Footswitch to switch between two speakers?

[Mr songwriter]

I've got a Laney LC30 combo and the stock speaker is very nice for cleans, but not so nice for the OD channel - I tried running the Laney through a cheapo 2 x 12" cab and the OD channel sounded a lot better, though the cleans weren't as nice, so I was wondering if there's a footswitch available that would enable me to switch between the two (both are 8 ohm loads) preferably without making any loud noises in the process.

[ggunn]

Originally Posted by Mr songwriter

I've got a Laney LC30 combo and the stock speaker is very nice for cleans, but not so nice for the OD channel - I tried running the Laney through a cheapo 2 x 12" cab and the OD channel sounded a lot better, though the cleans weren't as nice, so I was wondering if there's a footswitch available that would enable me to switch between the two (both are 8 ohm loads) preferably without making any loud noises in the process.

Just about any passive A/B switch will do this, but you need to be careful. Stringing all that speaker cable around underfoot increases the odds of shorts or opens in the speaker circuit, either of which can severely damage your amp.

[Mr songwriter]

Originally Posted by ggunn

Just about any passive A/B switch will do this, but you need to be careful.

Could you recommend a particular make please? I've read a few reviews of A/B switches, though these were being used to switch the guitar signal between different amps and quite a few of the reviewers were complaining about their tone being affected.

Stringing all that speaker cable around underfoot increases the odds of shorts or opens in the speaker circuit, either of which can severely damage your amp.

Yes, you're right, someone could trip over the cable and pull it out, new amp time. Hadn't thought of that.

[iwantmypie]

You could just pickup a DOD a/b pedal for about $30 bucks of if you are into wiring electronics, orders some parts and make your own for about the same price. An a/b box has got to be the easiest pedal one could make. I built one recently and it's puuuuurfect. Noiseless switching, metal case, DC jack, and LCDs all for $30 bucks. They also work in reverse say if you want to run two guitars into one amp and switch them when needed without having to put your amp in standby and unplug your guitars. hope this helps

[mikemorgan]

If your Laney has a solid state power section, switching speakers while power amp is on is a real no-no. Also, I would think that even the most passive of AB boxes will add resistance to the circuit, which doesn't matter much to a guitar signal, but may be death to a power-amp speaker relationship.
You better ask somebody smarter than me is all I'm sayin'

[Thurgood]

This has been asked before. My original answer was: In short no, no, no, more no. Think of this: With a swithch that a/b's between two speakers when you switch to one speaker (load) you leave speaker B (still connected to your output of your amp), but NOW you have an open circuit on the A speaker.In short, a no load situation. Open circuits and tube amps don't mix. Check your manual and I bet it says "Never operate this amplifier with no speaker connected" (assuming you have a tube amp of course.) As someone else said, "New amp time"!!!

Now having re-thought this, I conclude that you may be able to do this since the amp will "see" a load once you switch. Also assuming that both speakers are the same impedance. If not a whole new host of woolies grows from the mismatch. But that raises another problem in htat you may for an instant see a no load situation as you switch. A brief instant of no load. To a roaring amp that brief moment in time while actuating the switch is a lifetime to electrons. Don't do it, at least not on your dumble.

[Thurgood]

oops forgot: Transistor amps are far more forgiving. I switch speakers a/b on my home stereo on the fly all the time.. Sorry for the double post.

[ggunn]

Originally Posted by Thurgood

This has been asked before. My original answer was: In short no, no, no, more no. Think of this: With a swithch that a/b's between two speakers when you switch to one speaker (load) you leave speaker B (still connected to your output of your amp), but NOW you have an open circuit on the A speaker.In short, a no load situation.

Actually, the other guy was wanting to switch different amps to the same speaker. A big NO to that one, of course, but switching speakers on an amp shouldn't be a problem. That's theoretically speaking, of course; when you've got the output section of your amp connected to underfoot wires, then there is certainly a potential for disaster.

[Mr songwriter]

Well I tested my 2 x 12" cab with a multimeter and it's defininitely 8 ohms amd my Laney is all valve, but the things you are saying about the brief period of no load when you're switching speakers etc, plus the increased possibility of accidentally disconnecting them are making me think it's probably not a good idea. I'll probably just have to try and find a replacement for the stock speaker that does good cleans and an OD that I like too.

