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Can someone please explain me how to pair two amp heads

Gaddiel Vazquez

Gaddiel Vazquez

Jun 3, 2017
89
24
South Padre Island, TX
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#1
Hi there,

I have a doubt. I’m seeing an uploaded pic from Gallien Krueger on instagram and shows two GK 1001Rb ii ok stack, connected from send effects from one and connected to the return to the other.

What is the purpose of this connection?
Power (Watts) will be double?

See the attached pic :)
 

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#2
That is the only way to safely run those four cabs together.

Plug your bass into the bottom head and hook that head to the speakers on the left as usual.
To put the basses signal into the top head use the bottoms send to the tops heads return and plug the top head into the right speakers as usual.

Now the bottom head's eq will function for both heads and cabs equally, the top working as a separate power amp only to drive the second set of cabs.

Remember always that speaker out only gets plugged into a speaker.
 
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#3
So, bass amp head on top will be connected to both cabs on left side and bottom amp head for cabs on right? And bass guitar will be connected on bottom bass amp?

What about the Watts?

S-Bigbottom said:
That is the only way to safely run those four cabs together.

Plug your bass into the bottom head and hook that head to the speakers on the left as usual.
To put the basses signal into the top head use the bottoms send to the tops heads return and plug the top head into the right speakers as usual.

Now the bottom head's eq will function for both heads and cabs equally, the top working as a separate power amp only to drive the second set of cabs.

Remember always that speaker out only gets plugged into a speaker.
Click to expand...
 
#4
Watt about the Watts? You have two separate systems, running from the same audio source, so the Wattage is the total of the two separate systems. In dB terms it probably won't sound extra loud in an amazing way, Probably the kind of increase you could have got by turning the first amp up a notch or two, if it wasn't delivering maximum. 3dB isn't a huge amount of extra.
 
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#5
paulears said:
In dB terms it probably won't sound extra loud in an amazing way, Probably the kind of increase you could have got by turning the first amp up a notch or two, if it wasn't delivering maximum. 3dB isn't a huge amount of extra.
Click to expand...
since you'll not only double the watts but also double the speaker surface, you'll get +6dB, which is quite a lot.
On top of that, with two additional cabinets, you'll move a lot more air.
 
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#6
Gaddiel Vazquez said:
So, bass amp head on top will be connected to both cabs on left side and bottom amp head for cabs on right? And bass guitar will be connected on bottom bass amp?

What about the Watts?
Click to expand...
Yup.
Think about it as two completely separate rigs but one bass guitar is connected to each by way of the Effects Send and Return. This will allow you to use only one bass guitar and eq section for both rigs.

Watts? It says that head is 700 watts at 4 ohms. Being that each cab is 8 ohms and two together makes a 4 ohms load, that is 700 watts to the left and 700 watts to the right.

Most important as to why this was done is that the amp head is rated at 4 ohms minimum and to hook up all four of those cabs would equal 2 ohms, thus killing the amp. Hooked up this way each amp is at its minimum load of 4 ohms and is happy. Player has their four cabs safely together and is happy.
 
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#10
Depends

Most amps have a 4 ohm minimum load

So if you wanted to run alot of cabs it's easier to use 2 heads. Cause usually with common cab impedance it's easy to surpass 4 ohms pretty quick using 2x or 4x cabinets

Using the effect send is essentially using one amp as the tone control/ volume and it's power section.

The other amp is essentially a power amp. When you plug into the return. That goes direct to the power output section

Effect send comes from the pre.
Effect return is going straight to the power amp.

People have used other methods like. Splitter pedals. Or with most multiple input heads. Most have 2 inputs. Run a cord from the second jack to the other amp. Usually inputs are in parallel. So your just using the inputs as a splitter.

This though runs both preamps. And so tone controls and volume have to be adjusted on both heads.

Easier to run just one pre and control volume with one head.

Sunn, Matamp and few other earlier manufactures had pre amp outputs. And then they made "slave" heads. Which basically was a power amp no tone controls. Just basically a power amp that looked like the master head. so you could run one master head and as many slaves as needed.

Not always about blistering mind blowing watts. It is about getting loud by using alot of speakers. But as mentioned not many amps can do 2 ohms. And if you wanna run alot of speakers. Eventually you need another head.

But it's a pain in the butt to control volume and have tone settings match on 2 heads. So you just use one as a master. And all the others as a slave. Pretty easy to do with most heads now. Since effect loops are pretty common
 
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#12
I believe the term is called amp slaving. I used to daisy chain my SVT 4pro and SVP-1600 together using a duplicate set of 410's and 115's. I recently did the same thing with a 2 pro and SVT-300.

It's done more so for dynamics rather than output.
 
#13
This is a common method for expanding the system power and output capability of a bass rig, which is why (some) manufacturers design this feature into their amps. It's a safe and effective way to drive more cabinets that would otherwise present too low of an impedance to a single amp.

It doubles the potential available power and speaker capacity for higher maximum SPL.
 
#15
kmon said:
Is there any limit to heads and stacks? Can I theoretically chain as many stacks together as I want?
Click to expand...
Yes, because of how effects loops are internally configured (the return is post-send) this only works with 2 amps.

If you need more, a special splitter cable or splitter box is needed and you can then expand to maybe 5 or 6 amps this way.
 
#16
@agedhorse, the OP shows/talks about two heads/rigs that are the same. Is that important as well when wanting to connect two amp heads? I mean, if one head was, say 800 watts @ 4 ohm, and the second was 300 watts @ 4 ohm, would it make any difference which head SEND goes into which head RETURN? I would imagine in this case getting those two rigs balanced would be the hurdle.
 
#17
It generally doesn't matter, with a few cautions.

Most loops are pre master volume control, which allows for separate control of power amps with different sensitivity and power level.

Where issues can occur, most often between amps of different manufacturers, is that there's no standard for polarity at different points within the signal path. This means that you need to be aware of the possibility for reversed polarity issues in such pairings.
 
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