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should i buy?? 1 x Revox A 700 / 1 x Revox A77 / Studer B 67 mk 2!
Old 21st July 2011
  #1
Gear Maniac
 
ArisA's Avatar
 

should i buy?? 1 x Revox A 700 / 1 x Revox A77 / Studer B 67 mk 2!

Hi all,

I have the possibility to buy tape machines:

1 x Revox A 700
1 x Revox A77
Studer B 67 mk 2!

I think i will get them for a DAMN good price. He asks for about 1000$ for the studer. Dont have prices for the others yet. Should i get all of them even if i dont need em and sell them?

Does anybody have some infos to share of these babies? What should i pay for them? They are in very good condition as he told me. What should i be aware if aso?!?

Thanks alot

ArisA
Old 21st July 2011
  #2
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skythemusic's Avatar
I recently paid $500 for a B67. It is needing nearly that in maintenance so if you paid $1000 make sure it is fully gone through by a tech and fully functioning.
Old 21st July 2011
  #3
Gear Guru
 
John Willett's Avatar
 

In this order:-

Studer B67
Revox A700
Revox A77

I would put the Revox PR99 and B77 ahead of the A700 and A77 - I always found the A77 distorted earlier than the older G36 and later B77.


Posted via the Gearslutz iPhone app
Old 17th August 2011 | Show parent
  #4
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Studer_A80's Avatar
 

just go for the STUDER B67.......but don't forget whatever the price is, the maschine will only perform at is best when it has being fully inspected and freshly calibrated....!
Old 17th August 2011 | Show parent
  #5
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Hornblower64's Avatar
 

Sold my PR99 after acquiring a B67; the Studer is much better than any Revox. I use a Nagra VI now; mostly remotes, 6/8 channels, easy on the back, but I will not be selling the Studer. $1k is fair if it's in good shape. Have it looked over by a qualified technician first, if you can.
Old 17th August 2011 | Show parent
  #6
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ddageek's Avatar
 

I'll take the one in the best condition! If you don't know which to buy condition trumps all! If you can't judge condition be prepared to spend a ton!
Old 18th August 2011
  #7
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vincentvangogo's Avatar
 

If you go for the Revox check it runs at 15ips.
Old 18th August 2011
  #8
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crosscutred's Avatar
B67, no contest.
Old 20th August 2011 | Show parent
  #9
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pqlia's Avatar
I wish i had at least two of the listed machines so that i could be more helpful - but i've only ever used the A700 which was given to me.

I spent £100 to get it set up and repaired. I dont know how it compares to the others but i do know that it's very clean and precise sounding at 15ips and not at all like how some people expect tape to sound. It's in no way 'dull' sounding - but it 'glues' audio elements together in the most beautiful way.

It's input overloads fairly quickly and i dont even expect to totally mask any noise to any great degree.

I've found that it's signal path sounds great, and adds something desirable even before anything goes to tape!

However i'm not technical at all so i panic a little everytime i turn it on! - it's from 1974! and has been up in smoke twice! so if you are not technical too, then it may be best to get the machine which is the most serviceable and that's in the bet condition.

All the best.
Old 20th August 2011 | Show parent
  #10
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John Willett's Avatar
 

Quote:
Originally Posted by pqlia View Post
- but i've only ever used the A700 which was given to me.

<snip>

It's input overloads fairly quickly.
Sounds to me it has the same circuitry as the A77 as that was like this as well.

The earlier G36 and the later B77 and PR99 were better in this respect.
Old 20th August 2011 | Show parent
  #11
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pqlia's Avatar
Quote:
Originally Posted by John Willett View Post
Sounds to me it has the same circuitry as the A77 as that was like this as well.

The earlier G36 and the later B77 and PR99 were better in this respect.
Quote:
Originally Posted by Rick Sutton View Post
One thing that I remember about the A77 I had was that it had an amplifier in line on the inputs that couldn't take a full +4 level without clipping. The amp was before the input volume control so that didn't help. I installed a couple of 10k trim pots just after the RCA inputs and dropped the level by about 10dB and the problem was solved. Just a "heads up".
IF i knew what i was doing i'd love to try the above!!

With my very limited understanding of electronics would i be correct to assume from the above that the input just needs to be 'padded' down?? Like how you sometimes need to pad down a preamp input to prevent it from overloading? Is it the same principle?

Thanks.
Old 20th August 2011 | Show parent
  #12
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pqlia's Avatar
Sorry for taking the thread off into a little tangent but i read a GS post by Bob Ohlsson once who said that both the A700 and the A77 had low input headroom but he knew of an engineer who worked at Abbey Road who somehow bypassed the input electronics so that the input was routed more directly to the record heads - that's as much as i understood.

After the mod the input headroom was greatly improved.

I tried to find the thread here on GS but didnt manage to.

Peace.
Old 20th August 2011 | Show parent
  #13
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DarkSky Media's Avatar
Quote:
Originally Posted by crosscutred View Post
B67, no contest.
Agreed.
Old 20th August 2011 | Show parent
  #14
Motown legend
 
Bob Olhsson's Avatar
 

Actually I saw a bunch of A-77s at Abbey Road in the summer of 1968 and they told me about the mod when I asked about the machines.

With the mod my A-77 always sounded better than the A-700s and B-77s I tried.
Old 20th August 2011 | Show parent
  #15
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pqlia's Avatar
Quote:
Originally Posted by Bob Olhsson View Post
Actually I saw a bunch of A-77s at Abbey Road in the summer of 1968 and they told me about the mod when I asked about the machines.

