SQLGuy
Member
Hi folks,
I have a couple of quad decoders (CD4 and SQ). My preamp is a Marantz AV7005, which has 7.1 analog inputs, but the preamp does no processing for these inputs... net effect is that things like delay, bass management, and level adjustments, are not applied when using these inputs... and these are the inputs I need for quad sources. This is particularly a problem because the front speakers use an outboard digital crossover and EQ that add about 12ms of delay relative to the side and rear speakers.
I'm thinking that the most elegant solution would be if there were a device that takes 7.1 analog inputs and converts them to HDMI, so I could pass that to the preamp. I have not, however, been able to find such a device. Analog Devices makes some chips that would be great for this, but, while they run only about $12 a piece in small quantity, they appear to require a $10K HDMI adopter license to purchase. A less elegant, but more economically viable, option appears to be to use a custom kernel with a Raspberry Pi, and add an 8-channel I2S ADC. The Raspberry Pi has an HDMI out that, theoretically, can pass the 7.1 audio (with the custom kernel).
Anyone know of any boxes that would do the analog 7.1 -> HDMI thing?
Any other ideas of how to solve this? Two other things I was thinking of were either to add a digital delay processor to add a few ms delay to the rear channels between the quad decoder and preamp, or to first convert quad sources to FLAC4, and play those with the preamp. For the first idea, it's extra processing, equipment, and cabling I'd rather not add... and for the second, it's annoying to not be able to play quad sources live, as well as my not being sure whether the AV7005 can actually play FLAC4.
Thanks,
Paul
I have a couple of quad decoders (CD4 and SQ). My preamp is a Marantz AV7005, which has 7.1 analog inputs, but the preamp does no processing for these inputs... net effect is that things like delay, bass management, and level adjustments, are not applied when using these inputs... and these are the inputs I need for quad sources. This is particularly a problem because the front speakers use an outboard digital crossover and EQ that add about 12ms of delay relative to the side and rear speakers.
I'm thinking that the most elegant solution would be if there were a device that takes 7.1 analog inputs and converts them to HDMI, so I could pass that to the preamp. I have not, however, been able to find such a device. Analog Devices makes some chips that would be great for this, but, while they run only about $12 a piece in small quantity, they appear to require a $10K HDMI adopter license to purchase. A less elegant, but more economically viable, option appears to be to use a custom kernel with a Raspberry Pi, and add an 8-channel I2S ADC. The Raspberry Pi has an HDMI out that, theoretically, can pass the 7.1 audio (with the custom kernel).
Anyone know of any boxes that would do the analog 7.1 -> HDMI thing?
Any other ideas of how to solve this? Two other things I was thinking of were either to add a digital delay processor to add a few ms delay to the rear channels between the quad decoder and preamp, or to first convert quad sources to FLAC4, and play those with the preamp. For the first idea, it's extra processing, equipment, and cabling I'd rather not add... and for the second, it's annoying to not be able to play quad sources live, as well as my not being sure whether the AV7005 can actually play FLAC4.
Thanks,
Paul