Using the speaker of a DC-2 combo without using the amp

[bowery969]

I'm looking to test out a head (Hughes & Kettner Tubemeister 18).

I have a spare speaker that I intend to build my own cabinet with.

But in the meantime, can I use the 8 ohm jack on the back of my Studio Caliber DC-2?

I assume I would be able to do that, without powering the Mesa amp.

Should I unplug the jack that's plugged in, in the back of the Mesa, first?

 

[bandit2013]

Absolutely not! That would be disastrous to the amp trying to drive the speaker as the output transformer on the Mesa will still be connected and will have a very low impedance (may appear as a short circuit to the head you connect it too). Never do this! The output transformer should and will have a very low resistance since it is the source to the speaker load. Also, pumping in current from another source into a transformer will end up with voltage on the primary side. Then there is the negative feedback circuit that may be connected to the output side of the transformer going to the phase inverter. Not sure what that will do to the Mesa amp. It will tax the tubes in the head and probably cause them to fail. May even burn out the OT on both amps.

Best solution to make use of a combo speaker to be driven by an external amp is to get yourself a short coupling speaker cable. One that has a male and female end. Make sure it is rated for speaker use. TS type connectors only.

This will cost less than the repairs needed after trying to use the Mesa amp as a load coupler. These extension cables come in longer lengths. I just picked the shortest one.

https://www.sweetwater.com/store/de...16qqf-1.5-ts-ts-female-speaker-cable-1.5-foot

 

[marcel20855]

Your post is a little unclear on exactly what you're thinking of trying, but never plug the output of one amp into the speaker output jack of another amp.

And leaving the combo amp's speaker cable connected to the combo amp's output jack while using a separate cable with clips to connect a different amp to the combo speaker will still allow the output power of the second amp to go into the combo amp's output transformer, with the potential for the bad results Bandit mentioned.

I hope that made sense, because I think MY post may be a little unclear.

 

[bowery969]

Your post is a little unclear on exactly what you're thinking of trying, but never plug the output of one amp into the speaker output jack of another amp.

And leaving the combo amp's speaker cable connected to the combo amp's output jack while using a separate cable with clips to connect a different amp to the combo speaker will still allow the output power of the second amp to go into the combo amp's output transformer, with the potential for the bad results Bandit mentioned.

I hope that made sense, because I think MY post may be a little unclear.

All good.

As it turned out, I never came into possession of the amp head, so I won't be trying it.

 

[hellroco]

Your post is a little unclear on exactly what you're thinking of trying, but never plug the output of one amp into the speaker output jack of another amp.

And leaving the combo amp's speaker cable connected to the combo amp's output jack while using a separate cable with clips to connect a different amp to the combo speaker will still allow the output power of the second amp to go into the combo amp's output transformer, with the potential for the bad results Bandit mentioned.

I hope that made sense, because I think MY post may be a little unclear.

I probably misunderstood but...why u may have bad result by connecting the speaker of "B" amp with the power section of a "A" amp?

 

[DECEMBER]

Plugging the speaker output of a head into the speaker input of a combo won't make any sound. It will break both amps.
If you want to use a combo's speaker with a separate amp, get a pigtail (combo amp) speaker cable (1/4" TS to dual spade lugs). Put the spade lugs on the speaker terminals and plug the 1/4" jack into the head in the appropriate output tap. Make sure the speaker impedance matches the output tap impedance.

 

[DECEMBER]

I probably misunderstood but...why u may have bad result by connecting the speaker of "B" amp with the power section of a "A" amp?

It sounds like they were considering plugging the speaker output of a head into a speaker output on a combo. You CAN use a combo speaker with a separate amp, but not by plugging an output into an output. You just have to run a speaker cable directly from the speaker to the other amp, and leave the combo powered off.