Search found 65 matches

by knutolai
Fri Sep 15, 2023 1:51 am
Forum: FV-1 hardware questions
Topic: Two FV1 sharing a common EEPROM?
Replies: 7
Views: 18164

Re: Two FV1 sharing a common EEPROM?

If you are going to use a micro to control the clock, why not expand on the micro to also control the program changes, that way I think you could use one EEPROM for both FV-1's by introducing a delay into the program read of each FV-1. As Frank points out this will bring the I2C lines out of spec d...
by knutolai
Wed Sep 13, 2023 4:36 am
Forum: FV-1 hardware questions
Topic: Two FV1 sharing a common EEPROM?
Replies: 7
Views: 18164

Re: Two FV1 sharing a common EEPROM?

Thank you Frank. I'll go with 2 EEPROMs. Would there be an issue to have the S0 and S1 pins of the two FV1 chips share 1 toggle switch? That you can do. Even use a DPDT toggle switch and use one circuit for each FV1 Yes a DPDT would be very safe but I'm wondering if using a SPDT would be viable. Th...
by knutolai
Wed Sep 13, 2023 12:04 am
Forum: FV-1 hardware questions
Topic: Two FV1 sharing a common EEPROM?
Replies: 7
Views: 18164

Re: Two FV1 sharing a common EEPROM?

Thank you Frank. I'll go with 2 EEPROMs. Would there be an issue to have the S0 and S1 pins of the two FV1 chips share 1 toggle switch?
by knutolai
Tue Sep 12, 2023 8:53 am
Forum: FV-1 hardware questions
Topic: Two FV1 sharing a common EEPROM?
Replies: 7
Views: 18164

Two FV1 sharing a common EEPROM?

Can 2x FV1 and 1x 24LC32A EEPROM be connected and work on the same I2C line? I want to run a 4 channel setup where the two FV1 chips run different programs. My intention is 3 programs for each FV1. Thus the idea to have them share one EEPROM chip. If this is possible would it be an issue to change p...
by knutolai
Thu Sep 24, 2020 1:57 am
Forum: Algorithm development
Topic: Allpass filter calculator?
Replies: 8
Views: 11019

Re: Allpass filter calculator?

In the analog form you would choose a set of three(or more) frequency points that will overlap the responses to maximise uniformity in phase response over a range. The RC values are chosen such that XC = R at the frequency point chosen for a given stage. The XC = R is the point where gain is down 3...
by knutolai
Thu Sep 24, 2020 1:51 am
Forum: Algorithm development
Topic: Another Noise Generator
Replies: 5
Views: 15606

Re: Another Noise Generator

This noise generator has been so useful to me. Thank you so much Jack! I found a more efficient way to execute the same function that some of you may find useful. The benefits of this alternative method is that you only require one register (the LFSR reg) and that the new LFSR value is stored in the...
by knutolai
Thu Sep 03, 2020 7:40 am
Forum: Algorithm development
Topic: Allpass filter calculator?
Replies: 8
Views: 11019

Re: Allpass filter calculator?

OK so my experience with this so far is that the Transposed Form II allpass filters oscillate way easier, thus requiring even more downscaling in order to yield stable operation. I'm a bit puzzled by this, but can't find any clear errors in the filter implementation. I'll be sticking with the RDA/WR...
by knutolai
Wed Sep 02, 2020 3:49 pm
Forum: Algorithm development
Topic: Allpass filter calculator?
Replies: 8
Views: 11019

Re: Allpass filter calculator?

Came across this chapter in the knowledge base section of the website ("Programming the FV-1"): The opcode set has been optimized to execute subsets of code for various common audio tasks; the all-pass filter for example, is executed by only 2 operations, but must do this from delay memory...
by knutolai
Wed Sep 02, 2020 12:29 am
Forum: Algorithm development
Topic: Allpass filter calculator?
Replies: 8
Views: 11019

Re: Allpass filter calculator?

With your calculator I'm getting the following relationships @ 32768 Hz samplerate. Are negative constants problematic? Freq W' Constant 5,4 0,000518 0,99897 41,1 0,003940 0,99215 167,4 0,016049 0,96841 671,5 0,064379 0,87903 2693 0,258188 0,58959 11966,5 1,147273 -0,06859 18,8 0,001802 0,99640 83,3...
by knutolai
Tue Sep 01, 2020 11:38 am
Forum: Algorithm development
Topic: Allpass filter calculator?
Replies: 8
Views: 11019

Re: Allpass filter calculator?

Hey Would be very interesting! But I can't find the exel spreadsheet calculator you mention. Just this link: http://www.gj3rax.com/apf.htm EDIT : Nevermind I just found it. Would the -3dB freq @ 90 deg = 1/(2*Pi*RC) where RC is the lowpass/highpass pair in the opamp allpass filter? Is that what you ...
by knutolai
Mon Jul 27, 2020 8:56 am
Forum: Algorithm development
Topic: Allpass filter calculator?
Replies: 8
Views: 11019

Allpass filter calculator?

I want to run a modified version of the linear pitch shifter program on a FV1 clocked at 40KHz. In order to retain the same frequency response from the dome filter I would need to adjust all the filter coefficients. Is there a simple formula for calculating the coefficient taking [sample rate], [num...
by knutolai
Fri Jul 10, 2020 10:08 am
Forum: FV-1 hardware questions
Topic: Options for Simulation {Newbie Alert}
Replies: 13
Views: 15590

Re: Options for Simulation {Newbie Alert}

Haven't tried this, but there exists a FV1 module for the VCV eurorack DAW (software eurorack) where you can enter your own algorithms. Maybe someone who has tried this could chime in with their experience?

https://vcvrack.com/
by knutolai
Sat Jul 04, 2020 4:56 am
Forum: FV-1 hardware questions
Topic: Some things I've learned about the FV-1
Replies: 19
Views: 29059

Re: Some things I've learned about the FV-1

First, the thermal noise. I've seen people make comments about this. I think the published spec is -97dB typ? I can't remember. In my experience, If you're using a standard 78xx regulator in your design, it's going to be noisy. Consider using a modern LDO or an LM431 shunt, and split the supplies i...
by knutolai
Wed Jun 17, 2020 2:10 am
Forum: Algorithm development
Topic: Memory Address Interpolation Resolution
Replies: 4
Views: 7454

Re: Memory Address Interpolation Resolution

Decided to ditch this idea. For anyone who wants to pursue this there is also another thread discussing it here:
http://www.spinsemi.com/forum/viewtopic ... ation#p309
by knutolai
Thu Jun 11, 2020 3:02 pm
Forum: FV-1 hardware questions
Topic: Mid Reference Capacitor
Replies: 17
Views: 17111

Re: Mid Reference Capacitor

This is OT, but I managed to get the chip's noise performance below -100dB unweighted. I won't say exactly how low, but I will say that I don't have to use any external audio path filtration with the chip. My dev research showed that the FV-1 is sensitive to power supply noise (like all converters)...