Power-on delayRevox A77
for all Revox A77 MKI, II, III and IV
ESV 77 Version 1
We offer the power-on delay in two versions. Version 1 is without VU meter protection. This version is completely pluggable. This is particularly simple and cost-effective!
ESV 77 Version 2
The second version also includes VU meter protection. This requires four additional wires to be soldered in addition to the existing wires. This is very easy to do!
Electronic
Both versions have the same delay electronics, only the relays and the additional wires or the color of the wires make the difference.
Time
The delay time is approximately 5 to 7 seconds. This should be sufficient in most cases to effectively suppress the power-on pop! The circuit operates without electrolytic capacitors, making it very durable.
Installation of ESV 77 without
VU meter protection
Remove A77 from the case
Loosen the 4 rear housing screws and tighten the dummy plug for the wired remote control.Pull the device forward out of the casing and lever it forward. This is a bit difficult, so please be careful and patient!
Output A77
Place the device on its side on a Styrofoam base with the power plug at the bottom. Remove three flat receptacles (AG9 brown, AG8 violet, and AG7 green) from the Revox A77 switchboard and insulate them with the included heat shrink tubing.
Connect output
Now connect the flat plug sockets to the ESV 77, as shown in the photo, and plug the wires coming from the ESV 77 onto the freed flat plugs on the Revox A77 (AG9 br, AG8 vio and AG7 gn).
Tension
Disconnect the yellow wire (ground, DF2) and the purple wire ( 27V, DF1) from the drive controller.
To improve visibility, the design wasinterference capacitor C113 desoldered.
insulation
Although the other flat plugs do not necessarily need to be insulated, the flat plug sockets of the power supplies must be insulated!
Connect voltage
The strands are exposed and therefore require good and safe insulation!
We supply the appropriate shrink tubing.
With a heat source (a lighter also works if you are careful!), the tubes shrink 3:1
Connect ESV A77
Now plug the flat plug sockets ge and vio, coming from the ESV 77, onto DF1 (vio) and DF2 (ge) on the drive control of the Revox A77.
cable ties
The power supply cable is fixed with two cable ties for optical reasons.
Platinum
The circuit board is attached to the Revox A77 chassis with a cable tie. The power-on delay circuit board weighs nothing, and the attachment is perfectly adequate! It's sufficient to just loosely tighten the cable tie.
Installation ESV 77 with VU meter protection
ESV 77
The ESV 77 is installed in the same way as the ESV 77 without VU meter protection.Only here two additional white and two blue strands are needed.
Cable routing
The wires are placed over the audio plug-in boards and routed to the respective Rec-Amp circuit boards of the Revox A77.
Rec.-Amp. .705
After removing the shield plate, the rec. amp circuit boards can be easily removed and modified. The modification is limited to soldering two stranded wires. It's not rocket science. The strands are then secured with cable ties.
Detail
On the left is ground, on the right is the VU meter signal before the 10 µF capacitor C509.
Nothing more needs to be done.
Now insert the circuit boards into the Revox A77, mount the shield plate and push the device back into the housing!
ESV A77
in our shop
Here you will find the convenience gain for your Revox A77
