This document has notes on amplifier development and a list of off-shelf amps in testing and available to buy and other misc notes.

This doc is mostly related to the improvement of the CX Cards SNR or signal-to-noise ratio.

The most commonly deployed off-shelf RMS amplifier considered the go-to for HiFi/Video FM from tape and laserdisc formats, using 0603 parts it can be user modified if required.

AliExpress

ADA4857 GitLab Repo

Developed by Rene Wolf as a second generation, "adjust per unit" amplifier board based around the ADA4857 with 0805 pads for gain/input termination so requires an assortment resistor book and a entry to mid range benchtop type digital store oscilloscope.

GitLab Repo

Rene Wolf's first generation amplifier for due duel channel capture using the sgm8302 amplifier IC.

An off shelf board that is widely available on AliExpress.

(Confirmed on LD players)

Used by the DomesDayDuplicator

https://www.aliexpress.com/item/AD605-VGA-Dual-Channel-Voltage-module-Control-Adjustable-Gain-Amplifier-Module-Low-Noise-High-Precision-5V/33026097817.html 23GBP with VAT

The way the board is supplied, the 2 channels aren't configured the same.

Absolute gain range programmable −14 dB to +34 dB (FBK shorted to OUT) through 0 dB to 48 dB (FBK open)

One channel has FBK shorted to OUT (-14 to +34) gain range, and the other channel has FBK open (0 to 48db) range, controlled by R5 and R6.

Used by the DomesDayDuplicator

https://www.aliexpress.com/item/33008732817.html

https://www.aliexpress.com/item/32790115607.html

Analog Devices Linear Technology LT1252 Low-Cost Video Amplifier (built for application used by CubeTec's BetaCam add-in boards for example)