[ggunn]

Originally Posted by mikemorgan

If your Laney has a solid state power section, switching speakers while power amp is on is a real no-no. Also, I would think that even the most passive of AB boxes will add resistance to the circuit, which doesn't matter much to a guitar signal, but may be death to a power-amp speaker relationship.
You better ask somebody smarter than me is all I'm sayin'

I don't know about the risks of hot switching a SS amp between loads (though I can't think of a reason why it would hurt anything), but an A/B box that's only a switch and some wire won't add significantly to the load. Even if it did, more resistance (up to a point, of course) won't hurt anything.

[Mr songwriter]

I would really like to see an experiment conducted to test this theory...preferably using someone else's equipment.

[ggunn]

Originally Posted by Mr songwriter

Could you recommend a particular make please? I've read a few reviews of A/B switches, though these were being used to switch the guitar signal between different amps and quite a few of the reviewers were complaining about their tone being affected.

What you want is a box that is only a DPDT switch and some wire, like the old EH Switchblades I have. Some of the newer A/B boxes have a little buffer circuit between the ins and outs that a speaker level signal will probably blow all to hell. Using one of those in this application may damage your amp.

I wouldn't worry about a simple switch affecting your tone.

[Mr songwriter]

Ah right, ta for the info.

[Micter]

Originally Posted by Mr songwriter

Well I tested my 2 x 12" cab with a multimeter and it's defininitely 8 ohms amd my Laney is all valve, but the things you are saying about the brief period of no load when you're switching speakers etc, plus the increased possibility of accidentally disconnecting them are making me think it's probably not a good idea. I'll probably just have to try and find a replacement for the stock speaker that does good cleans and an OD that I like too.

Good idea! Check out the Eminence line. The Texas Heat, Tonker, Wizzard, etc.

The other thing you are going to have a problem with a loud POP when using a switch between speakers. Not a good idea in my opinion.

[Mr songwriter]

Originally Posted by Micter

Good idea! Check out the Eminence line. The Texas Heat, Tonker, Wizzard, etc.

The other thing you are going to have a problem with a loud POP when using a switch between speakers. Not a good idea in my opinion.

Yes, that could be a problem. As far as speakers go, these are the ones I've seen on the net: Tonker for £67, Texas heat for £55 and a Celestion G12 Century for £80, though from the reviews (and the soundclips on the Celestion site - I couldn't find any for any of the Eminence speakers) the Century sounds more like the kind of thing I'm after, wish there was some way to take the guesswork out of this.

[sile2001]

Another option is the Tonebone Cab-bone, which is an A/B switch designed to make sure that there is always a load on the head. If anything ever fails, then it falls back to connecting cab #1 to the head to ensure a load. Still, you have to make sure all the impedances match up. Yes, it's more expensive than a plain old A/B box, but then which is cheaper? Buying a Cab-bone, or replacing/repairing your head?

http://www.tonebone.com/tb-cabbone.htm

[Mr songwriter]

Thanks, that looks like exactly the thing I need, but the fact that they've included a feature like this:

And Cabbone is safe – switching is controlled by a timer IC that manages a ramped connection overlap. This ensures a constant load on the output, a major concern with tube amps.

...makes me wonder whether you really can do it safely with a simple passive switch, the only problem being that it costs $300, with which I could buy 2 or 3 decent quality speakers (or more if I managed to resell any ones I didn't like) ah well.

[Farview]

Put a Celestion in the Laney. Those HH speakers break up in a strange way, celestions always sounded better in my Laney setups. YMMV

[mshilarious]

Originally Posted by ggunn

Actually, the other guy was wanting to switch different amps to the same speaker. A big NO to that one, of course

Route the "off" amp to a hot plate, or a DIY resistor setup that can handle the current. With a simple passive switch, there could be a nasty pop though.

[Mr songwriter]

Originally Posted by Farview

Put a Celestion in the Laney. Those HH speakers break up in a strange way, celestions always sounded better in my Laney setups. YMMV

I know that earlier models of my amp had HH speakers in them because I've seen people moaning about them in Harmony Central user reviews, but this one has got a Celestion 70 80 in it, which as I said, does nice cleans, but the OD sound could do with being a bit tighter.

[ggunn]

Originally Posted by mshilarious

Route the "off" amp to a hot plate, or a DIY resistor setup that can handle the current. With a simple passive switch, there could be a nasty pop though.

I don't see why there should be a pop. Pops happen when a voltage surge or capacitance is suddenly dumped into an input circuit and amplified by the amp, like when you plug a mic into a hot cable or power up a mixer that is plugged into a hot power amp. I have hot switched PA speakers many times and never heard any pops.