What are for you the top 3 preamp of mytic tube amps?

[pogona06]

Hello,
As I play many music styles (from clean /jazzy to metal sounds), and want a single amp, I started a personal project of building a guitar tube amp where I want to integrate:
- 3 preamps which are both "mythics"and also very different
- 1 mixer/preamp switch/pedal
- 1 power amp (around 30 Watts)
- 1 reverb
- 1 power supply (supporting all 12AX7 required for 3 preamps...)

My current plan is to use a JTM45/50 style power amp.

For the selection of the preamps schemas, I'm in trouble as the choice is huge.
I was thinking about:
- AC30 preamp for clean sounds
- SLO 100 Preamp for Metal sounds
- JTM45 preamp for crunch sound

I'm not an expert on each preamp sound ranges where they are the best, and would be happy to get others opinions on alteratives 

[tubenit]

That would be an incredibly challenging project even for the more experienced amp builders.  IF the layout was not done right, there could be enormous problems with hum and/or oscillation issues.

The other challenge is the AC30 uses EL84 power tubes instead of the octal 6L6, EL34, KT66 etc ........... of amps more like Marshall and Soldano.  So the "preamp tone" of the AC30 really is the entire amp with the EL84's playing a major role in the tone.

I think you could do a version of Marshall and Soldano preamps switched into a Marshall style LTPI and power amp.
You could add some relay switching to get the Marshall preamp even cleaner sounding instead of the AC30 tone.

With respect, Tubenit

[pogona06]

Thanks for your advises tubenit!

Regarding the power amp, I was taking the assumption that if I don't push the volume into the zone where the EL84 start saturating significantly (playing at home for example), there shouldnt be significant sound coloration due to the power amp,  compared to 6L6. May be I'm wrong... I saw that the Vox AC30 doesnt have a feedback loop to the phase inverter for example.

I like the idea of switches on the JTM preamp to reduce gain and get a possibility cleaner sounding, instead of adding the full the AC30 preamp. I will study that option.
If other persons think about other great pre amp options to study, you are welcome :)

[Ed_Chambley]

I really like 4 output tubes in the power section and prefer either old 6v6gt RCA or Tung sol. They both when pushed sound a lot like Mullard El34. I designed a switching dual output trans, one for each pair. I used Baldwin Organ OTs as they are beefy and have bell ends to paint purdy. 10k reflected to 8 ohms. This is a inductor input and will drop voltages to around a factor of.88 to .9 lowering the voltage but cleaner steady current. So I have almost 12 and 24 watts in the power section with cool running tubes. Screens are about 4 volts less and the pricy tubes will last for a long time. It is fixed bias and cathode as I do have a versitle preamp with tweed tones.
V1 is a 12ax7 and feeds a blackface stack, but will switch to a brownface for a touch more gain. Mid pot is raw. Recovery next. These are high volt and pass clean. Next is a 6sj7 pentode that is relay added or removed and makes a nice drive. The phase inverter is a 6sl7. I found this tube to be versitle and drives a little different than the 12at7, but it took a lot of work to drive 2 or 4 tubes, but it will. I wanted to do a cathodyne PI for the clean, but it did not drive as well as a ltpi and another tube would be needed for recovery.
Of course I lifted Tubenits mid boost for even more mid Marshall tone.
I used an amp from a Hammond PR 20 tone cabinet which has everything needed for the power supply and it already has 2 OTs, but only one is good. The one for the bass. I got it for free to haul it off and all tubes were great. These have 4 alnico 10s and 1 alnico 12 and the wood is beautiful.


It is the most versitle amp I ever made. I plan to build another 3 amps from now and use a Fender twin chassis upside down like a Sunn as I like tubes up. I want to add the stereo Magnatone vibrato if I can get the new style varistors. This may be a dream.


Anyway, I thought I would mention this for some Ideas. I do like big plate preamp tubes and pentode tone. I do not think it is necessary to add a cold clipper like Soldano, however I think his amps are great designs especially the incorporation of loops as part of the tone. It is just what you mentioned of having versitility the Soldano doesn’t and trying to get it From that circuit would be hard for me.
There are a lot of real estate inside a twin chassis. I do prefer plate driven stacks, but tubes are made to regain any losses. I sinply find them more versitle for clean.