Voltage switching PT vs. Variac, for EVH tone ?

Tone Slinger · Post by **Tone Slinger** » Thu Mar 01, 2007 11:41 am

Hi, I'm getting real close to placing my plexi order and need to be sure on somethings. How does the lower voltage tap on the heyboer/dagnall PT sound in comparison to lowering the voltge with a variac ? Will either/or do the trick for EVH ?

rockstah · Post by **rockstah** » Fri Mar 02, 2007 6:30 pm

the variac has way more of an effect. u are bring the whole amp down, heaters and all.

the dual tap is kewl because you can get different tones out of the same amp.
one with 500dcv on the plates and one with 400dcv on plates as these two voltages sound different.

400 = tight, focused, compressed
500 = big, robost, chimey

my advice would be go with dual tap.

you can always get a variac as well. you want a 10 amp varaic.

Mark

mightymike · Post by **mightymike** » Fri Mar 02, 2007 8:35 pm

I like having both.

My upper taps are 470, and my lower are around 435 on my main sqeeze, and I can set it on the high 470, and that is a sweet spot, and from there I can variac it down to 435, without any danger of going too low on my heaters. Then if I want to go 435 or lower, then I set the variac back to 120, flip the dual tap switch down to the 435 lower tap, and then I can go from that 435 down to 390 and not be in any danger of going too low on my heaters. So 470 to 390 flexibility, and every point in between, without cathode striping. I still have the same tubes I put in when this amp was new.

On Some amps old amps you don't have that much wiggle room on your heaters. I was working on one, that was at 3.1vac on the heater pins to ground with 120vac wall voltage. So I could only drop it down from like 490 to 470. (This was a early 70s Marhsall) Oh but what a difference even that was....

Hey Mark, How low can you go from you high tap before you get to 2.9vac from your V1 Pin 4&5 , or Pin 9 to ground? I like to keep it above 3 to be safe, So I like the taps 35 to 40 apart.

I was thinking 480, and 440 would even be cool as set points. Cause I have a thing for 472 plates.
I really don't like it at lower than 400. I actuall like the taps set points, and 120v wall ac the best....Go Figure... But I still just love that flexibility.
But most of the time I'm using my variac like a Furman.

Tone Slinger · Post by **Tone Slinger** » Fri Mar 02, 2007 9:58 pm

Great info guy's, I'll get the dual tap unit, Hell, it's not much more or difficult. Just wanted to make for sure. Thanks.