Which preamps?

[maltikeks]

Hello,

Sooo... after some (long) thinking I've decided to make few preamps. The rules are:

1. Every preamp will be a separate module/unit - separate chassis, case (I'm not sure if it's called case, U know, that thing that covers chassis :D), etc.
2. There will probably be 1 channel per preamp.
3. No power amp section, I want to make a PP EL34 or 6L6GC in a seperate box.

The reason why I want to make it this way is that mostly, (I guess 99% of time) I play on headphones at home. I live in a small appartement with my gf, so there is just no way to play via some speaker. So making a complete tube amp would be just a waste of energy (and it's getting more and more expensive) and parts since the master volume would be always at 0.

I want just a preamp, so I could connect it into my guitar interface (Focusrite Scarlett Solo) and then add an IR in DAW.

This operation is a big challenge for me, and I'd really appreciate some help, so I have few questions:

Which preamps would U recommend? 1 channel per preamp.

I'd like to have a typical Marshall sound - I've almost finished a JCM 800 2204 preamp copy (it has some minor changes to the original, but U know, I'm testing so it changes).

Second one I'd like to get is a Dual Rectifier - classic Rectifier, scooped sound - which channel would be better for this? maybe some mix of both? I think this one will be most challenging.

Third would be for some clean/blues- I have no idea what direction I should choose, since it will be just a preamp I won't be able to push power tubes to break, any ideas what amp have some decent preamp clean? I guess I could just roll down Gain on JCM and it will be fine for blues, but I'd also like to have really nice clean sound.

What else would U suggest? Maybe someone has an experience with something like that? I will be using normal 12AX7/ECC83 tubes, no low-voltage alternatives.

About power amp unit - I guess I'll start a new topic about this soon, so it will be clearer.

Hopefully everything is understandable, I'm not a native speaker.

Best regards :)

[shooter]

classic Rectifier, scooped sound

that's a PA thing, the pre doesn't draw enough current to scoop


the best I can do for "what pre-amp";
do to your favorite store full of amps and play


what I like you won't, what Bob likes nobody likes, except Bob, he's a an odd one 

[labb]

take a look at this for some ideas on how to build...Dual Channel 1U bass/guitar preamp with low impedance transformer balanced output (frontiernet.net)


some preamps to consider    AX84.com - The Cooperative Tube Guitar Amp Project

[maltikeks]

take a look at this for some ideas on how to build...Dual Channel 1U bass/guitar preamp with low impedance transformer balanced output (frontiernet.net)


some preamps to consider    AX84.com - The Cooperative Tube Guitar Amp Project

nice links, didn't know them,  thank U :)

classic Rectifier, scooped sound

that's a PA thing, the pre doesn't draw enough current to scoop

ehhh I was afraid of that

Would U be so kind and give me some short explanation how does PA scoops exactly? I believe I'm missing something ;/

classic Rectifier, scooped sound

what I like you won't, what Bob likes nobody likes, except Bob, he's a an odd one 

And we all love Bob

[shooter]

with a fixed bias push-pull PA, you dig really hard on the strings the signal jumps in amplitude fast, the tubes are commanded to suck up lots of current, the PS sags voltage in response to the current demand.

[SILVERGUN]

with a fixed bias push-pull PA, you dig really hard on the strings the signal jumps in amplitude fast, the tubes are commanded to suck up lots of current, the PS sags voltage in response to the current demand.

I think maltikeks is asking about the "scooped" out mids that are inherent in a heavy metal type tone-stack setting. This sound comes somewhat from an extreme cut in mids with boosted highs and lows. Bass = 10, Mids = 0, Treble = 10
If you put enough gain stages in before the tone stack you can get a nice chainsaw/stroker motor with no exhaust type tone.


maltikeks, if the Dual Rectifier is what you are after you should just copy that preamp schematic. I'm sure this has been done somewhere on the internet.

[JPK]

Mesa Emgineering used to make a pre-amp that was like a big pedal. Check that out.

[shooter]

asking about the "scooped" out mids

Thanks, missed that one completely 
although when he gets around to the PA, he's ahead of the game 

[maltikeks]

Well,

Yes, I was asking about scooped mids, however Rectifier scooped sound is very charasteristic and I wasn't sure how much of that part, in Rectifier, is done in preamp and how much in PA, and Ur answer about PA was very interesting :D

ATM, after Ur explanation, I know what's going on in a PA, and lets say that I can imagine this, but I'm not sure if I can HEAR in my mind what exactly is that "PA sound scoop" :D - if that makes any sense

[sluckey]

what exactly is that "PA sound scoop" :D - if that makes any sense

I don't know what he's talking about either. Not my first time.   

[SILVERGUN]

Yes, I was asking about scooped mids, however Rectifier scooped sound is very charasteristic and I wasn't sure how much of that part, in Rectifier, is done in preamp and how much in PA, and Ur answer about PA was very interesting :D

I would say 90% preamp, 10% power amp. Most high gain power amps share very similar design characteristics.
It is the voicing of the preamp, tone stack values, etc. that will make the biggest difference from one amp to the next.

There is no PA sound scoop that I am aware of.
I think shooter saw the word "rectiifer" and "scoop" and related this to what we call sag. That is where the power supply drops in relation to the output swing. Most high gain amps are designed to not have any sag. They are designed to be stiff and able to reproduce more tight bass frequencies (especially for dropped tuned metal).

[shooter]

shooter saw the word "rectiifer" and "scoop"

...and it was all down-hill from there 
on the plus side this year saw my best crop ever 

[Williamblake]

The rules you have sound like plugin cards. But nobody does that.