yes you are correct,maveric,when i turned the lows( 63hz on my big five bander eq)i had no problems, only with the exterme lows( 20hz to 150hz) did this occur at a higher than normal volume,if you do find this too be a problem you have two option 1# keep the bass low running to the panels, 2# rebuild the panels with a thicker spacing.anyway i'm not going anywhere and will be waiting for your progress and you have my contact info besides,which you may pass on to charlie if he so wishes.good luck,have a good weekend and have a great anniversary and valintines day my friend. jer
listen audioaction, you have no idea what what you are saying in this thread. keep your personal life to your self. If you do not have anything nice to say. please do not say it all.
I have alot invested in this and care less about your flight, take a bus. and leave this thread to people who are working, not complaining. MAVRIC
someone is having problems with the data base here, i have tried to erase this message, however, it was in responce to my thread. no hard fealings here, just choose your words nicely, thats all, simple.
I have alot invested in this and care less about your flight, take a bus. and leave this thread to people who are working, not complaining. MAVRIC
someone is having problems with the data base here, i have tried to erase this message, however, it was in responce to my thread. no hard fealings here, just choose your words nicely, thats all, simple.
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audioaction,
i hope this is a one time thing, you deleted your post on this thred before anyone could read it, not fair at all. I have looked at all your post and can not find anything about " your plain ride with sceaming children." please stay a way from this post, all i ask is that if you have something to share, simple, but do not delete, as no one has read your post exect me.
So, carry on, parts will be here and the build will continue. mavric
i hope this is a one time thing, you deleted your post on this thred before anyone could read it, not fair at all. I have looked at all your post and can not find anything about " your plain ride with sceaming children." please stay a way from this post, all i ask is that if you have something to share, simple, but do not delete, as no one has read your post exect me.
So, carry on, parts will be here and the build will continue. mavric
hey guys check this out,as i was looking over my $20 200watt toroid transformers that i got on clearence from parts express i noticed a 13.8 volt winding so i did the calculations and 4 of these would give me 8 ohms on my 7.75"x22" panels.so i fired up the signal generator and scope and here's what i got,65hz-18khz flat -1db points, 46hz-25khz -3db,30hz-31khz -6db,18hz-50khz -12 db.pretty cool huh? since i have 10 of them i'll give them a try and i just might undue the secondary windings and rewind a new 13.8 whith some taps to change ratios,by getting rid of all the extra windings i don't need it should reduce the interwinding capcitance (to zero to start with) and extend the flat response past 30khz anyway here's some pics of one with a 2hz to 20khz .6sec sweeptest.while testing i got a clean 400v to 500v sine wave throughout the passband and a good looking square wave from 300hz to 10 khz in the critical range,i saw no signs of saturation or distortion even when loaded with a 130m 6kv capacitor and 3ft of coax cable.incredible! the scope graticule reads as follows from the center 50v per division 5 pionts per division, 9=-1db, 8=-3db, 5=-6db, 2.5=-12db,the two markers are set at -3db for reference.okay i'm going to go and build my new frames now. stay tuned and i'll keep you posted! jer
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Geeze Jer,
You said those trannys were a closeout deal? If you have a particular project in mind to use them on, I can't wait to see it. Finding suitable trannys at a reasonable cost seems to be one of the biggest impediments for DIY, especially those of us who are not learned enough to attempt modifications or winding our own. Please keep up the good work!
You said those trannys were a closeout deal? If you have a particular project in mind to use them on, I can't wait to see it. Finding suitable trannys at a reasonable cost seems to be one of the biggest impediments for DIY, especially those of us who are not learned enough to attempt modifications or winding our own. Please keep up the good work!
yes.i had intended too use them for a lm3886 type chip amp i got 5x lm4780ta chips as free samples from national semiconducter when they were first released. all i had to do was pay the shipping which was $14.however the main secondary winding is 35v and would yeild 49v in order to use two of them i would need a regulator to drop 7v as the maxium is -+42v.but i could use one of them to power 4 of them in a bridge parallel configuration too acheive 200+watts.there are several other discrete amp circuits i could use ,but you can't beat the simplicity and quality of a $6 to$7 68watt power opamp the lm4780 has two on one die for $9 (they went up through the years) check out their website for more sample info.my goal at the time was to use 8 of them in a bpa configuration as 3 or 4 of would yeild more than 300 to 400 watts into 4ohms and i was looking to be able to go down to 2ohms.just another project that got put on the back bruner till now,all intended for my esl's.i did alot of studying on transformer technology only to find out it is realy quite simple once you understand the basic's.most of the work is alread done for you using a power transformer.the only difference between an audio transformer and power transformer is basicaly two things audio ones have a higher quality core material and are design to go down to 20hz.to do this you have use a bigger core than power transformer of the same power rating.todays toroidal cores are becoming more and more the norm by todays standards and use a higher quality steel than the old e-i style which makes them so darn expensive.now here's alittle somthing that alot of poeple don't relize is that for every doubling of frequency the power rating is doubled and vice versa.so my 200watt transformer at 60hz now becomes a 400watt transformer at 120hz and so on.which is why your 600watt computer power supply has such small transformers,because their running at 40khz+. get it?now in order to get a flat response from 20hz to 20khz becomes tricky you start the design using 20hz as a factor than 60hz which roughly requires 2 to 3 times more core area and/or 2 to3 times more inductance on the primary.that is the basics of transformer design.most all of the factors are pretty much reciporcals of each other.on the other end of the scale to acheive a high frequency response, interwinding capcitance (the capcitance between the windings becomes the limiting factor(also core material in some cases).i hope that helps you to understand a little better.there is alot of websites out there that go more in great detail if you wish to know more,but don't be afraid to ask me anything if you wish. jer
Jer,
you are quite the mad scientest here. Congatats on your achivement there, you allredy have me scartching my bald head. you make it sound so simpe, even a cave man could do it. just kiddding. If i didnt have so much money tied up in this, i would order some coils and give it a try, as this is my first, i will stick to the basics. BTW, grill cloth and magnetic grill holders came in, those things are strong, allmost couldn't take em apart, good idea there Charlie.
