[sdiy] Frequency shifted from BBD?

[min struct]

https://www.preservationsound.com/2013/07/audio-obscurity-the-vsc-analog-pitch-correction-system-c-1980/

offered a pitch-shift range of 0.6x to 4.0x (300-5Khz bandwidth)

and its related patent ?
http://www.google.nl/patents/US4627090




Le lun. 21 oct. 2024 à 10:00, Kylee Kennedy via Synth-diy <
synth-diy at synth-diy.org> a écrit :

> You get a temporary pitch shift when you change the delay speed on a BBD
> manually. So I bet if you set up a scanner that goes through several BBDs
> that are shifting the speed as it scans you could replicate this effect.
> Each BBD acts as a playback head on that device. Probably phlanging would
> be included if there isn't a hard switch between BBDs via the scanner steps.
>
> - Kylee
>
> On Sun, Oct 20, 2024 at 11:12 PM Didier Leplae via Synth-diy <
> synth-diy at synth-diy.org> wrote:
>
>> Yes! That’s surprisingly simple solution for pitch shifting on tape. I’m
>> trying to think if such a brilliantly simple solution is possible for BBD
>> though.
>>
>>
>>
>> On Oct 20, 2024, at 7:45 PM, Ben Stuyts via Synth-diy <
>> synth-diy at synth-diy.org> wrote:
>>
>> For all you frequency shifter and tape delay aficionados:
>> https://youtu.be/U-4AMxkpyh0
>> That’s brilliant! :-)
>>
>> Ben
>>
>> On 9 Oct 2024, at 07:07, Mike Bryant <mbryant at futurehorizons.com> wrote:
>>
>> 
>>
>>    - Besides the point that Tom raises, there's another consideration:
>>    Using an MCU to program a complex digital signal is often more wasteful
>>    (think: battery-draining) than judicious use of logic gates.
>>
>>
>> Sorry but this usually isn't the case.  Unless you are switching at a
>> very low rate, discrete logic gates have to drive the capacitances on the
>> PCB between each other whereas MCUs do all the work internally and just
>> output the final waveform.   10 cent OTP MCUs cost less than many logic
>> gates due to higher volumes and usually use less power and PCB area so
>> system cost is lower.
>> ------------------------------
>> *From:* Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of brianw <
>> brianw at audiobanshee.com>
>> *Sent:* 09 October 2024 05:14
>> *To:* SDIY <synth-diy at synth-diy.org>
>> *Subject:* Re: [sdiy] Frequency shifted from BBD?
>>
>>
>>
>> On Oct 6, 2024, at 4:09 PM, Benjamin Tremblay wrote:
>> > Why not generate the clocks with the MCU and skip voltage control?
>>
>> Besides the point that Tom raises, there's another consideration: Using
>> an MCU to program a complex digital signal is often more wasteful (think:
>> battery-draining) than judicious use of logic gates.
>>
>> A counter can divide down a higher clock rate. A couple of AND gates plus
>> an inverter can generate non-overlapping clock signals from the two LSB
>> outputs of the counter. Gates like these are cheap in CMOS.
>>
>> Doing the same with an MCU would be unwieldy unless you have hardware
>> support. It might be possible to convince the timer/counter motor control
>> peripheral of certain MCU chips to create non-overlapping clocks at
>> identical rates.
>>
>>
>> > I just assumed Eventide used a digital pathway.
>>
>> I'm sure Eventide did use a digital pathway, but it was almost surely
>> built on a lot of discrete logic instead of pure software.
>>
>>
>> > As a teenager I got one of those Radio Shack kits to build the SAD1024
>> BBD delay.
>>
>> I also built a DIY BBD delay. I fudged many of the potentiometer values
>> to get longer delays - a much lower fidelity than a commercial product
>> would allow. Super fun experimentation. Basically, I allowed the clock to
>> be cranked much lower than the original schematic. I knew it would sound
>> bad, but I wanted the flexibility. That box had very sensitive controls,
>> because each pot spanned a much wider range than would be considered
>> ergonomic design.
>>
>>
>> > Anyways… I have thought it would be fun to get a huge BBD with 4096+
>> stages and run it at a really high speed.
>> > If I understand, there’s a problem with speed; the sample/hold cells
>> have slew rate caused by their capacitance, right?
>>
>> The FET switches between each pair of cells have some "on" resistance,
>> albeit small, so the RC circuit formed by the on resistance and the
>> capacitor put a limit on the clock speed. You can clock faster, but the
>> cells will not be fully charged. If the signal is low amplitude, then it
>> might pass through, but a high amplitude signal would require big changes
>> in the cell charge, and the voltages would not get through in full.
>>
>> > It seems like a lot of work to get a mid-quality sound.
>>
>> Don't forget the noise - you get a lot of noise, too.
>>
>> > Benjamin
>>
>>
>> ________________________________________________________
>> This is the Synth-diy mailing list
>> Submit email to: Synth-diy at synth-diy.org
>> View archive at: https://synth-diy.org/pipermail/synth-diy/
>> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
>> Selling or trading? Use marketplace at synth-diy.org
>> ________________________________________________________
>> This is the Synth-diy mailing list
>> Submit email to: Synth-diy at synth-diy.org
>> View archive at: https://synth-diy.org/pipermail/synth-diy/
>> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
>> Selling or trading? Use marketplace at synth-diy.org
>>
>> ________________________________________________________
>> This is the Synth-diy mailing list
>> Submit email to: Synth-diy at synth-diy.org
>> View archive at: https://synth-diy.org/pipermail/synth-diy/
>> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
>> Selling or trading? Use marketplace at synth-diy.org
>>
>> ________________________________________________________
>> This is the Synth-diy mailing list
>> Submit email to: Synth-diy at synth-diy.org
>> View archive at: https://synth-diy.org/pipermail/synth-diy/
>> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
>> Selling or trading? Use marketplace at synth-diy.org
>>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20241021/6d896825/attachment.htm>