Page 1 of 1
Jennings Electronic Industries (JEI) - Phaser
Posted: 09 Jul 2015, 07:39
by Bernardduur
Yesterday this pedal came in the mail. I was fascinated by the origin (from the hands of the AC30 designers) but also wanted to hear it in action.
Fired up the unit has a HUGE volume boost with the phaser engaged or in bypass mode. It is not true bypass I suppose. The phaser has no LFO and can be used by rocking the pedal forwards and backwards. It can be activated the same way as a crybaby wah.
The sound is surprisingly nice. A very complex phaser sound that I was not expecting from it. Looking at the circuit it only has transistors, no IC can be found. (if I recall, I've never seen a pure transistor based phaser).
More pics will follow; I'll trace it when I got some spare time!
http://www.hendrixguitars.com/Ef230.htm
http://www.effectsdatabase.com/model/je
Re: Jennings Electronic Industries (JEI) - Phaser
Posted: 09 Jul 2015, 11:14
by Fender3D
The very first issue of Elektor in Italy, back in the late '70-early '80, featured a phaser circuit, it had two 1-transistor-phase stages (outputs on E and C) ala ***vibe, a dual gang pot instead of LDRs, I'm sorry but I don't recall what the input and input stages were...
Re: Jennings Electronic Industries (JEI) - Phaser
Posted: 09 Jul 2015, 11:18
by Bernardduur
Oops, forgot the univibe
That one is a pure transistor phaser
Re: Jennings Electronic Industries (JEI) - Phaser
Posted: 10 Jul 2015, 06:19
by Bernardduur
Re: Jennings Electronic Industries (JEI) - Phaser
Posted: 10 Jul 2015, 06:21
by Bernardduur
Re: Jennings Electronic Industries (JEI) - Phaser
Posted: 10 Jul 2015, 06:25
by Bernardduur
Re: Jennings Electronic Industries (JEI) - Phaser
Posted: 10 Jul 2015, 11:50
by tube-exorcist
The original circuit can be found in Practical Electronics October 1973. The potentiometer should be alogarithmic type.
Re: Jennings Electronic Industries (JEI) - Phaser
Posted: 12 Jul 2015, 14:39
by Bernardduur
tube-exorcist wrote:The original circuit can be found in Practical Electronics October 1973. The potentiometer should be alogarithmic type.
Nice! I can't find that issue online; would you have one? I'm interested in the article....
Re: Jennings Electronic Industries (JEI) - Phaser
Posted: 12 Jul 2015, 15:17
by tube-exorcist
Bernardduur wrote:tube-exorcist wrote:The original circuit can be found in Practical Electronics October 1973. The potentiometer should be alogarithmic type.
Nice! I can't find that issue online; would you have one? I'm interested in the article....
Sorry, but I donĀ“t have an original one - I found the article on Mar 24, 2001.... ONLINE. And yes, it is still there waiting for interested ones:
http://www.synthdiy.com/show/?id=1118
(Download link at the the right bottom "pha.pdf".)
Re: Jennings Electronic Industries (JEI) - Phaser
Posted: 12 Jul 2015, 17:37
by Manfred
Hi Bernardduur,
thanks for dissectioning, great!
How is the size of the PCB?
Do you made a shot of the component side of the PCB too,
there are some components hidden by the plug sockets on the device shot?
I intend to create a replica PCB.
Re: Jennings Electronic Industries (JEI) - Phaser
Posted: 12 Jul 2015, 18:13
by Fender3D
lol
looking at the several magazines publishing(ed) this...
it may be a good argument for the "The Big Catfight: ethics/cloning/copying/stealing/personal" thread...
Re: Jennings Electronic Industries (JEI) - Phaser
Posted: 12 Jul 2015, 22:13
by Manfred
Fender3D wrote:lol
looking at the several magazines publishing(ed) this...
it may be a good argument for the "The Big Catfight: ethics/cloning/copying/stealing/personal" thread...
I guess there is no argument, because it is a discontinued product since more than 40 years.
Of course for noncommercial use only.
Re: Jennings Electronic Industries (JEI) - Phaser
Posted: 13 Jul 2015, 20:03
by Bernardduur
@ tube exorcist: Thanks for the link!!
@ Manfred: here ya go
Size: 7cm x 5.5cm
Re: Jennings Electronic Industries (JEI) - Phaser
Posted: 13 Jul 2015, 20:51
by Manfred
Hi Bernardduur,
thanks for the shot and the board size.
Re: Jennings Electronic Industries (JEI) - Phaser
Posted: 03 Jan 2017, 23:03
by Manfred
I create the PCB layout clone according to the the shots.