Bottlehead Forum

Bottlehead Kits => S.E.X. Kit => Topic started by: Doc B. on April 01, 2011, 07:47:23 AM

Title: Nice review of S.E.X. kit by Jeff Poth on Enjoy the Music DIY
Post by: Doc B. on April 01, 2011, 07:47:23 AM
Thanks Jeff and Steve!

http://www.enjoythemusic.com/diy/0411/single_ended_experimenters_kit.htm (http://www.enjoythemusic.com/diy/0411/single_ended_experimenters_kit.htm)
Title: Re: Nice review of S.E.X. kit by Jeff Poth on Enjoy the Music DIY
Post by: badman on April 06, 2011, 04:47:31 AM
Well, it's a great little amp and holds it's head up high against the very competent fleapower competitors I have had through here.  Anything else you wish to send along for review, let me know and we'll work out details. 

Jeff
Title: Re: Nice review of S.E.X. kit by Jeff Poth on Enjoy the Music DIY
Post by: dstrimbu on April 10, 2011, 05:13:25 PM
Hey Doc,

Has Jeff heard the Crack yet?  :-)

-Don
Title: Re: Nice review of S.E.X. kit by Jeff Poth on Enjoy the Music DIY
Post by: rbruinsma on April 10, 2011, 11:53:55 PM
Nice review, hope to finish my SEX amp soon ;)
Title: Re: Nice review of S.E.X. kit by Jeff Poth on Enjoy the Music DIY
Post by: badman on April 11, 2011, 10:46:20 AM
Hey Doc,

Has Jeff heard the Crack yet?  :-)

-Don


I haven't heard the Crack, nor the Quickie, nor the phono products.  I have heard FPIII, Paramounts, SEX, and a lot of the legacy products, even a couple pair of straight 8s.

Title: Re: Nice review of S.E.X. kit by Jeff Poth on Enjoy the Music DIY
Post by: JC on April 11, 2011, 01:09:51 PM
If you get the chance to review the Crack, badman, I hope you'll do so both with and without the Speedball upgrade, and give your impressions of the differences.  Nice writing, btw!
Title: Re: Nice review of S.E.X. kit by Jeff Poth on Enjoy the Music DIY
Post by: badman on April 13, 2011, 05:15:25 AM
If you get the chance to review the Crack, badman, I hope you'll do so both with and without the Speedball upgrade, and give your impressions of the differences.  Nice writing, btw!

That's not terribly likely.  While it seems like a fine product, I'm not much of a headphone guy.  I recognize their merits but prefer good 'ole speakers... like these I'm currently using. 

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fimg841.imageshack.us%2Fimg841%2F5450%2Fimg0528ya.jpg&hash=6df67502490e6a02a239beeba53848aeedc0f7bf)
Title: Re: Nice review of S.E.X. kit by Jeff Poth on Enjoy the Music DIY
Post by: Grainger49 on April 16, 2011, 09:05:07 AM
Looks like an old Heil AMT with plastic ears!  Tell us more about the ears, I know a lot about the AMT.
Title: Re: Nice review of S.E.X. kit by Jeff Poth on Enjoy the Music DIY
Post by: badman on April 18, 2011, 11:08:08 AM
They're not plastic, but white-painted wood.  The profile is pretty simple, with straight walls and a termination roundover.  My impetus was looking at the large amount of ripple in the off-axis response of these, along with the 2k dip.  I figured the 2k dip and 1k peak is probably related to the dipole action, and some of the off-axis ripple from mouth diffraction (the basic structure of these is basically a horn).  This symmetrical horn-loading will hopefully allow me quite a bit more 1k-4k output, but I'm working with the crossover still- there's an interesting anomaly in that my capacitor and the heil are not adding impedances- the heil at 6 ohms with the (current, testphase) capacitor being 8 @ 1kHz, is summing to... 10?!?!?

My more active project thread is over in the planars and exotics forum at diyaudio.com and will probably be an Enjoy The Music article eventually too, so keep an eye on those two if you want to see how this monster (the horn is 22" wide) shapes up longer-term.
Title: Re: Nice review of S.E.X. kit by Jeff Poth on Enjoy the Music DIY
Post by: Paul Joppa on April 18, 2011, 12:19:20 PM
... there's an interesting anomaly in that my capacitor and the heil are not adding impedances- the heil at 6 ohms with the (current, testphase) capacitor being 8 @ 1kHz, is summing to... 10?!?!?
Exactly right. The capacitor impedance is a reactance, 90 degrees out of phase with the resistance. They add like a right triangle - the hypotenuse (total impedance magnitude) is the square root of the sum of the sides squared. The phase angle of the resulting impedance is 53 degrees - the angle whose tangent is 8/6.
Title: Re: Nice review of S.E.X. kit by Jeff Poth on Enjoy the Music DIY
Post by: badman on April 19, 2011, 04:48:35 AM
Duh, brainfart.  Thanks for the corrective action Paul.