Tube Slave Amp Question

[djshawn47]

Heres my issue:

I have a Greenamp "Volume amp". Its 180 watts of tube power. And its simply not enough for what Im doing. I love the tone, but the bottom end drops out and it sounds like an overdriven guitar when I crank it.

So...Im thinking of adding an Aguilar 728 (there is one available to me). Its a 400 Watt tube power amp. I want to slave it to my Greenamp.

Im hoping this set up will give me the additional volume and low end I need whilst keeping the tone of my Greenamp.

Im running it through a 4 ohm 2x15 900 watt Greenamp cab.

Will this set up give me what Im trying to achieve?

Also The Greenamp has a 4 ohm minimum load, but the Aguilar has a switchable 2 ohm minimum load. Can i run a second 4 ohm cab daisy chained to the aguilar power amp or will it overload the Green master amp with its now 2 ohm load?

Thanks for the help.

[stingraysvt]

I'm not seeing a preamp out of any sort on the GreenAmp, how do you intend to slave the amp?

[djshawn47]

It has a preamp. There are three Greenamps:
Master Volume
Volume
Power

I have the Volume.

Im going to run Preamp Out of the Green into the power.

[coreyfyfe]

You'd need a second cab to run both of them, and with a second cab on the Green I think you'd be at the volume level you want. More speakers will get you there faster than more wattage.

[djshawn47]

But if I just run this set up into one cab I am getting the 400 watts of the power and the preamp from the Green, correct? I only need two cabs if I want to get the 180 watts out of the Green as well...is that correct?

Two cabs= 180 watts into one and 400 into the other with the Green’s preamp controlling the tone of all. Thats how I understand it.

Im not necessarily looking to add another cab. I just want more low end and volume out of the 900 watt cab I already have.

BTW- The Greenamp has a jack labeled “Slave Out” and it has an adjustable knob (Im guessing volume) next to it.

[Govier966]

tube amps need to feed something power, what if you get another 15 along with your 2X15 and have the greenamp power a 1X15 and the aggie power a 2X15 for maximum volume and low end!

[JMac4strngr]

More watts doesn't equal more volume. Just because Your cab is quote/unquote rated for 900 watts doesn't mean it'll take it. You gain more by adding more speakers, versus more amp. The reality is, the cab my be rated for 900 watts but it's actual power handling capabilities are way below that . Adding another 2-15 or switching to an 8-10 would get You more volume.

[djshawn47]

I think you are missing the point here (to a certain extent). Adding a second cab isnt going to solve my issue of the Greenamp not having enough power and losing its low end when cranked. If anything adding a second cab will worsen the issue because the 180 watts is going to have to power two cabs instead of 1. Not to mention I cant do that, because my 2x15 is 4 ohm and the Green has a minimum load of 4 ohms.

Im trying to get more usable power that holds the low end out of my current set up. My rig gets plenty loud, but without the low end when it gets to the volume that I actually want to be at. Im hoping the power amp will get me to that same volume (at least) while holding the low end.

Ultimately...Yes adding the 400 watt Aggie AND a Second 2x15 will give me way more volume, but Im just trying to get more volume than I currently have with adding a power amp that has double the power. I understand that a cab rated at 900 might not actually produce 900 watts, but it will def handle and push out 400 which is what the Power amp is rate at. Right now Im only getting 180 watts.

[stingraysvt]

You might find experimenting with different cabs could prove well, maybe you need to be running a 4ohms to really wake up that amp. I'd try other cabinets before I went through a lot of trouble slaving 2 amps together.

Maybe something with aggressive ports to enhance the low frequency response...

Maybe your 2x15 needs to be 4 ohms... Speakers can be had cheap...

[djshawn47]

My 2x15 is 4ohm, which is also the minimum load of the Greenamp, so I cant add a second cab without another amp.

[stingraysvt]

Originally Posted by djshawn47

My 2x15 is 4ohm, which is also the minimum load of the Greenamp, so I cant add a second cab without another amp.

My bad

[stingraysvt]

The Green amp site makes it sound like the Volume amp can really dish out the chest pounding volume...



From the site
"....Chest Pounding, Face Melting, BIG ROUND CLEANS and Natural Distortions."

[djshawn47]

Yeah, we play louder than that. Haha. Realistically 180 watts can only hold the low end frequencies to a certain volume. My guitar player brings down the house when he plugs in, but us Bass Players...

We need MOAR!!!!

[Remus_Redbone]

Are you considering running the Greenamp without a speaker connected at all? You have to connect some load to both amps or you will be back to a single amp rig shortly. Running your Greenamp without a load will likely end its life quickly. Tube amps run without a load can arc inside the output transformer which is not good.

