Mint Revox B77

[337alant]

Bought a mint Revox B77 of e-bay really excited about it as it is used but looks in superb condition
Its only the slow speed version but I have the high speed covered by 2 x PR99s

Wife said it has been delivered and confirmed it is in excellent condition :eyebrows:

https://www.ebay.co.uk/itm/REVOX-REEL-2-REEL-B77-MK-II-Fully-Woking-and-Superb-Condition-Nabs-and-Reels/192839906308?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

HIFI Hanger were a pleasure to deal with as well


Alan

[Ali Tait]

Looks great Alan, nice buy.

[The Black Adder]

Very nice machine

Well done you.. [emoji106][emoji16]

Sent from my 9001X using Tapatalk

[tommy6206]

I got one myself a couple weeks ago with full service in very good condition and Im loving it. welcome to the club

[337alant]

Thanks everyone looking forward to playing this old classic R2R
Mine hasn't been serviced but that's not a problem to me as I will do it myself anyway
Even if the seller says it has I always take that with a pinch of salt anyway.
I usually means it didn't catch fire when we switched it on:D

alan

[337alant]

Looks great Alan, nice buy.
Thanks Ali, you still got your Tandberg TD-20A ?
Another Classic R2R

Alan

[Ali Tait]

Yes still have it Alan, also couldn’t resist getting a rather nice RT909 which I think is worth having just to look at lol.

Doesn’t sound as good as the Tandberg though.

[337alant]

Agree the RT909 does look fabulous, I never owned one but they are also supposed to sound good as well.
The Tandberg will take some beating though the TD20A was a cracking R2R as were there final Cassette decks

Alan

[Audio Al]

Very nice :)

[Slammed56]

Lovely machine Alan and a great price too

[Cas]

One word comes to mind here, jealous, very nice find indeed :)

[sussex R2R]

Good machine and a good price,:reel::reel:

[337alant]

Yes it was a good price really compared to what they are going for normally on Ebay plus it was from a HIFI shop who had fully tested it, the photos show the condition, the heads look really good and the fascia is not sticky :D:cool:

I actually got it for £550 as I made him an offer

Ill give it a full service when I get time

Alan

[337alant]

When this B77 arrived I tested everything and it all worked
The pots and switches were scratchy so that means stripping down the lower section as they all screw into the basis board
You also have to remove all the audio boards and all the connecting wires from the back side of this board You can see in the pictures the gold plated switch tracks.
You just have to clean them up along with the switch wipers with a good contact cleaner, spray all your pots and switches.
Make sure all the cable connectors on the back of the board are clean and the long sliding speed switch has multiple contacts that all need cleaning

https://live.staticflickr.com/65535/40650302913_3e4c120aef_c.jpg (https://flic.kr/p/24W8qPB)IMG_2282 (https://flic.kr/p/24W8qPB) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr

https://live.staticflickr.com/65535/33739524928_d083e92574_c.jpg (https://flic.kr/p/TprTi3)IMG_2285 (https://flic.kr/p/TprTi3) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr

https://live.staticflickr.com/65535/33739521548_e182940399_c.jpg (https://flic.kr/p/TprShL)IMG_2289 (https://flic.kr/p/TprShL) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr

https://live.staticflickr.com/65535/33739572828_41ce93b7de_c.jpg (https://flic.kr/p/Tps8wU)IMG_2323 (https://flic.kr/p/Tps8wU) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr

first job done and all contacts are quiet now

Alan

[337alant]

I started recapping the Audio Boards

Reproduce Amplifier Board before and after
recapped with Nichicon Fine Gold and Elna Silmic2 for all caps in the signal path, also all trim pots replaced

https://live.staticflickr.com/65535/33739464578_a40ae5c231_c.jpg (https://flic.kr/p/Tprzmw)IMG_2358 (https://flic.kr/p/Tprzmw) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr

https://live.staticflickr.com/65535/46892473444_0d5f0bac0a_c.jpg (https://flic.kr/p/2erJbDs)IMG_2373 (https://flic.kr/p/2erJbDs) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr

Record Amplifier board again Nichicon FG and Elna silmic 2 caps and trimpots replaced

https://live.staticflickr.com/65535/46701258445_400599a146_c.jpg (https://flic.kr/p/2e9Qa68)IMG_2294 (https://flic.kr/p/2e9Qa68) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr

https://live.staticflickr.com/65535/33739435458_f5755f91dd_c.jpg (https://flic.kr/p/TprqGs)IMG_2313 (https://flic.kr/p/TprqGs) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr

