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previous: muddobber strange that there are no responses... -- 3/20/2000 4:20 AM View Thread

Re: supro supreme tone

3/20/2000 3:36 PM
Doc
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Re: supro supreme tone
I know of a guy in Collingswood, NJ who recones speakers. He does rebuilds for antique radio enthusiasts. Many of those old radios were from an era before permanent magnet speakers, so had field coils. The originality of the speaker is important, so it has to be rebuilt. Some have unusual cone sizes and profiles.  
 
The field coil is a simple solenoid, that is it's a single cylindrical coil. Anyone who can wind a basic coil bobbin can rewind the field coil. The snag is that, at least with the speakers I've seen so far, the field coil is held in by the magnetic pole frame. Sometimes there's a dovetail shaped mating seam that can be broken, but sometimes the frame has to be sawed apart to free the coil, then rewelded (a very tricky procedure) after the new coil is mounted.  
 
As you say, those old speakers were fragile and can't take abuse of modern guitar playing. If the amp were mine and I wanted to use it, I'd put in a modern (or reclaimed) alnico PM speaker and a choke. Actually, most of these small amps can get by with merely a series resistor. The voltage drop is even welcome, because line voltages have gone up more than 10% since the amp was built.  
 
No two speakers sound alike. But I would suspect that an alnico PM speaker would have sonic characteristics that were more similar to older electrodynamic speakers than a ceramic PM speaker would. If you don't have $ to experiment with new speakers, like Weber VST, find an old TV-hifi console or large record player from the 1960s or 70s that isn't worth restoring. Many of them had 8" and 10" speakers in them, suitable for low power guitar amps.