For oversaturation, adding a preamp before input is recommended. A bias adjusting knob is a more beneficial mod than the Abbey Road mod for B77.

Dolby noise reduction was a standard option in the A77 MKIV but became a rare customization in the B77 series.

The B77's left tension arm includes a pneumatic damper, a notable design improvement over the A77.

B77 MKII introduced a varispeed feature with remote control capability, enhancing its versatility over earlier models.

The B77 MkII features full logic transport and larger VU meters, which are functional during both recording and playback, unlike the simpler relay system in the A77.

The guide post wear is common and typically doesn't affect tape engagement with the heads.

The A77's electronic motor-speed control and solid-state electronics offer lighter and smaller build compared to the G-36, despite both having three motors and two speeds.

A77's audio circuits are completely discreet, offering a more colored sound, while the B77's circuits are cleaner, enhancing tape saturation capabilities.

A77 often suffers from broken trimmer potentiometer sliders over time, a noted issue affecting both A77 and B77 models.

The Revox B77 MK1 has a built-in wear indicator on the heads; when worn flat areas match the guide flats, replacement is needed.

The A77's discrete relay logic for transport is simpler but more challenging to troubleshoot due to complex inter-card connections, making repairs more time-consuming.

Head alignment should only be adjusted when new or re-lapped; realigning used heads is not recommended.

Calibration for Quantegy 406 tape is mentioned; using new stock tape may require recalibration.

The A77 features gold-plated audio card connectors, which some users appreciate for their quality and durability.

B77 is preferred for high-speed (15ips) recording due to its availability, whereas the A77 high-speed model is rare and hard to find.

The unit is effective for processing stems before mixing, similar to outboard compressors and EQs.

Owners report tape bouncing issues at the start in high-speed models due to inadequate tension arms, with potential customization solutions from PR-99 parts.