Alan

[337alant]

The Monitor Amplifier Board before and after, again Nichicon FG and Elna Silmic 2 including trim pots replaced

Note when replacing Trimpots measure the resistance of the one you remove and with the same orientation set the replacement one to the same value so you are some where near the correct value

https://live.staticflickr.com/65535/46892441484_e84cbba4f1_c.jpg (https://flic.kr/p/2erJ29q)IMG_2356 (https://flic.kr/p/2erJ29q) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr

https://live.staticflickr.com/65535/47616652991_52e3d97b22_c.jpg (https://flic.kr/p/2fxHMZH)IMG_2365 (https://flic.kr/p/2fxHMZH) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr

Alan

[337alant]

The Input Amplifier before and after
recap with F&T axial caps and Elna Silmic 2

https://live.staticflickr.com/65535/47616637911_5afa832cc8_c.jpg (https://flic.kr/p/2fxHHvH)IMG_2304 (https://flic.kr/p/2fxHHvH) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr


https://live.staticflickr.com/65535/46701211405_76685d1dd6_c.jpg (https://flic.kr/p/2e9PV76)IMG_2317 (https://flic.kr/p/2e9PV76) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr

Alan

[Firebottle]

Nice work Alan, like the edge adjustable pots on the monitor board. Also have you cleaned the relay contacts on the same board?

[337alant]

Hi Alan
Yes the Piher Trimpots with the edge adjusters are a nifty solution to the pots being banked like that, the original pots were all bent over where someone had been trying to get a screw driver in.

Good point about the relay I will have to have a look at how to get that cover off ?.
I did try head phones into it and they do sound clean on the signal but still worth cleaning whilst its apart

Alan

[337alant]

Capstan Motor Control board recapped with Panasonic FC, bridge rectifier changed, X2 cap had already been renewed

https://live.staticflickr.com/65535/32674015677_e8ab571a83_c.jpg (https://flic.kr/p/RMhSvT)IMG_2230 (https://flic.kr/p/RMhSvT) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr


https://live.staticflickr.com/65535/33739368848_2ca6e053a8_c.jpg (https://flic.kr/p/Tpr5U1)IMG_2235 (https://flic.kr/p/Tpr5U1) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr

Alan

[337alant]

Tape Deck Control Board
This board came with an additional DIY board that had been patched into it
Turns out this add on board is to change the momentary Pause function to a latching pause function
I didnt like this bodge up so I disconnected it.
Turns out you can actually get a plug in board that does the same thing from Revox online so I have ordered one of them, looks a much more professional option
https://www.revox-online-shop.com/zubehoer/pausenschaltung/pausenschaltung-fuer-revox-b77-pause-77-r0023

https://live.staticflickr.com/7884/32624678107_f1b748ed8b_c.jpg (https://flic.kr/p/RGW1b8)IMG_2246 (https://flic.kr/p/RGW1b8) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr

https://live.staticflickr.com/7887/46651618815_13ea6ab2e8_c.jpg (https://flic.kr/p/2e5rJXr)IMG_2247 (https://flic.kr/p/2e5rJXr) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr

https://live.staticflickr.com/7918/47596757421_1466ddc343_c.jpg (https://flic.kr/p/2fvXPJD)IMG_2253 (https://flic.kr/p/2fvXPJD) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr

[337alant]

Been doing some more work on my B77 recently to resolve a few issue’s
I was getting a regular wow from it that I put down to the capstan roller wheel as it was a bit tired but when I got a new one the problem was still there after cleaning the whole tape drive. I thought it might be some oscillation from the capstan drive motor board so I checked out the electrolytics I recapped this board with and they were just general purpose ones from a A77 service kit I bought a while back but they had very low ESR, so I decided to change them back to some new AVX tantalums that I had and this has cured the problem.
https://live.staticflickr.com/65535/48108391378_7aeebde28f_c.jpg (https://flic.kr/p/2gib5FL)Capstan drive board (https://flic.kr/p/2gib5FL) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr

[337alant]

I was never very happy with the corrosion on the main audio switch board so when I seen a decent one come up on ebay for £20 I bought it and switched it over, this board was in very nice condition and had metal film resistors to was a recent version
https://live.staticflickr.com/65535/48108395693_8a0bdf6743_c.jpg (https://flic.kr/p/2gib6Ya)Basis boaerd 2 (https://flic.kr/p/2gib6Ya) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr
https://live.staticflickr.com/65535/48108457817_f7de0ae8b7_c.jpg (https://flic.kr/p/2gibqrg)Basis board 1 (https://flic.kr/p/2gibqrg) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr.

