Bottlehead Forum

Bottlehead Kits => S.E.X. Kit => Topic started by: Doc B. on May 06, 2016, 05:37:08 AM

Title: S.E.X. 2.1 Retired!
Post by: Doc B. on May 06, 2016, 05:37:08 AM
The last S.E.X. kit sold early this morning. We have decided to retire the Single Ended eXperimenter's kit due to the supply of 6DN7s getting so sparse that we can no longer purchase the volume of tubes necessary to justify continued production. There will be plenty available in small quantities for some time if you need a spare. Thanks so much to everyone who purchased a S.E.X. kit in one (or more) of its iterations over the past 21 years. It's the kit that got us started, and we plan to continue cooking up unique and great sounding products like it for as long as I have new ideas - of which there continue to be plenty.
Title: Re: Retired!
Post by: Bonzo on May 06, 2016, 07:27:49 AM
Looking forward to see the new masterpiece!!

S.E.X. is dead, long live the ______ ! :)
Title: Re: Retired!
Post by: tdogzthmn on May 07, 2016, 04:21:42 AM
Love my little SEX 2.1 it's been awesome as a headphone amp and diving my Orcas's.

I'd personally be interested in seeing Bottleheads take on an OTL power amp for speakers!  Love to hear some thoughts on this.
Title: Re: Retired!
Post by: Natural Sound on May 07, 2016, 05:33:15 AM
Before I knew about Bottlehead I built a 6T9 amplifier that was featured in the August 2004 issue of Nuts and Volts magazine. At the time the 6T9 was plentiful and cheap. Fast forward to 2016 and the 6T9 is often difficult to find but if you do it comes with a hefty price tag. I still have that amp but I don't use it anymore. My S.E.X. 2.0 and 2.1 amps sound much better. I did learn my lesson though and amassed a small stock of 6DN7's that should get me to the end of the line. ;)

http://www.sparetimegizmos.com/Hardware/Stereo_6t9.htm (http://www.sparetimegizmos.com/Hardware/Stereo_6t9.htm)


Title: Re: Retired!
Post by: Doc B. on May 07, 2016, 09:34:11 AM
Love my little SEX 2.1 it's been awesome as a headphone amp and diving my Orcas's.

I'd personally be interested in seeing Bottleheads take on an OTL power amp for speakers!  Love to hear some thoughts on this.

My thought is that it might be pretty cool if you had 600 ohm speakers. For 8 ohm speakers, what I would do would not be very practical.
Title: Re: Retired!
Post by: tdogzthmn on May 07, 2016, 02:02:32 PM
My thought is that it might be pretty cool if you had 600 ohm speakers. For 8 ohm speakers, what I would do would not be very practical.

I've built and enjoyed the Crack a few years ago with my 600 ohm AKG's but I also know there are some manufacturers that make OTL Tube amps designed to work with speakers.  I can't comment about the efficiency differences between designs (OTL vs SET), I just know it has been done before.  Mostly I was wondering if it was something you had explored previously and abandoned? 
Title: Re: Retired!
Post by: Paul Joppa on May 07, 2016, 02:56:25 PM
I have considered how to do that periodically, and always came back to the same point - it's just not practical without using a push-pull topology with lots of feedback.

Example: if the Crack works well into 600 ohms, then 75 paralleled cracks should work equally well into 8 ohms. But it's still a cathode follower, which means there is still some negative feedback sound. And it would consume 2 to 3 kilowatts, producing maybe 20 watts.

That's a crude analysis, and could probably be improved - but not dramatically.
Title: Re: Retired!
Post by: Jim R. on May 08, 2016, 04:55:02 AM
I have always found it interesting that an awful lot of people with OTL speaker amps use impedance matching autoformers with their amps. If you have as warped a sense of humor as I do, you'll see the supreme irony in this :-).
Title: Re: Retired!
Post by: Brent on May 08, 2016, 05:34:18 AM
Jim,

I have observed the same with some amusement. It's like the ingredients list on a slim Jim, which includes both 'defatted beef' and 'beef fat.'  It's just weird. But whatever floats your boat. I'm sure I do plenty of things other people think is pointless or wrong.  :)

Brent
Title: Re: Retired!
Post by: Paul Birkeland on May 08, 2016, 08:37:06 AM
I have always found it interesting that an awful lot of people with OTL speaker amps use impedance matching autoformers with their amps. If you have as warped a sense of humor as I do, you'll see the supreme irony in this :-).
Yeah, god forbid that you tell that they no longer have an OTL amp, you'll cause a miniature meltdown on whatever forum you happen to be on.
Title: Re: Retired!
Post by: Jim R. on May 08, 2016, 08:52:45 AM
Yeah, That's why I just shut. Up and let it be. :-)

As Brent said, I probably do plenty of things that other people think is odd.

