The best Jfet clean preamp?

Started by meffcio, November 06, 2009, 04:39:14 PM

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meffcio

Well guys, here's the story. I'm building a DIY solid-state 2-channel amplifier. It will contain Dr Boogie as the heavy channel, B.Blender or ROG Splitter-Blend as an fx loop (btw. which one of those two is better?), and of course a clean channel. But wait... which one? I was thinking of using Fet-2B (alembic), but it is meant to be used mostly for bass guitar. I was also thinking of using Professor Tweed, but it has only one tone control. Are there any other and maybe even better possibilites?
Thanks in advance,
Meff.

Quackzed

you could add a full fender tone stack to the professor tweed... or even find a shem where someone added one to their own build if that is the only reason against..
how clean do you want to be able to get?
if you want a lot of headroom (so you can use pedals in front of it) you might go with a clean boost like a mini booster or any circuit that has little to no distortion untill you really slam it with a booster or overdrive stompbox.
if it has a bit of overdrive with a strat at low settings on its own, youll never het a clean sound out of it with hot humbucker equipped guitar...

nothing says forever like a solid block of liquid nails!!!


arawn

Damn that fet twin sounds really good to bad I can't deciper the cyrrilic stuff on the scheme
"Consistency is the Hobgoblin of Small Minds!"

Gus Smalley clean boost, Whisker biscuit, Professor Tweed, Ruby w/bassman Mods, Dan Armstrong Orange Squeezer, Zvex SHO, ROG Mayqueen, Fetzer Valve, ROG UNO, LPB1, Blue Magic


meffcio

#5
Quote from: Quackzed on November 06, 2009, 06:43:03 PM
you could add a full fender tone stack to the professor tweed... or even find a shem where someone added one to their own build if that is the only reason against..
Well, I'm pretty sure I saw Prof. Tweed with 3 band tonestack somewhere, but I think this layout was old and unverified, and somebody said he'll check it sometime. But yesterday after starting this topic I thought that I don't need 3 band tonestack that much. It would be REALLY nice, but it isn't necessary. But there goes another problem..

Quote from: Quackzed on November 06, 2009, 06:43:03 PM
how clean do you want to be able to get?
if you want a lot of headroom (so you can use pedals in front of it) you might go with a clean boost like a mini booster or any circuit that has little to no distortion untill you really slam it with a booster or overdrive stompbox.
if it has a bit of overdrive with a strat at low settings on its own, youll never het a clean sound out of it with hot humbucker equipped guitar...
I want to be able to get clean tones. If there's a possibility - clean to crunch. And hearing the PrT samples - it sounds really ovedriven, but it's used before other amp's clean channel, BUT it's recorded with a strat, and I have humbs. PrT has a power tube also 'jfeted' in it... But using it not before a normal amplifier, but only a poweramp, I think I could get what I want?
I'd also like to use Red Ranger Booster or Distortus Maximus (unity gain) before the preamp sometimes.

Quote from: anti-idiot on November 06, 2009, 09:14:40 PM
This one maybe:
http://www.redcircuits.com/Page120.htm

Or this other one:
The source (i hope u know russian)
http://diyfactory.ru/index.php?option=com_content&task=view&id=89&Itemid=47
Well, in fact I was the person to mention them in the topic on the other forum :P But I forgot to mention them here. Anyway, too big voltages. I want to use 9 - 12V, because I already have a power transformer which I'll be using.
The second problem, about first cheme - I suck if it's about making PCBs from the schematics. I just can't do it.
And nope - I don't know russian.

Quote from: arawn on November 06, 2009, 09:36:30 PM
Damn that fet twin sounds really good to bad I can't deciper the cyrrilic stuff on the scheme
Sry for advertising..
http://....org/viewtopic.php?f=28&t=6462
There's a PCB out there, and some informations.

[EDIT]
What about this?
http://i24.photobucket.com/albums/c22/umafloresta/FX/RunoffGroove/SuperBassmanumble.png
It's umble made to recreate the bassman specs.

Auke Haarsma

Quote from: meffcio on November 07, 2009, 03:31:45 AM
Anyway, too big voltages. I want to use 9 - 12V, because I already have a power transformer which I'll be using.
you could use a simple voltage doubler to get 20V+ out of your 9-12V.

meffcio

Quote from: Auke Haarsma on November 07, 2009, 07:39:29 AM
you could use a simple voltage doubler to get 20V+ out of your 9-12V.
Example? I know about the MAX1044 IC, but it's unavilable here in Poland.. Oh no, wait, it is avilable. One guy an allegro (kinda polish e-bay) sells it for enormous price..

jimosity

Quote from: meffcio
Sry for advertising..
http://....org/viewtopic.php?f=28&t=6462
There's a PCB out there, and some informations.

Are you referring to a PCB for the FET Twin??
Your link here doesn't work - can you fix it or PM it to me - I'm really interested in the FET Twin and if a PCB already exists, that'd save me a lot of trouble.
Jim Rodgers
jim@americanhc.com

bobp1339

#9
f r e e s t o m p b o x e s .org

You can use the BF245 FET in place of the Russian FETs... I use the BF245 in my clean boost and my distortion pedal and they provide a nice sound...
"I love the smell of solder in the morning..."

...Bazz Fuss, EA Trem, Ross Comp, MXR Env Filter, Orange Squeezer, custom bass preamp...
http://chindigband.com

jimosity

Would the 'Double Chip Doubler' get it enough voltage to work?
I would hate to have something other than a 9vdc power supply for this guy.
Jim Rodgers
jim@americanhc.com

meffcio

#11
Quote from: jimosity on November 08, 2009, 08:56:48 PM
Are you referring to a PCB for the FET Twin??
Your link here doesn't work - can you fix it or PM it to me - I'm really interested in the FET Twin and if a PCB already exists, that'd save me a lot of trouble.
As bobp1339 said, it's http://www. f r e e s t o m p b o x e s .org/viewtopic.php?f=28&t=6462
Yes, censorship sucks.

Anyway, anybody knows is Professor Tweed or Umble with bassman mods capable of clean tones as a preamp?

MikeH

Most of those ROG preamp type designs are designed to provide nice distortion, not necessarily clean tones.  Somewhere there was a schem floating around of a FET design based on an Orange 100 which would was said to be really clean.
"Sounds like a Fab Metal to me." -DougH

meffcio

Quote from: MikeH on November 09, 2009, 01:33:27 PM
Most of those ROG preamp type designs are designed to provide nice distortion, not necessarily clean tones.  Somewhere there was a schem floating around of a FET design based on an Orange 100 which would was said to be really clean.
Actually couldn't find it, only some fuzz pedal based on one of Orange's amps..

solderman

Quote from: meffcio on November 07, 2009, 09:45:33 AM
Quote from: Auke Haarsma on November 07, 2009, 07:39:29 AM
you could use a simple voltage doubler to get 20V+ out of your 9-12V.
Example? I know about the MAX1044 IC, but it's unavilable here in Poland.. Oh no, wait, it is avilable. One guy an allegro (kinda polish e-bay) sells it for enormous price..

Here's a good site with a lot of tone stacks http://amps.zugster.net/articles/tone-stacks
MAX1044 are available at http://www.banzaieffects.com/ for 3.15 €
The only bad sounding stomp box is an unbuilt stomp box. ;-)
//Take Care and build with passion

www.soldersound.com
xSolderman@soldersound.com (exlude x to mail)

ELS122

Quote from: arawn on November 06, 2009, 09:36:30 PM
Damn that fet twin sounds really good to bad I can't deciper the cyrrilic stuff on the scheme

well basically the transistors are KP303G and in the output KP303A

if you still care 10 years later...