Hughes&Kettner RED BOX CLASSIC

[George Giblet]

> Would a transistor based gyrator provide the same amount of boost /JMP-1/ as the opamp one?  This way the cabsim can be built around a single TL074.

I haven't tried the JMP-1 style gyrator using a transistor.  It looks like there should be no problem doing it though.

You could also use the other (more common) type of gyrator but you have to be careful that the non-ideal properties of the gyrator aren't changing things too much.  For the JMP-1 you would probably have to rescale the circuit so the feedback resistors were in thr 5k to 10k region.

[cg]

THANK YOU VERY MUCH George!MY simulations was maded by sofeware called circuitmaker use computer,and i will try you suggestion.

[MartyMart]

I made the Ed Rembold Marshall sim a while ago and thought is was OK.
It was a little "bottom heavy" but the rest of the tone was quite good.
The little Behringer Gi-100 DI/Cab sim is very nice sounding ...

MM.

[GFR]

I don't know if this is the same Behringer box, but...

If you're into dsp, there's an impulse response for the behringer Ultra-G direct box at the noise vault:

http://noisevault.com//index.php?option=com_remository&Itemid=29&func=fileinfo&filecatid=163&parent=category

You need a convolution plugin (more often used for reverbs etc) to use this.

Or you could simply do a FFT of this to have a look a the frequency response.

[bancika]

Anyone built one from V-Twin?

[Pauldebass]

Hi i built the mesa simulator, but it sounds like straight sound without simulation, no idea y, Green Paul

[PRR]

Welcome!

> i built the mesa simulator

What is the "mesa simulator"? Link?

[peterc]

The Mesa sim is the last image on page one of this thread, with the .22h inductor

[Rob Strand]

but it sounds like straight sound without simulation,

The cut-off frequency is higher than most sims so it could sound subtle.

Are you sure you have used 0.22H ie. 220mH.   This is a large value.  If you used 0.22mH it let a lot of highs through.

Beyond this you would need to tweak the design to suit your needs.  Something easy to try is to decrease the input 10k resistor to 6k8 or 4k7.  At least that will drop the cut-off.  I can't vouch for the how that will sound.  You could of course redesign the thing by changing the R's and C's but that's a whole new project.

[opacheco]

Here's some cabinet sims which includes the redbox2:

http://www.herby.kielce.pl/~piter/konstr/cabsims/schem/

Note it uses inductors which makes it inconvenient to build.

There's also some cabinet sims/amp sims at the 'run off groove' site:

http://www.runoffgroove.com/articles.html

For example,

http://www.runoffgroove.com/condor.html

As I recall, the last three filter stages are pretty close to the redbox and some of the other sim circuits (including stuff I've done myself).

(I think there's a name for restricting information based on country of origin......)

Dear George Giblet,
Do you have the RedBox schematic still?, I appreciate you help in order to get it!
Thanks
opacheco

[deadastronaut]

^ google it....its there.