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Cab Impedence Switchbox


PaulyWally

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It is possible, but it requires big ass transformers with multiple taps.


The Accu-switch was a magical black box that contained a capacitor. All it did was change the DC resistance of the cab. Most amps can actually run at lower impedances than the manufacturers claim, so no one blew up am amp as a result of the accu-switch, but it has been proven by independent electronics geeks that it is total bull{censored} and a marketing scheme that blew up in Accugroove's face.

 

 

Again, I don't need anymore namecalling, really. I know it didn't/doesn't work AS advertised, but I have only heard that it's impossible, which is being contradicted here. That's what I needed to know.

 

So according to your calc's, what kind of thing are we talking about here that could handle say, an 800W load, which is what my Whappo is?

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So according to your calc's, what kind of thing are we talking about here that could handle say, an 800W load, which is what my Whappo is?

 

 

Take the biggest output transformer you've ever seen on a tube amp... and triple its size.

 

 

 

 

 

 

I really don't know... but I guess that's probably about right.

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Again, I don't need anymore namecalling, really. I know it didn't/doesn't work AS advertised, but I have only heard that it's impossible, which is being contradicted here. That's what I needed to know.


So according to your calc's, what kind of thing are we talking about here that could handle say, an 800W load, which is what my Whappo is?

 

 

I'm not calling anyone names. The accu-switch was a big fat lie.

 

Here's an example of a high power output isolation transformer.

 

It is rated at 600 watts and weighs 10 pounds. It is designed to step up the output voltage to drive numerous 70 volt speakers such that a single amp can run an entire building's worth of PA speakers.

 

The transformer required to impedance match would require multiple taps to step the amp's output voltage such that it would be at an ideal output current for a given load. That requires multiple windings and results in a bigger transformer.

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I'm not calling anyone names. The accu-switch was a big fat lie.




It is rated at 600 watts and weighs 10 pounds. It is designed to step up the output voltage to drive numerous 70 volt speakers such that a single amp can run an entire building's worth of PA speakers.


The transformer required to impedance match would require multiple taps to step the amp's output voltage such that it would be at an ideal output current for a given load. That requires multiple windings and results in a bigger transformer.

 

 

I know, just meant w/ all the BS and HS, etc.., we all know and that's why I was even hesitant to bring it up-

I've just been told by all the "experts" at TB and other places that you can't change a cab's ohmage, or the signal it sees. I'm seeing differently now, even if takes a little bit more but that it is possible.

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I know, just meant w/ all the BS and HS, etc.., we all know and that's why I was even hesitant to bring it up-

I've just been told by all the "experts" at TB and other places that you can't change a cab's ohmage, or the signal it sees. I'm seeing differently now, even if takes a little bit more but that it is possible.

 

 

The reason everyone says it cannot be done is because it's totally pointless with a solid state amp when you are driving a couple of speaker cabs as a bass player.

 

You really don't gain anything by doing it, but you add a huge amount of weight to a cab and drive up the cost by a huge margin.

 

People get too hung up on ohms and watts when they should be more concerned about getting the right gear for what they are playing.

 

If you take two cabs, say Avatar B212s, one loaded with two 16 ohm speakers and one loaded with two 8 ohm speakers and play them with the same amp at the same level settings, you will not hear much of a difference in output level, even though the 4 ohm cab is getting a few more watts.

 

If you get an output transformer that knocks up the voltage so an 8 ohm cab is "seen" as a 4 ohm cab by the amp, you will gain even less because of losses in the transformer.

 

It is pointless.

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The reason everyone says it cannot be done is because it's totally pointless with a solid state amp when you are driving a couple of speaker cabs as a bass player.


You really don't gain anything by doing it, but you add a huge amount of weight to a cab and drive up the cost by a huge margin.


People get too hung up on ohms and watts when they should be more concerned about getting the right gear for what they are playing.


If you take two cabs, say Avatar B212s, one loaded with two 16 ohm speakers and one loaded with two 8 ohm speakers and play them with the same amp at the same level settings, you will not hear much of a difference in output level, even though the 4 ohm cab is getting a few more watts.


If you get an output transformer that knocks up the voltage so an 8 ohm cab is "seen" as a 4 ohm cab by the amp, you will gain even less because of losses in the transformer.


It is pointless.



While I agree it's not exactly a great idea in the first place, I was just always told it's impossible to do. Impractical and impossible are quite different, as I know you know.

So, my interest is sated. Thanks. :)

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Well, it is impossible to do with an 8 ounce black box, unless that 8 ounce black box contains a super high tech digital switching power supply that can somehow run off of the amp's output.


;)

It's impossible to do with capacitors, how's that?


Regarding the AccuSwitch, your avatar says it all. :D

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Well, it is impossible to do with an 8 ounce black box, unless that 8 ounce black box contains a super high tech digital switching power supply that can somehow run off of the amp's output.


;)

It's impossible to do with capacitors, how's that?



Works for me! :D

But hey- one computer used to take up half a warehouse and use 8 bagillion tubes for power.
One day, maybe... ;)

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No, it make no sense at all, actually.


You want to run more cabs, buy a pre/power amp rig with a 2 ohm stereo power amp. Then you can do whatever the hell you want and never have to worry about hurting anything.


I don't think anyone makes a swtichbox like you've described, but if you're a Double EE, like you claim, it should take you all of 2 minutes to design one.


It could be built in an afternoon.

 

Wow - his feet must be really wide! :freak:

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