Over in Japan, I have group of friends who are passionated about field coil drivers. They convert their favorite vintage drivers to field coil magnet circuit. They are the most well known field coil gurus in Japan.
They did conversion for Altec 515B, 802D, and WE 2090A.
Now they are planning to convert JBL LE8T.
If they can find some more people to join this project, they can reduce the cost(and maybe yours as well) . They can also share information or supply conversion kit for Altec 515B, 802D, WE 2090A and 288.
First, You need to prepare LE8T baskets.
Option 1:
They will send you machined magnet circuits and field coil. you needs to assemble them, then You can recone or use your local shop for recone.
Option 2:
After removing diaphragms, Ship your drivers to Japan. They will assemble the field coil magnet circuit, and ship back to you. You can recone or use your local shop for recone.
Yes, I am a full range feild coil guy (Feastrex) but had love affair with VOT in my past
If anyone interested, please let me know! I will help you communicating with them in Japanese
Altec 515B:
Altec 802D:
WE 2090A:
They did conversion for Altec 515B, 802D, and WE 2090A.
Now they are planning to convert JBL LE8T.
If they can find some more people to join this project, they can reduce the cost(and maybe yours as well) . They can also share information or supply conversion kit for Altec 515B, 802D, WE 2090A and 288.
First, You need to prepare LE8T baskets.
Option 1:
They will send you machined magnet circuits and field coil. you needs to assemble them, then You can recone or use your local shop for recone.
Option 2:
After removing diaphragms, Ship your drivers to Japan. They will assemble the field coil magnet circuit, and ship back to you. You can recone or use your local shop for recone.
Yes, I am a full range feild coil guy (Feastrex) but had love affair with VOT in my past
If anyone interested, please let me know! I will help you communicating with them in Japanese
Altec 515B:
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An externally hosted image should be here but it was not working when we last tested it.
Altec 802D:
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An externally hosted image should be here but it was not working when we last tested it.
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WE 2090A:
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An externally hosted image should be here but it was not working when we last tested it.
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An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Hello fabcam,
so far, I did not get much response for field coil conversion. My friend's latest work is converting Fostex T90A tweeters.
Cheers,
Kenji
so far, I did not get much response for field coil conversion. My friend's latest work is converting Fostex T90A tweeters.
Cheers,
Kenji
Probably would help if it were in the right forum which is the multi-way forum.
Moving to appropriate forum..
I run vintage JBL and Altec hardware, but my suspicion is even if this stuff were available for my specific drivers it is so far outside of my price range that I can't even consider it. I think this is the real problem with these conversions. I've heard RCA theater drivers with field coils and like them, but these are a rich man's game.
Moving to appropriate forum..I run vintage JBL and Altec hardware, but my suspicion is even if this stuff were available for my specific drivers it is so far outside of my price range that I can't even consider it. I think this is the real problem with these conversions. I've heard RCA theater drivers with field coils and like them, but these are a rich man's game.
I suspect I would probably like your full range drivers, but haven't been thrilled at all with the Fostex FE-165 based stuff I have played with. (To the extent that I more or less gave them away.) My exposure thus far has been pretty limited. Some of the Tang Band stuff like the W8-1772 looks interesting.
The best full range driver I have ever heard is the RCA LC-1 (not sure which version off the top of my head) and again under very limited circumstances.
The things I listen for generally are not well served by FR drivers.
The best full range driver I have ever heard is the RCA LC-1 (not sure which version off the top of my head) and again under very limited circumstances.
The things I listen for generally are not well served by FR drivers.
Yes, expensive... unless used for a lucky guy/girl (for 75 bucks!) RCA Field Coil 15" + Baffle,
RCA Field Coil 15" + Baffle
Incredible fullrange driver, Rullit 12" field coil in massive horns
HQ Speaker | Wolf von Langa
Decware FRX Full Range Driver
RCA Field Coil 15" + Baffle
Incredible fullrange driver, Rullit 12" field coil in massive horns
HQ Speaker | Wolf von Langa
Decware FRX Full Range Driver
230 volt field coil woofer ,driver and tweeter with tube power supply
another photo
audiofilofine field coil speakers
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
another photo
audiofilofine field coil speakers
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yes are fedi "perspecta " electronic from old cinema and geloso el 503 100 watt mono amp.
effetti channel are surround channel .
i use only 2 channel.
sorry for my english.
Ha!, "Perspecta" surround with 3-MonoChannels or multidirectional soundsources with optic control of the sub/low (30Hz) tones for their automatic operation (3 speaker surround).
Better than cote: "Dolby stereo surround, which mainly confines the dialogue to the centre channel". Nice.
Reel Deals - Perspecta Sound
..."Amplificatore" GELOSO [Mr. John Geloso (Italy)] with the EL503 valve/tube. Are they (tubes) available/manufactured now or you had to make a conversion for new ones?
http://www.chambonino.com/modify/mod1.html
http://www.chambonino.com/modify/mod1.html
no, my geloso 3270 are all original except 2 little cap.
i use only 100% original vintage
for muti driver system, field coil driver benefit couple of things.
1. better permeability for the same flux density.
2. by adjusting field coil voltage, we can make woofer, mid-driver, and tweeter, etc to the same speed. (If you played with VOT, you know what I am talking about)
Field coil driver is just like an audio transformer.
Primary = voice coil
Secondary = field coil
yoke, pole, and plate... are core.
We have to be vary careful about field coil power supply. hint hint
I'm not sure if I really want to touch this subject since there are so many myths wrapped up in it.
What are the measurements? What gap flux are we achieving? Is it really higher than an Alnico or Ferrite structure would achieve?
"Everybody reveres the Western Electic drivers"
"Western Electric drivers used field coils"
"Therefore field coils are magic and all drivers would be improved by the addition of field coils"
Anybody want to comment on the logic of that train of thought?
Note tht I was at JBL when the conversion from Alnico to Ferrite was happening and there were differences between the two structure types. Flux modulation did give higher distortion in the early ferrite prototypes. Once the SFG design was worked out there was no difference between the two types (other than poor demagnetizing resistance for Alnico units).
Flux in the gap is flux in the gap.
David S.
What are the measurements? What gap flux are we achieving? Is it really higher than an Alnico or Ferrite structure would achieve?
"Everybody reveres the Western Electic drivers"
"Western Electric drivers used field coils"
"Therefore field coils are magic and all drivers would be improved by the addition of field coils"
Anybody want to comment on the logic of that train of thought?
Note tht I was at JBL when the conversion from Alnico to Ferrite was happening and there were differences between the two structure types. Flux modulation did give higher distortion in the early ferrite prototypes. Once the SFG design was worked out there was no difference between the two types (other than poor demagnetizing resistance for Alnico units).
Flux in the gap is flux in the gap.
David S.
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