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Can I safely change tube in Micro Dark ?

Posted: Tue Dec 11, 2018 2:39 am
by Pi3rral
Hello,

I love my Micro Dark, but I'd like more headroom without distortion on my gain knob.
I've read about replacing the 12AX7 with a 12AT7, but I'm afraid about voltage..

Can I safely do that ?

Thanks for your help!

Re: Can I safely change tube in Micro Dark ?

Posted: Wed Jan 30, 2019 4:07 am
by Jspur01
Headroom has little to do with tubes and everything to do with speakers? Changing tubes can be dangerous and even cause death or injury and should not be taken lightly. ..trying to chase tone with a tube change is pointless in this case....headroom as you state really resides in the speakers you play through

Re: Can I safely change tube in Micro Dark ?

Posted: Wed Jan 30, 2019 4:24 am
by Jspur01
Although you may experience a slight increase in headroom with a tube change, it will be minimal at best. Headroom is really a speaker capability as I have found. ...

Re: Can I safely change tube in Micro Dark ?

Posted: Wed Jan 30, 2019 4:30 am
by Jspur01
Plus re biasing your amp correctly after a tube change can be tricky even if you manage not to electrocute yourself during the tube change. I know these amps are meant to be tech friendly, however if it's headroom you are after its more than likely the speakers and not the tubes...what speakers and at what ohms are you running?

Re: Can I safely change tube in Micro Dark ?

Posted: Wed Jan 30, 2019 11:12 am
by Sooner
Pi3rral wrote:
Tue Dec 11, 2018 2:39 am
Hello,

I love my Micro Dark, but I'd like more headroom without distortion on my gain knob.
I've read about replacing the 12AX7 with a 12AT7, but I'm afraid about voltage..

Can I safely do that ?

Thanks for your help!
Sure. Just don't touch anything except the tube inside the chassis when you change it.

Re: Can I safely change tube in Micro Dark ?

Posted: Wed Jan 30, 2019 11:13 am
by Sooner
Jspur01 wrote:
Wed Jan 30, 2019 4:30 am
Plus re biasing your amp correctly after a tube change can be tricky even if you manage not to electrocute yourself during the tube change.
There's nothing to re bias in this amp. :roll:

Re: Can I safely change tube in Micro Dark ?

Posted: Fri Feb 01, 2019 3:48 pm
by Rlw59
When an amp is off, there's no voltage present at the tube socket. Preamp tubes don't need to be biased.

So compatible preamp tubes can be safely swapped. Let the tube cool down before you pull it out, and take care to align the pins on the new tube when you push it into the socket. (That's a little tricky on the Micros because the socket is deeply recessed and the tube blocks your view.)

Won't really give you more "headroom". Might be able to turn the gain knob up a bit higher before distortion, giving you a less abrupt transition, but the actual maximum clean volume coming from the speaker will be about the same.

But if you're actually looking for 'tamer", "more vintage" edge of distortion tones, it might be just what you want.
--------------------
If you're actually looking for more clean volume, you either need a more efficient speaker, or a different amp. TT, MT20, DT, MD20 all have nice cleans, but they're all designed to be low headroom, early breakup amps.

If you're using the Micro 8" cab, any decent 12" cab will give you more clean volume. If you're already using a larger speaker, depending on what it is you might be able to get a significant increase with a different type.