[Tone Chaser]

I have been reacquainting myself with the Garnet Session Man amp. I have been having ideas and want to find out if anyone has the knowledge that I am seeking.

The amp is a combo. It has a speaker output for the speakers for the combo, and an output for speaker extension. This amp also has the ability to change the impedance, by means of using a screw driver and locking the wire under the screw, for the appropriate ohm setting required.

I am considering replacing the screw and wire impedance method with a toggle switch.

I had assumed that the extension speaker output was parallel; but it must be something entirely different. If you pull the combo speaker input, and relocate it to the extension speaker output, the amp volume start cutting out almost immediately. I then need to reconnect the combo speaker input back to the required input. So the first question is: How are the speaker inputs wired, and at what ohms (each, separately, together)?

I have been running the amp with a variety of speakers, in search of ones that offer something unique and different than the other amps in my horde. So far, I am liking the 8 ohm Eminence Reignmaker, run singly, rather than a 212. It makes the amp something I want to play again, and it offers a wide variety useful tones. This also means that I will be robbing the Reigmaker from my YGM3 and putting the Celestion G12H30 Anniversary back in the Traynor, (it was always very sweet with that speaker and I don't play that amp for driven tone that much anyway. I have other amps for that).

So here is what I am going to try. I bought an 8 ohm Eminence Maverick from Next Gen (Good shopping experience). I intend to wire up the Maverick with its own input plug, and do the same for the Reignmaker. This way I can run each speaker independently or together. I am thinking that I can just plug one speaker into the available speaker outputs ( combo and extension), and set the proper impedance for what I am doing with the switch. Or should I make a Y speaker harness that allows me to run the speakers as originally wired by Garnet?

I want to do thing right and keep the old amp in safe working form. Any ideas or suggestions? I also want all the versatility I can get out of the Garnet.

 

[Granny Gremlin]

They MUST be in parallel - if series you'd get no sound at all when plugged into Ext but not Combo. Problem is likely a bad connection (that Ext jack is probably dirty as hell due to not being used much).

Replacing wire + screw terminals for Z selection with a switch is a great idea. That's one thing that always botherred me about Garnets (my old Sessionman Vocal head had separate jacks for 4 and 8 ohms, which is also an improvement).

The speaker switching by plugging them in to the diff jacks is a good plan - simple/effective and no weird mods.

 

[Tone Chaser]

Problem is likely a bad connection

When I use both speaker outputs, they both work. Using the extension output alone appears to put the amp in distress.

 

[Granny Gremlin]

Could still be bad connection.

Assuming that the combo jack is a switching/ shorting type ( which would allow Ext to work when nothin plugged in to Combo if wired in series). It could be the switch leaf spring in that jack that is the issue. It's likely had a jack in it since the 70s so when you unplug it it doesn't bend back into contact as well as it should.

You need to look at the jack wiring anyway to check if series or parallel,so clean everything out and check the leaf spring contact while at it. I bet you sort it out just by doing that and there's no further issue.

 

[epis]

Most likely main (combo) speaker jack has internal switch to ground. It's activated when speaker jack is unplugged. You can run extension cab only together (in parallel) with main speaker.

 

[Granny Gremlin]

That makes sense if series, but then there'd be no signal at all (again, unless the switch is faulty). Either way, he needs to take a peak in there and then all will become known.

 

[jb welder]

Most likely main (combo) speaker jack has internal switch to ground. It's activated when speaker jack is unplugged. You can run extension cab only together (in parallel) with main speaker.

This is correct as shown on the schematic. Same setup as typical BF Fender like Deluxe AB763 etc.
If using only one jack, you must use the 'Int.' or whatever they call the one that is NOT the 'Ext.'
Likely the shorting switch on your int spkr. jack is oxidized or dirty, so the signal is not shorted out all the time like it would normally be.
When using both jacks they are in parallel.

www.thetubestore.com - Garnet Amp Schematics