Bottlehead Forum

Bottlehead Kits => S.E.X. Kit => Topic started by: tttubes on January 27, 2025, 08:48:46 AM

Title: S.e.x. with iron upgrade
Post by: tttubes on January 27, 2025, 08:48:46 AM

How would i wire  the magequest otf for 4 ohms.

Title: Re: S.e.x. with iron upgrade
Post by: Paul Joppa on January 27, 2025, 10:17:23 AM

That depends on which S.E.X. amp version you have. Here are the versions:

Original SEX monoblocs (Magnequest upgrade TFA-204)
Revision 1.0 (1996) (Magnequest upgrade TFA-204)
Revision 1.1 (1996) (Magnequest upgrade TFA-204)
Revision 2.0 (1997) (Magnequest upgrade TFA-204)
ParaSEX (1999) (no upgrade)

Stereo SEX
Version 2.0 (2004) (Magnequest upgrade BH-2 choke, BH-1 transfprmer 8 ohms only)
     (Bottlehead upgrade PC-3 choke, OT-2 transformer)
Revision 2.1 (2011) (stock Bottlehead PC-3 choke, OT-2 transformer - no upgrades)
Revision 3 (2017)  (stock Bottlehead PC-3 choke, OT-2 transformer - no upgrades)

Title: Re: S.e.x. with iron upgrade
Post by: tttubes on January 27, 2025, 11:19:10 AM

Quote from: Paul Joppa on January 27, 2025, 10:17:23 AM

That depends on which S.E.X. amp version you have. Here are the versions:

Original SEX monoblocs (Magnequest upgrade TFA-204)
Revision 1.0 (1996) (Magnequest upgrade TFA-204)
Revision 1.1 (1996) (Magnequest upgrade TFA-204)
Revision 2.0 (1997) (Magnequest upgrade TFA-204)
ParaSEX (1999) (no upgrade)

Stereo SEX

ersion 2.0 (2004) (Magnequest upgrade BH-2 choke, BH-1 transfprmer 8 ohms only)
     (Bottlehead upgrade PC-3 choke, OT-2 transformer)
Revision 2.1 (2011) (stock Bottlehead PC-3 choke, OT-2 transformer - no upgrades)
Revision 3 (2017)  (stock Bottlehead PC-3 choke, OT-2 transformer - no upgrades)

Do these pics help I it saw a one

Title: Re: S.e.x. with iron upgrade
Post by: tttubes on January 27, 2025, 11:20:58 AM

and this

Title: Re: S.e.x. with iron upgrade
Post by: Paul Joppa on January 27, 2025, 01:32:56 PM

Thanks for the pictures. That is a SEX 2.0 with the Bottlehead Iron Upgrade kit (and a lot of other cool mods!)

On pages 10 and 11 of the upgrade kit manual, there are detailed instructions and photos for wiring the OT-2 output transformer for 4/8/16/32 ohms.

In case you no longer have the manual, I've attached a set of connection instructions, unfortunately without photos. The numbers refer to the solder lug numbers embossed on the transformer bobbin. (Lugs 4 and 9 are the missing ones.)

Title: Re: S.e.x. with iron upgrade
Post by: Cary on January 27, 2025, 03:14:24 PM

You will love the SEX 2.0 upgrade kit, I installed it about a year ago and it takes the amp to new heights.