Burn-in and Biasing


I just got a new VTL integrated (IT85) tube amp yesterday. Two questions:

BURNIN:
--Is it OK to leave it on, on a low level, overnight and during the day, running constantly? (Hope so! that's what I'm currently doing, but I can turn it off when I get home if I have to)

BIASING:
--The manual says that only a recommended VTL tech should bias the machine. It seems kind of complicated. The person who does the biasing needs to use some kind of digital multimeter equipped with autoranging feature. I guess I wouldn't mind trying it myself, but I have never done this.

The manual recommends that the amp is biased when it first is setup. What are people's opinion on this? Is biasing something I could do myself, with that meter?

TIA....
dennis_the_menace

Showing 7 responses by dennis_the_menace

i must be using it in tetrode... i didn't see any switch mentioned anywhere in the manual, and haven't found one, but i wasn't really looking either. I'll check it out when i get home... thx
Thanks.

Just from your experience, do you usually check the bias when you first buy a piece of equipment, fresh from the factory? I'm going to buy this meter from Radio Shack, and have sent a message to VTL, asking for advice and maybe for a tech person I could have come out to my place and show me "how to", but in the meantime, I'd like to hear some music! You think it's OK to do that while I'm still figuring out how to adjust the bias?

(PS... I re-read the directions; they were actually pretty clear, and I think I could probably figure this out by myself, but I'll still wait to hear from VTL...)
Thank for the help... the fuses are actually ceramic already (according to the manual).

I'm getting the meter tomorrow. I've already started listening... and i'm really blown away. I just stop and stare into space listening to the music coming out of my martin logan's, in a trance... god, the VTL is SOOOOOOOO much better than that NAD i had.
Well, went to radio shack, got the product VTL recommended (digital multimeter with autoranging), and also got a plastic screwdriver...

read the instructions..

TOTALLY EASY. i was surprised.. this was no big deal. the tubes were actually a tiny bit under the recommended measurement.

thanks for the help...
I just checked the bias again tonight (around 10:30pm), and it was actually a little under the amount I set it at yesterday afternoon. The acceptable reading is supposed to be anywhere between 275 and 300. I set the bias yesterday at around 285 on each tube. Tonight, when I measured them, they all read either 272 or 275.... I just left them as is... i guess they will vary slightly. VTL said that if the reading falls within 10% of the acceptable range, then that is OK...
BTW, Luke Manley emailed me a response today. At least it came from his email address LManley@VTL.com.... answered my questions about the biasing and burn-in, and really took some time to be thorough. i was pretty impressed...