Organ Reverb and Chorus Effects

Hardware questions and issues with the FV-1

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Zetopan
Posts: 7
Joined: Tue Jan 13, 2009 1:05 pm

Organ Reverb and Chorus Effects

Post by Zetopan »

I must explain that I am hearing impaired; I can only hear sounds up to
3KHz and I am totally deaf to sounds at 5KHz and above. I am also not
musically inclined, hence these acoustically related questions.

(1)
Would the default programs in the FV-1 provide for suitable Reverb and
Chorus effects for an electric organ. My daughter plays an electric organ
that I built about 30 years ago and I would like to add Reverb and Chorus
effects to it, but being musically illiterate and hearing impaired I would
most likely be unable to determine if this is a reasonable starting point
without a some assistance from someone who has functional hearing
and is musically literate.

(2)
If the builtin programs in the FV-1 are unsuitable could you suggest some
starting programs for me. I'm very familiar with DSP so programming the
FV-1 is a very reasonable task for me. Although I must also point out that
your documentation is lacking and the FV-1 assembly code pneumonics
are unintuitive. It would benefit users if you explained what each of the
pneumonic acronyms stands for. Some are obvious (
frank
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Joined: Wed Oct 19, 2005 12:26 pm
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Post by frank »

Hi Zetopan

(1)
Most likely the built in reverb and chorus in the FV-1 will be fine. Reverb is a very subjective effect, what one person loves another may dislike. If it is close but needs some adjustment the source for the effects are all available on the Spin web site.

(2)
All the source for the built in effects along with some others are available on the Spin web site so feel free to grab a copy and experiment with them as a starting point. On the pneumonics, I guess they make sense to me as I've been designing DSPs for pro-audio since the early 90's and we've used our own pneumonics based more around the desired function (i.e. WRLX used for a low shelf) than the literal operation. Takes a bit to get used to but makes sense after a bit.

(3)
Contact the distributor for your area for boards and pricing http://www.spinsemi.com/distributors.html

(4)
There are a number of DIY people using the part and a few have released their board designs. Check http://www.diystompboxes.com/smfforum/ for some ideas.

(5)
Feel free to mod the mixer design and post it.
Frank Thomson
Experimental Noize
Zetopan
Posts: 7
Joined: Tue Jan 13, 2009 1:05 pm

Post by Zetopan »

Frank:

(1)
OK, thank you. I did not know if there was anything specific to guitars
or other musical instruments that would be bad for electronic organs in
your reverb and chorus algorithms.

(2)
As I previously stated, an explanation of what each pneumonic acronym
stands for would be useful in your documentation. I think that it would
also be a good idea to generally not assume that your user audience has
spent the same time (or even any time) in audio DSP (my experience
is in computer graphics, image processing, multi-GHZ spectral analysis,
etc). For example: "WRLX used for a low shelf" does not explain anything
to someone (like me) who does not know what is meant by "low shelf" in
an audio context. I have low and high shelves in my shop, but not in my
DPSs. A pointer to a website with audio DSP terminology could provide
some education for your similarly uninformed readership, if it's available.

(3)
The US distributor website does not seem to have anything online in
the form of information or ordering capability; only a phone number
and (potentially) an email address. I sent some email.

(4)
Thank you, I will check that "diystompboxes" web site out.

(5)
"Feel free to mod the mixer design and post it."
Thank you. I actually thought of that after I had posted my questions
when I should have thought about it before posting.
frank
Posts: 1244
Joined: Wed Oct 19, 2005 12:26 pm
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Post by frank »

A good site to read the basics of different effects, filters, etc. is http://www.harmony-central.com/Effects/ ... ained.html

Another good DIY site is http://www.generalguitargadgets.com/ Boards, kits, schematics, etc. I don't think they have an FV-1 based unit but they have lots of other effects.
Frank Thomson
Experimental Noize
Zetopan
Posts: 7
Joined: Tue Jan 13, 2009 1:05 pm

Post by Zetopan »

Frank:

Thank you, I will check both of those sites out.
Markus
Posts: 12
Joined: Fri Oct 26, 2007 2:03 am

Post by Markus »

A stompbox based on FV-1 is available here: http://www.tonepad.com/project.asp?id=68
But I wonder about the input sensitivity of this board. Shouldn't there be an input gain stage (with gain > 1, especially if you want to use it with a guitar)? Otherwise, you could get high noise level. Is it right, Frank?

Mark
frank
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Joined: Wed Oct 19, 2005 12:26 pm
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Post by frank »

The Tonepad board is a nice stereo board, you definitely want to buffer the input such that a maximum input signal creates a maximum signal to the FV-1 for best noise performance. The problem here is that guitar outputs can vary greatly (80mV to 1V) so a variable gain input would be desirable. I would probably pair the board with one of the preamps also at Tonepad.
Frank Thomson
Experimental Noize
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