Help wiring a Marshall style transformer outputs

[WORMDIRT]

I don't know if I worded the topic right... oh well
Anyway I'm helping a friend wire some speaker out on his Nomad High Gain head. He wants there to be that old school style, no selector, just jacks set up.
I'm thinking, run the 8 ohm tap from the transformer, to the jack for an 8 ohm output. Then, run the 4 ohm tap to 2 (A and B we'll say) jacks wired in parallel. Just use "A" or "B" and you have 4 ohms, run both at the same time and you have 8 ohms from each. Is this thinking along the correct lines?
Also, this is the transformer that is installed on it. http://www.classictone.net/40-18026.html

A little bit of background on me, I have loads of pedal building experience, some amp experience, a la, PCB mods, bias/plate voltage measuring adjustments, cap changes etc.

[Firestorm]

If I understand you correctly, yes you can wire a dedicated 8 ohm jack and a pair of 4 ohm jacks. That pair would let you use a single 4 ohm cabinet or two 8 ohm cabinets. No 16 ohm jack? Why not do that too.

[WORMDIRT]

If I understand you correctly, yes you can wire a dedicated 8 ohm jack and a pair of 4 ohm jacks. That pair would let you use a single 4 ohm cabinet or two 8 ohm cabinets. No 16 ohm jack? Why not do that too.

Ok cool, thanks. He doesn't want too many holes drilled out, but I'll convince him with one of those "you, know, while I'm in here" kinda deals.

[WORMDIRT]

Hopefully this revives this thread..


I want to use Cliff jacks, and I would like to wire them in the HiWatt style, so that they gound out to 0 ohms instead of infinite when not connected, but I am out of my depth as far as how to wire them.

EDIT- Not as confident as I thought haha

[Jana]

double post

[Jana]

I have gone the route of multiple jacks like you describe but gave it up. I suggest sticking to a selector switch and a pair of jacks. But, it's his amp.

Here is a way to do the switching for two jacks that short if nothing plugged in. Plugging into either jack lifts the short. With enough coffee, there might be a way to do it with three jacks--not sure though.

[Leo_Gnardo]

Hopefully this revives this thread..


I want to use Cliff jacks, and I would like to wire them in the HiWatt style, so that they gound out to 0 ohms instead of infinite when not connected, but I am out of my depth as far as how to wire them.

EDIT- Not as confident as I thought haha

Not so easy to do if you're offering a selection of output Z as you wrote, with an 8 and a pair of 4's.

You could do like some amps, CAE (Suhr+Bradshaw design) for instance, use "stereo" jacks and put the output tubes' cathode on the ring connections. Then no bias current flows in the output tubes unless a jack is inserted into one of the output jacks.

[WORMDIRT]

So this is how I ended up wiring it. Before I run power through it, I need to know how to check it with a DMM and what the Red wire coming from the Phase inverter is for. It was there when I opened the amp up, it goes from the cliff jack, to a resistor to pin 3 or 4 of the phase inverter. Everything else looks good to me. I've been using a Cieratone wiring diagram as a reference.
Any critiques are much appreciated.