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pedalguru
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Post by pedalguru »

Maybe you can tell me, where there is a current mirror used in the Retro Channel design ?


It speaks volumes that neither you nor mictester can see it for yourselves.  Maybe it's because it's something you haven't seen before, and you are therefore not familiar with it?

But wait, doesn't that defeat your argument that it is in no way a novel circuit topology?  Clearly in some part it must be, otherwise, why so confused?

And please enlighten us mictester:  How well does the original MKII tonebender circuit work if you simply replace the germanium transistors with silicon transistors?

Exactly the same, but with no temp issues?  Or perhaps, not too well, actually?

We both know it's the latter.  So then explain to us all how a bias scheme that makes it work correctly can be a waste of parts and battery current, as you claim.

On another note RnFr claims to build and sell pedals.
Under what brand?
Are these devices original designs or lifted designs obtained from this board?
It's a fair question I think.
Is it that you share ideas but don't sell designs shared here with the general public for financial gain, or do you have a company that builds and sells the designs of others?
If you do lift designs and sell for profit it would make you no better than the brands you profess to debunk would it?

Just a thought

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Post by pedalguru »

BTW, the Fuzz Face part is NOT temperature stabilized, only the first transistor stage, can you tell me why ?

The fuzz face circuit topology uses negative DC feedback to maintain bias stability, whereas there is no DC negative feedback around the first transistor stage, making it prone to DC bias drift with temperature.

You knew that and were just testing me, right?

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Post by jreeves47 »

Dude it's a silicon tonebender

Go dazzle tgp with your germanium voiced circuit theory current mirror topology.

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Post by minnow »

pedalguru wrote: Are these devices original designs or lifted designs obtained from this board?
It's a fair question I think.
Is it that you share ideas but don't sell designs shared here with the general public for financial gain, or do you have a company that builds and sells the designs of others?
If you do lift designs and sell for profit it would make you no better than the brands you profess to debunk would it?

Just a thought
RnFR's The Toe Cutter: https://www.freestompboxes.org/viewtopic ... 678#p39950
:secret: Please search - you've been advised before, a few times already, by a number of people, on a few different occasions.

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Post by tube-exorcist »

pedalguru wrote:
BTW, the Fuzz Face part is NOT temperature stabilized, only the first transistor stage, can you tell me why ?
The fuzz face circuit topology uses negative DC feedback to maintain bias stability, whereas there is no DC negative feedback around the first transistor stage, making it prone to DC bias drift with temperature.

You knew that and were just testing me, right?
No, I only know that if you build a Fuzz Face with BC108 and you touch the first transistor the collector voltage of the second transistor will drift. Not so much as with germanium, but it will drift. Try it for your own.
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Post by tube-exorcist »

pedalguru wrote:
Maybe you can tell me, where there is a current mirror used in the Retro Channel design ?
It speaks volumes that neither you nor mictester can see it for yourselves.  Maybe it's because it's something you haven't seen before, and you are therefore not familiar with it?
Therefore I asked a guru, but sadly no reasonable answer.
pedalguru wrote: But wait, doesn't that defeat your argument that it is in no way a novel circuit topology?  Clearly in some part it must be, otherwise, why so confused?
Not confused, only curious.
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Post by tube-exorcist »

One additional question for the guru:
When the duty-cycle of a square wave changes, does it have an effect on the sound or not ?
"I've noticed there's an inverse relationship between cost of gear and talent. If you need the most expensive gear to get decent tones, then you suck as a player."

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Post by pedalguru »

jreeves47 wrote:Dude it's a silicon tonebender

Go dazzle tgp with your germanium voiced circuit theory current mirror topology.


Dude, you started this whole exchange by making claims you ultimately could not substantiate.

Still can't, I take it?

Then why don't you dazzle everybody here: be a man about it and just admit that you have no proof to back up your claims, and publicly withdraw them?

Or you can just resort to name calling and diversion and hope the whole thing just goes away and people forget that you were called out and was unable to provide a meaningful response.

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Post by culturejam »

Aren't you the guy that was asking about a simple loop box?

viewtopic.php?t=13813

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Post by Seiche »

pedalguru wrote:Is it that you share ideas but don't sell designs shared here with the general public for financial gain, or do you have a company that builds and sells the designs of others?
If you do lift designs and sell for profit it would make you no better than the brands you profess to debunk would it?
Is there maybe another possibility? :roll:
pedalguru wrote:Just a thought
sorry, maybe you should keep your thoughts to yourself next time. thinking doesn't seem to be one of your strengths.
pedalguru wrote:And please enlighten us mictester: How well does the original MKII tonebender circuit work if you simply replace the germanium transistors with silicon transistors?

Exactly the same, but with no temp issues? Or perhaps, not too well, actually?

We both know it's the latter. So then explain to us all how a bias scheme that makes it work correctly can be a waste of parts and battery current, as you claim.
Please explain why "not too well" Mr. Guru, you seem to be quite knowledgable on the subject. Possibly defending your awesome proprietary design?

how about this? It doesn't work? A Tonebender seems to be military or spaceage technology if the same principals applied to make a si fuzz face work don't apply here. It's magic surely.

