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REVOX B77 Mk 2

beans said:
I went on and picked up the B77 for $200. It is a half-track Mk II, and I was close to calling the whole deal off since I don't know how much I'll use it in light of that. The only reason I went ahead with it is because he threw in all of his tapes... 4 blank Maxell XLI 35-180B and 4 Quantegy/Ampex 456. It has issues, so I am going to restore it then see how much I use it. It needs a pinch roller kit and one of the meters is not working. But the big thing is that I think it needs new heads. Also the counter isn't working.
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I managed to get a box of 10 meters for the B77 in an auction a few years ago, I only needed two of them. If you want to pay the postage you are welcome to one to replace the broken meter. The ones I have are all as new! (taken out of new pr99s when the meters were uprated to digital ones before delivery), pm me if I can help you. The pinch roller is available from Italy on "THAT" auction site for a good price!
 
Boy, was I wrong. I'M STOKED!!!!
Last night I cleaned the heads as well as I could with rubbing alcohol and a Qtip and mounted a tape. It sounded MUCH better and I'm getting clear sound from both sides now, so that means I won't be replacing the heads any time soon. Without the capstan engaged I just turned the reel by hand to get sound out of it. The best thing is that I've now proven that I was wrong about it being half-track. The only way I could have been happier is if were auto-reverse, but I'm still thrilled about it.
Many thanks to Persil :bigok:
 
beans said:
Can anyone tell for sure if this is a half-track head?
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=190247286520

I wrote the seller and he said "yes" but was a little vague and I can't tell for sure... but I think he's right. Hell, I thought my deck looked like it was half-track but that turned out to be wrong.
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Yep! thats a half track record head (and very very cheap!) the two wider outer bands are the heads and the narrower inner bands are the guard bands.

There should be a lable on the rear of the machine (next to the power and audio sockets) saying "2 stuck" or "4 stuck" to identify the configuration.

persil
 
persil said:
Yep! thats a half track record head (and very very cheap!) the two wider outer bands are the heads and the narrower inner bands are the guard bands.

There should be a lable on the rear of the machine (next to the power and audio sockets) saying "2 stuck" or "4 stuck" to identify the configuration.

persil
Click to expand...

Thank you for that, Persil. You've been a huge help. I will look for the configuration label, but it plays my quarter track tapes correctly, front and back.
That is such a good price I now kinda wish I had a half-track :D
 
So, from what you say Beans, I understand that your deck's heads are 4 tracks. Right?

The head you found on that auction is a 2 track PB head. The 2 track heads have part codes that end in 22 for PB and 27 for REC. The 4 track heads have codes that end in 42 and 47.

The PB heads have that green paint spot and the REC heads a red one.

If you click on that picture a slideshow of larger pics will show the head from different angles. That particular head is in mint condition. Actually, I should even say unused, as I cannot see any solder on the leads. This is probably a spare head never used before. I would guess it will sell in excess of $80~100.
 
SaSi said:
So, from what you say Beans, I understand that your deck's heads are 4 tracks. Right?

The head you found on that auction is a 2 track PB head. The 2 track heads have part codes that end in 22 for PB and 27 for REC. The 4 track heads have codes that end in 42 and 47.

The PB heads have that green paint spot and the REC heads a red one.

If you click on that picture a slideshow of larger pics will show the head from different angles. That particular head is in mint condition. Actually, I should even say unused, as I cannot see any solder on the leads. This is probably a spare head never used before. I would guess it will sell in excess of $80~100.
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It must be quarter-track because last night it played a tape correctly in both directions... and yes I made sure I was playing a section of tape that had signal on both. Tonight I will look for those markings and get back...
 
Just a correction from my part. The REC heads are the ones with the Green spot. The PB heads have a Red spot.
 
SaSi said:
Don't even mention it. I've received ample help from lot's of good guys here. Just returning as much as I can.:smoke:
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Very good. I just don't have as much to offer as a lot of others, but I help out when I can.
 
