sneak preview - SEX!

Posted by Doc B. (M) on April 29, 2004 at 18:22:01

Here's proof that S.E.X. never goes out of fashion. PJ and I spent the last couple days building this first prototype of the newest version of the Single Ended eXperimenter's amp. The original S.E.X. amp went out of production a few years ago, but I felt the concept was more valid than ever, as more and more folks are considering reasonably priced ways of getting into tube audio. I also felt that we could use our 10 year experience base to develop and offer a far more versatile product than one finds in other tube audio kits. And so we put this S.E.X. for the 21st century project ahead of everything else.

The new integrated stereo single ended parafeed S.E.X. amp uses 6DN7 dual triode tubes like the original, but only one per channel rather than the original parallel pair, for improved clarity and resolution. One can use 6EM7s as well with a little reworking of the circuit, along with a whole slough of other tubes if one wants to get into the Frankenstein school of homebrew amp/preamp/headphone amp design. Output transformers are the same as used in the stock Paramour, but they are wired as autoformers in this design. PJ spec'd dual bobbin plate chokes have 30H inductance (mounted under the chassis), and performance is about 2wpc into 4 or 8 ohms (using the corresponding tap), 30Hz-30kHz. The single power transformer sports two separate high voltage windings, so there are actually dual mono B+ supplies. The input stage is biased with 431 precision voltage reference chips.

Like the Paramour, the speaker outs (which are on the back with the RCA inputs and the IEC power cord socket) can be wired for 8 ohms or 4 ohms, and as you can see we are experimenting with setting the circuit up so that the integrated amp can optionally be used as a headphone amp via a Neutrik 1/4" stereo jack wired with the IHF standard 120 ohm series resistance. And you could even make up a stereo 1/4" plug to dual RCA jacks adapter and use the SEX amp as a preamp if you were really hungry for an inexpensive autoformer output preamp. An adventurous type seeking more power on a budget could even try rewiring the circuit into a push-pull monoblock. Like I said, it's all about versatility.

We still have some refinements to make, and we are not quite ready for orders yet, but the project is progressing well. Price is hoped to come in around $299.

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Topic - sneak preview - SEX! - Doc B. 18:22:01 04/29/04 (32)

Nice going Doc!! What's the approx output? (nt) - JP 13:06:42 04/30/04 (2)

Re: Nice going Doc!! What's the approx output? (nt) - Doc B. 14:10:12 04/30/04 (1)

Thanks Doc, I gotta get those wipers reinstalled on my glasses ;-) (nt) - JP 04:44:25 05/01/04 (0)

Very cool - GLF 08:49:04 04/30/04 (2)

Re: Very cool - Doc B. 09:37:43 04/30/04 (1)

Re: Very cool - GLF 12:52:07 04/30/04 (0)

If you were not around then, a pic of the Original S.E.X. - Wardsweb 07:15:59 04/30/04 (0)

Dude, - tcain 07:02:12 04/30/04 (0)

Finally time to build that tubed 5.1 system - Mudhiker 21:48:45 04/29/04 (0)

S.E.X. from behind - Doc B. 18:25:51 04/29/04 (22)

re: and plug right into that cool soundcard you bought... - artsybrute 15:45:23 04/30/04 (0)

Oh baby! Sign me up! - John Bennitt 19:40:17 04/29/04 (2)

Re: Oh baby! Sign me up! - Doc B. 20:17:34 04/29/04 (1)

Whoo whee! (nt) - John Bennitt 20:25:26 04/29/04 (0)

Re: S.E.X. from behind - Binayak Bhattacharyya 19:38:39 04/29/04 (0)

Re: S.E.X. from behind - Matt in Dayton 19:23:47 04/29/04 (14)

Re: S.E.X. from behind - Grainger49 08:05:37 04/30/04 (1)

Well said - Steve Culton 08:16:08 04/30/04 (0)

um, think FCC and Bono... - pRC 19:51:56 04/29/04 (4)

Re: um, think FCC and Bono... - UK Ray 04:05:55 05/02/04 (2)

Re: um, think FCC and Bono... - pRC 05:15:32 05/02/04 (1)

Two Peoples Seperated by a Common Language - UK Ray 10:59:17 05/02/04 (0)

Re: um, think FCC and Bono... - Doc B. 20:01:50 04/29/04 (0)

Re: S.E.X. from behind - Pete B. 19:50:57 04/29/04 (4)

probably a good thing... - mrh (Mark Hardy) 08:51:04 04/30/04 (0)

Re: S.E.X. from behind - Doc B. 20:36:37 04/29/04 (2)

No offense here - Steve Culton 06:54:18 04/30/04 (0)

Re: offended wives..... - Matts 20:45:50 04/29/04 (0)

S.E.X. from the side - newsjeff 19:49:25 04/29/04 (1)

LOL! He(a)r, He(a)r! - John Bennitt 19:56:49 04/29/04 (0)

Re: S.E.X. from behind - BR 18:59:00 04/29/04 (0)

Re: Thats cool!(nt) - Spaaaz 18:42:11 04/29/04 (0)

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