Tube Amp + Cabs (Power Question)

[LouisNeilson]

Hi guys

I'm sure this has been asked before, but I've spent over an hour looking around the forum and couldn't find my answer - so forgive me.

My question is this -
I recently bought a 30 Watt all valve Bass head (Ashdown Little Bastard) and now I'm unsure of what kind of cab it can power.

I see cabs with ratings of 400 Watts @ 4ohms (example) and my head goes "30W != 400 W"

I'm afraid of under-powering a cab, so I want to know if there's a formula (Im sure there would be) that I can use to workout what cabs I can power?

[seamonkey]

Top of the forum - FAQ

[LouisNeilson]

Yes I read through those and didn't find an answer to my question...

[paganjack]

Underpowering is not a real thing, but over-excursion of the speakers is.
Tube amps pair best with sealed cabs IMO.
Since your head is low powered (although I think it's 2 EL34s, so 30W is a conservative rating) find some cabs that are nice and efficient and you'll be set. It's probably going to be nice and dirty at band volumes, but you know that already.

[Mr. Foxen]

It is the second stickied thread, the Amps FAQ, an the section "Over/Underpowering Cabs" is relevant. Basically, the watt ratings on cabs are meaningless at the best of times, and are totally irrelevant to your amp.

[LouisNeilson]

Originally Posted by paganjack

Underpowering is not a real thing, but over-excursion of the speakers is.
Tube amps pair best with sealed cabs IMO.
Since your head is low powered (although I think it's 2 EL34s, so 30W is a conservative rating) find some cabs that are nice and efficient and you'll be set. It's probably going to be nice and dirty at band volumes, but you know that already.

I actually don't :P

I bought my amp here (in the UK) where I'm studying for a year, but when I got back to South African in a few weeks I'll finally have my cab... I haven't got much chance to use it

My issue is that I have a 4x10" cab back home (some brandless workhorse that loves me), and I don't have the cash at the moment to buy a new cab

I'm starting to regret the haste of my purchase lol

I'm still quite new to the whole gear side of Bass, I always had a friend who micro-managed everything :<
I'd just turn up, plug in and find my tone ?

Guess I can always run a DI out into the house system for extra cover

[MAMMOTHvolume]

Originally Posted by paganjack

Underpowering is not a real thing, but over-excursion of the speakers is.
Tube amps pair best with sealed cabs IMO.
Since your head is low powered (although I think it's 2 EL34s, so 30W is a conservative rating) find some cabs that are nice and efficient and you'll be set. It's probably going to be nice and dirty at band volumes, but you know that already.

is 4 84's.

just get any cab over 50watts. go for sensitivity if you want more volume

[Mr. Foxen]

Overexcursion won't be an issue either. An the sealed cab thing is questionable, the link is via the sort of speakers that function well in sealed vs. ported cabs, an who they interact with the output transformer, which won't affect the speakers anyway, plus either sort of speaker can be found in either sort of cab. Make sure your cabinet is the impedance you think it is, make sure the amp is set right, and you are good to go.

[RooseOnBass]

What do you think about pairing the Ashdown 414T Deep Cab (4ohms) with the Ashdown 330 Spyder head?

[paganjack]

Originally Posted by MAMMOTHvolume

is 4 84's.

just get any cab over 50watts. go for sensitivity if you want more volume

+1

Ah it's 4xEL84s? That makes more sense.

The long and short of it is that head will work fine with your current cab, it won't hurt it or anything. You'll need to do some research of your own to find out what sort of a cabinet will get you the sound you want. Everyone has different opinions on that topic, but look for higher sensitivity ratings if you want to get the most volume out of a small amount of power.

[LouisNeilson]

Thanks a lot, you guys have calmed my nerves <3

[bunomatic42]

I run the Little Bastard through a 2x10 or 4x10 cab depending on the gig. It sounds great through both setups.

There is an output for both 4 ohms and 8 ohms on the head. Just make sure and match the correct output to your cab.

These are wonderful heads and are much louder than you might expect. No regrets .

[gbarchus]

Find a used 1X15 cabinet with an EV 15L (2" voice coil) or JBL D140 (4" voice coil), $200~300 in the US, and be prepared to smile a lot.

Gale

[chaosMK]

How's the overdrive on the Bastard?

[BassmanPaul]

Originally Posted by paganjack

Since your head is low powered (although I think it's 2 EL34s, so 30W is a conservative rating)

Not if the amp is cathode biased, 30W would be about right. Running with fixed bias will get you 50W from a pair.