Add a 'Mixture Stop' to DC8?

[Phillip]

Craig [and other interested parties];

I have frequently experimented with the DC8 Sub-Harmonic and Octave Synthesizers, using both on low-quality mp3 recordings [that have a minimum amount of encoding artifacts], and have had surprisingly good results 'restoring' these files to full fidelity.

For those who do not know, all mp3 files, and especially low bit rate mp3 recordings [32 to 64 kbs range] significantly chop off the high frequency components of the original recording source [if these components were even there in the first place]. Using the DC8 harmonic synthesizers, it is possible to restore much of the lost frequencies when the only audio source one has to work with is the low bit rate mp3 file. This was a great revelation to me.

An example would be choosing any of the low-quality OTR mp3 files at archive.org and experimenting with enhancing the fidelity of, for instance, a Jack Benny Show radio recording. It is great fun to do this, and if you are very careful, making good use of the synthesizers, the frequency equalizers, and the DC8 Spectrum Analyzer, you will be very surprised at the results.

Which leads me to this next question -

Craig, I wonder if you would consider enhancing the Octave Synthesizer to add controls to turn it into kind of a organ mixture stop. This would mean additional controls for something like this:

8ve 4 foot stop - [as the Synthesizer is now]
15th 2 foot stop - [add this]
19th 1 1/3 foot stop - [add this]
22nd 1 foot stop - [add this]

Possibly a similar enhancement to the Sub-Harmonic Synthesizer would be useful - but this would have to be carefully thought out.

One would have to be careful manipulating something like this, but I see the infinite possibilities of using it to enhance older recordings. And no other audio software I know of has this feature. Just a thought.

Phillip

[Craig Maier]

Hi Phillip,

Thanks for the suggestion; is it not possible to obtain the results you want by adjusting the frequency control setting?

Craig

ps - as an aside, the Virtual Valve Amplifier should also be quite useful to brighten up mp3s with weak top-ends. Give it a try. I usually use the 12AT7 Triode for this.

[Phillip]

Craig;

Moving the frequency control [to the left, as an example, to cover more lower frequencies] is not the same thing as adding more diverse harmonics to voice or music.

The mixture stop on organs adds a brilliance to what is already being played on the keyboards because the stop adds a predefined upper harmonic structure to every note that is played. The disadvantage to this stop is that there is no level control for each of the upper harmonics. This is similar to what the DC8 Harmonic Synthesizer is already doing, except it is just adding the second harmonic [the octave]. I am suggesting the capability of adding the third harmonic, the fifth above that, and possibly the fourth or even sixth harmonic above that.

I believe in audio recordings, this is one of the components we call ‘high fidelity’. Of course, none of these upper harmonics ever made it into early recordings and they are completely stripped away in mp3 files.

So I propose leaving the DC8 Harmonic Synthesizer just as it is, but adding the capability for adding more upper level harmonics, i.e., the 15th, 19th and possibly the 22nd or 24th harmonic. The default condition would be to have these controls turned OFF. There would have to be a level control for each harmonic, since each added harmonic must be set quite low compared to the fundamental frequency. The software would toss out any synthesized harmonic over 20 khz. The proper declining level of the added harmonics related to the increase of the frequency spectrum can be adjusted via the existing DC8 frequency equalizers. I envision a recording that has virtually no frequency components out beyond 4-7 khz , can be synthesized to have interesting frequency information to 20khz. We may not actually hear all of this information, but it may be what gives recordings character, sparkle, and ‘life’.

Thanks for suggesting the Virtual Valve Amplifier - I had not thought of using that....

Phillip

[Craig Maier]

Hi,

I see - - - I think that you can get what you want by cascading (using the Multifilter) the sub-harmonic synthesizers and overtone synthesizer with the Virtual Valve Amplifier. On the bottom end of the spectrum, the "Fat Bass" mode can add odds and even harmonic overtones to bass notes. The "Warm" and "Sweet" modes can add those odds and evens to mid end and the upper end of the spectrum. Push-Pull Circuits (you can choose those circuits with the Advanced Controls) eliminate the evens just leaving behind the odds. The Class A circuits provide both odds and evens.

You can use two VVAs if you want in the same multifilter. One could be set for Fat Bass and the other set for Sweet for top end enhancement.

Give that a try - - - you may be pleasantly surprised by what you can get from such a combination of effects.

Craig