Charlie if you are reading, how is this weekend looking for you? Sunday 20th?
Mavric
you are quite the mad scientest here. Congatats on your achivement there, you allredy have me scartching my bald head. you make it sound so simpe, even a cave man could do it. just kiddding. If i didnt have so much money tied up in this, i would order some coils and give it a try, as this is my first, i will stick to the basics. BTW, grill cloth and magnetic grill holders came in, those things are strong, allmost couldn't take em apart, good idea there Charlie.
Charlie if you are reading, how is this weekend looking for you? Sunday 20th?
Mavric
hey,my theory worked! 10 turns of wire is all it took.now all i need is a bais supply and these baby's will be driven harder the ever before 750v+ out of one 120v winding and there's two of them.i just saved myself six awsome power transformers.charlie and mavric you'd better build another pair for quadro phonic or surround sound because you truly only need one doughnut each.i was using my awia cd changer at full tilt before clipping and it has a very sensitive shutdown protection circuit. if i had some bias on it my ears would have started to bleed, at that level!what do you think? here's the proof. jer
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Hi Jer,
I was playing around with my toroids yesterday also. I tried to make a pair of 1:50 for my ESL headphones. Your info just make my life a lot easier. These trannies only come with primary windings of 0V, 110V, 220V. It's very easy to only make a secondary winding for them. I got them for around US$8 each, and they are good for 50VA.
Wachara C.
I was playing around with my toroids yesterday also. I tried to make a pair of 1:50 for my ESL headphones. Your info just make my life a lot easier. These trannies only come with primary windings of 0V, 110V, 220V. It's very easy to only make a secondary winding for them. I got them for around US$8 each, and they are good for 50VA.
Wachara C.
good,i'm glad you got some use out this,there was no way that i would spend $100,$200 or even $300 for a transformer unless it was a really really big one.i wanted to to prove that a good quality device can be had for the diy'er for cheap and i have all of you to thank for getting me back into it.im not done yet.i still think a decent direct drive amp can be had for the price of one or two transformers.take my knowledge and learn with it as im not twenty years old any more ,but i still feel like i am .so if i can help to make some one elses day go by a little easier then it's all worth it . no,thank you! jer p.s. now i can finnish my headphones too and get my panels running so that i can truly enjoy them .i built them seven years ago and they have been sitting in closet since.it'sjust hard to believe sometimes that i had most all the components the whole time.
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Jer, you really are a scientist. I hope you can help me on this one, going to try and post some pics of me Adcom preamp, i mentioned that button was wore out and instead of breaking it down and pelacing it, just solder a jumper, tell me what you think or call me, will be up till around 1:00 est. thanks
the adcom preamp model numerGTP-600, i know its old, but built well. just tried to upload so check your email, hi res pics.
the adcom preamp model numerGTP-600, i know its old, but built well. just tried to upload so check your email, hi res pics.
here is a cool spreadsheet for esl spl's DIY audio, Electrostatic Speakers, ProjectESL-220-30 by MS
Hi,
I certainly don´t want to spoil Your euphoria, just keep in mind, that such few windings mean a low inductance. The inductance defines the lower bandwidth limit. Small values mean a high frequency of limit. So with a single coil the bandwidth will be small with a high lower limit.
Try several paralleled windings to improve things.
The lower inductance value is the one parameter where a dedicated ESL-transformer succeeds the standard power toroid. Hence standard power toroids are usually not usable as Fullrange Trannies, but just for Hybrids.
jauu
Calvin
I certainly don´t want to spoil Your euphoria, just keep in mind, that such few windings mean a low inductance. The inductance defines the lower bandwidth limit. Small values mean a high frequency of limit. So with a single coil the bandwidth will be small with a high lower limit.
Try several paralleled windings to improve things.
The lower inductance value is the one parameter where a dedicated ESL-transformer succeeds the standard power toroid. Hence standard power toroids are usually not usable as Fullrange Trannies, but just for Hybrids.
jauu
Calvin
thank you calvin for simplifying that.i believe did cover this in post #149 " now in order to get a flat response from 20hz to 20khz becomes tricky you start the design using 20hz as a factor than 60hz which roughly requires 2 to 3 times more core area and/or 2 to3 times more inductance on the primary.that is the basics of transformer design.most all of the factors are pretty much reciporcals of each other.on the other end of the scale to acheive a high frequency response, interwinding capcitance (the capcitance between the windings becomes the limiting factor(also core material in some cases)." now that i have working model i plan to investigate this further.on my new test winding i think i did gain 2khz on the -1db figure compared to the 13.8v winding. but however i didn't notice any siginificant change on the low end from a winding of 88 turns to a winding with 10 turns for a primary.i should have.it may be the low end response of my ampilfier itself causing this to occur.i will retest it in more detail later today and post my findings. jer
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