Musicman 2275-130 Extension Cab

[Prattacaster]

I have a Musicman 2275-130 in the shop that has a matching extension cab. The amp has two speaker jacks on the back panel that are wired in series and the amp has a 4 ohm load(2x10 8ohms each wired parallel). An impedance switch allows for 4 or 8ohm loads.

The customer had his cousin wire up the matching speaker cab, which is a 2x10; 4ohms speakers wired in parallel.

There are multiple ways to solve the impedance matching issue but I'd like to get thoughts from the panel.

I could keep the ext. cab wiring the same and have a total of 6ohms. Which is safer, the 4ohm or 8ohm selection, or a wash?

Option two is wire the ext. cab in series for a total of 12ohms. And use the 8ohm setting. Would this be safer or as safe. I consider this because the practicality of having an 8ohm cab vs. a 2ohm cab.

Being that it is from the Fender lineage the OT would handle any of these mismatches. Some might sound better than others or be less stressful on the EL34 tubes. Any thoughts?

 

[jbltwin1]

Either way will work and as to tone, you will have to try it. I DOUBT you could tell the difference. Either way, you have a 50% mismatch which isn't bad. If you use the extension cab wired to 2 ohms and one of the speakers take a dump, you still have a functioning side cab. If wired in series and one goes down, the cabinet goes down. I'm not too hot on having a two ohm cabinet though as it is pretty useless unless you are using it ONLY for that amp. Mike.

 

[Prattacaster]

If you use the extension cab wired to 2 ohms and one of the speakers take a dump, you still have a functioning side cab. If wired in series and one goes down, the cabinet goes down.

You just made up my mind. If one speaker does go out then the ext. cab load would be 4ohms. This would be in series with the "in house" 4 ohm load making operation safest with the impedance set on "8ohms".

I'm not too hot on having a two ohm cabinet though as it is pretty useless unless you are using it ONLY for that amp. Mike.

My thoughts too. The MusicanMan amp cab is built out of Mahogany and the ext. cab matches it perfectly. So they would be used and sold as a set.

Thanks for the input.