 hi freqs. become comprimised, I would guess around a 6lb core, as there are few big ones, but that could also be cost, then again, hammonds are around 11lb and not expensive.
if you go for biglaws on ebay, he is great, nice and reliable, and for the cash they are fine.
hammond, james and magnequest, and cheap chinese inc.
I tried both of those ebay ones, I wasn't keen on the chrome ones, but I thought the eastern audio rather good, esp for the price, they were very small tho'.
They are both finished to a very nice standard.
From my search so far in terms of weight, for a 300b tx, there seem to be around 3 types, cheap ones are 2kg or less in weight, the optimum seems to be around 3kg/6lb, and the big ones, around 10lbs plus.
Once you get over a certain size, the hifreq. starts to suffer, so its really a balance of either low freq, or hi freq, the japanese certainly seem to thing hi freq is important, and when you realise that even 3db down at 100khz actually may begin rolling off around 10khz, that's why its sometimes important, also, phase extends way down into the audible band, too.
Another problem is the low freq. there are at least 2 ways of describiing this, and most specs. give the small signal lo freq. which almost always is less than 12hz. And that's what you see on the plots.
A much more accurate one is the large signal, which they don't quote, as most small transformers attain around 40-50 hz with this, that's why they don't quote it.
I am sure there is an optimum winding configuration for each size to maximise hi freq regardless of core size, but havne't the knowledge to determine that theoretically, and I am not sure about what is tha max core size b4 hi freqs. become comprimised, I would guess around a 6lb core, as there are few big ones, but that could also be cost, then again, hammonds are around 11lb and not expensive.
if you go for biglaws on ebay, he is great, nice and reliable, and for the cash they are fine.
Please, let me know why you didn´t like them!
I have a pair of those 3,5k transformers incoming and I don´t really don´t know what to expect in terms of performance, I took chance just because the price was right.
I´m planning to use them in an 808 SE amp.
Mine were posted in the end of December, feels like I shouldn´t be too eager to check my mailbox every day...
The mail tracking servive at hongkongpost.com only says "In transit".
Br
/Daniel
There was nothing wrong with them, they worked ok, I just found them a bit bright sounding, not as well balanced as the eastern audio, but they do the job fine which is what they should, so for the price, nothing wrong, don't worry, you may love them.
Its a pesonal opinion.
I also didn't have them in very long at all, so they may improve with time in circuit.
just my taste in sound. ymmv.
support these guys, they are doing us a favour by making these things affordable
Its a pesonal opinion.
I also didn't have them in very long at all, so they may improve with time in circuit.
just my taste in sound. ymmv.
support these guys, they are doing us a favour by making these things affordable
Thank you very much, I was afraid that it was something seriously wrong with them. These are waaaay cheaper than Hammonds new 3,5K SE OPT, and I have some bad experiences from using hammond irons.
BTW, I just checked the mail tracking again and now it says "Processed for departure", I guess ´that´s a good thing
BTW, I just checked the mail tracking again and now it says "Processed for departure", I guess ´that´s a good thing
yes hammonds are getting a bit pricy, I think the big ones, powers and outputs are generally pretty good, but I had a bad experience with a small power tx, the magnetic field was huge and infected circuitry.
And from what hammond say, don't pot the 2 range, that means they run very hot, which means they are wound to be run on maximum flux close to saturation, this means either a small core or turns, ie made cheaply.
I know people slate the hammond 162* series, I found the 1627 sounded good, do you have anything bad to say about these, or other pointers?
as I am about to buy some off a friend?
thanks
The chinese are great for the cash, nothing serioiusly wrong imo. FWIW I suspect there is a fair bit of one upmanship going on with transformers.
My top pointer for superb transformers at good prices, and again deserve support, is
sacthailand, silk
paste that into google.
I have some 300b potted outputs, that I suspect may be amongst the best in the world, and flat to 150k!! cheap too.
Has anyone tried a few out and come to a kind of ranking list? I would very much like to see opionions, I heard that one electron are thought more higly than hammond?
And from what hammond say, don't pot the 2 range, that means they run very hot, which means they are wound to be run on maximum flux close to saturation, this means either a small core or turns, ie made cheaply.
I know people slate the hammond 162* series, I found the 1627 sounded good, do you have anything bad to say about these, or other pointers?
as I am about to buy some off a friend?
thanks
The chinese are great for the cash, nothing serioiusly wrong imo. FWIW I suspect there is a fair bit of one upmanship going on with transformers.
My top pointer for superb transformers at good prices, and again deserve support, is
sacthailand, silk
paste that into google.
I have some 300b potted outputs, that I suspect may be amongst the best in the world, and flat to 150k!! cheap too.
Has anyone tried a few out and come to a kind of ranking list? I would very much like to see opionions, I heard that one electron are thought more higly than hammond?
I have used Transcendar transformers available on Ebay:
http://cgi.ebay.com/Pair-3K-Audio-O...ryZ50593QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
I bought a pair of his earlier design "300B transformers", I liked them well enough to buy 10 more pairs! I just put a pair in a SE KT88 (triode wired) amp. I also built an identical amp with the Hammond 1628SEA transformers (triode or UL switchable). The transcendars win hands down for the ability to resolve details that are missed with the Hammonds. The Hammonds are the transformers to use if you want to play rock music loud (in UL with cathode feedback). The Transcendars are less than half of the price of the Hammonds.
