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Mad Professor 1

Posted: 09 May 2017, 03:12
by rmroza
Man, I was searching and looked up Top pedals to get VH tone (and late 70's/early 80's) and this pedal came up at the top of the list.

I looked at the videos and it sounded amazing. I ordered one to try out andsure enough, it really does mimic the tone in a clean amp!

I took a quick look inside and discovered a myriad of things from the SpinSemiconductor FV-1 reverb chip, NE5534 Op Amps, 2N7000 MOSFETs, and BC550 BJTs!

Does anyone else have any information on this pedal? If so, please post. If not and in any event, I may take this apart and trace it completely to understand the design.

The reverb is nice, but I'd like is seggregated from the distortion. Likewise, I'd like some tone controls added to adjust the TMB. I wonder if say the Mighty Red Distortion pedal is the same distortion, but without reverb or a variation??!?

Stay Tuned!

https://www.mpamp.com/factory-pedals/1-factory-pedal/

https://youtu.be/8L2cF_89HdM

Re: Mad Professor 1

Posted: 09 May 2017, 19:29
by caspercody
Yes, please take it apart and trace.

I have not found any schematics on the web for this pedal.

Re: Mad Professor 1

Posted: 09 May 2017, 21:16
by FuzzMonkey

Re: Mad Professor 1

Posted: 02 Jun 2017, 17:07
by howmuch
rmroza wrote:... I may take this apart and trace it completely to understand the design.
It would be excellent if you did. :applause:
And if you need any help, just give us a shout.
That pedal sounds really good.
rmroza wrote:... I wonder if say the Mighty Red Distortion pedal is the same distortion ...
Not sure if the Mighty Red Distortion is the same as the BJF/Bearfoot Dyna Red Distortion, but it probably is, so looking at the schematic here :
http://revolutiondeux.blogspot.co.uk/20 ... rtion.html
the Dyna Red only has one op-amp and one JFET, so it's probably quite different.

Re: Mad Professor 1

Posted: 04 Jun 2017, 07:48
by BJF
Hi there,

I can say this, that if you read the product text it says the circuit has two overdrive stages. MP was not keen on my designing a circuit like this from ground up….though I might have preferred to, but they preferred I’d use building blocks from proven designs I had made.
The circuit uses a low level, slow slope expander to minimize noise…and you might also then figure that the absolute forte of AD797 is ultra low noise….there are a number of noise reducing tricks used through out circuit- note that you can derive the envelope of a signal, for expansion detection from a point where signal is strong and not necessarily from the output of circuit.
There were problems with the 2000 first produced units ranging from one transistor stage being biased wrongly to expander being hooked up in three different ways all being wrong but in latest iteration of ONE all parts of circuit should be hooked up correctly and with the latest iteration you should be able to get a good representation of the intended sound through a clean amplifier and the noise reduction circuits should allow you to get this sound at a rather loud level without excess noise and if all parts are hooked up correctly in the circuit you should also be able to turn down volume control on guitar for a less distorted sound without hick ups from expander or dead band response from any of the stages.

There is a built in reverb supplied by the internal FV-1, much because this sound intended craves reverb to sound authentic. Now you can certainly write a custom algorithm onto the FV-1 itself without having to store it in an external memory and that saves pcb space- however my digital designer was not involved in the development of ONE and neither in any MP product much because his views on the Red Cable- therefore there are no digital designs made by BJF for MP.

Typically when designing heavily saturated distortion cascaded stages show the best noise performance and multiple distortion knees can certainly aid dynamics of distortion even in a highly saturated circuit.

Important for the authenticy of this sound is the processing of treble and as a side note of this I know a technician in Florida that collects waveforms at the output of amplifiers as a signature of sound from various artists and he has a rather extensive library of such waveforms-it follows that exact eq is a vital part of signature.

The Treble control of ONE can fairly easily be rewired into a three band T-type eq as a hint for anyone who wants to rebox ONE and extend controls.


At your service
BJ
BJF Electronics

Re: Mad Professor 1

Posted: 04 Jun 2017, 14:37
by howmuch
Hi BJ,

Thank you for your generous input here and elsewhere on this forum. Always a great insight.
I don't suppose you could talk us through your aims as you went through the design process, in terms of distortion/harmonic characteristics and that all important EQ that you mentioned.
Could you explain the EQ needed to get this particular sound?

BTW - Great job on this pedal.

Thanks

Re: Mad Professor 1

Posted: 06 Jun 2017, 10:56
by modman
Fanboy paradise again?

Re: Mad Professor 1

Posted: 20 Jun 2017, 14:52
by howmuch
rmroza wrote: Stay Tuned!
Yep, still tuned...

If you've changed your mind, any chance of some gutshots?

Re: Mad Professor 1

Posted: 21 Jun 2017, 08:19
by modman
That's why BJ posts here, to try and keep off the member from tracing.
Probably the guy is contacted in pm not to publish.

Re: Mad Professor 1

Posted: 27 Jun 2017, 16:35
by rmroza
"Yep, still tuned...

