freestompboxes.org

I made a few adjustments - used dual ganged control for high response, reset mid scoop to 400Hz, punch to just above 1kHz and other minor adjustments to more closely emulate real speaker cabinet driven by tube amplifier. Only my version - not meant to replicate the DSM Noisemaker pedal - you are most welcome to try it and let me know what you think of it.
cheers
bajaman
this graph shows the response with the controls set as above

Thanks Bajaman,, you do good work mate.
I've just simulated the original as well as your previous mods and it looks interesting.
So when time permits I'll lay this out on the BBoard an see how it sounds.
Years back I built a cab sim from the JTM 30 Amp but it was a bit noise prone.
This one looks to have a deeper bass slope so I'll have to try it out.
I also built a modified Nobels cab sim which I've used now for ages and it works well but could be improved.
Give me a week or so and I'll give you some feedback.
Phil.

Lithium_Grim wrote:

bobbass4k wrote:
I got it bread boarded and on vero and on both it really suck the distortion/overdrive out of the signal. Do you have any pics from the pedal guts left so we can double check the values?

That is not necessarily a bad thing,, The cab sim will alter the distortion but that is the whole point.
Example; When using a flat response As you crank up the distortion the guitar will very quickly lose note definition.
By focusing the energy into a narrower band of frequencies you retain better definition.
so with a the cabsim engaged you can run your OD harder and get a much better sound that cuts through.
But yes if you have a wrong value it might be a problem.
Phil.

So, I've breadboarded bajaman's circuit. I like it. I'll try to record some samples.
ps. too many knobs. There is a constant temptation to adjust settings. This one... no, maybe this one..

T.

Looks like I have some kind of breadboarding mistake.. or not. I have a constant peak around 1.5-1.8kHz. There's also huge amount of highs starting from 1/2 of the "high response" potentiometer range.
I attach couple of frequency response plots. Firs one - all knobs @ noon. Last one - "high response" @ 15 o'clock, resonance @ max, cab size @ max.

T.

not a total redesign - just changed the 100k pots to 10k and the 500k pot to 50k (and re-scaled the capacitor and resistor values)- same response characteristics as my last rev 1 cheers
bajaman

here it is with a balanced output option cheers
bajaman

bugg doesn't waste any time..
https://www.pedalpcb.com/product/unicab/

Well I assembled *Baja's* circuit Rev2 on my BBoard and it's interesting.
My observations;

One thing that stood out immediately was the *Resonance pot* although useful was very much dependent on the position of *Cab Size pot* they interact too much. I think the Cab size pot can be replaced by a fixed value, maybe 47k.

The *High Resonance* just expands the bandwidth from about 2kHz way past what is really useful for a cab sim. Maybe if it only went from 2kHz up to 5kHz would be better.

The *Punch control* is useful but depends where the *High Res control* is set, high res at wide bandwidth is too much top end.

The mid dip seems a bit wide in bandwidth robbing a lot of volume which forces you to have to readjust gain.
So you end up doing a lot of knob twiddling which is not a good thing for live players.
Of course this is only one day of testing so I will get back to it as I may have made a circuit mistake.
If I was to build this I would delete Cab size pot for sure. One less knob to confuse me.

Either way it has given me some ideas so thanks guys, all very useful stuff.
Phil.

Hey!!! i got you!!! what are you doing stealing my designs you bstrds!!!

Just kidding..it´s quite flattering that you have been making such an effort to reverse engineer the Omni.. Lucky for me it´s the first version, that i don´t make anymore (the following versions are quite different..but overall the same concept)..

OTOH, I just don´t like that much that pedalPCB is making money out of my design (a small fee would have been nice), and i would be very sad if this thread facilitates the release of a JHS or Vertex cabsim.

The Omni pays my bills and feed my kids, so please be respectful and fair. It´s not easy to make a living out of this, and much harder being in Chile.

BTW for the headphone amp, first i used an LM386..Loud as hell, but it was too noisy.. i use a MAX9722 headphone amp chip now..much better.
The through takes the signal from the first buffer..that´s all.

phatt wrote:Well I assembled *Baja's* circuit Rev2 on my BBoard and it's interesting.
My observations;

One thing that stood out immediately was the *Resonance pot* although useful was very much dependent on the position of *Cab Size pot* they interact too much. I think the Cab size pot can be replaced by a fixed value, maybe 47k.

The *High Resonance* just expands the bandwidth from about 2kHz way past what is really useful for a cab sim. Maybe if it only went from 2kHz up to 5kHz would be better.

The *Punch control* is useful but depends where the *High Res control* is set, high res at wide bandwidth is too much top end.

The mid dip seems a bit wide in bandwidth robbing a lot of volume which forces you to have to readjust gain.
So you end up doing a lot of knob twiddling which is not a good thing for live players.
Of course this is only one day of testing so I will get back to it as I may have made a circuit mistake.
If I was to build this I would delete Cab size pot for sure. One less knob to confuse me.

Either way it has given me some ideas so thanks guys, all very useful stuff.
Phil.

Yup.. first version needed to be improved..

Dsmnoisemaker wrote:OTOH, I just don´t like that much that pedalPCB is making money out of my design (a small fee would have been nice)

Hey bud, I'm not a monster (nor am I getting rich off of it), shoot me an email.

bugg wrote:

Dsmnoisemaker wrote:OTOH, I just don´t like that much that pedalPCB is making money out of my design (a small fee would have been nice)

Hey bud, I'm not a monster (nor am I getting rich off of it), shoot me an email.

Sir, you are a gentlemen. I´m glad you contacted me.

i found this

mailinator wrote:i found this

Arghh..at least they should make them prettier...

Hi bajaman,

can you suggest what type of potentiometer is best suited to your cabsim project (rev2) ? A or B for mid scoop, resonance, punch?

T.

temol wrote:Hi bajaman,

can you suggest what type of potentiometer is best suited to your cabsim project (rev2) ? A or B for mid scoop, resonance, punch?

T.

A, B, B
cheers bajaman

I guess the tapers stay the same so Mid, Cabsize and Gain are A rest is B

Thank you guys!

Rev2 with xlr out (xlr not tested yet). Fits into 125B or Gainta BS13. With BS13 there's no chance to fit the xlr socket. No problem with 125B.



T.