Another choice is the One Electron UBT series (available from Antique Electronics). They are priced near $100 each though. I did a listening test a while back comparing them to the Transcendars. One person in five could tell the difference, but could not reliably pick a winner. The UBT's have a slightly better HF response when measured, but it doesn't show up in listening tests.
The $18 Edcors will surprise you if you have efficient enough speakers so that you can run the amp at low enough power to keep the transformers out of saturation on strong bass notes at high volume. They also work well if your speakers can't produce any sound below 70 Hz, or you use a subwoofer. I have Yamaha studio speakers in my lab. Big expensive transformers are wasted on these speakers because they don't have any response below 70Hz.
The $75 Edcors don't have the best measurements, but they sound reasonable. I would rather use the UBT's or the Transcendars unless you need the power capabilities below 40 Hz that only larger iron can deliver.
http://cgi.ebay.com/Pair-3K-Audio-O...ryZ50593QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
I bought a pair of his earlier design "300B transformers", I liked them well enough to buy 10 more pairs! I just put a pair in a SE KT88 (triode wired) amp. I also built an identical amp with the Hammond 1628SEA transformers (triode or UL switchable). The transcendars win hands down for the ability to resolve details that are missed with the Hammonds. The Hammonds are the transformers to use if you want to play rock music loud (in UL with cathode feedback). The Transcendars are less than half of the price of the Hammonds.
Another choice is the One Electron UBT series (available from Antique Electronics). They are priced near $100 each though. I did a listening test a while back comparing them to the Transcendars. One person in five could tell the difference, but could not reliably pick a winner. The UBT's have a slightly better HF response when measured, but it doesn't show up in listening tests.
The $18 Edcors will surprise you if you have efficient enough speakers so that you can run the amp at low enough power to keep the transformers out of saturation on strong bass notes at high volume. They also work well if your speakers can't produce any sound below 70 Hz, or you use a subwoofer. I have Yamaha studio speakers in my lab. Big expensive transformers are wasted on these speakers because they don't have any response below 70Hz.
The $75 Edcors don't have the best measurements, but they sound reasonable. I would rather use the UBT's or the Transcendars unless you need the power capabilities below 40 Hz that only larger iron can deliver.
I made an amp with 372JX (IIRC) and 1627SE transformers a few years ago. Nothing wrong with the output irons, but the power TX buzzed mechanically.
A friend of mine made something with a pair of 1628SE and found out that their HF behaviour left alot to wish for. The same guy also recieved different Hammond units with a variety of strange manufacturing faults like different colours, horrible paint jobs and stuff like that. He even got one completely smashed up transformer in an undamaged box.
For me, that tells something about Hammonds quality control.
They might have straightened thing up since then though, this was a few years ago.
A friend of mine made something with a pair of 1628SE and found out that their HF behaviour left alot to wish for. The same guy also recieved different Hammond units with a variety of strange manufacturing faults like different colours, horrible paint jobs and stuff like that. He even got one completely smashed up transformer in an undamaged box.
For me, that tells something about Hammonds quality control.
They might have straightened thing up since then though, this was a few years ago.
I have a 3 year old pair of 1628SE's that have a 5 to 6 db rolloff at 20KHz. They are not as bad as others have seen. I got a new pair of the 1628SEA's. They are about 2 db down at 20KHz. Neither of these make their claimed 30Hz to 20 KHz +- 1db. I don't know how they measure their transformers, but I measure them in a real (trioded KT88) amp with a resistive load and zero feedback. Other transformers make 44KHz (the $18 Edcors) so my system can measure good HF.
There was a long thread about Hammond OPT's here a while back with some measurements:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=83138&highlight=
There was a thread on the $18 Edcors that also referenced other threads:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=72654&highlight=
rdf said:
FYI, I was looking for 5K and 10W is fine. I'm using Gary Kaufmans's 6EM7 directly coupled amp and I like it a lot. Its a bit low on power but I don't play it to load. Its driving a pair of Fostex 167E in a ML-TL boxes that need a bit more low end then what they are receiving now.
These guys in the link are in the US. Hopefully they have a stock of these...
Thanks for the link!
I heard Euphonia's prices weren't anything special. You could try direct:
http://myweb.hinet.net/home3/jianshin/
Jianshin have been very responsive and courteous to my inquiries in the past.
http://myweb.hinet.net/home3/jianshin/
Jianshin have been very responsive and courteous to my inquiries in the past.
RockysDad said:
What!?!?!
Bummer, no wonder they went out of business. They were selling these at a lost! Got to start looking for these now...
I have a pair of these (in black) that I used very briefly in a breadboard headphone amp. I'd love to use them for a speaker amp, but realistically I am not going to get to any projects that would use them for months, if not years. So, I could probably stand to part with them for a decent price -- which means not as much as I paid at Euphonia, but not necessarilly a lot less either
You can see them at http://www.head-fi.org/forums/showthread.php?t=210871 One has a very slight scuff on it that was there when I got them. It wasn't enough for me to complain. I still have the original boxes and all that.
Contact me through the board's email system, or at dsavitsk at ecp dot cc for more.
-d
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