1960 Question

[Bryan]

Ok.... so pretend like I know nothing (because this is my first 1960)

What are my options here?

I have a JCM 2000

1. How do I plug the amp in so that all 4 speakers work?

2. If I switch from left to right, does that go from 2 speakers to 4?

3. Can I plug 2 different amps into this cabinet and have one amp through 2 speakers and the other amp through the other 2? ( I do have a Freidman JEL20 head)

There's a lot going on here and i just want to make sure i don't accidentally mess anything up.

Again, excuse my ignorance but this is my first Marshall cab and I've never seen a back plate like this before.

 

[6StringMoFo]

Cab set to mono, use the 16 Ohms out of the amp into the 16 Ohms in of the cab.

 

[fitz]

I have a JCM 2000

1. How do I plug the amp in so that all 4 speakers work?

2. If I switch from left to right, does that go from 2 speakers to 4?

3. Can I plug 2 different amps into this cabinet and have one amp through 2 speakers and the other amp through the other 2? ( I do have a Freidman JEL20 head)

1. As @6StringMoFo said, set to mono - 16 ohm cab jack to 16 ohm amp jack.
2. Yes, switching to stereo, you get 2 speakers to each jack at 8 ohms.
3. Yes, 2 amps - one to each 8 ohm cab jack - stereo amps is awesome.

 

[RLW59]

When the switch is set to mono, one jack is all 4 speakers all in parallel for 4 ohms total, the other jack is all 4 speakers in series/parallel for 16 ohms total.

When the switch is set to stereo, one jack is connected to one pair of speakers (8 ohms for two speakers) and the other jack is connected to the other pair of speakers (also 8 ohms).

In stereo, yes you can run one amp into one pair and another amp into the other pair at the same time.

Some solid-state amps put out max power into 4 ohms, and some old Fenders were 4 ohms only. But with your amps there's no need to ever use the 4 ohm option.

 

[RLW59]

"JCM 2000" is a whole series of models, from 20 watts to 100 watts. The DSL100 and TSL100 actually put out 160 watts or more when cranked all the way up. If you have one of those, avoid cranking it with the cab in mono mode. (The 20, 40, 50 and 60 watt JCM 2000's are all safe when cranked through 2 speakers in a 1960.)

 

[Bryan]

First and foremost, thank you all for the quick and understanding answers. I appreciate it.

Let me reacap:

1 amp 4 speakers

Amp (16ohm out)
Cab switched to Mono
Plugged into right input

1 amp 2 speakers

Amp (8ohm out)
Cab switched to stereo
Plugged into either left or right input

2 amps 2 speakers each

Amps (8ohm out each)
Cab switched to stereo
1 amp into left input, second amp into right input

Is this right?

 

[RLW59]

First and foremost, thank you all for the quick and understanding answers. I appreciate it.

Let me reacap:

1 amp 4 speakers

Amp (16ohm out)
Cab switched to Mono
Plugged into right input

1 amp 2 speakers

Amp (8ohm out)
Cab switched to stereo
Plugged into either left or right input

2 amps 2 speakers each

Amps (8ohm out each)
Cab switched to stereo
1 amp into left input, second amp into right input

Is this right?

Yes, you've got it!

 

[Bryan]

Sorry.... here's my JCM2000

 

[RLW59]

Most of the 1960 switching jackplates work fine forever. But it's not uncommon for them to develop faults where the actual impedances are way different than they're supposed to be.

It's a very good idea to use a multimeter and check each jack in both switch settings. Multimeters read DC resistance instead of AC impedance so the readings will normally be lower than the labels. 12-14 ohms for the 16 ohm setting, 5-6 ohms for the 8 ohm setting, around 3 ohms for the 4 ohm setting.

It's a good idea to measure any used cab, especially if you haven't opened it up to verify that it still has the stock speakers.

 

[fitz]

Sorry.... here's my JCM2000

Is that the 50 or 100?

The 1960AV should have Marshall/Celestion G12 Vintage speakers.
70w each, so even a pair on the stereo setting would give you 140w power handling.

 

[Bryan]

Is that the 50 or 100?

The 1960AV should have Marshall/Celestion G12 Vintage speakers.
70w each, so even a pair on the stereo setting would give you 140w power handling.

100 Watt