Ohm switch mod

[Rob Capizzi]

Hello again, I would like to install an ohm switch for the paramount. I have the manual and will see in there what will help me. But any wiring diagram would help. What perticular switch and wire should I use? Thank you. 

[Paul Joppa]

I believe I have a diagram; I'll be back in town Sunday and will look for it.

[Rob Capizzi]

I believe I have a diagram; I'll be back in town Sunday and will look for it.

Awesome! Have a great weekend!

[Adrian]

I performed a similar mod to my S.E.X 3.0.
I posted this mod under the S.E.X. forum.
It is on page 7 dated January 25.2021, titled "4-8 ohm switch".
There is a diagram showing the wiring of the switch and pictures of the connections for the S.E.X. amp.
This isn't a Paramount (I also have a pair of these), but it may give you some guidance on how to proceed.

[Adrian]

To clarify, you could use the same switch on both mono blocks.
You would only utilize half of the contacts, though.

[Paul Joppa]

The pinout and winding design of the OT-2 (SEX and Stereomour) is different from that of the OT-1 (Paramount), and the switch arrangement is thus also different.

The OT-3 (Mainline) and OT-5 (Kaiju) are also unique to themselves.

I will try to document the various options, but it may take me a few days.

[Paul Birkeland]

Here is PJ's schematic for switching the OT-1.  I believe he intended it to use a 4P3T rotary switch per chassis, which is a standard part that we have tons of, but a 2P3T switch would also work.

[Rob Capizzi]

Is that schematic the final info? I definitely want to understand the wiring 200% before I go and mess with the opt.

[Rob Capizzi]

Also I doubt I'm going to utilize the 16 ohm tap so double throw double pole?

[Paul Joppa]

Here is PJ's schematic for switching the OT-1.  I believe he intended it to use a 4P3T rotary switch per chassis, which is a standard part that we have tons of, but a 2P3T switch would also work.

Yes, that's the diagram I was going to look for - thanks for finding it!

It was my intent to use the 4-pole switch, wired as two 2-pole switches in parallel to make a 2-pole switch with lower resistance and better reliability. The switch on hand was used as a preamp input selector at much lower current than the power output produces.

[Paul Joppa]

Also I doubt I'm going to utilize the 16 ohm tap so double throw double pole?

That should work well. Most DPDT are rated for 15 amps so there is plenty of current-handling capability.