Can I use my amp for bass?

[milothicus]

i have an old amp i inherited that's a Lifco brand model 630. Canadian made, ipm guessinglate 50's early 60's. i have nothing to back that up...

basically, i want to know if i'm going to damage the speaker if i use it for bass.

the speaker is original, and i'm pretty sure (it's not in front of me) it's an RSC (radio speakers canada) which is basically an old Jensen (or so i'm told). 15", if i remember correctly.

the amp has 4 inputs, which leads me to believe that it was intended for multiple instruments, one of which would probably have been a bass guitar...

am i right to think it was designed with multiple instruments, including bass, in mind?

will i tear the speaker to bits if i play my bass through it?

[cbarrow7625]

Does the amp have an output power rating?

Does the speaker have a power rating?

How loud do you need to play?

You risk running into excursion limits with the speaker (and possibly self-heating problems) if youplan to play at full volume & the speaker was not designed to handle that kind of power from the amplifier.

The good news is that you have a 15" speaker, they will be more forgiving in the excursion area just because the cone and suspension are typically going to be more flexible than in a smaller driver. It may be desinged for longer excursions as well if it was designed for bass.

First check to see how the power ratings match up & get back to us here.

[milothicus]

the amp has no power rating. the power section is 2 EL84s. does that put it at about 12w?

can't remember what specs, if any, are marked on the speaker...

[cbarrow7625]

That at least tells us the power range that the amp could possibly be in. About 12-18W max. If that is the case, I think it is fairly safe to say that your speaker is probably in no imminent danger of being torn to pieces. I'm not entirely sure it is even possible to make a 15" speaker that can't handle at least 18Watts!

The amp probably won't make a terribly good bass amp but you should be able to play through it without much worry. If something feels, or sounds funny to you just turn down the Bass control some (assuming there is one - if not just reduce volume). It is bass excursion you have to worry about. If you play it fully cranked with the bass control turneds all the way down you would never have to worry about hurting the speaker (not that I recimmend this setting - just making a point). Good Luck.