Distorting CC resistors

[dave////irongater]

In a speaker box that is more or less mated to the head (or combo Box) it will work with forever.. Could 3 equal ohmage woefully underpowered cc resistors wired with 1 speaker, "S/P" be made to create some in a reactive way? More or less a half-volume switch. CC does "stuff" if pushed too hard, right?

[Corona Blue]

you would need some hefty wattage resistors for most amps (20? 30? 50? 100 watts?). Remember, you're talking about wasting power, converting it into heat. The carbon comp "resistor distortion" idea is really better applied to the amp's circuitry and even then, only really works where you have a large voltage swing at a power dissipation level somewhere near the resistors own limit.

Of course, some people will swear that they can hear a "browner" sound in their carbon comp modified TS-9's or 10's... hey... maybe so...

[dave////irongater]

I was thinking three 10 watt 4 ohm resistors in a 4 ohm box for a Bassman. To do anything the ccs have to be straining.

[Corona Blue]

don't know how it would sound, but it should work. be aware that if something fails on the resistor side it could be unfriendly to your speaker.

[dave////irongater]

Thanks Corona, but is anyone out there from the CC distortion thread from about a year ago?

[R.G.]

Thanks Corona, but is anyone out there from the CC distortion thread from about a year ago?
I don't know about being here from the CC distortion thread a year ago, but I wrote up the only article I've seen which explained why and how CC resistors can distort.

I'll help if I can.

The amount of distortion you can get out of CC resistors nondestructively is limited. The distortion is caused by the resistance changing in response to the voltage across the resistor. To get much distortion, high voltages are required, on the order of hundreds of volts of signal. Speaaker outputs are generally much lower than that, and the proposed 4 ohm speaker load won't generate much distortion. Some, and measurable with the right equipment, but not a lot.

[Shea]

... The amount of distortion you can get out of CC resistors nondestructively is limited. The distortion is caused by the resistance changing in response to the voltage across the resistor. ...

And a device that would do the same thing much more effectively in a speaker output would be a lightbulb.

Shea

[dave////irongater]

Thanks RG & Shea. Bad idea then? Would you have an idea on a starting point for a AB165 lightbulb? Parallel, right? Thanks in advance..

[Shea]

Thanks RG & Shea. Bad idea then? Would you have an idea on a starting point for a AB165 lightbulb? Parallel, right? Thanks in advance..

I never tried it, so I don't have any worthwhile advice to give. But I don't think there's any reason why you couldn't try a series lightbulb for a compressing effect.

Also, you might try using some fixed resistors to limit the effect of the lightbulb, if it becomes necessary to protect your amp's output circuit from extreme loading or underloading. For example, if you connect a lightbulb in parallel with the output, then putting a resistor in series with the lightbulb would prevent shorting out the output when the bulb is cold. And if you connect a lightbulb in series with the output, then putting a resistor in parallel with the lightbulb would limit the max resistance when the bulb is hot. I don't know if those things are really necessary, but it's something to consider.

Shea

[Jeremy]

bulbs in series with the output transformer, if they burn out, will leave the transformer with no load. I'd be leary of doing it without a resistor in parallel with the bulb.

[dave////irongater]

Thanks Guys!

[Enzo]

Light bulbs can burn out, but so can speakers. If you are worried about the bulbs, add a parallel 100 ohm resistor to them.

[Rick Erickson]

I was thinking three 10 watt 4 ohm resistors in a 4 ohm box for a Bassman. To do anything the ccs have to be straining.

Where would you find these 10W CC resistors? I've never seen one. btw - a straining CC resistor is one that is overheating and burning up, changing value and eventually opening. Not exactly a stable circuit design.

RE

[dave////irongater]

Thanks Rick, Yeah by this point i pretty much knew it was a dead horse. Know anything 'bout UL Twins ;)