Bitrate and samplerate change realtime
Hi,
as controlling a 1701 with a mcu now is working ok I was wondering whether it is possible the reduce the samplerate and the bitrate of the incoming signal so that I can use a pot on the mcu to set those things in realtime over i2c.
Also is there any collection of audio fx patches?
Has anyone any experience in doing hybrid designs like analogue saturation with compressor by the dsp etc?
Most examples I see are for speaker applications and I am wondering if there are any ither people who are interested in creating creative audio effects for use in electronic music (maybe on eurorack modules).
I just read it is possible to integrate third party algorithms. Are there any resources for that?
Thanks for helping.
Hello jenskuehnemann,
Is the incoming signal coming in on the serial port?
This processor is one of our early SigmaDSPs and so it has a lot of limitations that we improved upon with later designs. You can slow down the master clock coming into the DSP to reduce the sample rate below 48kHz but you will not gain any MIPS with this processor. The most instructions per sample will be 1024. So no reason to change the rate to a lower rate, you do not gain anything.
For the serial input you have to be synchronous so give me more details about this input rate?
In the library there are several compressors and there is a soft clipper. Some people have done some distortion pedals and things like that using this part. Search the forum you should find some examples.
With the SigmaDSPs you have to use SimgaStudio and you cannot import code directly. You have to use the graphical environment to program the DSP.
There has been some people who have done some synth modules with this processor but most people have used our larger DSPs but the good old 1701 can still do a lot. There is a lot on the forum for this part.
Dave T
Thanks for your answer. Is it possible to reduce the samplerate and bitrate with a fader to delibertly crunch the signal? The signal is coming tvrough the ad converters.
Yeah I know that it is quite limited. I was hoping to make nice "degradation patch" which then could be used for a delayed signal to be fed in again and again and get a delay with lots of possible tweaks and continuing degradation.
Might just buy an analogue bucket brigade kit otherwise.
There are so.e modules that degrade quite well.
Ohh and is there anywhere a collection of audio projects? I wouls also like noisegates, lfo patches etc.
Thanks for helpi f
jenskuehnemann said:
Thanks for your answer. Is it possible to reduce the samplerate and bitrate with a fader to delibertly crunch the signal? The signal is coming tvrough the ad converters.
Not easily. All the master clock would have to slew and be changed. The PLL may lose lock if it is done too fast and too far so no, this is not good to do.
This part has two inputs and four outputs. You certainly could send a signal out of one of the unused outputs and feed it back into the input all in the analog domain to get some degradation happening. You can also do this within the DSP. You can certainly truncate the audio to be 8-bit and then then feed it into a delay line and then feed it back into the input to sum with the incoming signal. The old bucket brigade parts were only 8-bit so that was part of the classic early "sound" of that part. Then it added noise as well and you could do that in the DSP to simulate the bucket brigade chip adding noise. Actually, I should not call it "noise",... it was "Dither"!! LOL
For audio projects. You will have to search the forum for some possible examples but I am not sure you will fine exactly what you are looking for. Most people just set these up themselves or keep them as protected IP.
Dave T
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