SaSi said:
So, from what you say Beans, I understand that your deck's heads are 4 tracks. Right?

The head you found on that auction is a 2 track PB head. The 2 track heads have part codes that end in 22 for PB and 27 for REC. The 4 track heads have codes that end in 42 and 47.

The PB heads have that green paint spot and the REC heads a red one.

If you click on that picture a slideshow of larger pics will show the head from different angles. That particular head is in mint condition. Actually, I should even say unused, as I cannot see any solder on the leads. This is probably a spare head never used before. I would guess it will sell in excess of $80~100.
Click to expand...

Well, SaSi, I couldn't see the head markings but it does have a tag on the rear apron that says 4-TRACK.. in english!
 
Slightly off topic (and my apologies to the OP for the jack) but what would be considered a "fair" price for an A77 MkIII with two 10.5" NATB reels. It plays but is definately "used". Seen one at a yard sale yesterday but was marked at $300 which seemed a bit much, so I just took the guys number. Too much??
WOT
 
$300 if it's in good working order (good heads, caps changed, new trim pots installed) is about right. That's about what I have invested in mine. If it's not up to snuff, that's a bit steep indeed. I bought two A77 basket cases (albeit working ones) with fair cosmetics for $40 (as a point of reference).
 
If find it steep right off the bat...

But if the heads are good and everything is well-fuctionnal (brakes, motors, pinch roller...) aside from the looks... it could be worth looking at.

You're likely to find one for cheaper if you keep looking though... I got mine for 30 bucks. I got lucky but still...

Actually, there is a guy here in montreal who gave me a boxful of old tape I needed... He also had two A77's MKIII 15ips with brand new heads. He had replaced them in '88 just before getting a huge contract that enabled him to buy digital equipment. He's selling one for 300$ canadian. Tip top shape... amazing, in fact...
 
UPDATE: Got new meters (thanks, persil!) and installed the pinch roller/tape counter kit. The sound is awesome, and everything works except the VU limit LEDs on the meters, but that's my fault I'm sure. I'm afraid I ran the machine with those leads to the LEDs shorted and damaged the circuitry.
I wish I had paid the extra $20 for the bigger repair kit (Italy) instead of the pinch roller kit. Last night I hit rewind, then stop, but the hub brakes on this thing aren't working and I had to catch the takeup reel before tape went flying all over the room. Sadly, though, I grabbed it too quickly and the tape snapped, jerking it up into the side of the supply reel. Ruined that section of my "Ghost In The Machine" tape :tears:
What can I do for the brakes until I can fix them, too? Any adjustments possible?
 
What you can do until you repair them is the following:
When rewinding, to stop the tape, you press FF and wait for the tape to slow down close to stop. At that moment, you press Stop. Then Play. When you FF, in order to stop the tape you press REW, wait for the tape to slow down to a stop and before reversing direction, press STOP.

May sound cumbersome, but in reality this is what more sophisticated machines do with electronic brakes.

I think the practice even has a name, "rocking the wheels".
 
Thanks for that, SaSi.
As for these LEDs, they are definitely not shorting as before. Since this meter assy is newer, from a PR99, is it a matter of calibration/adjustment? Or have I definitely fried something?
 
It could well be a matter of adjustment. On the PR99 there are two trimmers that control when these LEDs light up. "Unfortunatelly" my B77 came in pristine condition and I never had a chance or reason to check calibration or the circuits.

I suspect it should have similar controls though. Do you have a service manual? I just had a look in that and in section 6.4.6 it states that the overload indicators are "calibrated" by the values of R37 & R34 in the monitor amplifier (1.177.260). In newer versions (I suspect MkII) these resistors are replaced by trimpots R30 & R38.

These trimpots, if available, should be accesible from the bottom of the machine, however, unlike the PR99 where they are readily available through the bottom, in the case of the B77 you need to remove the unit from it's housing and lay it on it's back. Then you have access to the trimmers at the bottom.
 
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