Sunn Bass Cabinet Speakers and Input Jacks

[Wasnex]

It is a switching type, and should not be used by itself.

I don't see any reason why you shouldn't use the EXT out by itself with the factory wiring.

Per the schematic, the tips for the output jacks are wired in parallel. The EXT jack switches the impedance and there is no shorting contact on the Speaker jack. So you can use either jack, depending on the load impedance.

If the amp is set up for 16 ohms and 8 ohms, it should work likes this:

1. One 16 ohm speaker connected to Speaker out--Amp configured for 16 ohms
2. One 8 ohm speaker connected to EXT out--Amp configured for 8 ohms
3. Two 16 ohm speakers, one connected to Speaker out and one connected to EXT out--Amp configured for 8 ohms.

 

[agedhorse]

I don't see any reason why you shouldn't use the EXT out by itself with the factory wiring.

Per the schematic, the tips for the output jacks are wired in parallel. The EXT jack switches the impedance and there is no shorting contact on the Speaker jack. So you can use either jack, depending on the load impedance.

If the amp is set up for 16 ohms and 8 ohms, it should work likes this:

1. One 16 ohm speaker connected to Speaker out--Amp configured for 16 ohms
2. One 8 ohm speaker connected to EXT out--Amp configured for 8 ohms
3. Two 16 ohm speakers, one connected to Speaker out and one connected to EXT out--Amp configured for 8 ohms.

Correct.

 

[Michedelic]

I don't see any reason why you shouldn't use the EXT out by itself with the factory wiring.

Per the schematic, the tips for the output jacks are wired in parallel. The EXT jack switches the impedance and there is no shorting contact on the Speaker jack. So you can use either jack, depending on the load impedance.

If the amp is set up for 16 ohms and 8 ohms, it should work likes this:

1. One 16 ohm speaker connected to Speaker out--Amp configured for 16 ohms
2. One 8 ohm speaker connected to EXT out--Amp configured for 8 ohms
3. Two 16 ohm speakers, one connected to Speaker out and one connected to EXT out--Amp configured for 8 ohms.

That is how it was always explained , and I spent many years on the old Sunn Forum before it disappeared(with all that information).
Here are a couple screen grabs from ancient posts on TGP…someone had contacted Conrad:

I’ve got a couple of Traynor Bassmaster YBA heads, and I think the arrangement with main/extention outs is similar. They do not like just using the second jack out by itself.

 

[bridgebuilder]

Ok Good information. I intend to wire the two 8 ohm drivers in the cabinet in parallel that I assume will be 4 ohm. To one jack. Which output jack from the amp should I use. 16 ohm or 8 ohm

 

[Wasnex]

That is how it was always explained

What I wrote says the same thing:

If the amp is set up for 16 ohms and 8 ohms, it should work likes this:

1. One 16 ohm speaker connected to Speaker out--Amp configured for 16 ohms
2. One 8 ohm speaker connected to EXT out--Amp configured for 8 ohms
3. Two 16 ohm speakers, one connected to Speaker out and one connected to EXT out--Amp configured for 8 ohms.

 

[Wasnex]

I’ve got a couple of Traynor Bassmaster YBA heads, and I think the arrangement with main/extention outs is similar. They do not like just using the second jack out by itself.

The output section for the Bassmaster is not wired the same.

• The Bassmaster has only an 8 ohm output that is connected in parallel to two jacks.
  • The amp is designed to push an 8 ohm or 4 ohm load, but there is no impedance switching.
• The main jack shorts the output section unless you insert a plug.
  • This is to protect the amp from a no-load situation.

 

[bridgebuilder]

I think I got it Thanks for everyone's help

 

[Matt O]

I’ve got a couple of Traynor Bassmaster YBA heads, and I think the arrangement with main/extention outs is similar. They do not like just using the second jack out by itself.

This is true. I believe the yba is wired so that the ext speaker jack is dead unless there is a 1/4” jack plugged into the main speaker out closing the circuit.

Edit: sorry, I see @Wasnex covered it

 

[Matt O]

Yeah, been a long time since the 70's - sorry the fake news not intentional....))

No biggie man. I do wonder why Sunn named it the 200s, it does cause confusion about the watt output for sure. Too bad it’s not based on watts, because that would mean a 2000s could level a small city. It would also weigh close to 1000 lbs.

 

[6thplanet]

Ok Good information. I intend to wire the two 8 ohm drivers in the cabinet in parallel that I assume will be 4 ohm. To one jack. Which output jack from the amp should I use. 16 ohm or 8 ohm?

Wire the speakers in series for 16ohm, use the 16ohm output jack.