Showing posts with label Field Coil. Show all posts
Showing posts with label Field Coil. Show all posts

Wednesday, February 25, 2015

Very Early Pro Sound - Field Coils with Horns and Triodes 245 250

This is one of my favorite early ads because it has it all like field coils, horns, triodes in the flavor of 250 and 245.

$20 in 1930 equals about $275 today.
 Nice selection of field coils from the early guys Jensen and Utah.
 I want everything I build to look like these early pro amps.

Wednesday, January 9, 2013

Tuesday, June 28, 2011

1937 Stentorian 12" Field Coil Driver

Nice early British hifi. I've never seen any of these in person. Quality seems very good though.







This post originated at retro vintage modern hi-fi http://itishifi.blogspot.com

Friday, December 3, 2010

Atelier Rullit Projects

Atelier Rullit builds alnico and field coil drivers. They build alot of other gear but I find their drivers most interesting. I'd like to spend more time with a field coil speaker system.

Here is the RF-C805 field coil.

Excerpt fromt the site.

You see a very unique driver here - a 15" full range unit. It was under development since the end of 2007. At first it was planed as support for a front loaded horn with an 8" RF-C803. First listening tests revealed its huge potential and I decided to keep working on it hoping to create a full range unit. After trying various kinds of cellulose, I decided to employ a hybrid cone (of my own design). Sleepless nights resulted in total success. Real huge full-range driver was born.

Some applications may still need a tweeter. Sensitivity: about 100 dB. Weight: about 17 kg. 4 kg of copper were used for the field coil, which gives 1.5 times reserve of the magnetic field power. (2.5 kg could already provide 17000 Gauss in the gap).

Cone is of a unique Rullit hybrid design: Special Rullit cellulose in the center, balsa wood around (soaked by Rullit recipe), all on leather surrounds and traditional wooden spider.



Alnico full range driver.



They offer a glimpse of a new line of drivers in the works on their site.


Visit their site for a look at their crafted drivers. http://www.field-coil.com/