Ohms

[Bobby Damit]

Hi,
I have an old 1980's laney 30 watt 1x12" combo amp. it has an ohms selection or 4 or 8.
I also have an older 1969 (model, not year) Vintage 4x12 cabinet (stereo) which has 4 or 16 ohms and a mono / stereo switch. I want to use the combo amp as the head to also power the 4x12 cab. What should the ohms be set at on both amp?
Also, how can I run the cabs in stereo?
I also have an early 90's digitech RP7 valve pedal board that has a stereo output.
Thanks for your help.

 

[Jethro Rocker]

Are you planning to run the combo speakers as well? If not, you habe not much choice. The amp has a switch for 4 ohm but not 16. So set amp and cab to 4.

The stereo cab switch simoly allows you to run 1 pair of the speakers at 8 ohms separate from the other pair. Since your amp has one output amd is mono, you can't run it stereo.

 

[Frodebro]

First off, to run in true stereo would require two amps.

As for the impedance, the combo likely has an eight ohm internal speaker. The cab allows four or eight ohms, so you're not going to get a straight match with both the cab and the internal combo speaker. I would just disconnect the internal combo speaker, set the 4x12 to four ohms, and use the four ohm jack on the amp.

 

[Bobby Damit]

First off, to run in true stereo would require two amps.

As for the impedance, the combo likely has an eight ohm internal speaker. The cab allows four or eight ohms, so you're not going to get a straight match with both the cab and the internal combo speaker. I would just disconnect the internal combo speaker, set the 4x12 to four ohms, and use the four ohm jack on the amp.

thanks for taking the time to reply. Sounds llikea good plan to disconnect the combo amp speaker. I thought because my pedalboard Digitech RP7 has a stereo output, that I could get the full stereo chorus by using the 2 cabs. but I hear you saying that I would need two heads... Thanks much

 

[Bobby Damit]

Are you planning to run the combo speakers as well? If not, you habe not much choice. The amp has a switch for 4 ohm but not 16. So set amp and cab to 4.

The stereo cab switch simoly allows you to run 1 pair of the speakers at 8 ohms separate from the other pair. Since your amp has one output amd is mono, you can't run it stereo.

Thank you very much for taking the time to reply. You are right, the amp only has one mono output, But I thought that because my tube pedalboard digitech RP7 has a stereo output, that I could somehow do it???
It would be awesome to have the stereo chorus sound coming out of the two speaker cabs... Let me know you have any additional thoughts.

 

[Bobby Damit]

Hello Again Jethro,
I just realized that you really know your stuff. I have an unrelated question. For my Marshal 4.12 Cab I'm trying to figure out what would be a good head to buy. I like a warm sound with not too much high end as I have tinnutus. I like a low watt head because they distort at a lower volume. I really liked 50 watts over 100 wt. But now I'm starting to see that marshal makes 20 and 30 watt heads? is this true? are they any good. I assume they are tube and not solid state. Which low watt head that has two channels do you think is the best investment? or would you look for a used?
Also, what about Boggie or an alternate brand?
Thanks again for taking the time to reply.

 

[usednabused]

I sometimes forget to change the settings on a head when I switch cabinets...no problems at all over the years...

 

[MarshallDog]

Dam, thought this was a YOGA Thread

 

[Gutch220]

I would just disconnect the internal combo speaker, set the 4x12 to four ohms, and use the four ohm jack on the amp.

This is how I'm reading it as well, assuming he's not using the combo speaker. Since your combo has as options of 4 or 8 ohms, I'm also assuming it has a parallel speaker output to go with your internal 8 ohm speaker. But you'd have to disconnect your internal speaker, and run the amp at 4 ohms to go into the 4-ohm cabinet input.

 

[Jethro Rocker]

Hello Again Jethro,
I just realized that you really know your stuff. I have an unrelated question. For my Marshal 4.12 Cab I'm trying to figure out what would be a good head to buy. I like a warm sound with not too much high end as I have tinnutus. I like a low watt head because they distort at a lower volume. I really liked 50 watts over 100 wt. But now I'm starting to see that marshal makes 20 and 30 watt heads? is this true? are they any good. I assume they are tube and not solid state. Which low watt head that has two channels do you think is the best investment? or would you look for a used?
Also, what about Boggie or an alternate brand?
Thanks again for taking the time to reply.

It's very subjective.
Firstly, the stereo out on the Digitech does have 2 outputs but for stereo you need 2 separate amps. Plus usually you want the speakers spread out wide for good stereo separation, and each side of a 4x12 isn't very wide.
As for new amps, depends so much on your style. Marshall does make some new 20 watt models. The Classic series SC20 is only a single channel amp.
The Mini Jubilee 2525 head is sort of 2 channel with a shared Gain control. It has a fairly unique tome and EQ. You should look on Marshalls website to see what might suit you best. The DSL20CR head might work for you, or the 40CR combo.
Figure out what features you like best. Some modern amps don't necessarily sound better when the power section is pushed so the wattage becomes less important.
Used would depend entirely on what is available in your area, the age, model, etc.

 

[Bobby Damit]

thank you very much Jethro, very helpful