Revox A77 restoration

[Deleted User]

Here's a photo of the brake mounting plate with actuating arms attached. These arms control the two stainless steel bands that go around the brake hubs.

[Deleted User]

Here's a photo of the brake solenoid attached to the main actuating arm on the other side of the mounting plate.

[Deleted User]

With the brake mounting plate attached to the transport frame. Now to work on the two brake hubs and the associated hardware.

[Deleted User]

This a photo of the two brake drums and the associated washers and fastening nut. I was able to soak the cloth fabric on the two drums and wash with soapy water and restore the material.

honestaquarian

DRUM BRAKES?!?
What?
No disc brakes?????
Good stuff Kenneth

[Deleted User]

Here's a photo of a really nice component offered on eBay, replacement reel platters. They are extremely well made and come with all the necessary hardware.

[Deleted User]

After mounting the brake drums and the revolution counter, which is connected by a rubber belt and the lower panel. It took a while to clean up the panel mounting hardware, getting off rust and corrosion, After cleaning one of the brake bands for a while I decided that they were too worn and had some kinks, so I've ordered a brake overhaul kit from Nagravox in Australia. It may take a few weeks to get, so I'll come back to that when it arrives.

honestaquarian

Yeah make sure you bleed those brakes as well and get all of the air out of the brake line.............................................Oh wait are we talking about car brake or Revox brakes????????

[Deleted User]

Here is a photo of one of the more complex mechanical subcomponents of the deck, this is a single switch that does several things. It selects the playing speed, reel size and the record and playback EQ settings. It uses a shaft with a rotary cam that turns switches on and off to set the desired speed and reel size.

[Deleted User]

Here's a photo of the switch mechanism all put back together, plenty of cleaning and some painting to get rid of the accumulated grime and partial rust.

[Deleted User]

The other side.

Tony M

You've got serious skills.

I'm impressed.

Love the detailed close-up pics.

I have yet to open a cheap Nakamichi cassette deck that doesn't work.

honestaquarian

Tony M wrote: »

You've got serious skills.

I'm impressed.

Love the detailed close-up pics.

I have yet to open a cheap Nakamichi cassette deck that doesn't work.

@Tony M Maybe we can sucke....................I mean TALK Ken into doing our Naks??

ALL212

Mine lurks in the dark. Waiting for a rebuild.

[Deleted User]

Thanks, @TonyM I've been trying to learn more about the manual functions of this camera, working to maximize depth of field and clarity.
Anybody who does really good work with cassette decks, @honestaquarian has my admiration. The transport mechanisms are so complex and interwoven, to get to one part requires removing lots of layers. More like clock repairing.
@ALL212 that is a Dolby equipped deck as I'm sure you're aware. Really nice! One of the things I've thought about doing to this deck I'm working on is to add Dolby.

JayCee

KennethSwauger wrote: »

One of the things I've thought about doing to this deck I'm working on is to add Dolby.

CP...."Wow, Ken. You have skills". Ken replies...."I can add Dolby". Maybe throw in some DBX for good measure? Because you can? I need a neighbor as talented as you. I'm tired of talking fertilizer and grass seed in our yards.

Can't say Dolby without this...
https://youtu.be/7sz5OrACPn8

[Deleted User]

Ah, Dobly ...!

[Deleted User]

Here is a photo of the selector switch after being installed in the frame.

[Deleted User]

This is a particularly difficult part to restore, the headblock assembly which contains the three heads, the two tape guides, the tension arm and the pre-capstan guide. All of these have to remain in perfect alignment. This means not much disassembly is possible so cleaning and polishing have to be done carefully.

audioluvr

When this thing is done you'll have about $1,500,000 in labor into it!

ken brydson

audioluvr wrote: »

When this thing is done you'll have about $1,500,000 in labor into it!

If it was me I'd also have an Ess ton of leftover parts...

dromunds

Tony M wrote: »

I have yet to open a cheap Nakamichi cassette deck that doesn't work.

No such thing as a cheap Nakamichi

tonyp063

audioluvr wrote: »

When this thing is done you'll have about $1,500,000 in labor into it!

Or an unmeasurable amount of satisfaction and joy.

Lovely stuff Ken. Just lovely.

[Deleted User]

Here's a photo of the head block assembly installed on the frame, it's starting to look like an A77 now. The installation is a little tricky, the same four bolts that attach the capstan motor are used for the head block. But, supporting the motor from the bottom lets the holes get lined up.

[Deleted User]

One of the changes I want to make to the transport is to convert the fixed right hand tape guide to a rotating version. To do this I will use the same ball bearing arrangement that is used in the left hand tape guide. This photo shows the two brass threaded openings that the tape guides will go into.

ALL212

SIR! (Someone told me to be nice...the struggle continues)

I am no where near your level of competence on work like this but would you entertain a question or two?

My take up side can’t handle the end of a 10” reel - wows and flutters very bad. 10w 30? JK... easy fix?

Biggest (easiest) bang for the buck upgrades on these decks?

Thanks
Aaron

[Deleted User]

Hi Aaron,
A few questions. Is this an A77 deck you have? When you hear the speed errors is this on a tape you've made on this deck or on another machine? Does it sound like the playing speed is getting slower and then speeds up? If you gently push up on the pinch roller does the wow and flutter change? Is the entire tape path (tension arm, tape guides, heads, capstan and roller) completely clean?

ALL212

I’ll get the easy answers to you now.

Yes, my A77.
Tapes were made 100 years ago on an Akai GX635. That has gone the way of the dodo some time ago (miss that deck... )

I’ll try the mechanical stuff tomorrow.

Sound is good until about 1/2 inch (or so)of tape shows on the supply side. Speed variations get worse the closer to the end.

Reverse tape and it sounds fine - until the end.

CLEAN? We don’ need no stinkin clean!!
Ya, I’ll check that.

jdjohn

tonyp063 wrote: »

audioluvr wrote: »

When this thing is done you'll have about $1,500,000 in labor into it!

Or an unmeasurable amount of satisfaction and joy.

Lovely stuff Ken. Just lovely.

Agreed. It's a labor of love.

[Deleted User]