Looking to build a tube pre amp/overdrive need suggestions

[whomeno]

I want to put a real tube pre amp overdrive in front of my boss kantana. I have the vt999 now, but looking for for some thing better.
What would be a good pedal to build?

[vigilante397]

Depends on what kind of tone you're after. The Alembic F2-B will always be a popular pick, based on a Fender front end. If you're looking for something with a bit more balls I've become a fan of the Soldano Supercharger GTO, goes from little grit to full-blown high gain mayhem.

Or if you're looking for something nice and simple, hard to go wrong with a Matsumin Valvecaster

[Marcos - Munky]

Bear in mind tube circuits usually works in high voltages. A high voltage shock will surely hurt you a bit, if not worse. It's not telling you to not build a tube circuit, just telling you to be careful.

[vigilante397]

Bear in mind tube circuits usually works in high voltages. A high voltage shock will surely hurt you a bit, if not worse. It's not telling you to not build a tube circuit, just telling you to be careful.

+1

That's one of the big draws of the Valvecaster, it can run on 9V

[printer2]

Easy enough generating a voltage more than 9V to run a tube, now days there is no reason to limit yourself to anemic tone coming from a tube on low voltage.

[vigilante397]

Easy enough generating a voltage more than 9V to run a tube, now days there is no reason to limit yourself to anemic tone coming from a tube on low voltage.

Tone is subjective, but I've never thought the Valvecaster sounded anemic. That's part of why it's such a popular build in my opinion. Low parts count, dead simple to build, runs off 9V, won't kill you if you mess it up, and frankly sounds very good.

[whomeno]

I looked at the Valvecaster, but he said it was based for a single coil pick up. I'm looking for one to run humbuckers through.
what i want to do is run fuzz pedal then tube preamp to amp

[Marcos - Munky]

I use the valvecaster with a humbucker pickup. It sounds amazing. Mine have a gain knob, volume knob, no tone knob. Also, be sure to use a 12AU7, a 12AX7 sounds ok in a valvecaster but the 12AU7 sounds way better.

In Nathan's words:

Low parts count, dead simple to build, runs off 9V, won't kill you if you mess it up, and frankly sounds very good.

Easy enough generating a voltage more than 9V to run a tube, now days there is no reason to limit yourself to anemic tone coming from a tube on low voltage.

Yeah, it's pretty easy to get a high voltage from 9V. Just need to be careful when working with, let's say, 200V. But it's pretty doable. Like I said, not telling to not build, just telling to be careful.

[vigilante397]

I use the valvecaster with a humbucker pickup. It sounds amazing.

Same. Every guitar I own has humbuckers because that's the sound I like, and humbuckers sound great with the Valvecaster.

[PRR]

> be sure to use a 12AU7

+1.

An old rule in tube work is to use Mu lower than B+. This is another way of saying there is +/-1V uncertainty in tube bias due to "contact potential".

Mu of 12AX7 is 100 and it can be hard to get working for B+ much under 100V.

Mu of 12AU7 is 20 which is a lot closer to our 9V-12V B+.

(Few miniature tubes have Mu as low as 9.)

[whomeno]

ok thanks guys

[amptramp]

12AX7's are going for stupid money these days, so some alternatives would be the 12AV6 / 12AT6 / 6AV6 / 6AT6 / 12SQ7 / 6SQ7.  The -AT6 has a µ of 70 and the rest of the tubes have a µ of 100 and the -AV6 triode is identical to the triode in a 12AX7.  The other part of the tube is a pair of diodes which have a common cathode with the triode but plates that can be used as shunt diodes for a distortion or rectifiers for an envelope-based function.

[PRR]

> 12AV6 / 12AT6 / 6AV6 / 6AT6 / 12SQ7 / 6SQ7.

These are (as you say) all high-Mu and fussy to get working at 12V of B+.

I got curious. Duo-Diode/Triodes with low Mu.

12AE6 - 15
12BF6 - 16
12BU6 - 16
12DV7 - 14
12EL6 - 55 (but intended for 12V battery)
12FK6 - 7 (for 12V use)
12FM6 - 7 (for 12V use)
12FT6 -14 (for 12V use)
12SR7 - 16
12SW7 -16 (octal) (6R7)

Some of these are rare. The others will be like $5.

[PRR]

12EL6 is interesting. One alone will not distort much on guitar, but a gain of 10 (or another 12EL6) in front, it will slam.

[amptramp]

You are correct about these low-voltage tubes being rare.  They were used in car radios in the late 1950's to early 1960's and rarely show up even at surplus stores.  If you check out sophtamps:

http://www.sophtamps.ca/www.sophtamps.ca/mambo/index862b.html?option=com_content&task=view&id=25&Itemid=37

They also use the 12U7 which is not in Paul's list (µ=20) and the 12K5 as a power amp.  This is a site dedicated to low-voltage amps and they even have a Ruby Tuby using a 12AX7 operating at 12 volts, so it is not impossible.

[printer2]

How about something intermediate in terms of voltage. DC booster with an output voltage of 35V for under $2. Might give some more tube options.



https://www.ebay.ca/itm/1pc-dc-dc-adjustable-voltage-booster-power-supply-step-up-1-5v-35v-xl6009-BI/183362214010?epid=18022151238&hash=item2ab13d587a