Headphone on / off switch for SEX amp

[sdritchey]

I'd like to have some sort of switch so I can select between the headphones and / or the speakers.  Ideally this would be a 3-way switch mounted to the chassis and not a switch internal to the headphone jack.  What are the factors involved in an external switch vs an internal switch?

Concerning the internal switch I found a thread here: http://db.audioasylum.com/cgi/m.mpl?forum=bottlehead&n=93907&highlight=sex+switch&r=&session= explaining a bit about the internal headphone jack switch.  My headphones however are low impedence, so I am afraid that the phones would be too loud if I remove the critical resistor and go with the internal jack switch.  There is another thread here: http://www.bottlehead.com/smf/index.php/topic,629.0.html in which Paul Joppa mentions a part that it sounds like can accomodate the resistor, is this the case?  I cannot find the conversion instructions mentioned by Paul however.

I know nothing about circuits, and will be having a local tech work on the amp for me.  Any info I can pass along to him to make sure that the work is done right is most welcome.

Thanks in advance!

[denti alligator]

You could install a shorting jack which would allow you to leave the speakers plugged in at all times. The headphones could then only be used without the speakers working (though they would remain plugged). But this wouldn't allow you to play both speakers and headphones at the same time. But I can't image why you would want to do that, unless you had a pair of 'phones to break in.

[JC]

I seem to recall that Bottlehead had the necessary switching jack available to upgrade the standard one while continuing to use the IHF-standard resistors.  I certainly can't seem to find it now, though.

Perhaps an e-note to Bottlehead could tell you if I'm losing it, or such a thing actually exists.  IIRC, they sold it with a couple of new resistors to aid in the retro-fitting, since the existing resistors would be difficult to re-use. 

Alternatively, I believe a double pole switch would be all you would need to make a "Headphone OR Speaker" arrangement; you would switch the left and right "+" output signals to go to either the speaker outputs OR the headphone jack resistors.  As far as I know, there would be no reason to switch the "-" output lines, they could stay connected.

[Paul Joppa]

JC, you are correct. I think Eileen sent one off just a couple weeks ago. The OP can ping her on Monday if interested.

It's no big secret, just that the right jack is hard to find. It has not been manufactured in quantity since telephone lines were switched by people (Ernestine, I think her name is?) and has become rare.

[sdritchey]

Just called in and yes, the conversion kit is available and it comes with instructions.  Figured that was the easier route than adding an external switch.

Thanks for the help!

[JC]

Hey, good deal!

Not only will you get what you're after, but that means my imagination didn't just make the whole thing up!  And, thanks to Paul for his memory, too!

So, the only question I have is: Is this little conversion kit described on the website somewhere and I am just not good at finding these things, or has it not been put up here for whatever reason?

[Armaegis]

How much is the conversion kit?

[Armaegis]

I think one of these would do the trick...?
http://www.neutrik.com/us/en/audio/210_165491/NMJ6HC-S_detail.aspx

[sdritchey]

The kit is $10.

[Paul Joppa]

I think one of these would do the trick...?
http://www.neutrik.com/us/en/audio/210_165491/NMJ6HC-S_detail.aspx

Afraid not. The part we use is a KobiConn 161-0083; you can download the data sheet from Mouser. The switching is different.