triode sound, pentode sound, oh my

Started by jibberish, May 23, 2012, 04:22:05 AM

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jibberish

even tho i was asking about rockerverb 50's etc, i am going to build a 2 tube style 1 watt amp as my first actual thing i build.  i spent severel rounds at weber and looking at build articles and now i have hit the next wall.

i was thinking of doing an ec99 with 12ax7 at first. seems simple. then i see "99 is triode,  for real pentode sound , use a 579??(sry i will screw the numbers up from now to eternity). then i see weber using some tube i need to read about for a "gritty" or grainy wtf sound(cheap 50's amp section right near top of list, only a combo)

what is the real deal on these types of "sounds" based on implementation. more subtle tonal variation and breakup characteristics, or some real winners and losers?

Hemisaurus

Tubes don't have a sound, until you put them in circuit.

If you are worried EL84 is a real(common) pentode.

Some cork sniffer will now tell you how the different tubes sound ;)

jibberish

heh, i'm not far enough along to be worried if i have a pentode or not. im trying to get info regarding these implementations, because maybe i would like one over the other...

all the noise hit me with a new set of design parameters.   is this where certain like fender champ or marshall families got started by their circuit configs?

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also, i did a lot of meditating over that ant 12ax7 output. i'm thinking it had like a 50k impedance to the OT, something big..anyway  i have a question: could a pair(or more i suppose once you get rolling) of those be paralleled to the primary of an OT to cut the impedance in half?

i see you can get something like a 22k/8 ohm OT no problem or something thereabouts

Hemisaurus

#3
Yep, paralleling output tubes halves the required impedance.

I was going to say, a lot of times things like the OT price / availability, will help narrow down what tubes you use. I came across this on my travels, just another iron maker http://www.musicalpowersupplies.com/2.html



speaking of sniffing, the V20 in this clip uses 20 12AX7's as it's output.

VOLVO)))

I was goofin' with Nick last night about making a mini mesa 400+ with 12 6v6s.. :D

I mean, they do make the mini recto...
"I like a dolphin who gets down on a first date."  - Don G


CHUB CUB 4 LYFE.

I,Galactus

Quote from: Hemisaurus on May 23, 2012, 09:06:41 AM
speaking of sniffing, the V20 in this clip uses 20 12AX7's as it's output.

Are they NOS?  As every sniffer knows, old glass smells better.  Corkier even.

Quote from: SunnO))) on May 23, 2012, 09:56:07 AM
I was goofin' with Nick last night about making a mini mesa 400+ with 12 6v6s.. :D

I mean, they do make the mini recto...

:D I'd love to see that.
"Why don't you take a flying fuck at a rolling doughnut? Why don't you take a flying fuck at the mooooooooooooon?"

Hemisaurus

#6
It would produce what, something like 120-150W, it would be getting the OP tranny to match that would be the issue, and enough heater current from the PT, if you could get round that. Time to troll the datasheets.

OK 10K for a pair @ 250V for 10W or 8K for a pair @ 285V for 14W, so that's 1.7K or 1.3K for a dozen. That's do-able, a quad of EL-34's can do 1.7K. .45A per for heater so 5.5A for heaters, plus whatever you have in pre and phase splitters.

Time for you to get building.

dunwichamps

you could try 6bm8s for a small pentode and the ECC99 for a nice bigger triode. I have used ECC99 on a couple flea amps. Pretty loud for such a small package

dunwichamps

Quote from: Hemisaurus on May 23, 2012, 10:11:49 AM
It would produce what, something like 120-150W, it would be getting the OP tranny to match that would be the issue, and enough heater current from the PT, if you could get round that. Time to troll the datasheets.

OK 10K for a pair @ 250V for 10W or 8K for a pair @ 285V for 14W, so that's 1.7K or 1.3K for a dozen. That's do-able, a quad of EL-34's can do 1.7K. .45A per for heater so 5.5A for heaters, plus whatever you have in pre and phase splitters.

Time for you to get building.

you would need a super built phase inverter, as grid leak will scale down per tube

clockwork green

I'd like to see more amps with tubes like this:
"there's too many blanks in your analogies"

Hemisaurus

Quote from: dunwichamps on May 23, 2012, 10:29:15 AM

you would need a super built phase inverter, as grid leak will scale down per tube
Copy Chamber's, he uses the same design, on all his ridiculously huge, drive 20 807's amps, and the like, and he has the schematics up http://chmbonino.com

dunwichamps

#11
if I had to pick the guy with best lead dress it would be him, i have checked his site out before. Wow, what a builder

He is using a similar design to mine in Annunaki but its not direct coupled. However it does use followers off the PI to drive low grid leaks.

Hemisaurus

Don't you wish you had the facilities to wind your own transformers, think of the possibilities that would open up.

Mind you, having a fun job has it's downside, he still lives with his mum ;)

dunwichamps

Quote from: Hemisaurus on May 23, 2012, 11:26:45 AM
Don't you wish you had the facilities to wind your own transformers, think of the possibilities that would open up.

Mind you, having a fun job has it's downside, he still lives with his mum ;)

yea winding whatever iron you want dammmmmm

even my own pile of iron doesnt compare to the ones you did for those big boy amps


Hemisaurus

I like it when he just runs copper busses ;D

dunwichamps

Quote from: Hemisaurus on May 23, 2012, 12:04:21 PM
I like it when he just runs copper busses ;D


yea for those heaters runs and the ground runs, so sharp