Ok I have the full package of values of this thing.  I noticed that R.G. changed a couple of things on the original that Moeller did like adding some mods to the Bass/treble circuit and some substitutions here and there for harder to find parts.  SO what gives man!!!!!!!!!!!  You've changed the circuit so why can't you post a new AC30 sim pedal with your mods and let everyone else share in trying to build this thing.  It would be nice to have some input and experimentation of others here.  I thought since the circuit is not exactly like Moellers now with the few improvements made by RG that everyone can see it now provided RG doesn't mind showing off his ideas on the AC30 sim.  I mean aren't the two circuits different now with RGs improvs?!!!  :x

Copyright law in the US says that you must change the invention 30% as a minimum. In any case, the folks who received that circuit had to sign a non-disclosure agreement. It's very objectionable to me to see people go back on agreements.

-Peter

30%?  How would you measure that?  Don't put words in my mouth!  I didn't say break the agreement.  I mentioned putting the modified version up.  

Seriously, how would you measure a 30% change?  I would think in dealing with audio circuits that one is very subjective.  I mean one change in a part or value changes the sound 100%.  

I didn't sign no agreement but I did give someone my word.  Which is something pretty important to us Southern Country boys.

Also where can I reference that Copyright law 30% thing you mention.

I'm not putting words in your mouth brother. Just statin' my opinion.

I was told the 30% figure by Stanley Mouse who is one of those big 60's poster artists that did many of the famous rock posters. He and the other poster gurus "appropriated" a fair amount of artwork from other sources so he's "in the know".

http://www.mousestudios.com/gallery/skellroses_poster.htm

I think this one was originally from a book of Robert Frost poems. He colored it up.

As far as measuring 30%.... that comes down to how much you pay your lawyer.

Take care,
-Peter

Now that would be cool....
 Neat to see if it could be made to respond similarly to the way a tube AC30 does to a Rangemaster !!!

QuoteSO what gives man!!!!!!!!!!! You've changed the circuit so why can't you post a new AC30 sim pedal with your mods and let everyone else share in trying to build this thing.

It's a matter of principle. I realize that this will seem like splitting hairs but
(a) I have great respect for the technical prowess that went into the AC30 sim and the work that went into it. It's a far greater set of work than designing a MOSFET booster, for instance. Stephan set the terms for the use of his set of values, and did not ever post them publicly. Even though I did not sign a NDA with him and did not receive the secret values from him, I would respect his wishes. He earned it.
(b) I changed, enhanced, or offered alternatives only for things that were part of the publicly disclosed information. As such, I have no trepidation about telling people about the stuff I modified - and I did. For instance, Stephan made public statements about the circuits that let me compare the tone controls to those of a Vox AC30 TB and discover that he scaled the tone controls down in impedance as befits the lower voltages, and from that a way to more flexibly emulate the full range of adjustments of the AC30 sim, instead of having a fixed setting. The alternate parts were obvious to one skilled in the art; knowing a ZXY47 (for a made-up example) zener is a 4.7V 100mW pare, one can easily suggest a 1N4237 type as a replacement if the 1N4237 is also a 4.7V zener. My changes do not, in my mind, qualify as substantial enough changes to post the whole mess even if I had signed Stephan's NDA.
(c) I regard the publicly available material as a usable starting point for much more than an AC30 simulator. I think it's a clever way to simulate triodes, and it is an avenue of exploration that I will not cut off for myself by signing an NDA. By taking this position, I have satisfied my internal requirements for ethical dealings with the situation. I believe that I remain free to use the circuit concepts Stephan displayed publicly without restriction. In a manner of speaking, I believe the concepts are too valuable to piss away on just building an AC30 sim.
(d) Stephan's circuit as separate from the schematic drawings, etc. that he made is not copyrighted nor copyrightable. (Note - both Stephan's schematic , viewed as a work of art, and my PCB layout *are* copyrightable, and copyrighted. It's the circuit concepts that may not be protected by copyright.) If I encountered a version of that circuit that I did not have a hand in putting together, I would be ethically free to reverse engineer it, and do whatever I wanted with the information. Copyright includes the right to control derivative works. I believe the "30% changed" feature that was referred to is not correct. I believe all literary and artistic derivative works are controlled by copyright if there is even a small part of the original work. Even better, if you are about to do something that involves sailing that close to the wind, better get a lawyer's advice.