If you've changed your mind, any chance of some gutshots?"

No, no change mind, it's Summer and just busy as fuck! Just got done with 2 amps and 2 pedals before moving to this ("1" and Mighty Red). Going on vaca 6/30 thru 7/17, so if not done before then will be a few weeks.

Re: Mad Professor 1

Posted: 27 Jun 2017, 22:37
by bajaman
Hi modman
That's why BJ posts here, to try and keep off the member from tracing.
Probably the guy is contacted in pm not to publish.
I have to disagree with you on this one - in my experience BJF has always been very helpful with regards to explaining the details of some of his designs, however this is not a pedal produced by him but Mad Professor :wink:
In much the same way as any designer is always happy to explain their design process, the owner of the intellectual property in this case is not Bjorn but the MP business. As explained by BJF, MP was not happy with him designing something from scratch and i think that this may have been one of the reasons that Bjorn no longer has any dealings with MP to my understanding :secret:

This is a forum where we all learn a little from each other - if rmroza is willing to take some high res photos of both sides of the pcb and supply component values as much as possible then i am sure that one of us will be more than willing to help trace a schematic to enable greater understanding of how the ONE works and to gain some further insight into Bjorn's design process. :thumbsup

Of course, without the FV-1 programming data the reverb will be a little more difficult but not impossible to determine :wink:
Always at your service and having fun :D
cheers
bajaman

Re: Mad Professor 1

Posted: 29 Jun 2017, 16:50
by rmroza
"if rmroza is willing to take some high res photos of both sides of the pcb and supply component values"

I have no issues with this. I took it AND the Mighty Red apart last night!

I took Hi-Res photos, but something happened to many of them on my cell and were not able to dump them!! :O

I will have to retake and post tonight. I'm on vacation after work tomorrow straight up after work, so this will not be a quick thing beyond the initial dump of images.

As I said, I'm really not concerned with the reverb at all to tell you the truth. Just use Reverb of choice and set the levels. What I want to know if the distortion pedal design to get the tone and compare it to Mighty Red. I think them may be one and the same and just reverb added to "1" with some voicing tweaks. We will find out.

Re: Mad Professor 1

Posted: 30 Jun 2017, 13:39
by Ice-9
Looking forward to seeing some photo's, I doubt the FV-1 is anything other than a standard program built into the IC although I could be wrong. I do know the EVH 5150 combo also uses the FV-1 for reverb and uses the internal program so if its good enough for Eddie !

If you are able to post the pics before your vacation it might be all traced when you return. :D

Re: Mad Professor 1

Posted: 01 Jul 2017, 02:49
by caspercody
First time actually having a pedal that is not traced yet. Here are some pictures to hopefully get started with.

Thanks
Rob

Re: Mad Professor 1

Posted: 04 Jul 2017, 02:03
by caspercody
Pictures of pots

Re: Mad Professor 1

Posted: 04 Jul 2017, 09:56
by howmuch
I notice on Spin Semiconductor's "Free DSP Programs" page that there's a free "Reverb plus flange plu 4-pole low pass" (sic) program for the FV-1.
Now, if there was a "Reverb plus Flanger plus Phaser" program in this pedal, with the Flanger and Phaser switched via external control footswitches - the ultimate VH all-in-one pedal.
How about it MP/BJ?
Any clever FV-1 programmers here?

Re: Mad Professor 1

Posted: 04 Jul 2017, 11:09
by Ice-9
howmuch wrote: Now, if there was a "Reverb plus Flanger plus Phaser" program in this pedal, with the Flanger and Phaser switched via external control footswitches - the ultimate VH all-in-one pedal.
How about it MP/BJ?
Well that is totally doable, you would have to remember though that you could have reverb/flanger or reverb/phaser, but not likely reverb/flange and phaser all at the same time, but then I think that's the way it should be as I can't think of any VH songs where I would need both flanger and phaser at the same time.

Sounds like a great VH project to me. :hmmm:

Re: Mad Professor 1

Posted: 06 Jul 2017, 20:17
by Ice-9
Having looked at the pictures supplied by caspercody this won't be an easy trace to follow and get right just from pictures, but so far looking at the bottom pcb what I can see is from the input jack the signal goes into the first op amp stage, an NE5534 single op amp which is non inverting and has 2 SMD leds in the negative feedback loop (bottom left next to the footswitch in the picture).

The signal from here then looks like it goes into the NE570D compander so a clue on this config might be in some of the other pedals that have been traced.

The top right in the picture shows another NE5534 which again is a non inverting op amp which looks like 2x 2n7000's mosfets are used in a distortion hard clipping to ground.

That's it for now.

Re: Mad Professor 1

Posted: 08 Jul 2017, 17:25
by Ice-9
@ Caspercody, can you post the values of the pots please, I can't make out all the pot values from your picture,

BROWN =
PRESENCE =
REVERB = A50K
LEVEL = B50K

Re: Mad Professor 1

Posted: 10 Jul 2017, 01:27
by caspercody
Brown = C50K

Presence = B50K

Please let me know what else you might need?

Thanks
Rob