[djshawn47]

I do have a 2x12 that I can run into it, but I guess that's where I was not sure about this set up...

So the 2x15 into the power amp then into the Green won't load the Green? It will only load the Aggie Power amp?

[B-string]

You have to have a preamp or effects send on the Greenamp (which must be connected to a speaker cab). The Preamp or effects send from the Green to the effects return on the Aggie which also must run a different cab. Never connect two amps to one mono speaker cab and all tube amps MUST be connected to their own speaker cab.

[Remus_Redbone]

To provide a load to an amp, you will have to connect some kind of speaker cab to the speaker output jack(s). Just connecting something to the pre amp out does not provide any load on the amp. It sounds like you would be better off just running the Ag and leaving the Greenamp at home. Does the Ag have a "power amp in" jack? If you run your pre amp out into the instrument input on the Ag, you are putting a preamp signal into a preamp which will cause you other problems, first of which will likely be major distortion. Bottom line is that you need a speaker connected to the speaker out jack on both amps, and you will need to go from your preamp out jack of the amp you plug you bass in to the power amp in jack of the second amp.

[BogeyBass]

Using the green would make it the most heavy preamp ever made.and yes the amp needs a load so you have to run 2 cabinets anyways.

a 2x15 is usually 4 ohm because its 2 8 ohm speakers in parallel.
which makes it a 4ohm cabinet.

If you ran the 2 speakers in series it would make it a 16 ohm load.

so if you had 2 x 2x15 cabinets at 16 ohms it would be a 8 ohm load.

in fact, you could run 4 2x15 cabinets total which would be 4ohms.

is your greenamp 6l6 tubes or EL34?

a 8x10 is 100dB and a 2x15 is 100dB their is no benefit changing
unless of course you want less bass and you want to add 45 more pounds with the 8x10.

The Green Amp is 180watts at 16, 8 or 4 ohms the wattage dont change to magic make belief watts like solid state.

Buy a second matching 2x15 cabinet rewire to 16ohms run both cabs as a 8ohm load.

you are not adding another cabinet to be louder, you are adding another cabinet to increase sensitivity of the speaker system.

more sensitivity equals less watts needed, then you will not saturate the tubes and reduce the bass with distortion.

Dont know what speakers are in your cabinet, but if they are the typical Legend 15's then that pair is only good for 250watts of clean reproduction and 300 watts of dirty speaker distortion.

so pushing the pair with a bigger amp you will just find speaker distortion instead of amp distortion.

how do you fix that......add another cabinet...then 2 amazing things happen...you need less power and you get more bass with less distortion.

Green Amp + 2 x 2x15 matching cabinets = solution.

[djshawn47]

BogeyBass- thanks for the good info. The tubes are KT88s and the speakers are Kappas. Is rewiring the speakers in series something That can be done easily(myself)?

[Sartori]

Originally Posted by djshawn47

I think you are missing the point here (to a certain extent). Adding a second cab isnt going to solve my issue of the Greenamp not having enough power and losing its low end when cranked. If anything adding a second cab will worsen the issue because the 180 watts is going to have to power two cabs instead of 1. Not to mention I cant do that, because my 2x15 is 4 ohm and the Green has a minimum load of 4 ohms.

Im trying to get more usable power that holds the low end out of my current set up. My rig gets plenty loud, but without the low end when it gets to the volume that I actually want to be at. Im hoping the power amp will get me to that same volume (at least) while holding the low end.

Ultimately...Yes adding the 400 watt Aggie AND a Second 2x15 will give me way more volume, but Im just trying to get more volume than I currently have with adding a power amp that has double the power. I understand that a cab rated at 900 might not actually produce 900 watts, but it will def handle and push out 400 which is what the Power amp is rate at. Right now Im only getting 180 watts.

It doesn't matter if you don't think adding a second cab will solve your problem. You have to anyway.

The Greenamp is a tube amp.

It MUST be connected to a cab to operate. Slaving with tube amps only works if you have as many cabs as amps, or more. If the Greenamp is not connected to anything, you will soon encounter serious problems that will take it out of commission.

It's not a preamp, it's an integrated amplifier head. It includes both the preamp, and the power amp. You can't connect the speaker out of the Greenamp to the input of a power amp. That speaker out is sending 180 watts out through the cable. Inputs on power amps are not designed for that.

The Greenamp probably has a slave out, since they do sell a slave amp (the power unit). This, or the effects send, or the preamp out, whichever it's labeled as, is what you send to the input of a power amp.

But the Greenamp still needs its own cab. No matter what, you will need two.


Basically, listen to Bogeybass.