[337alant]

I was also getting some intermittent output fro m the left channel and I traced that to the poor quality RCA sockets which were loose and tarnished.
The RCA plugs on the A77 and B77 are crap and too close together to get the plugs in properly so I bought a set of replacement ones from Revox online in Germany. Fitting was straight forward but yo have to do some work with a round file to accommodate the extra spacing in the new circuit board
I also did away with the 5 pin din radio socket wiring as it was also knackeered.
I changed the 2 output pots for a couple of Sfernice P11S ones I had form a passive pre amp.
This cured the intermittent output so sounding much cleaner now with even channel balance.
Before
https://live.staticflickr.com/65535/48108382933_44f707f7c7_c.jpg (https://flic.kr/p/2gib3ba)Old in out board (https://flic.kr/p/2gib3ba) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr
https://live.staticflickr.com/65535/48108387748_f4191386fd_c.jpg (https://flic.kr/p/2gib4Bb)In out board 2 (https://flic.kr/p/2gib4Bb) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr

After
https://live.staticflickr.com/65535/48108389498_57716ca496_c.jpg (https://flic.kr/p/2gib58m)In out board (https://flic.kr/p/2gib58m) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr
https://live.staticflickr.com/65535/48108384818_0f0d6dd72f_c.jpg (https://flic.kr/p/2gib3JE)New RCA Board (https://flic.kr/p/2gib3JE) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr
https://live.staticflickr.com/65535/48108738153_c3e8b85b78_c.jpg (https://flic.kr/p/2gicRLD)IMG_2456 (https://flic.kr/p/2gicRLD) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr

[337alant]

My record board didn’t have the muting circuit board so again I picked a one up from ebay and fitted it
Whilst I had everything apart I also changed out all the carbon film resistors directly in the signal path for Takman Rey metal films on the input, record and reproduce boards
https://live.staticflickr.com/65535/48108450662_65900c9a67_c.jpg (https://flic.kr/p/2giboiU)Muting circuit board (https://flic.kr/p/2giboiU) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr

[337alant]

So after all this I calibrated the deck for RTM LPR90 tape and the frequency response form it is within +- 1 db and it sounds really good
Here is a short video of the calibration check after adjustment, input was from an NTI Minirator MR Pro signal generator and the output was monitored with a Leader 186A dual channel AC Voltmeter all set for -10dB


https://www.youtube.com/watch?v=t5GNxtpHkMA

[337alant]

Just got round to painting the back panel on my B77 when I first got this machine the nextel was not sticky but after a few months it is now? .
So after removing the sticky Nextel coating and a good rub down and de-grease with panel wipe, I gave it 2 coats of Halfords Gray Primer.
The best match I could find for the colour of the front panel was peugeot graphite grey metallic which needs a couple of clear lacquer coat as well.
These aren't the best spray cans but did a half decent job in the end

https://live.staticflickr.com/65535/48608342558_a22fa3b303_c.jpg (https://flic.kr/p/2h4msKG)IMG_2477 (https://flic.kr/p/2h4msKG) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr

https://live.staticflickr.com/65535/48608851857_b8843309fd_c.jpg (https://flic.kr/p/2h4p59H)IMG_2507 (https://flic.kr/p/2h4p59H) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr

https://live.staticflickr.com/65535/48608701446_8acf1f9f34_c.jpg (https://flic.kr/p/2h4oirq)IMG_2512 (https://flic.kr/p/2h4oirq) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr

https://live.staticflickr.com/65535/48608851632_4a02c59ae9_c.jpg (https://flic.kr/p/2h4p55Q)IMG_2509 (https://flic.kr/p/2h4p55Q) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr

Alan

[337alant]

Checking the Frequency response after calibration for RTM LPR90 tape

https://www.youtube.com/watch?v=t5GNxtpHkMA

Alan