Marshall 1936 2x12 doesn't work in Mono???

[napalmdeath]

I've got a 1936 cab, version with no switch for mono/stereo. However, it says it will run 150 ohms mono in the 8ohm mono jack, but only one speaker works?? What gives?

I took the back off - shouldn't there be a set of wires from one speaker to the other, in addition to the set running from each speaker to each jack??

 

[Rdodson]

I'd repost this in Tech Corner with a pic or two - probably something simple.

 

[Rayneman]

I've got a 1936 cab, version with no switch for mono/stereo. However, it says it will run 150 ohms mono in the 8ohm mono jack, but only one speaker works?? What gives?

I took the back off - shouldn't there be a set of wires from one speaker to the other, in addition to the set running from each speaker to each jack??

I have a 1936 with no switch. It runs both speakers in mono when plugged into the 8 ohm jack, so that is odd yours doesn't do the same. I've not taken the back off, so I can't say anything about the wiring.

 

[napalmdeath]

Just like this. There's no switch, so I don't get it?

 

[SpiderWars]

Not familiar with the switch/wiring but there probably would not be wires from speaker-to-speaker because then you can't really separate them. So the wires should run to the switch. If the switch is bad or if signal has to go 'thru' a jack and the jack is bad, that could explain it.

FWIW, I'm in Tampa so if you need any help/soldering/etc just hit me up.

EDIT: Yeah, that goes 'thru' the jack and those jacks are notorius for failing on those 'thru' terminals. A lot of FX loops have issues with exact same thing. When it comes to speakers and their importance in not blowing up our beloved tube amps...Marshall did some questionable things that I yank out pronto.

 

[sg guy]

its been straight wired, its something I always do, im assuming theyre 16 ohm speakers, with each wired to its on jack, you could get a quality "Y" speaker cable and run it at 8ohms with both speakers, or with it being a 2x12 you can re-wire both speakers to one jack in parallel for 8 ohms, or you could use that piece of shit, tone sucking, transformer killin, PCB switching assembly,.. I have one i'll give ya if that's what ya wanna do

 

[eternal_idol]

Got a DMM?

 

[napalmdeath]

its been straight wired, its something I always do, im assuming theyre 16 ohm speakers, with each wired to its on jack, you could get a quality "Y" speaker cable and run it at 8ohms with both speakers, or with it being a 2x12 you can re-wire both speakers to one jack in parallel for 8 ohms, or you could use that piece of shit, tone sucking, transformer killin, PCB switching assembly,.. I have one i'll give ya if that's what ya wanna do

It seems to be designed that way? I stole that pic off google, it's wired identical to what mine is. I believe it switches to mono internally in that mono input?? Obviously, something is faulty, or I have no idea what I'm talking about. Both are possibilities here.

 

[sg guy]

-yes, i would replace the input jack's, like eternal idol said, ya got a meter?

 

[napalmdeath]

-yes, i would replace the input jack's, like eternal idol said, ya got a meter?

I bought it off Reverb, "like new" from a dealer. They're asking me for "evidence" it doesn't work as it should. I told him, "how about I return it on YOUR DIME, (62lbs.), and you can plug it in and see for yourself". I got it cheap, but they charged $85 shipping. Just got the stupid thing today.

 

[eternal_idol]

testing speaker cabs is easy.

check each speaker, if they are not exactly 8 or 16 ohm its not a big deal an ohm up or down
, check continuity of the cables (the setting that makes the buzzer sound when you put the two leads together)

check the continuity of the speaker cable, then plug the speaker cable in and check the ohms.

you should be able to see if the cone is torn (but torn cones still make noise) with a flashlight or bright light.

if everything checks out, the driver in questions might have be seized and load bearing, battery check should be able to sort out a seized voice coil from a properly functioning one.

a picture of your actual cab is needed beyond this, not some random one from reverb.

 

[napalmdeath]

testing speaker cabs is easy.

check each speaker, if they are not exactly 8 or 16 ohm its not a big deal an ohm up or down
, check continuity of the cables (the setting that makes the buzzer sound when you put the two leads together)

check the continuity of the speaker cable, then plug the speaker cable in and check the ohms.

you should be able to see if the cone is torn (but torn cones still make noise) with a flashlight or bright light.

if everything checks out, the driver in questions might have be seized and load bearing, battery check should be able to sort out a seized voice coil from a properly functioning one.

a picture of your actual cab is needed beyond this, not some random one from reverb.

No need to reinvent the wheel here, or pics of the cab necessary. It's the jack/jack plate assembly, plain and simple. Both speakers work in stereo, both work individually, (in their input jack), but not together in mono. I ordered the parts I need.

 

[Mesa\Kramer]

On my 1936, plugging into the Left Jack only the left speaker works, but plugging into the right jack both speakers work.
(I don't have a swtich either)

I have never tried running amps one into each input at the same time

 

[Chris O]

Those are nice cabs. I prefer them to the 1960 4x12s.