P1 preamplifier

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Thanks Andrew :nod:

During assembly these could be mounted on Chassis, the inputs could be configured as both balanced and unbalanced depending on application area, the MP4 AAC is a very interesting standard Advanced Audio Coding - Wikipedia , with a suitable sound card Sound Cards, Audio Cards - Newegg.com . The boards could be configured for 1 channel, 3 channel or more ? need more suggestions on this. all channels may not even need be three way

:cheers:

Are AC 1 V1 & AC 1 V3 the balanced impedance audio signal?

If so, then the RF attenuation (C3 & C4) should be connected back to the Chassis socket or to Pin1 and thence to chassis/enclosure. This should be done as close to the chassis socket as possible.
Do not bring the RF interference along wires that can re-radiate EMI into other internal receivers.
I suggest that R27, R8, C3 and C4 be fitted to the input socket, not to the internal wiring.
 
havent send them to the board house yet, there will be different BOMs same layout for different crossover frequencies.
The universal three way being 308Hz and 2kHz, feel free to post your preferred frequencies, chances of these being ready by Christmas is low
 
understanding a man by his speakers

To some every other equipment apart from the speakers is second in importance, so if a man has a two way bookshelf (Buchardt s400, Elac b6.2 etc) or some towers assisted by some sub woofers, add in bi-amping, what kind of preamplifier would he be shopping for?

The below is just a specification and implementation would yield varying results
 

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revision 1

attached. some may wonder how distortions add up per active stage and whether these distortions interact to create unpleasant artifacts, these specifications look at functional requirements, some implementations maybe magical, while some not soo good. Others maybe worried by the contribution of each active stage on the phase, but so long as each active stage is fast enough and the overall response time is within 1us you should be fine with audio, even the OPA134 does 8Mhz meaning its quite fast despite being an IC, but there are many factors that need addressing before you can please an audiophile,a purist or a minimalist

Comments are welcome
 

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Lets make the assumption that all modern source material has been mixed on a DAW , laptop or other and its sounds great, we will assume no one complains that their yester years analog material sounds so much better, with that behind us one way we could implement this is mostly digital the other is analog

$7-$16 chips

fpgas aside cost cutting options

Option 1
http://www.ti.com/tool/aicpurepath_studio
http://www.ti.com/lit/ds/symlink/pcm3070.pdf
PCM3070IRHBT Texas Instruments | Integrated Circuits (ICs) | DigiKey

Option 2
VisualDSP++ 5.1 | Analog Devices
https://www.analog.com/media/en/technical-documentation/data-sheets/ADSP-21477_21478_21479.pdf
https://www.digikey.com/product-det...DSP-21477KCPZ-1A/ADSP-21477KCPZ-1A-ND/3196901

advice and ideas needed

Later*The digital implementation can have datalink support with AES/EBU(prof), SPDIF(cons), USB, HDMI and codec support for (Dolby Atmos, DTS X)*converted into stereo playback just for the kick of it), however we move the phono preamp off to another board and consider adding support for qualcomm bluetooth, Ethernet and Wifi plus codecs
 
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