I am informed that we will have a room as usual, and this time I plan to
bring a new open baffle speaker with some Lowther field coils and of course
electronics to play them. The F6 will be there, as well as some SIT amps.
People with their own DIY power amplifiers are invited to bring them to
demonstrate in this system.
I also plan to give a tutorial talk about the F6 design, along with amusing
general comments.
bring a new open baffle speaker with some Lowther field coils and of course
electronics to play them. The F6 will be there, as well as some SIT amps.
People with their own DIY power amplifiers are invited to bring them to
demonstrate in this system.
I also plan to give a tutorial talk about the F6 design, along with amusing
general comments.
............
I also plan to give a tutorial talk about the F6 design, along with amusing
general comments.
Lovely!
I hope there will there again a video for us outsiders...
+1 on the video... suggestion for the videographer: last year was a worthy effort for those of us far far away, but reckon we need the camera zoomed in and focussed on the screen... accompanied with a reasonably close miked voiceover of nelson's dulcet tones
That said, however good the video may be, it would still be a poor substitute for the experience of being there in person ...
That said, however good the video may be, it would still be a poor substitute for the experience of being there in person ...
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Please show the impedance versus frequency plot/curve of the OB speaker above; or a published one like it. Thank youI am informed that we will have a room as usual, and this time I plan to
bring a new open baffle speaker with some Lowther field coils and of course
electronics to play them. The F6 will be there, as well as some SIT amps.
People with their own DIY power amplifiers are invited to bring them to
demonstrate in this system.
I also plan to give a tutorial talk about the F6 design, along with amusing
general comments.
They serve beer there also....
For this reason I cannot attend. I have an demeted side that exhibits itself when beer and music are mixed. All attending people would be forced to flee from the impending irrational and overly exuberant conversations, interesting only to me.
HAve fun
One day.
That actually sounds very interesting, and entertaining. You should go! What the heck, last minute stuff can be cheap...
The Lowther website writes about a Hi-Ferric technology in its DX series. Interesting mechanism of action. A rear-view picture of a DX driver did not show independent connections to "field coils"; as reminescent of ancient drivers. It has a magnet, and only the usual two connections to a power amp. The peak excursion of the diaphragm was quoted at 2 millimeters peak to peak. Prices [in Pounds Sterling] appeared reasonable in the range for~280-550. However; no impedance versus frequency plot was shown for any one driver.
The following is a brief excerpt from the write-up on the field Coil Lowther at www.lowther-america.com.
"The field coil Lowther is a brand new design. It uses current through a large copper coil to create the magnetic field rather than the standard permanent magnet".
Details at web site.
"The field coil Lowther is a brand new design. It uses current through a large copper coil to create the magnetic field rather than the standard permanent magnet".
Details at web site.
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SIT [or other FET] driving the Field and Voice Coils of Lowther
Mr. Pass: The Rothacher SIT amp Version 2 used an inductance as a load to the SIT. I have [mentally] replaced Rothacher's coil with the Field Coil of the Lowther you'll be using for BAF 2012. The attached file [lowthersit.pdf] shows a proposed schematic whereby a SIT [or other FET] simultaneously drives the Field and the Voice Coils of this loudspeaker. This is a new situation of a fixed plus a signal modulated loudspeaker magnetic field. By comparison, Lowther-America recommends using a clean DC power supply to generate a fixed magnetic field.
Mr. Pass: The Rothacher SIT amp Version 2 used an inductance as a load to the SIT. I have [mentally] replaced Rothacher's coil with the Field Coil of the Lowther you'll be using for BAF 2012. The attached file [lowthersit.pdf] shows a proposed schematic whereby a SIT [or other FET] simultaneously drives the Field and the Voice Coils of this loudspeaker. This is a new situation of a fixed plus a signal modulated loudspeaker magnetic field. By comparison, Lowther-America recommends using a clean DC power supply to generate a fixed magnetic field.
somehow I have impression that both Lowther and your ears wouldn't be happy with that solution
in dark ages , FC of speaker was used as choke in PS , for tooboolar amps ; and even then,when Movie Theater was crowded , demanding more A2 from flea powerful amps ..... entire first row of spectators wasn't entirely happy .......
then they invented pentodes and PP , screaming how there is free lunch , at last
in dark ages , FC of speaker was used as choke in PS , for tooboolar amps ; and even then,when Movie Theater was crowded , demanding more A2 from flea powerful amps ..... entire first row of spectators wasn't entirely happy .......
then they invented pentodes and PP , screaming how there is free lunch , at last
never say never.somehow I have impression that both Lowther and your ears wouldn't be happy with that solution
in dark ages , FC of speaker was used as choke in PS , for tooboolar amps ; and even then,when Movie Theater was crowded , demanding more A2 from flea powerful amps ..... entire first row of spectators wasn't entirely happy .......
then they invented pentodes and PP , screaming how there is free lunch , at last
I think you could get away with it at low levels. I will be using a regulated
supply, however.
intention of revived (not just nowadays) using of FC in speaker construction is impeccable constant magnetic flux , not influenced with constant variable EMF made by vibrating voice coil
sort of idea that FC is having much lesser "intrinsic impedance " than any permanent magnet
even if you embrace idea of using FC as (even just partial ) choke load for amp , connected to counteract non-linear distortion in rest of speaker/amp combo , I resume that having any success demands sooooooooo complicated and loooong process
not fun
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