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GK rails in a pedal?
- Thread starter sprag
- Start date
Hilarious.
That's exactly what the "GK sound" is.
But what does "hitting the rails" mean?
It refers to GK's rare ability to "break up" under certain circumstances. Get a little grindy and growly. Which is more of a tube amp response. But somehow they do it in solid-state form.
Ah ok, thank you for the explanation, I will add it to my English Vocabulary!
The "Boost" is nothing more than a clean boost. "Hitting the rails" refers to the preamp section overdriving the power amp.
Assuming you're referring to my post? I know it's not the same thing. The clean channel on the MB heads doesn't come close to that sound but the Boost channel can. Sorry if I wasn't clear.
Like I said in the 1st post it's literally not possible to hit the rails on an MB head.
The 800RB sounds cool but the power section is what he's looking to cop.
That's not really accurate. It's the power section overdriving itself when pushed hard. Very similar to a tube power amp section.
Yup. It technically should work. I just haven't fabricated the board yet. The only part of the preamp I removed is the crossover, as I personally don't find it necessary for a pedal.
You said it has to do with the preamp, but it has nothing to do with the preamp.
It's the voltage rails inside the power amp putting out as much as they can and distorting in a musical way.
I'd agree about the Xover being unnecessary. Are you running it at the same voltage?
If yes, I'm very interested.
You did the 360+ preamp a while back right?
Maybe I'm confusing two things. I was under the impressing that the "hitting the rail" sound is from the boost circuit being boosted high. Is that not correct? How would the power amp get pushed without help from the preamp?
It'll run at the same +/-15v like the real preamp. While I do build the 360+ preamp, it was designed by jcm at Viva Analog.
Hitting the rails isn't the boost circuit.
It's the poweramp running out of headroom. Effectively running at the rails of its power supply.
Its a high power fuzz. And is incredible through a big cab at high volume.
Correct. I guess I'm really bad at explaining what I'm trying to say. My point is there's no actual volume control on the power amp section, so it's the preamp that's controlling how hard the power amp gets pushed. It takes a loud signal from the preamp section to push the power amp. While not the only way to do it, the boost circuit can bass used to push the power amp.
No, that's not correct. Again, it has nothing to do with the preamp or boost pushing the power amp.
What causes the voltage rail to make the power amp start distorting? That's the part I'm not getting.
Its the power amp running all-out, as in its output transistors running completely non-linear.
I believe it's possible to do by bypassing the preamp entirely. Substituted by another preamp of course
I believe it's possible to do by bypassing the preamp entirely. Substituted by another preamp of course
The voltage rail IS the power amp. Your giving it as much voltage as it can take once the master volume is opened up all the way.
If you just just barely turn up the input volume you'd still hear distortion.
I really can't explain it more technically than that, but you can always ask Bob a Gallien or any of the amp tech guys in the GK club threads (B-String for example).
If you just just barely turn up the input volume you'd still hear distortion.
I really can't explain it more technically than that, but you can always ask Bob a Gallien or any of the amp tech guys in the GK club threads (B-String for example).
