Currently Converting an AC30 combo to head, question about speaker leads

[ejendres]

It was a 212 combo. The speakers were hardwired in series. How could I go about wiring this as a single speaker jack? Solder one set together and wire the other set to a jack?

[The Dude]

Your question is vague (at least for me). First you say you want to wire it as "a single speaker jack", implying there will be only one speaker. Then, you say, "solder one set together and wire the other set to a jack", implying there is more than one speaker. What exactly are you trying to do?

[ejendres]

Your question is vague (at least for me). First you say you want to wire it as "a single speaker jack", implying there will be only one speaker. Then, you say, "solder one set together and wire the other set to a jack", implying there is more than one speaker. What exactly are you trying to do?

The combo amp originally had 2 speakers. They were hardwired into the chassis, not connected to a jack.

I would like to have a single output jack so I can connect the amp to cabs.

[pdf64]

What exactly is meant by ‘solder one set together’?

[The Dude]

There are a few different AC30 versions. The output configuration may or may not be the same for all of them (I don't have time to look). Can you post the schematic for your version? The one I just looked at shows that when using the external speaker jack, the internal speakers are disconnected via the switching jack. If that's the case, just remove the wires and use the external speaker jack. Make sure impedance is the same (16 ohms on my diagram). HOWEVER, this assumes your amp matches my schematic. As I said, there are different versions. It would be best if you post a schematic for your amp so we can verify.

[nevetslab]

The combo amp originally had 2 speakers. They were hardwired into the chassis, not connected to a jack.

I would like to have a single output jack so I can connect the amp to cabs.

Nice Cabinet!

Some of the AC30's have an Ext Speaker Jack, or an Impedance Select Switch. Does yours, or is it a single Secondary winding without additional taps? Nominal Output Impedance load is 16 ohms. If you only have the single secondary winding, then you could just add a single output jack. Or, a pair of jacks that would use two 8-ohm cabinets that end up being wired in series with the jack wiring. You can always load the amp down with a second cabinet....just don't load it down to 4 ohms.

I thought I had some impedance plots of various Guitar Speakers here on my home computer, but they must still just be on the computer at my shop. Here's an impedance plot of an Ampeg BXE-115HL4 bass speaker with horn, nominal impedance is 4 ohms, seen in the 120Hz-250Hz region, as well as the port tuning region 30-40Hz region. Open back speaker cabinets and sealed cabinets won't have the LF dual peaks as seen in this port-tuned cabinet. But the impedance trend will be very much like this, just scaled up to the nominal speaker impedance of 16 ohms (or 8 ohms).

[g1]

If the speakers were hardwired in series, then there are only 2 wires coming out of the amp. Is that the case?
If so, those 2 wires go to the new jack.