ABY switcher box

lazgun · #1 03-14-2011, 04:19 PM

Hi.

The set-up:
I have a Goliath III 4 ohms driven by a SWR WorkingPro 700 and a Son of Bertha powered by a SWR SM-400.

I can't for impedance reasons power both cabinets with one amp. So I bought a Radial BigShot ABY switcher.

The problem is that it very noticeably degrade the sound. Not an option.

Does anybody have a solution? Is it possible to modify the Goliath III impedance to 8 ohms or is there a truly transparent ABY switcher box out there, or....

Thanks

Jim Campbell · #2 03-15-2011, 07:47 AM

Quote:

Originally Posted by lazgun

Hi.

The set-up:
I have a Goliath III 4 ohms driven by a SWR WorkingPro 700 and a Son of Bertha powered by a SWR SM-400.

I can't for impedance reasons power both cabinets with one amp. So I bought a Radial BigShot ABY switcher.

The problem is that it very noticeably degrade the sound. Not an option.

Does anybody have a solution? Is it possible to modify the Goliath III impedance to 8 ohms or is there a truly transparent ABY switcher box out there, or....

Thanks

is the aby box is designed to work with the signal that comes from a guitar pick up......i suppose you could re wire one with a speaker cable were that the case.....is a second head with the aby on the front end practical to better use the capabilities of both cabs,and/or a swap for a cab that better matches the impedance of one you have....

hensonbass · #3 03-15-2011, 09:41 AM

Check under Lehle and Radial products.

4Mal · #4 03-15-2011, 10:18 AM

Plug into one head - the one with the better front end, probably the SM-400 I'm guessing, run a cable from a line out to the front end of the other head. Maybe the effects loop out.

If it sounds mid rangy, funky in a bad way, try flipping the polarity on one end of the cable as there might be a phase issue.

Always turn on the head that you plug your bass into first, then power on the 'slave' amp. Always power the slave amp off first, then the head you plug your bass into and you will avoid any nasty spikes sent down the line !

Always start withthe volumes on both amps low or all the way off !

Effects loop out of the main amp to the front end may work if there is no line out on it but it seems to me like those old SWR's had pretty flexible I/O options - it's been ages for me since I messed with one though...

After you've messed with all that for a while - might as well sell that rig, and get a single head & another cab that will do it for you without all the extra BS - there's nothing technically wrong with the multi-headed approach but it can get tedious moving and setting up all that cr@p if you're gigging a bunch.

Alex1984 · #5 03-15-2011, 10:49 AM

But in the master-slave configuration, you will lose the ability to switch rigs using the button without some knob turning.

Also, I'd try to see if the degradations actually coming from the box or from the 2 rigs being out of phase or different polarity.

Bassmec · #6 03-15-2011, 12:13 PM

Quote:

Originally Posted by lazgun

Hi.

The set-up:
I have a Goliath III 4 ohms driven by a SWR WorkingPro 700 and a Son of Bertha powered by a SWR SM-400.

I can't for impedance reasons power both cabinets with one amp. So I bought a Radial BigShot ABY switcher.

The problem is that it very noticeably degrade the sound. Not an option.

Does anybody have a solution? Is it possible to modify the Goliath III impedance to 8 ohms or is there a truly transparent ABY switcher box out there, or....

Thanks

I use a Lehle Dual for this purpose, its about as transparent as a high impedance transformer gets.
The Lehle P split is just as good and quite a bit cheaper if you don't want to foot switch it about.