Question about running two whole amp rigs together

Killens84 · #1 04-27-2011, 12:38 PM

I've noticed that Pino Palladino has two separate Ampeg 8x10" cabs, and both have an Ampeg SVT-VR head on them. So I'm guessing he's running his bass into both heads to get double the watts. How is he doing that? Stefan Lessard with Dave Matthews Band also uses two amp heads with two separate cabs. I'm just curious how that works.

Bass_Pounder · #2 04-27-2011, 12:42 PM

A signal splitter, or one head is the master and the other is run as a slave. that is done by using amp1's line out or FX loop send going to amp2's preamp in or FX loop return.

tdub0199 · #3 04-27-2011, 12:42 PM

A signal splitter... it can be done numerous ways, one being a A/B pedal.... Y cables....

I<34080 · #4 04-27-2011, 12:43 PM

a/b/y box

one signal two outputs, you can choose to send to one amp or both.

or get a bass wired stereo.

MuzikMan · #5 04-27-2011, 01:12 PM

With two matching rigs it probably makes sense to use the master -> slave configuration. On the SVT-VR that would be either preamp out or slave out (amp 1) to power amp in (amp 2). The EQ controls on amp 1 would control both amps that way.

Selta · #6 04-27-2011, 01:36 PM

Of note, they're not doing it for "more watts"... doubling the wattage is buying them nothing. Doubling the speaker area, though, is buying them a lot.

MuzikMan · #7 04-27-2011, 01:39 PM

Quote:

Originally Posted by Ray Salamon

Of note, they're not doing it for "more watts"... doubling the wattage is buying them nothing. Doubling the speaker area, though, is buying them a lot.

I'm not sure where you got that idea. Doubling the watts = 3db increase. Doubling speakers = 3db increase. Doubling both = 6db increase.

Selta · #8 04-27-2011, 02:27 PM

Quote:

Originally Posted by MuzikMan

I'm not sure where you got that idea. Doubling the watts = 3db increase. Doubling speakers = 3db increase. Doubling both = 6db increase.

Metal Matt · #9 04-27-2011, 03:30 PM

They way I've always understood it is adding more speakers results in more volume gain than simply doubling wattage, although I don't really remember the specific numbers at this point, there's been quite a few threads about this on here.

To the OP. What everyone else has said is correct. I run three amps to power 4 cabs. One amp is a master, the pre-amp output of that (usually marked "line out" or "FX send" on a modern amp) into the input of a slave amp (power amp without the tone controls), which has an output to another slave amp. That way the whole mess runs as one single rig and the tone of the first amp applies to all three.

A variation of this would be using two full amps (say the svt-vr) and running the line out of the first amp to either the input of the second amp to have the tone controls of both amps, or the line in (FX return) of the second one to have the tone controls of the first amp and the second simply running as a power amp.

Some choose to go the way of using a splitter box to send the signal from the bass, to the front of both amps. This way you can have both rigs with different tone settings not affected by one another if you should choose to do so, or to have different effects going to each amp.

Sartori · #10 04-27-2011, 05:36 PM

Indeed, as others have said.

For identical amps going to identical cabs, the master/slave setup is common. Preamp out or slave out to the other amp's power amp in. Some amps are even made to be the slave amp in this set up, like Metal Matt's Sunn concert slaves, or the SVT-300, or the Mesa M-180 and M-190, etc.

When the rigs are not identical, chances are high that someone's using a splitter before the inputs of the amps so that they can run the rigs independently.

I'm pretty sure that Al Cisneros' rig when I saw Sleep was an example of both. He had two SVT+810 rigs and a Marshall full stack. I would guess that one SVT was slaved to the other, but the Marshall was used independently, with the signal split before the inputs of the SVT and the Marshall head.

If you're willing to cart around two separate rigs, there's some cool stuff you can do.

Killens84 · #11 04-27-2011, 06:18 PM

Thanks for the info, guys. I've been curious about how that works.

Rick Auricchio · #12 04-27-2011, 08:30 PM

There's no evidence he's actually using both amps. Maybe one is a backup.

Awesomenaut · #13 04-27-2011, 08:37 PM

Quote:

Originally Posted by MuzikMan

I'm not sure where you got that idea. Doubling the watts = 3db increase. Doubling speakers = 3db increase. Doubling both = 6db increase.

It takes ten times as many watts to double perceived volume.

MuzikMan · #14 04-28-2011, 03:45 AM

Quote:

Originally Posted by Awesomenaut

It takes ten times as many watts to double perceived volume.

That is very true. 10 times the power = 10db increase = double perceived volume.

anderbass · #15 04-28-2011, 05:45 PM

I've been using this stereo-rig lately in my rock trio project. I'm just using a cheap Morley ABY splitter pedal but its working out pretty sweet and I haven't had any major hum issues so far.

I usually just kick the little overdriven rig on for the harder rockers. Next step is to patch a volume pedal so I can smoothly roll the Oranges volume up/down. Its a 60watt Orange head /12" bass cab.

The small size/wedge shape of this SWR cab causes it to naturally roll off most all the lows. For this reason, this rig pairing doesn't seem to suffer from Comb-filtering issues nearly as bad as all other stereo-rigs I've tried to make work in the past. Although I can notice just a little unless I stack both cabs.

93Jazz+ · #16 05-25-2011, 09:03 AM

I am also interested in this setup and have one further question for clarification.

Here is the setup im working on.
400w amp 1 --- 400w amp 2
1 4ohm cab --- 2 8ohm cabs

If I understand correctly, I use power amp 1 (master) for tone control and to power my 4ohm cabinet. Then, send from "FX Send" to "power amp in" on amp 2 (slave) to power my 2 8ohm cabinets?

MuzikMan · #17 05-25-2011, 09:11 AM

Quote:

Originally Posted by 93Jazz+

I am also interested in this setup and have one further question for clarification.

Here is the setup im working on.
400w amp 1 --- 400w amp 2
1 4ohm cab --- 2 8ohm cabs

If I understand correctly, I use power amp 1 (master) for tone control and to power my 4ohm cabinet. Then, send from "FX Send" to "power amp in" on amp 2 (slave) to power my 2 8ohm cabinets?

Yep, that will work on most systems. One never knows though, maybe you have some kind of amp from a parallel universe that doesn't behave.

What rig are you using?

Caca de Kick · #18 05-25-2011, 09:22 AM

Well that's if you want the tone of amp 1 to control amp 2. If the rigs are matching with matching speakers, then that works. But if rig 2 has different speakers, then the eq of amp 1 isn't going to be set right for them.
For two different rigs it is best to use a splitter.

In the past, most bassists who used two or more amps to simply cover more 'space' were set the same, so they'd essentially daisy chain them.
The more modern approach with bassists pushing the tone envelope is using a rig for clean and a different rig for dirty, often using different amps, so you have to split the signal.

I went with the Lehle P Split box. It keeps a clean noise-free signal, requires no battery, and you can get 3 outputs from it.

93Jazz+ · #19 05-25-2011, 09:26 AM

Quote:

Originally Posted by MuzikMan

What rig are you using?

2 x Traynor DB400H
TC1510 / soon to have TC115 & TC210

I like the idea of the master/slave setup so i can cater my rig to different places and so i dont have lug that 1510 to light jams

rtslinger · #20 05-25-2011, 09:28 AM

I had been thinking about doing this with two combo amps one is a Fender Rumble 100 and the other is a Randall RB-60 both have 1*15 the Fender is the one I want to be amp 1 but the Randall only has a pre-amp out not in and nothing in the way of effects how would I do this?