For all models Mk2 – Mk 4 and later Mk1 (except very early Mk1 – see separate listing kit), including:
• STANDARD models with Transistor Speed Control PCB 1.077.725 which is later Mk1’s, Mk2 and early Mk3’s.
• PLUS For models with IC Speed Control PCB 1.077.724 or /729 which is later A77 Mk3 and all Mk4’s.
N.B. If you have a Mk1 we suggest the universal kit also sold here. Very early Mk1’s have slightly different PSU, tape drive and capstan boards and a separate kit is listed for them. Please check it out as it has photos of what to look for.
This kit contains:
• components to cover both transistor and IC speed control versions
• replacement capacitors for all the electrolytics
• replacement for all tantalum capacitors
• brand new specially manufactured non polarised motor capacitors
• all troublesome suppression capacitors on the drive control, capstan and
• power supply.
• a full set of fully enclosed cermet type preset potentiometers
• small “upgrade” blank labels are provided so you can appropriately mark your upgraded boards.
• capacitors =74, preset trimmers =18
The kit is suitable for the following circuit boards:
• PSU 1.077.540
• Tape Drive 1.077.370
• Switchboard 1.077.435/426
• Input amp 1.077.700
• Record 1.077.705
• Oscillator 1.077.712
• Record relay 1.077.715
• Playback amp 1.077.720
• Speed control 1.077.725 and 1.077.724 or /729
• 3x chassis mounted motor capacitors.
Tools you will need.
• soldering iron and solder (prefer lead type but lead free is OK)
• desoldering tool or a good solder sucker
• switch contact cleaner
• isopropyl alcohol or flux remover solvent for cleaning
• screwdrivers, nose pliers, side cutters
• a multimeter
Please Note: Some pictures in gallery show a typical A77 restoration in progress in our workshop. These are for information only and are not what is supplied in our kit of parts which are shown in pictures 1 and 2.
The kit contains specially sourced, new, freshly manufactured components from reliable manufacturers whom we have been dealing with for many years. No NOS(new old stock) or 2nd hand items!! The motor capacitors are specially manufactured for us for Revox tape deck motors as is the large power supply can type electrolytic. The audio signal path capacitors are specially selected low noise, low leakage / high stability types. The preset pots are cermet and fully enclosed guaranteeing decades of trouble free operation and adjustment.
Please note – other audio path caps and transistors – our kits have what is most likely to be degraded without going over the top. We don’t supply any audio path paper, mica, poly or other caps
PLEASE ALSO NOTE: Our precision high-grade motor capacitors are specially made to our specifications for us for Revox and Studer tape decks. There are NOT generic white washing machine / fan capacitors which have wide specification tolerances. They are also the exact Revox capacitance values not “approximately close”. Anyone who implies that a higher capacitance value is better is talking nonsense.
Full instructions for each board are included with pictures before and after detailing exactly which components go where and a host of useful tips, checks and basic calibration.
Don’t waste your time replacing just one or two capacitors on machines that are now 25 – 40 years old, replace ALL the troublesome electrolytics and tantalums. Usually the old high voltage capacitors associated with the motors and tape drive will be poor electrically and also visually. Some capacitors may test OK initially on a low voltage modern tester. However capacitors usually need to be tested after they have operated for a while at working voltage and cycled through a few ON / OFF surges. For such relatively low cost components its prudent to just replace the lot. CAUTION: be careful of buying 2nd hand motor capacitors – it just is not worth it! Ours are new recent manufacture and specially designed as a worthy replacement for the originals.
We list separate kits for the optional accessory boards such as Loudspeaker amps and Dolby.