Bottlehead Forum

Bottlehead Kits => Legacy Kit Products => Stereomour => Topic started by: Jim R. on October 02, 2010, 10:42:12 AM

Title: Push-on connectors for OPTs?
Post by: Jim R. on October 02, 2010, 10:42:12 AM

Does anybody know if there is a standard size push-on type connector that will fit the tabs on the stereomour's OPTs?  I'm thinking I'd like to make some jumpers using these quick-connects so that I don't have to bother with a switching arrangement in order to experiment with different output impedance configurations.

Thanks,

Jim

Title: Re: Push-on connectors for OPTs?
Post by: 2wo on October 02, 2010, 04:03:28 PM

I haven't seen it but it is probably a spade lug. There are only a few sizes and you can probably find them at any auto parts store or Walmart. Measure it and maybe I can get some kind of a part number...John   

Title: Re: Push-on connectors for OPTs?
Post by: Jim R. on October 02, 2010, 04:12:38 PM

Hi John,

I would measure it but I don't have a braille vernier caliper or any other tool with tthe capability to make accurate small measurements.  I'm hoping that santa will bring me a braille micrometer and vernier calipers this year :-).

I figure it is a standard size and was hoping somebody here knew it off the top of their head.  If not I can always take the transformer to our local electronics parts store and try some until I find he right one.

thanks for being willing to help though.

-- Jim

Title: Re: Push-on connectors for OPTs?
Post by: Dyna Saur on October 02, 2010, 05:19:57 PM

There are  crimp-on "push-on" lugs available  in both 1/4 inch and 3/16 inch sizes, one or the other should do the job. I haven't seen a Stereomour "in person" so I don't know if either of these would be  a compatible fit for the OPT's secondary taps.  I know that  the 3/16 nicely fit the older style, open-frame Edcor XSE and GXSE OPTs.

These push-on s are available at auto parts shops, and perhaps at Radio Shack.

/ed

Title: Re: Push-on connectors for OPTs?
Post by: Paul Joppa on October 03, 2010, 07:37:43 AM

The terminals are combination solder-lug/slip-on terminals, 3/16 wide. The coil wires are bonded by dipping the whole lug in solder so the lugs are coated. That might make it a little harder to force the connector on, but otherwise it should work well enough.

I'll attach a table of jumper connections.

You can do the switching with two DPDT switches per transformer. One switch selects series or parallel wiring of the two secondaries (2/4 vs. 8/16 ohms), the other switch selects the tap or the full winding. In the table I added the asymmetrical wiring which gives 12 ohms. (The table shows both the 4K Stereomour impedances and the 8K SEX impedances, though this transformer is not yet used in the SEX amp.) If you only need three impedances (4, 8, 16 ohms) you could use a 4-pole 3-throw rotary such as the Foreplay source selector switch. I have not found a convenient location for any switches yet.

Title: Re: Push-on connectors for OPTs?
Post by: Jim R. on October 03, 2010, 08:13:35 AM

Thank you, Paul!

I'll take a look at the PDF to see if I can make sense out of it.

-- Jim