OT mod for Princeton Reverb issue???

[mozz]

2 eight ohm speakers(into the pair of 4 ohm jacks), 2 16 ohm speakers(into the pair of 8 ohm jacks), 1 16 ohm speak into the 16 ohm jack. Singles of each. Rather confusing though it does work, if you are familiar with it.
EDIT: think it would be easier 1 jack each, and have a "y" cable if you decide to run 2 cabinets.

[Helmholtz]

Ok, I didn't mention it before because it might be confusing.
But any secondary load combination that results in the correct primary impedance will work.
As the OP's amp will have 4, 8 and 16 Ohm outputs, an 8 Ohm speaker into the 4 Ohm output + a 16 Ohm speaker into the 8 Ohm output should work fine.

[Chuck H]

Does open up the option of connecting mismatched cabs though - an 8ohm cab on the 4ohm out and a 16ohm cab on the 8ohm out provides nominal primary load. My preference is for 2x4ohm jacks, 2x8ohhm jacks, and a single 16ohm. Using jacks with a ring shunt you can still wire this arrangement to short the secondary with no plug inserted like typical Fender wiring for no-load protection. Clear labelling is important of course, but that's always true.

This is an option. But there's still a confusing number of jacks and allocations for what goes where. I'm remembering a Mesa product that had an arrangement like you propose. As in: The two 4 ohm jacks are there for a 4 ohm load. So you could plug in a 4 ohm cabinet into a plug marked "4 ohms" OR you could plug two 8 ohm cabinets into both plugs marked "4 ohms".

To be honest I don't know one low tech rock guitar player that's going to get that right.

JM2C.

[Greg Robinson]

I don't understand how this works? For the same reason that the Fender doesn't have the shunt on the 'ext.spkr' jack (and Marshall's don't have 'no-load' protection).

It relies on a switched contact on each of the jacks being in series - so it's not quite so robust as the Fender shunt on the main out - increased chance of an oxidised contact defeating the protection, but it's certainly better than nothing. Inserting a plug into any of the jacks defeats that series chain and disables the short. I've attached an image below, hopefully it makes sense to you.

2 eight ohm speakers(into the pair of 4 ohm jacks), 2 16 ohm speakers(into the pair of 8 ohm jacks), 1 16 ohm speak into the 16 ohm jack. Singles of each. Rather confusing though it does work, if you are familiar with it.
EDIT: think it would be easier 1 jack each, and have a "y" cable if you decide to run 2 cabinets.

Parallel jacks for 4 and 8 ohm just avoids the need for y cables (for 2x8ohm or 2x16ohm cabs respectively), and given there's normally no shortage of space on the rear of an amp, why not? Only a few dollars extra for a couple of extra jacks and no Y cables to misplace.

To be honest I don't know one low tech rock guitar player that's going to get that right.

JM2C.

Definitely requires clear labelling, and Mesa could do a better job of that on their amps. But as a counterpoint, I've got plenty of meathead clients with Boogies that cope just fine.

[pdf64]

I don't understand how this works? For the same reason that the Fender doesn't have the shunt on the 'ext.spkr' jack (and Marshall's don't have 'no-load' protection).

See https://ampgarage.com/forum/viewtopi...267223#p267223

[Helmholtz]

See https://ampgarage.com/forum/viewtopi...267223#p267223

Nice, but requires 2 different impedance taps.

[Chuck H]

I still like the idea of two parallel jacks and a switch. Plenty of utility in the real world when compared and harder to screw up. Whatever.