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My pre-amp tubes were faking it.
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| CReddick |
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!
FIG2
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| camsr |
| thats interesting. how does it sound? |
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| CReddick |
| 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. |
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| CReddick |
| 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. |
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| 3F05Q |
| 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. |
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| CReddick |
| 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. |
Do it. I'd be into that . |
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| 3F05Q |
| quote: | Originally posted by CReddick
Do it. I'd be into that . |
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! :wtf: |
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| 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.
Here, I found a pic:
:haha: |
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| CReddick |
| 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.
:haha: |
Wow... I feel like we've uncovered some sort of conspiracy or something. |
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| Pjotr G |
| consumers get a kick out of it, so the manufacturers fulfill their desires. Doesn't make any difference to the sound, so I don't care. |
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