Is there a way to use an 8 ohm speaker with a Bassman

[01redcobra]

I'm wondering if there is a way to wire the output on a Bassman to use an 8 ohm speaker. I want to use a single 12" and the choices are limited in a 4 ohm.

[bob p]

You have a couple of easy options:

a) Just use the 8 ohm speaker with the 4 ohm amplifier output
b) Wire an 8 ohm, 25 watt power resistor in parallel with the 8 ohm speaker, so that your net load is 4 ohms.

I would go with the first approach. An 8 ohm mismatch is not really a bad mismatch for a Fender bassman. The amp will probably tolerate the mismatch quite well.

[stokes]

As well as make your power tubes run a little cooler,not a bad thing at all.

[AL30]

I have a BF bassman head that I run through an 8 ohm a few times a week. I've had no problems with the mismatch.

AL

[harry]

b) Wire an 8 ohm, 25 watt power resistor in parallel with the 8 ohm speaker, so that your net load is 4 ohms.

Would this be a safer option, in that it'd put no strain on the amplifier at all? I regularly turn my amp up to max, and sometimes I have to use an 8 ohm load instead of a 4 ohm load. I'd like to be sure that it's not doing my amp any harm.

As I'm finding myself in exactly the same situation, I've been trying to find solutions.

(Here's my thread: http://music-electronics-forum.com/s...ead.php?t=3543 )

Basically it says that in my research I found this:

https://taweber.powweb.com/store/zmatch.htm

Which looks useful, although it's usefulness hasn't been proven.


Weber also make a autotransformer for this purpose. I don't know anyone who's used it though.

[stokes]

Would this be a safer option, in that it'd put no strain on the amplifier at all? I regularly turn my amp up to max, and sometimes I have to use an 8 ohm load instead of a 4 ohm load. I'd like to be sure that it's not doing my amp any harm.

As I'm finding myself in exactly the same situation, I've been trying to find solutions.

(Here's my thread: http://music-electronics-forum.com/s...ead.php?t=3543 )

Basically it says that in my research I found this:

https://taweber.powweb.com/store/zmatch.htm

Which looks useful, although it's usefulness hasn't been proven.


Weber also make a autotransformer for this purpose. I don't know anyone who's used it though.

Running an 8ohm speaker on a 4ohm output wont put any strain on the amp at all.It will result in slightly less output watts but will not be very noticeable.There may or may not be a change in tone,again it may not even be noticeable.

[Regis]

Just plug it in and rock. I have two SF Bassman heads that I abused for over 20 years with an 8 ohm load.

[petemoore]

..

It will result in slightly less output watts but will not be very noticeable.
the volume control will compensate, unless you're diming your amp already [consider larger amp], should have plenty of push to N/P handle a 12''.