MOSFET amp emulator and MOSFET Mu Amp

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MOSFET amp emulator and MOSFET Mu Amp

Postby POTL » 26 Jun 2017, 23:30

Hello
Last time I built a lot of amps in a box using JFET transistors
And remembered that when I was building the Box Of Rox, the Catalinbread RAH / WIIO sound was more saturated (albeit a bit noisier)
Tomorrow I want to collect a trial layout using MOSFET, you can share your experience in creating such schemes
In particular, is it interesting to create an analog of Mu Amp or how to replace the second tube in the circuit (V2A + V2B) correctly?
Since with MOSFET behave differently than JFET I'm not quite sure how to act properly.
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Re: MOSFET amp emulator and MOSFET Mu Amp

Postby POTL » 26 Jun 2017, 23:32

If in nature there are schemes besides Zvex / AMZ / Catalinbread I would be glad if you share
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Re: MOSFET amp emulator and MOSFET Mu Amp

Postby FuzzMonkey » 27 Jun 2017, 04:35

This may help you in terms of a MOSFET Mu Amp:

http://www.muzique.com/news/superhot-mosfet-boost/

FYI, V2a is the second gain stage (or third gain stage if plugged into the 'High Sensitivity' input); V2b is a cathode follower (or buffer) to drive the tone stack that follows it. It's not a Mu Amp stage. I hope this helps?

For this message the author FuzzMonkey has received thanks:
POTL (27 Jun 2017, 12:18)
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Re: MOSFET amp emulator and MOSFET Mu Amp

Postby POTL » 27 Jun 2017, 12:18

Thanks :thumbsup
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Re: MOSFET amp emulator and MOSFET Mu Amp

Postby FuzzMonkey » 27 Jun 2017, 22:30

Glad to have helped.
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Re: MOSFET amp emulator and MOSFET Mu Amp

Postby POTL » 28 Jun 2017, 00:19

Collected today
In general, I detected one problem mu amp the bottom transistor is very hot, after 10 minutes of work I decided to disassemble the circuit and felt the transistor was very hot, like it was grilled
:cry:
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Re: MOSFET amp emulator and MOSFET Mu Amp

Postby FuzzMonkey » 28 Jun 2017, 10:30

POTL wrote:Collected today
In general, I detected one problem mu amp the bottom transistor is very hot, after 10 minutes of work I decided to disassemble the circuit and felt the transistor was very hot, like it was grilled
:cry:


I built this version a while back and had no problems. Let me try again tomorrow.
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Re: MOSFET amp emulator and MOSFET Mu Amp

Postby POTL » 28 Jun 2017, 12:59

FuzzMonkey wrote:
POTL wrote:Collected today
In general, I detected one problem mu amp the bottom transistor is very hot, after 10 minutes of work I decided to disassemble the circuit and felt the transistor was very hot, like it was grilled
:cry:


I built this version a while back and had no problems. Let me try again tomorrow.


I built without a resistor at the source of the bottom transistor, perhaps the problem is this.
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Re: MOSFET amp emulator and MOSFET Mu Amp

Postby POTL » 01 Jul 2017, 23:07

In general, if anyone is interested, I built and started this pedal
It works fine, but no more, Saturation is more, but it's too much, the sound is too colored (to someone it's a plus, to somebody's minus), a lot of clang (this is typical for MOSFET), it's a little bother, especially at high frequencies, or They are cut and clanking is acceptable but the sound is deaf or the sound is bright, but the clang is too much, the balance is hard to find.
In general, the sound is like Box Of Rock.
In the drain, I used the trim, in the source resistors from the amplifier circuit.
Perhaps the result would be better if I used smaller values ​​at the source, as is done in Box Of Rock.
For myself, I concluded that JFET is still better, Sound balanced, more natural, not colored
At least it became clear why almost all manufacturers use JFET and not MOSFET.
Thanks to everyone who replied
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