Registered: Apr 2005
Location: Los Angeles (Burbank), CA
My pre-amp tubes were faking it.
Hey kids, thought you might get a kick out of this. I re-tubed my preamp over the weekend and made an interesting discovery.
I've peeked through the air vents at the 12AU7 tubes inside glowing orange... I assumed because tubes in my mind were supposed to get red hot.
See FIG1
So I removed the old tubes to replace with the new ones... (yes I unplugged it first) and what did I discover? But an orange LED light down in the tube mount. yeah, the tubes get warm... but not red hot, and my preamp was faking it for the look~! What a disappointment!
Registered: Apr 2005
Location: Los Angeles (Burbank), CA
quote:
Originally posted by camsr
thats interesting. how does it sound?
Well, long story short, way better than before. I got some JJ/Tesla replacements and they rock. the gain ratio is tad hotter than the old ones, but I'll survive.
i think i mentioned in another thread that anytime you buy any gear with tube pre's, they usually load em with crap-o chinese production tubes. Not totally the case here, but pretty typical. worth the $40-50 upgrade.
Registered: Apr 2005
Location: Los Angeles (Burbank), CA
quote:
Originally posted by Leon
haha you got vtec'd
totally. this is a DBX 386 dual channel pre. I called a friend with a diff DBX unit and his had the same thing. Based on some research today, I have to assume any gear with tube pre-amps is using the fake-o technique above.
Registered: Sep 2006
Location: Seattle . . . . . Skill Level: Mediocre At Best Clothing: Sometimes
quote:
Originally posted by Leon
haha you got vtec'd
vtec pwns joo!
Okay enough of that.
Reddick, Man I HATE things like that. At the NAMM show I saw a keyboard with some tubes in it. The sad part was that they had 3 TINY LEDs on wired POINTING at the sides of the tubes randomly. I'm going to try to meet with THD this week and throw out the idea of a HOT tube preamp setup. They do well with their hot-plate setup to crank tubes up and then attenuate the output.
Feb-11-2008 04:39
CReddick
balls
Registered: Apr 2005
Location: Los Angeles (Burbank), CA
quote:
Originally posted by 3F05Q
I'm going to try to meet with THD this week and throw out the idea of a HOT tube preamp setup. They do well with their hot-plate setup to crank tubes up and then attenuate the output.
Registered: Sep 2006
Location: Seattle . . . . . Skill Level: Mediocre At Best Clothing: Sometimes
quote:
Originally posted by CReddick
Do it. I'd be into that shit.
Really? I'd like to get a rollcall on such a thing.. maybe? I'd be lying if I said I wasn't trying to get a job!
Feb-11-2008 05:18
Sanguis Mortuum
Senior tranceaddict
Registered: May 2007
Location:
Haha, theres a Behringer tube thing that does the same, looks like it glows and its because its got an LED behind it.
Here, I found a pic:
Feb-11-2008 15:55
CReddick
balls
Registered: Apr 2005
Location: Los Angeles (Burbank), CA
quote:
Originally posted by Sanguis Mortuum
Haha, theres a Behringer tube thing that does the same, looks like it glows and its because its got an LED behind it.
Wow... I feel like we've uncovered some sort of conspiracy or something.
