Sorry...but another impedence question...

[Robert Burns]

Why wouldnt i always select a lower amp setting, and just stay "above"
that setting with the speakers? I guess what im saying is if i have
an 8 ohm speaker cab...why not choose 4 ohms on the amp, just in case?
Or does the sound suffer if you have a 16 ohm load...and choose 8
ohm switch on the back of the amp?
Rule is to NEVER be UNDER) the impedence selected right? Over is ok?

Gettin a bit nervous over possibly not doing the right hookup with the
VHT 2/90/2 coming in a day or two. :-))

[thebisch]

"why not choose 4 ohms on the amp, just in case?"

Just in case of what?

[rjohnstone]

Set the amp to match the cab.
It will be fine.
Setting it lower will kill your output.

[toejam]

If you have two 8-ohm speaker cabs, then you'd set the amp to 4 ohms.

[Robert Burns]

Set the amp to match the cab.
It will be fine.
Setting it lower will kill your output.

*********** thanks.i knew there had to be a reason!
Best would be with a multimeter to actually check what the
1/4" plug has on it from shaft to tip, right? Then i know for
sure what the impedence is.

[Robert Burns]

"why not choose 4 ohms on the amp, just in case?"

Just in case of what?

***********************
Total Global Warfare !! :ROTF:

[Cleveland Metal]

*********** thanks.i knew there had to be a reason!
Best would be with a multimeter to actually check what the
1/4" plug has on it from shaft to tip, right? Then i know for
sure what the impedence is.

That oughtta freak ya out cuz, with a regular DVM, it will usually never be quite exact... usually, 16 ohms will be like 13-15, 8 ohms will be 6.**, 4ohm will be 3.**. Sometimes they will be close on, but not all the time.

[cbope]

That oughtta freak ya out cuz, with a regular DVM, it will usually never be quite exact... usually, 16 ohms will be like 13-15, 8 ohms will be 6.**, 4ohm will be 3.**. Sometimes they will be close on, but not all the time.

Correct. That's because speakers are rated at their "impedence" values and a multimeter measures DC resistance only. Resistance is only valid for DC circuits, while a speaker never sees a DC current, it sees an alternating current or AC. Impedence is the resistance to the flow of AC current and cannot be measured using a multimeter because it varies depending on the frequency content of the signal. Impedence has to be calculated based on the circuit and speaker in use. DC resistance and AC impedence values for speakers are not so far apart in the real world, typically within a few ohms. End of electronics lesson 101...

[Robert Burns]

Ok...this is what i "Want" to do..but tell me if im nuts?
Kustom 4/12 cab (measured on the digital meter at 7.2 ohms)
Plug this one into the VHT "Use First"! output of Channel A"
set at 8 ohms.
Then use one of my Crate 2/12 open back cabs (digital meter
says 6.1 ohms) plugged into the other "USE FIRST" speaker output
of Channel "B" on the VHT 2/90/2
Then... this is the wierd part.. use my other 2/12 crate plugged into
the 3rd speaker option of "B" channel unmarked. 6.3 ohms on the digital
meter. So that Channel A' would be my left channel thru the 4/12 cab
and... channel "B" would be both the Crate 2/12 cabs.
Will not using my 4th" (unmarked) Speaker output hurt anything?
And... should i set both my VHT speaker ohm settings to 4 ohms so
that in reality im 'Above" in (actual) resistance with my cabs? Just to
be safe? Or is this going to be "Killing" my tone? The tone is wonderfull
(played just the 2/12 crate cabs last night for about a 1/2 hour using
the 8ohm setting on the VHT outputs "Use First". But super bright sounding! Im wondering if i set both channels at 4 ohms, if this would
be safer on the power tubes, and transformers..plus maybe warm up the
tone somewhat? Obviously at 2:30 AM its bugging me! :-)