Two heads into Stereo 1960 cab?

hagcel · 07-17-2009, 08:40 PM

I have a JCM 900 1960B.

The stereo selection allows for two 8 ohm inputs. Can I run two heads through this?

I have 50 watt JCM 800, 900, and Mesa Single Rec.

I am assuming since it says 150 watts per channel stereo I could run up 150 watt heads in each channel?

Also is it safe to run in stereo mode with only 1 input being used?

Also just to be clear: The (4) 16 Ohm switch position means 16 ohms using one output and 4 ohms using two outputs (on the JCM 900)?

***Adwex*** · 07-17-2009, 11:02 PM

Sure you can do it, as long as both heads are set for 8 ohms, and the switch on the cab is set to Stereo.

It won't be true "stereo" of course (left/right channels), it'll just be two heads, both in mono.

Ace · 07-19-2009, 08:42 AM

Well some thoughts about this. Don't know if you plan on playing the 2 amps at the same time trough that cab ?

I'm planning on swapping 2 of the Greenbacks in my 1960 classic for 2 vintage30's and mounting them diagonally. As an extra I thought: Well, thanks to the stereo possibility and if wired correctly I could choose to only hear Vintage30's if I'm more in a metal kind-a mood, and only hear Greenbacks for crunchy rock stuff.

But.... a local amp builder here said that a 2x12 big diagonal cab and a 4x12 where you only use 2 speakers are not the same. The compression produced by the 2 active speakers will be partly countered/absorbed by the 2 non-active speakers, making them soak up some. Probably primarily the case in a closed cab. I guess this effect would be almost none existing in an open cab. Using a cab this way would give a misrepresented auditive image of speakers.

I'm curious to hear what other would have to say about this. If you run the 2 amps at the same time with 1 guitar, I suppose this effect would be a lot less.

iwanarok · 07-21-2009, 12:41 PM

JJJJJJEEEEEEEEESSSSSSSS! EEETTSSSOOOKKKK!

Landshark · 07-27-2009, 01:50 AM

soooooo.... why not just get another cab and an a/b switch?

Landshark · 07-27-2009, 01:59 AM

Another thought, if you have a "Y" cable you can hook two heads up at the same time... but you still would need an a/b switch.

07-17-2009, 08:40 PM	#1 (permalink)
hagcel Member Join Date: Jul 2009 Location: Minneapolis Posts: 68	Two heads into Stereo 1960 cab? I have a JCM 900 1960B. The stereo selection allows for two 8 ohm inputs. Can I run two heads through this? I have 50 watt JCM 800, 900, and Mesa Single Rec. I am assuming since it says 150 watts per channel stereo I could run up 150 watt heads in each channel? Also is it safe to run in stereo mode with only 1 input being used? Also just to be clear: The (4) 16 Ohm switch position means 16 ohms using one output and 4 ohms using two outputs (on the JCM 900)?

07-17-2009, 11:02 PM	#2 (permalink)
*Adwex* Super Moderator Join Date: Sep 2006 Location: Long Island, NY Posts: 2,214	Re: Two heads into Stereo 1960 cab? Sure you can do it, as long as both heads are set for 8 ohms, and the switch on the cab is set to Stereo. It won't be true "stereo" of course (left/right channels), it'll just be two heads, both in mono. __________________ http://www.youtube.com/MarshallLesPaul

07-19-2009, 08:42 AM	#3 (permalink)
Ace Senior Member Join Date: May 2009 Posts: 100	Re: Two heads into Stereo 1960 cab? Well some thoughts about this. Don't know if you plan on playing the 2 amps at the same time trough that cab ? I'm planning on swapping 2 of the Greenbacks in my 1960 classic for 2 vintage30's and mounting them diagonally. As an extra I thought: Well, thanks to the stereo possibility and if wired correctly I could choose to only hear Vintage30's if I'm more in a metal kind-a mood, and only hear Greenbacks for crunchy rock stuff. But.... a local amp builder here said that a 2x12 big diagonal cab and a 4x12 where you only use 2 speakers are not the same. The compression produced by the 2 active speakers will be partly countered/absorbed by the 2 non-active speakers, making them soak up some. Probably primarily the case in a closed cab. I guess this effect would be almost none existing in an open cab. Using a cab this way would give a misrepresented auditive image of speakers. I'm curious to hear what other would have to say about this. If you run the 2 amps at the same time with 1 guitar, I suppose this effect would be a lot less.

07-21-2009, 12:41 PM	#4 (permalink)
iwanarok Junior Member Join Date: Jul 2009 Location: Sunny California Posts: 22	Re: Two heads into Stereo 1960 cab? JJJJJJEEEEEEEEESSSSSSSS! EEETTSSSOOOKKKK!

07-27-2009, 01:50 AM	#5 (permalink)
Landshark Senior Member Join Date: May 2009 Location: Terre Haute, Indiana Posts: 581	Re: Two heads into Stereo 1960 cab? soooooo.... why not just get another cab and an a/b switch? __________________ Gibson Les Paul Studio Schecter S-1 Elite Marshall JCM 2000 TSL Vox AC 100 CPH Laney 4x12-WGS ET65's modded basketweave grill cloth

Today
Marshall Amps	Sponsored Links __________________ This advertising will not be shown in this way to registered members. Register your free account today and become a member on Marshall Amp Forum

07-27-2009, 01:59 AM	#6 (permalink)
Landshark Senior Member Join Date: May 2009 Location: Terre Haute, Indiana Posts: 581	Re: Two heads into Stereo 1960 cab? Another thought, if you have a "Y" cable you can hook two heads up at the same time... but you still would need an a/b switch. __________________ Gibson Les Paul Studio Schecter S-1 Elite Marshall JCM 2000 TSL Vox AC 100 CPH Laney 4x12-WGS ET65's modded basketweave grill cloth

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode