products for impedance matching?

[Hot _Grits]

Does anyone know if anyone makes a box, perhaps a pwer attenuator, that allows you to output a different impedence than the amp's out put. IE, something that will take my Vibrolux' 4 ohm output and reconfigure it to 8 ohms for an impedance match with my 2x12.

ta...

 

[some_dude]

Re: products for impedance matching?

Why? Just plug it in. You can mismatch a higher impedance load to a lower impedance source.

To do what you want, you'd need to get your amp modded.

The only other option I can think of is to drop your load to match your source. If you added a second 8ohm cab wired in parallel you'd have a 4ohm load, which would match your amps output impedance.

 

[Hot _Grits]

Re: products for impedance matching?

Good points, screaming, but I already do that. I gig with the 4ohm output into my 8ohm mesa 2x12. I'm after the extra headroom that getting the impedance matched would deliver. Another option is going to 8ohm v30s in parallel, but supply of aftermarket speakers where I live isn't great. I could get a new transformer with multiple taps, but I'd much prefer to keep what I have and use something outboard to correct impedance if it exists.

 

[some_dude]

Re: products for impedance matching?

I've never heard of anything. You could always stick some crappy 8ohm loudspeaker in a homemade isolation box........

....it'd probably be cheaper than having something custom made out of resistors or something.

 

[Chi3f]

Re: products for impedance matching?

i was gonna say get a different transformer but ya already thought of that

 

[Kent S.]

Re: products for impedance matching?

Good points, screaming, but I already do that. I gig with the 4ohm output into my 8ohm mesa 2x12. I'm after the extra headroom that getting the impedance matched would deliver. Another option is going to 8ohm v30s in parallel, but supply of aftermarket speakers where I live isn't great. I could get a new transformer with multiple taps, but I'd much prefer to keep what I have and use something outboard to correct impedance if it exists.

The answer is to actually get a matching transformer for your power rating from a transformer company ... I'm not aware of any commercially availble plug into box that is made especially for that (sounds like a good idea). Ideally tubes want to be matched perfectly, you can dive into a higher impedance, but hey still want to see what they want to see.S.S. is a little less picky about driving into a higher impedance though. One thought though, you could get some power resistors ( be things rated about 100 watts), and wire though into your cabinets with a switch (that's only if you need to use the cab for it's normal impedance also). You'd have to build some kind of mount on the insides walls of the cab, and you want them to stick out into the air (not lay against the sides of the cab as they will get hot and need some air flow). The old Sholtz's power soaks, selected the input and output Z separately (at least i think it did it been more than a few years), and you don't have to use the attenuator, you could leave it at -0dB (full output).
If that's correct, then that woul be ideal (ebay).
Sounds like what you want is a 1:1 transformer with two different impedances on the primary and secondary, use it one way and you go (for example only) from 8 in, 16 out; turn it around and go 8 in, 4 out. I'd call the tech deparments at a few transformer companies.

 

[Naps]

Re: products for impedance matching?

This may be a little late - I found this topic when searching, it was about 490th - anyway I found a product that you could use.

https://weberspeakerscom.secure.powweb.com/store/zmatch.htm

 

[Hot _Grits]

Re: products for impedance matching?

Very cool!