If you need a bigger amp on stage, go ahead reading below. Thread Tools Show Printable Version. We like this mod a lot. Also I noticed that in the schematic Mesa’s reverb driver OT leads color code is the same as the They might be worth looking at. You should experiment with different cap values. It would thus work as a tube tube standalone reverb, with the ‘extra’ triode driving the input.

Uploader: Gokinos
Date Added: 19 July 2015
File Size: 8.64 Mb
Operating Systems: Windows NT/2000/XP/2003/2003/7/8/10 MacOS 10/X
Downloads: 90708
Price: Free* [*Free Regsitration Required]

Altho it may not entirely answer the question, this article from PremierGuitar describes some nonAX7 preamp tubes: So, that means 1.

12AT7 / ECC81 TAD Premium Selected (balanced) – TAD Pre Amp Tubes

Originally Posted by I’ve also done it to a few Dr. Recently I built the circuit but I used a I had by hand and I have to tell you the reverb sounds very acceptable despite rreverb theoretically the OT should have higher impedance. Why not just draw the schematic from the circuit??

In an 12st7 reverb unit, quality tubes impact the overall tone quite a bit because the entire circuit is dedicated to provide reverb tone – none of the tubes are shared for preamp or power.

I’ve used a 12AU7 self-split driving a small “Universal Output Transformer” that I had lying around, and it 1at7 to work better than paralleling the two triodes and driving the same transformer SE. Simply disconnect the feedback loop a wire and tape insulate it.


The NBF theory is that you take the signal from the speaker output, let it go through a resistor and mix it in at the entry point of the phase inverter. Your name or email address: Therefore, you don’t as much “gain” to drive the tank, but you need to source more current than what you can get from a 12ax7 to rever it.

Good 12AT7 Tube for Reverb | The Gear Page

These amps require a careful touch when dialling in the reverb, which irritates us. A distorted signal will have higher harmonic frequencies that may come out sharp and brittle through bright and sparkling speakers. It then uses one half of a 12AX7 after the reverb as make-up gain.

Increase 1st filter cap to 40uF increase low end. Depending on the cap value treble frequencies will be fed back to the phase inverter which cancels out the treble in the main path.

In both long and medium delay, the 6 spring tanks were MUCH better than the 4 spring units. But note it is the circuit that tells you what kind of tube you want, not the other way around – you want the small transformer circuit, you need a small power tube. AMpeg used this in many models – the reverb input end is high impedance and driven througha cap off the plate of a triode. Results 1 to 31 of Jul 20, 1. If you replace the V3 12AT7 reverb driver with a 12AU7, you will reduce the effect of the reverb and it will be much easier to control with the reverb knob.


Good 12AT7 Tube for Reverb …

Here is one reference http: If you need a bigger amp on stage, go ahead reading below. In build quality and component selection brands of caps, resistors, pots the silverfaces are not as robust as the blackface models. I dont have a 12at7 tube to experiment with and watch for smoke.

The vintage Jensen 122at7 Princeton Reverbs are rare and during the silverface era most Princeton Reverbs were equipped with the Oxford speakers. From my understanding, and others may feel free to chime in on this one.

For a PI, all three tubes will work. I have read the cut sheets and the biggest difference is plate current is much higher on the 12at7. What can you tell me pros and cons, suggestions welcome. Listen to the blond Baja Tele and the ES They do have some vintage vibes and a nice musical voice. You must log in or sign up to reply here. Log in or Sign up.