Thinking about a Portaflex mod; please advise

[sloppy_phil]

Hey, I've got an old B-18 from 1960 I believe, and it's great but somewhat strangely, the speaker cable and input jack are XLR, not typical 1/4". Sometimes I'd like to use the cab with a different head (mostly for when I'm at home practicing; I'd rather not have to burn the tubes for that). But I'm a little concerned; I don't really plan on selling this thing, but for whatever reason, would changing the jack and cable to 1/4" be something that would devalue the amp in any way? Is it even a feasible/reasonable change to be making? I've never seen an XLR speaker cable/jack before, and it's the one small frustration I have about the amp. In my mind I put a change like this as being along the logic lines of updating a 2-prong cord to 3-prong, minus the whole safety hazard thing... does that make sense?

[Ben Clarke]

no need. If the attached speaker wire looks to be in good condition, just get an adapter cable to go from the 4 pin XLR to 1/4". Fliptops sells them or they are easily made by anyone who can make a cable. I got parts from Parts Express and a friend made some up for me for not a lot of money.

It's not terrible to convert it to 1/4" but I like the xlr better.

[JimmyM]

Yes, it would devalue the amp to change it. But you can buy adapters from Welcome to Fliptops -- Parts for Ampeg and other Vintage Amp Lovers to change it to 1/4" and use it with other cabs.

[sloppy_phil]

an adapter sounds smart; a good way to preserve the pieces if I can! I'm pretty sure my store has an XLR>1/4" adapter I can grab for le cheaps.

Jimmy, I'm more interested in using another head with this cabinet rather than the other way around (for practice at home), so I'd have to change the XLR input jack also. Assuming I held onto the original jack, this could be an easily reversible mod, no?

[JimmyM]

Easily reversible, but why bother when you can just get an adapter?

[coreyfyfe]

It's not a standard 3-pin XLR jack, and I doubt a normal music store would stock the 4-pin to 1/4in connectors, you'll probably have to order from fliptops. These things worked as a means of ensuring you didn't apply high voltage to the tubes without a load connected - pins 2 and 3 on the cab are connected and completed the standby circuit. If it were me (and it is me, since I have the connectors ) I would leave it stock and just get the connector for whichever direction you want to go (ie into the cab or from the head).

[sloppy_phil]

Yes of course, 4-pin would make it tougher. And I didn't realize there was an adapter available for the jack itself; that's definitely the way simpler method! I'll be looking into that ASAP. Thank you, gentlemen