So: (a) I choose to respect his preference for an NDA (b) I changed only public parts, or parts I reverse engineered (c) I will not limit my future freedom of action and (d) Copyright law is not what is active here - it's trade secret law. I choose where I stand on trade secret law.

As an aside, the secret values are not that huge a deal. Someone skilled in the art could take Stephan's public work tinker and think a bit, and come up with the mystery values, close enough. But the concept is far more valuable than the specifics; I have the concepts, as freely given. There may be more there someday when I have time to mess with it.

I dig those posters man!  I love that kind of stuff.

Funny!  That 30% lawyer statement. :lol:

Well I was just wanting everyone with the skill to have a crack at this pedal and possibly make some other creations or maybe even make the pedal better.  I would dig a Fender Tweed Twin sim.  Which I thought could be hacked out of  this circuit.  But the guru clik once again rules here on the forum, I guess and another great circuit will never be updated or recreated into something greater or better.   :cry:

It just kills me to wonder what some of the great minds here could cook up from that circuit.  
:cry:
[/quote]

Quote from: Bluesgeetar...But the guru clik once again rules here on the forum, I guess and another great circuit will never be updated or recreated into something greater or better.   :cry:

Guru clik??? Not here man.... everyone is equal here. This is about respecting the work of the author who doesn't want the info made public.

There's nothing stopping you from doing a detailed circuit analysis of an AC30 and building your own pedal from it. It's a tall task to do it to the depth he did, but it's pretty basic task over all.

If you want a tweed sim the AC30 sim won't help you much. Check out the Fetzer Valve from Runoffgroove to see how to get started on that adventure. Next check out the "eighteen", the Matchbox, and the Supreaux for more complete emulations including some speaker emulation. Next on the list would be to check out Doug Hammond's Meteor and compare that to a real 'Wreck.

You can see that it's not too hard to make a simulator. Make a better one, or better yet, make the one that you want! you could always release it like the 'Groove folks did and hope that others will improve it somewhere along the way or use it as inspiration to make yet another circuit.

I scanned the US copyright law and didn't see 30% mentioned by number, but I can tell you for sure that after almost 40 years of making event posters, Stanley Mouse and the other big poster artists have the details of how copyright works in the real world.

Take care,
-Peter

So, a 30% change would mean it would come out as an AC20 or AC40, right?  :lol:

Sorry, couldn't resist.

I think it depends on the channel, a 30% change to the top boost channel would be the AC40 and the regular channel would be the 20.  

Meanwhile, at the runoffgroove.com proving grounds...

http://runoffgroove.com/voxAC30TB.mp3

Quote from: B TremblayMeanwhile, at the runoffgroove.com proving grounds...

http://runoffgroove.com/voxAC30TB.mp3

Haha! When I first saw this I missed the ".mp3" file extension and assumed it was another emulator. I thought, "Oh no, those Runoff boys are at it again!":-)

Doug

Quote from: R.G.But the concept is far more valuable than the specifics;

And I would say that applies across the board, on this board. A good example is what the  Runoff Groove guys are doing with their emulators.

But the idea that "it is better to teach a man to fish..." will be buried under the next wave of requests for the xyz schematic that is being cloned.

Doug

What about this schematic? This is the preamp of the AC30, I think it will be easy to change it in a amp emulator.
http://www.blueguitar.org/new/schem/vox/ac30_pre.gif

Don't look here.....wonder what  this is....hmmm...... (alt+p)

sorry, no one likes an ass but I couldn't resist :oops:

Oh well, can't make the picture work, nevermind. :shock:

IIRC, Stephan sold his design to a commercial manufacturer, yes/no?

So, does anyone know anything about who he sold it to and when "THE" commercial version might become available?

~ Charlie

Could be the box discussed in this thread

http://www.diystompboxes.com/sboxforum/viewtopic.php?t=21877

Timing seems right. etc.

Quote from: B TremblayMeanwhile, at the runoffgroove.com proving grounds...

http://runoffgroove.com/voxAC30TB.mp3

Patience, Grasshopper.  The time is near.

This has been in the works for a couple of weeks now.
Along with a few other circuits (cue the mysterious-sounding music)...

Quote from: Bill Bergman Don't look here.....wonder what  this is....hmmm......

http://www.freewebs.com/elroy2/ac30%20sim1s.jpg

sorry, no one likes an ass but I couldn't resist :oops:

Very nice Bill! (or should I say Elroy)

If you cut-n-paste the address just like a geocities link it works. For off-site image hosting photobucket.com looks like a good way to go.

Take care,
-Peter