has any one made this Fender Blackface preamp?

[doug0147]

I'm thinking about putting this pre amp in front of my solid state amp.

http://www.redcircuits.com/Page120.htm

Here is the amp I want to use it in front of.

http://www.aaroncake.net/Circuits/amp20w.asp


Has any one made this preamp? Any suggestions? What do you think?

[Paul Marossy]

I haven't seen this circuit before, but it looks like something cool to play around with. It would be way cool if it could combined with a reverb circuit of some sort in the same box. Actually, I think Boss has a pedal that does basically just that.

Anyway, you may not get the results that you want by sticking this in your solid state amp, but I could be wrong. Does your amp have reverb on it? If it has a good reverb circuit in it, it might be a reasonable emulation of a blackface Fender amp.

[MikeH]

I haven't tried it, but I can tell you it's going to be very 'clean' sounding.  If you want more breakup you should try the prof tweed, or something like it, at ROG.

Of course running this at 9v, instead of 18 will give it more breakup.

[doug0147]

So far all my amp consist of is the schematic in the link I posted. It has no reverb (yet). It sounds really bland, and that is what I was told it would sound like since it is really just an audio amplifier. I am looking for as clean a preamp as possible. I was thinking for distortion I would put a stomp box dist in front of the preamp.

[MikeH]

Yeah.  Super clean solid state audio amplifier = no harmonics = really bland sounding.  That's for sure.

A fet preamp will help out a little, but it will sound pretty 'stale' without some harmonics (ie- distortion) in the mix.  It all boils down to harmonic content.  Tubes sound great even clean because they are rich in harmonic distortion (even if you can't noticeably discern that it is distorted), and solid state amplifiers dont really achieve this.  FETs distort pleasantly, so they do... a little, kind of.

[doug0147]

Stale is how my amp sounds by it self. ...So are you saying that no matter what preamp I put in front of it, it will always be "stale"? Right now I'm running a Ruby 1/2 watt amp in front of it and it gets loud, but like you said - stale.

[MikeH]

No, I was saying that a pre that will introduce some harmonic distortion will help greatly.  The Fet bassman design you posted might work well, but at 18volts it's going to have a lot of overhead and not break up as easily.  Or it might sound like angel tears raining down from heaven, I can't say.     But I'd try it at 9V too.

[doug0147]

Angel tears raining down from heaven  . In my dreams LOL. Thanks for the advice. I'll just bread board the preamps and see what sounds best.

[petemoore]

   Looks like 2 seriesed Mu Amps.
  They're nice because the 'slight grit' or mild distortion helps add nicely to the tone.
  They self bias too.

[Ice-9]

I would build it and run at the 18v stated for the nice clean sound with lots of headroom, then maybe you will need another gain stage in between this and the power amp to get the full volume out of the poweramp.
Secondly after testing this i would think of building another similar preamp with extra Mu stages in it to add some distortion this way you will end up with a 2 channel clean/distortion switchable amp. then think about some reverb.

[doug0147]

Ice - you allways have the coolest ideas! .....Uhhh - what's an Mu stage?

[petemoore]

Mu stage
http://www.google.com/search?q=Mu+stage&rls=com.microsoft:*:IE-SearchBox&ie=UTF-8&oe=UTF-8&sourceid=ie7&rlz=1I7DKUS
p.s. here is the Mini-Booster schem
http://www.muzique.com/amz/mini.htm
  GEO for info, the Mu Amp is no exception.
  There aren't a whole lot of

[MikeH]

You could also add a switch for "low power".  9, or even 6 volts.  Mu amps get really 'spongy' and distorted when they get starved.

[Ice-9]

Ice - you allways have the coolest ideas! .....Uhhh - what's an Mu stage?

As Petemoore said above.

If you look in your schematic of the preamp, the mu amp is the first stage of jfet transistors, so you could expand the whole preamp adding many stages.

[JHS]

IMHO not the best idea to use a stock Fender preamp (tube or FET) as a boost to goose up the input of an amp. The frequency curve is the big problem, the tonestack is not able to compensate the lacking mids.

JHS

[doug0147]

Do you have any sugestions for a better preamp? I have a lttle 15W vox combo with a line out that I plugged into the power amp. It sounded pretty OK.

[Morocotopo]

I made the red circuits mu-stage preamp. It doesn´t sound anything like a Fender thing. Pretty bland, and not very nice distortion. I´d rather make any of the Runoffgroove circuits... Just my experience.

[sean k]

R1 on the Arron Cake circuit, the amp, might be the resistor setting gain so a couple of diodes accross it might introduce a few harmonics.

Or it might break it...

One of my first amps was solid state from the london power book. I found two old RCA output transistors and it's single ended and uses heaps of power but its a cool amp for silicon. Class A outputs are cool. 

[elberto]

I built this a while ago, but with a few changes: big muff-ish single knob tone control, used J201s, running 24v into a LM1875 power amp, and I used a buffer at the end.. I actually like the sound of it a lot!  It IS kind of neutral sounding, with a little bit of grit and jangle at higher volume settings - not unlike a minibooster?  actually I think using a minibooster at higher voltage with a tone control and buffer will probably bring similar results straight into a poweramp.

[doug0147]

Hi Elberto, It's nice to hear that someone actually built it. How did you replace all the tone controls with the big muff tone, and what type of buffer did you use?

It's funny that you mentioned the mini booster idea. I was just thinking about doing that with an MXR head phone amp and an EQ in front of it.