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Post by culturejam »

Oh well now, this sure does explain things. Looks like our guru shares an IP with another recent poster. :secret:
dupe
dupe

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Post by Seiche »

culturejam wrote:Oh well now, this sure does explain things. Looks like our guru shares an IP with another recent poster. :secret:
scrennie.png
Seiche wrote:thinking doesn't seem to be one of your strengths.
:roll:

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Post by tube-exorcist »

pedalguru wrote: Dude, you started this whole exchange by making claims you ultimately could not substantiate.

Still can't, I take it?

Then why don't you dazzle everybody here: be a man about it and just admit that you have no proof to back up your claims, and publicly withdraw them?

Or you can just resort to name calling and diversion and hope the whole thing just goes away and people forget that you were called out and was unable to provide a meaningful response.
Mr. Guru, did you start now to talk with yourself ?

I am still waiting for your answers....
"I've noticed there's an inverse relationship between cost of gear and talent. If you need the most expensive gear to get decent tones, then you suck as a player."

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Post by jreeves47 »

I PUBLICLY WITHDRAW MY CLAIMS whatever they were. Now run along and don't make me draw claims on you again!

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Post by pedalguru »

Glad you bring this up, because it basically is all you have been able to present to defend your position so far.  Ask yourself:  Does the original germanium design have a resistor from collector to base?  No.  Does the original germanium design have a resistor between emitter and ground?  No.  Would this somehow change the input impedance from the point of view of the guitar?  Yes.   Do things such as input impedance affect how a pedal sounds?  Yes.  Therefore, is it the best possible solution to replacing the germanium input transistor with a silicon transistor, if the objective is to make it sound exactly the same?

I'll leave you to figure that out for yourself.

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Post by tube-exorcist »

pedalguru wrote:Glad you bring this up, because it basically is all you have been able to present to defend your position so far.  Ask yourself:  Does the original germanium design have a resistor from collector to base?  No.
Yes, a virtual, it is inside the transistor. Ever heard about leakage ?
Does the original germanium design have a resistor between emitter and ground?  No.  Would this somehow change the input impedance from the point of view of the guitar?  Yes.
Yes, the emitter resistor will increase the input impedance. If it gets too high for you, you can simply add a resistor with the desired impedance at the input.
Do things such as input impedance affect how a pedal sounds?  Yes.
see above
Therefore, is it the best possible solution to replacing the germanium input transistor with a silicon transistor, if the objective is to make it sound exactly the same?

I'll leave you to figure that out for yourself.
I figured, and now I have another question:
If the input stage is so important for the sound, why don´t you ommit the Fuzz Face part ?

And yes:
If the collector voltage of the second transistor in the Fuzz Face part varies, does that have an effect on the duty cycle ?

Maybe you could be so kind and make some tests on an rectal-chanel pcb ? It is easy, you only need a cold-spray, a heating gun and an oscilloscope. Or should I do that for you and present the results ? I only don´t want that you will say: That´s a different circuit.

So what do you think will have more effect on the sound:
The input impedance, or the duty cycle of the square wave generated by the Fuzz Face part ?
"I've noticed there's an inverse relationship between cost of gear and talent. If you need the most expensive gear to get decent tones, then you suck as a player."

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Post by pedalguru »

Yes, a virtual, it is inside the transistor. Ever heard about leakage ?
Yes. But I've also heard that semiconductor junction leakage is usually represented as a current source, not a resistor. There is a big difference. Have you heard?
Yes, the emitter resistor will increase the input impedance. If it gets too high for you, you can simply add a resistor with the desired impedance at the input.
You think so? What about the non-linear input impedance presented by the BE junction? How do you compensate for the fact that the emitter resistor has linearized the transistor input impedance with yet another linear impedance?

The theory of operation of the input transistor is large signal. Your suggestion of a small-signal compensation will not hold up in practice.
If the collector voltage of the second transistor in the Fuzz Face part varies, does that have an effect on the duty cycle ?
All this harping on about the temp stability of the FF section: Be careful, because another position taken by your compadres is that Si circuits are already temperature stable enough that making claims of temp stability are redundant.

Are you now suggesting that there may actually be something to it?

Look, I think we can at least agree that the amount of drift for a Si FF is negligible for all practical purposes. You could add circuitry to make it sensibly zero drift, but you would be well beyond the limit of diminishing returns, and in this particular instance mictester would have a good case to claim the effort was a waste of parts and battery current.

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Post by mictester »

pedalguru wrote:BTW, the Fuzz Face part is NOT temperature stabilized, only the first transistor stage, can you tell me why ?
Yes - because you got the resistor values wrong!

What a maroon!
"Why is it humming?" "Because it doesn't know the words!"

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Post by pedalguru »

mictester wrote:
pedalguru wrote:BTW, the Fuzz Face part is NOT temperature stabilized, only the first transistor stage, can you tell me why ?
Yes - because you got the resistor values wrong!

What a maroon!

Er, I think you'll find I didn't actually write that to begin with.

Who's the maroon now?

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Post by coldcraft »

pedalguru wrote:

Er, I think you'll find I didn't actually write that to begin with.

Who's the maroon now?
this is true. pedalguru just recently learned how to properly quote.
Black Dynamite wrote:you need to shut the fuck up when grown folks is talkin.

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