dummy loads?

[brake]

how do these work? would I be able to run my 4 ohm head into an 8 ohm cab if I had an 8 ohm dummy load?

[Mudbass]

Sure if you don't mind 1/2 of your power being wasted as heat. There's a reason they're called dummy loads.

[Detox]

 

Originally posted by brake how do these work? would I be able to run my 4 ohm head into an 8 ohm cab if I had an 8 ohm dummy load?

 

 

That's exactly what I did with an 8-ohm HotPlate, an 8-ohm speaker, and my 4-ohm Traynor head.

[brake]

 

Originally posted by Mudbass Sure if you don't mind 1/2 of your power being wasted as heat. There's a reason they're called dummy loads.

 

 

 

 

I dont mind only getting half of the power. I'd prefer it in this situation, actually.

 

 

What exactly is a dummy load? What can be used as one?

[Jazz Ad]

It's a big ass resistor with a radiator.

totally useless for bass amps.

[Mudbass]

Are we talking a tube amp here that you're trying to match the impedance up with?

 

The best way to match an 8ohm cab up with a 4ohm amp is to add another 8ohm cab.

[megadan]

 

Originally posted by Mudbass Are we talking a tube amp here that you're trying to match the impedance up with? The best way to match an 8ohm cab up with a 4ohm amp is to add another 8ohm cab.

 

 

+1 to that

 

dummy loads are only useful to guitarists who want to crank their 200W tube amps without killing small animals (though most of them are going for that effect, I think)

[boseengineer]

Any solid state amp with a 4 Ohm rating is perfectly happy with an 8 Ohm load (or no load at all).

 

Many tube amps do have an output impedance selector.

 

"Tube" or "Solid State" in this context means the power amp section. If the head as a tube preamp but solid state power, 8 Ohm is perfectly okay.

[brake]

the gear involved:

 

Peavey mark VI head - 400w into 2 ohms, 250w into 4 ohms

Ampeg SVT410HLF - 4 ohms

Yamaha 412S - 8 ohms

 

my situation:

 

 

We're gonna start rehearsing at my drummers place, he's got alot of... sketchy friends that come through there. Since I dont feel like lugging a 4x10 or 4x12 back and forth every time, I'm leaving a cab there (taking the head home, though).. it'd be nice to be able to take this to gigs, too, since it's alot lighter and not as awkward (casters on all 4 corners and it's shape makes it easier for carrying).

 

I dont wanna leave my Ampeg there at all - I paid 10 times the price for the Ampeg that I did for the Yammy. I havent got anything that can run the Yamaha though, as I dont have another 8 ohm cab. What can I do?

[Mudbass]

Shucks, that Mark VI doesn't care if it's an 8ohm load. All this time I thought you were trying to match the impedance to a tube head.

[NeonVomit]

True, one of the nice things about SS heads, they don't care about loads.

 

I thought you were going on about this...

 

 

[brake]

 

Originally posted by Mudbass Shucks, that Mark VI doesn't care if it's an 8ohm load. All this time I thought you were trying to match the impedance to a tube head.

 

 

 

 

it doesnt? you mean it'll actually run at 8?

[JenjaBen]

Yes, as long as the impedance is not below 4 it'll run fine with a solid-state head. Running a speaker with more ohms into a head will only cause problems with tube amps. An 8 ohm cab will run fine with that head.

[boseengineer]

 

Originally posted by brake it doesnt? you mean it'll actually run at 8?

 

 

Absolutely. No problem whatsoever. You could actually run both cabinets at the same time (total load of 2.8 Ohms) without harming the head, although the Ampeg will get twice the power than the Yamaha. Since the Ampeg is probably more efficient anyway, it's probably not worth bothering.

[der oxenrig]

 

Originally posted by boseengineer Absolutely. No problem whatsoever. You could actually run both cabinets at the same time (total load of 2.8 Ohms) without harming the head, although the Ampeg will get twice the power than the Yamaha. Since the Ampeg is probably more efficient anyway, it's probably not worth bothering.

 

 

I thought Ampegs were very INefficient, so it should balance out nicely.

[brake]

 

Originally posted by The Ox I thought Ampegs were very INefficient, so it should balance out nicely.

 

 

 

 

put that sunn up against any ampeg, a/b them. c'mon. do it.

[beam]

Originally posted by brake put that sunn up against any ampeg, a/b them. c'mon. do it.

 

 

[brake]

i love you too, beam almost as much as you love that emoticon.. haha

[boseengineer]

 

Originally posted by The Ox I thought Ampegs were very INefficient, so it should balance out nicely.

 

Not in my experience. Ampeg has a different (and more probably more reaslistic) way of measuring and publishing sensitivity so it looks that way on paper. In the flesh, SVT410HLF is IMHO quite efficient.

[FreestyleIntruder]

Originally posted by The Ox I thought Ampegs were very INefficient, so it should balance out nicely.

 

Ampegs have a lot of girth, so although they might look inefficient on paper they more than have it where it counts

 

Peavey Firebass + Ampeg PR410HLF = Anti-Tank weapon

[MageZ]

Originally posted by FreestyleIntruder Ampegs have a lot of girth, so although they might look inefficient on paper they more than have it where it counts Peavey Firebass + Ampeg PR410HLF = Anti-Tank weapon

 

 

Yeah, drop the Firebass on the tank....even depleted uranium don't have chance...