DSM OmniCabSim

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Re: DSM OmniCabSim

Postby bajaman » 02 Nov 2018, 10:21

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

baja omnicabsim rev 1.png


this graph shows the response with the controls set as above

graph baja rev 1.gif
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Lithium_Grim (02 Nov 2018, 10:41)
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Re: DSM OmniCabSim

Postby phatt » 02 Nov 2018, 13:56

Thanks Bajaman,, you do good work mate. :hug:
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. :thumbsup
Phil.

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Re: DSM OmniCabSim

Postby phatt » 02 Nov 2018, 14:07

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,, :secret: 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.
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Re: DSM OmniCabSim

Postby temol » 03 Nov 2018, 20:52

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.
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Re: DSM OmniCabSim

Postby temol » 04 Nov 2018, 10:20

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.
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Re: DSM OmniCabSim

Postby bajaman » 04 Nov 2018, 11:53

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 :wink:
baja omnicabsim rev 2.png

cheers
bajaman
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Re: DSM OmniCabSim

Postby bajaman » 04 Nov 2018, 22:26

here it is with a balanced output option
baja omnicabsim rev 2 balanced output.png

cheers
bajaman
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Re: DSM OmniCabSim

Postby J0K3RX » 08 Nov 2018, 15:17

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

Postby phatt » Today, 12:55

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. :evil:

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. :D

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