Tuning to 432Hz

[WitchMaster]

Hi!

I have been tuning my guitars and synths to 432Hz instead of 440Hz. Is there a way to this on the Midibox SID? Thanks in advance!

[nILS]

Why would you do that?

Yes, that is possible. All you'd need to do is modify the values in SID_FRQ_TABLE in src/sid_frq_table.inc accordingly. Recompile, upload, yay.

[WitchMaster]

Ok, thanks for the quick answer.

Here is a link that will answer your question:

http://www.schillerinstitute.org/music/rev_tuning_hist.html

[WitchMaster]

Sorry nILS, I was studying the SID specs now and the inc file, I would be very thankful again if you can answer two questions. :)

Some values in the frequency table in the inc file differ from the SID specs, why is that, is that something I have to take into account when re-tuning? I know this is a VERY small difference but...

For example 0x0112,0x0122 vs 0x0112,0x0123

Secondly, the specs go down to 0x0112 (C0), but the inc file goes lower, do I need to change these, these notes are so low anyway aren't they?

Thanks for your patience!

[TK.]

The values of the original SID spec have rounding errors (consider that the spec has been written around 1982...)

E.g., take 274 for C0 as an example.

Multiplied by 12th root of 2 (=1.05946) makes 290.293, rounded: 290 and not 291

Thats btw. one of the reasons why MBSID sounds better compared to other SID synths ;)

It's your own decision if you want to re-calculate the lower frequency values as well. It isn't so much effort...

Best Regards, Thorsten.

[nILS]

Excel table + 3 minutes :)

[Smithy]

Why would you do that?

Take the 3 out of the number and you have your answer. :wink:

[WitchMaster]

Thanks a lot, yes, I figured later that it wouldn't take so much time when the formula was in the specs. Good to know about the rounding errors!

[WitchMaster]

Thanks for all the help, I got this working fine. I'm attaching the frequency table for A4=432Hz if anybody else wants it (probably not). :) This is for version 1 of Midibox sid, I don't know if this file is different for version 2.

sid_frq_table.inc

[X11]

hi im new in building the mbsid.

have my other gear also tuned into this frequency.

so this was nice to see:)

thnx