Hi All
I just purchased a 20K Brick Wall filter card that is used in AP System One, Two & Cascade from Mr Ultranalog. The preformance is stellar, like the orignal AP and much less costly. He also has some others filters.
I do a lot of AP repairs and this makes is easy on my customers. I hope this may help some of you.
Duke
I just purchased a 20K Brick Wall filter card that is used in AP System One, Two & Cascade from Mr Ultranalog. The preformance is stellar, like the orignal AP and much less costly. He also has some others filters.
I do a lot of AP repairs and this makes is easy on my customers. I hope this may help some of you.
Duke
Wow. Thank you Duke. Coming from an former AP authority like you, that is high praise indeed.
Yes, the project was in stealth mode but it's true, for all DAC and class-D freaks out there, I recreated the 20kHz low-pass measurement filter as a scratch-an-itch kind of solution. With it, you can run AES17 measurements even with a System One, which was built and sold well before the standard came into effect.
By using AES17, you can not only post better THD+N numbers, but also better find distortion in the audio band without being dwarfed by out of band (e.g. modulation) energy.
More info here
With all the high precision components and calibration on the board, I'm thinking about EU 129 retail including 23% VAT. However if I get enough interest from the DIYaudio community (20+) I'll commit to EU 99. As I'm doing hand-built production runs, that is just about covering components, time and the tax man.
Production run boards should be available about 4 weeks from green light. Shipping at cost at buyer's expense.
As Duke mentioned, I have designs for several other filter plugins, including AWT, CWT, D75R (reverse RIAA) and others as well that I'll publish when I have first runs built and testing procedures in place. Feel free to inquire though.
Oh, and hey DIYaudio. It's been a while. 🙂
- Remco.
Yes, the project was in stealth mode but it's true, for all DAC and class-D freaks out there, I recreated the 20kHz low-pass measurement filter as a scratch-an-itch kind of solution. With it, you can run AES17 measurements even with a System One, which was built and sold well before the standard came into effect.
By using AES17, you can not only post better THD+N numbers, but also better find distortion in the audio band without being dwarfed by out of band (e.g. modulation) energy.



More info here
With all the high precision components and calibration on the board, I'm thinking about EU 129 retail including 23% VAT. However if I get enough interest from the DIYaudio community (20+) I'll commit to EU 99. As I'm doing hand-built production runs, that is just about covering components, time and the tax man.
Production run boards should be available about 4 weeks from green light. Shipping at cost at buyer's expense.
As Duke mentioned, I have designs for several other filter plugins, including AWT, CWT, D75R (reverse RIAA) and others as well that I'll publish when I have first runs built and testing procedures in place. Feel free to inquire though.
Oh, and hey DIYaudio. It's been a while. 🙂
- Remco.
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