DSM OmniCabSim

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Anjang
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Post by Anjang »

its work for Guitar and Bass ??

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J0K3RX
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Post by J0K3RX »

Anjang wrote:its work for Guitar and Bass ??
https://www.youtube.com/watch?time_conti ... lBLAt-1bq4

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temol
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Post by temol »

What's the proper wiring of the GND lift with balanced output? Simple swith disconnecting pin1 from GND is good enough? I've also seen R and C in a different configurations along with a switch.
gnd_lift.jpg
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Dsmnoisemaker
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Post by Dsmnoisemaker »

I used both..both works..I think the one with the cap and resistor is more "legal" :D

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temol
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Post by temol »

Thank you for the reply Daniel.

Here is my version of the sim, boxed and almost ready (I have to wire GND switch) .
IMG_9100_600.jpg
IMG_9101_600.jpg
IMG_9102_600.jpg
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Post by Dsmnoisemaker »

Be aware that some xlr jacks will have a chassis ground connection which will defeat the ground lift.

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Post by lukatosh »

Hi Daniel, Lucas here...from Chile. (Escribo en inglés por si alguien más se anima a responder).

may i ask some questions about your design?

What about using phantom power?

What would be the values of the resistor and capacitor in the "ground lift" arrangement? Different values are used on different schematics even when (apparently) they do the same function.

what about the power rating of the resistor? Here i'm looking at a PCB of a preamp that has XLR out and there is a 49R9 resistor (SMD) tied to pin 1 of the XLR jack

http://sound.whsites.net/p35-f2.gif
http://www.hansenaudio.se/Active%20DI%20box%201975.jpg
http://www.hansenaudio.se/Active%20DI-b ... ematic.png
https://i.warosu.org/data/diy/img/0008/ ... 357746.gif
https://www.prosoundweb.com/images/uplo ... igure6.jpg


Muchas gracias!!

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plush
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Post by plush »

lukatosh wrote:
What about using phantom power?
Hi Lukatosh

Based on my experience, most phantom power sources do not provide enough power for your preamps/cabsims to operate properly.

Resistor+cap @ ground lift is essential if you are using phantom power. Total ground lift will basically remove ground connection and phantom power won't work.
Knowing, that there should be DC signal path, the resistor must be of pretty low value, ~10-100R. Cap usually ~100n.
The purpose of the resistor is to lift the part of the circuit, preventing stray currents, which are pretty low at this point. Very typical implementation, changing the values won't make much difference.

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temol
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Post by temol »

Here is the build document for the BAJA version of the Omnicabsim - omnicabbaja-xlr_build_doc.pdf

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Ben N
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Post by Ben N »

I see the space advantage of using a pair of quads, obviously, but it seems to me that NE5532 would make more sense for outputs--single, balanced or headphone. Given that this puppy may well be last in a signal chain before amp/pa/desk/interface, it ought to have a little line driving oomph.

BTW, Daniel, that 2015 video is of this version, right? Because, whatever its limitations, it sounds mega. :applause:

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Post by Dsmnoisemaker »

Yes is that version..:)

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Post by fersynes »

I just built the bajaman version and it sounds very great! A friend of mine have an origilan deluxe version that I will take borrow to compare.
The only thing I found is that the gain is too much that saturates the input of my presonus audio interface so easy. I tested with a POD HD 500X direct to the audiobox and run it trough my studio monitors. Trust me, you don´t want to take it of!

I will reply after compare them, thank you for this great pedal!

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Post by fersynes »

O compared them and there are a lot of difference between them. First, whith the same parameters the bajaman's always sounds with less body, anyway with some tweak You can reach very similar results. Second, bajaman's have considerably a LOT of More gain. For the last, the deluxe version have all single potentiometers. I am out of city right now but next week I Will upload some pictures

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Ichabod_Crane
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Post by Ichabod_Crane »

I'm following the veroboard version here: http://tagboardeffects.blogspot.com/201 ... absim.html
It's still not verified and seems to have some problem. I checked quickly and the veroboard layout follows the same schematic on PedalPCB: https://www.pedalpcb.com/docs/UniCab.pdf
I don't know if the PedalPCB version is an exact clone of the original DSM OmniCab.
If someone built the veroboard layout just tell us, please. ;)

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Post by fersynes »

Here are some pics of an original omnicab. The first noticeable difference is that de mid pot is different with the pedalpcb version but the others are right. Pretty different with the values of bajaman´s version

https://www.dropbox.com/sh/iuyvnbn8c5qp ... XLuqa?dl=0

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Ichabod_Crane
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Post by Ichabod_Crane »

Thanks! ;)
I don't know well the Bajaman' version because I didn't follow all the discussion, maybe I can read it soon.
I'd like to know if the PedalPCB is a real clone of the DSM, at least the main circuit of the sound. If just the Mid pot has a different it could be just a little detail we could modify.
I have interest in the tagboard veroboard laout because probably I may build that, usually I don't buy pcb.

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Post by Lithium_Grim »

fersynes wrote:Here are some pics of an original omnicab. The first noticeable difference is that de mid pot is different with the pedalpcb version but the others are right. Pretty different with the values of bajaman´s version

https://www.dropbox.com/sh/iuyvnbn8c5qp ... XLuqa?dl=0
Is this the same "era" version that the trace was based on or is it more recent?

fersynes
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Post by fersynes »

Lithium_Grim wrote:
fersynes wrote:Here are some pics of an original omnicab. The first noticeable difference is that de mid pot is different with the pedalpcb version but the others are right. Pretty different with the values of bajaman´s version

https://www.dropbox.com/sh/iuyvnbn8c5qp ... XLuqa?dl=0
Is this the same "era" version that the trace was based on or is it more recent?
This is the Deluxe version, more recent with aux, phones out, etc

Fabiosg
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Post by Fabiosg »

Pls, what is the phones amp IC ? I can't read it. Thank you.

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Post by fersynes »

Fabiosg wrote:Pls, what is the phones amp IC ? I can't read it. Thank you.
This is a LM386 but now they are using a MAX9722 for better

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