-- Jim
Title: Re: Retired!
Post by: murray on May 08, 2016, 09:37:37 PM
I have always found it interesting that an awful lot of people with OTL speaker amps use impedance matching autoformers with their amps. If you have as warped a sense of humor as I do, you'll see the supreme irony in this :-).

I think I see what you did there.  Yes, those big transformers would be very "irony". Lots of iron. :D
Title: Re: Retired!
Post by: murray on May 08, 2016, 09:44:31 PM
I think the universe is trying to tell me something. I was slowly saving for the recently retired kit. It was to have been my first foray into tubes after years of transistors and MOSFETs.  Meanwhile, in the weekend, my old oscilloscope has died (fried) for what looks like the last and final time, so my first job will be to look around for a new one, as there's several projects on hold now.
I'll still keep an eye out here, though.
Title: Re: Retired!
Post by: Jim R. on May 09, 2016, 02:00:09 AM
Hi Murray,

Yes, the universe is telling you to get one of the other kits ASAP -- you won't need the scope to build one. Of course, I have no idea what else is on your bench, so maybe the scope is more important to you right now.

Good luck with whatever path you take.

Take care,

Jim
Title: Re: Retired!
Post by: Wardsweb on May 09, 2016, 10:19:28 AM
This will always be one of my favorite little amps.

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fwww.wardsweb.org%2Faudio%2Fsexamp%2Fsexamptop.jpg&hash=1fed3fb12cc354f410f9aab6f3ed81d7)
Title: Re: Retired!
Post by: freakmech on May 10, 2016, 04:30:41 PM
Im proud to say that I purchased the last S.E.X. kit and look forward to receiving and building it. I have a small recording studio/ workshop/ place of solitude to which the S.E.X. will be utilized. For leisure, when not working on music, I love to search the internet for new and interesting music and talk radio. But I find streaming digital audio, be it youtube, podcasts, soundcloud etc, to be very harsh sounding to my ears through my powered studio monitors. A few years ago I built a Pete Millett designed Jonokuchi amp and a pair of Overnight Sensations just for streaming audio. I was very happy with the lack of ear bleeding harshness of streaming audio. How ever, the Jonokuchi has never been a good match for my favorite casual listening headphones, Grado SR125's. I know they arent great but to my ears they are the least fatiguing utility headphones I have owned, particularly with streaming talk radio. Long story short, Ive been wanting the S.E.X. for a long time now because of the claim of working well with low ohm headphones but still able to push small, efficient speakers. When i saw the last kit was up for sale I couldnt pass it up. I would also like to pair it with some Blumenstein Audio speakers though the DIY in me wants to build something myself. anyhow, thanks Bottlehead community, and my wife, who despite being Mothers Day weekend, allowed me to buy the final S.E.X. kit. I will try to do the heritage justice.   
Title: Re: Retired!
Post by: Doc B. on May 10, 2016, 04:38:54 PM
Thank you!
Title: Re: Retired!
Post by: tsingle999 on May 11, 2016, 04:43:05 AM
Wardsweb that is one stunning amp!
Freakmech I think you will love the SEX amp! I just compared my orca deluxe with 83en drivers to planet -10's microfonken with 85wk drivers that I built with their flat pack. They both sound good but the orca cabinet is a much superior enclosure and it is more resolving to my ears. Good luck!
RIP SEX amp! Thanks for all the fun Doc and company!
Title: Re: Retired!
Post by: HF9 on May 11, 2016, 11:07:07 AM
So sad :( My hot-rodded S.E.X. is my favorite headphone amp and through the years has become such a versatile little unit... but I can understand needing to put models out to pasture for business reasons. I referred a couple of my customers to run over and snatch up the last of the units before they were gone  ;D
Title: Re: Retired!
Post by: cspirou on July 20, 2016, 06:28:40 AM
Is a 3.0 version in the pipeline or a similar spud amp?
Title: Re: Retired!
Post by: Doc B. on July 20, 2016, 07:46:01 AM
We're going to be working on some ideas tomorrow.
Title: Re: Retired!
Post by: boulos on August 16, 2016, 05:36:20 PM
Is the Output Impedance Switch Kit going to be available for those of us who have the SEX but weren't wise enough to purchase one earlier for protection  ??? :-\