With the mod my A-77 always sounded better than the A-700s and B-77s I tried.
There you go . . . the man himself!!!

Thanks for making an appearance!

I imagine there'd be a big demand for that mod now with all the renewed interest in A77, 700 etc.

I'm wondering what the first step would be to find out more about that modification? I have a feeling the details may be long lost . . . but wouldnt it be great if we hobbyists (and pros) could improve on the already great sound?
Old 20th August 2011 | Show parent
  #16
Quote:
Originally Posted by pqlia View Post
There you go . . . the man himself!!!

Thanks for making an appearance!

I imagine there'd be a big demand for that mod now with all the renewed interest in A77, 700 etc.

I'm wondering what the first step would be to find out more about that modification? I have a feeling the details may be long lost . . . but wouldnt it be great if we hobbyists (and pros) could improve on the already great sound?
Revox is for amateurs. their transport sux and unbalanced input-section is a pita..

the A-77 or 700 are not worth modding, if you don't live in 1977 in the abbeyroad studios...

B-67 in good shape.. there you go.
Old 20th August 2011
  #17
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s.d.finley's Avatar
Great thread! Kinda OT I recently aquired a Revox PR99 mkII. Any mods or advice/user expeirence with these? It does 15ips but one channel is out. :-(
Old 20th August 2011 | Show parent
  #18
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pqlia's Avatar
Quote:
their transport sux
I cant tell if you're having a laugh! .... i'm only a hobbyist these days so not really qualified to contest what you've stated... though i've heard and read some great things about the A700 transport.

Quote:
and unbalanced input-section is a pita..
Yes. they were designed as consumer models - the unbalanced thing frustrates me too sometimes.

Quote:
the A-77 or 700 are not worth modding, if you don't live in 1977 in the abbeyroad studios...
Not worth modding because they're not great... in your opinion?
or because they have all been 'trashed to death' in amateur broadcast studios?

and yes, i've heard that the B67 is very well respected - though i have no first hand experience of it.
Old 20th August 2011
  #19
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EV676's Avatar
The TV station I work for had 5 B-67s, all purchased in the early to mid 80s.. One was sold, the second was given to a friend of mine, the other three are all functioning. Now they rarely get turned on and regular maintainance stopped several years ago but I fired one up just last week to dub a tape that was recorded at 3 3/4ips and it worked fine.

Remember these machines sold for 4-5K in the early 80's.

They are workhorse machines, not as sophisticated as an A-80 or the 8XX models but reliable none the less. The only sticking point are those ITT pushbutton switches which were crappy when they were new. MCI had those things as well.

The C-270 Revox isn't a bad machine either. I have one of those at the station too.
Old 20th August 2011
  #20
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cdog's Avatar
Quote:
Originally Posted by pqlia View Post
.

Not worth modding because they're not great... in your opinion?
or because they have all been 'trashed to death' in amateur broadcast studios?

and yes, i've heard that the B67 is very well respected - though i have no first hand experience of it.


Yeah, hes saying dont bother having it modded because its consumer grade...

But consumer grade from the 70s is pretty decent compared to anything today made of plastic in china for $.02!
Old 20th August 2011 | Show parent
  #21
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pqlia's Avatar
Quote:
Originally Posted by cdog View Post
Yeah, hes saying dont bother having it modded because its consumer grade...

But consumer grade from the 70s is pretty decent compared to anything today made of plastic in china for $.02!
arrrgh! I was a bit slow on the uptake!

Consumer grade maybe, but it was given to me and i only paid £100 to bring it back to life. I could've paid that for a tape emulation plug.

I will say that i was completely surprised at the sound when i first heard it. I expected all the top end to be rolled off and some kind of glowing bloom, and fuzzy, sepia, nostalgic retro tone.

Instead it sounded clean, precise, accurate, not 'shut in' at all with full range 'beaty' music. (admittedly it can be a fight against noise with some quiet single instruments and i've never tried to subject a piano to it's wow and flutter!) I was only a kid in 1974 so didnt know anything about the A700 or any Revox for that matter. I was surprised that a machine from 1974 could sound like that. I played a recording against it's source to my 17 year old music technology studying nephew and he was surprised too - he thought i was playing a trick on him in fact.

I think many people would be surprised if they'd never heard one.
Old 20th August 2011 | Show parent
  #22
Motown legend
 
Bob Olhsson's Avatar
 

The EMI mod was simply re-connecting the inputs to the record pots thus bypassing the mike preamps.

You'd also need to replace the caps, the alignment trim pots can be loose and there's a problem with the head connections getting pinched and broken by the front panel. Finally, the high speed two tracks were commonly used as part of broadcast automation systems which means lots of used ones are going to have heads and bearings in pretty rough shape.

My machine was only used occasionally at home, has all high-end film caps and has actually won shootouts with stock ATR-100s. It's a very simple design compared to their later models and the heads and transport were really good compared to most machines in the late '60s.
Old 21st August 2011 | Show parent
  #23
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pqlia's Avatar
Quote:
Originally Posted by Bob Olhsson View Post
The EMI mod was simply re-connecting the inputs to the record pots thus bypassing the mike preamps.

You'd also need to replace the caps, the alignment trim pots can be loose and there's a problem with the head connections getting pinched and broken by the front panel. Finally, the high speed two tracks were commonly used as part of broadcast automation systems which means lots of used ones are going to have heads and bearings in pretty rough shape.

My machine was only used occasionally at home, has all high-end film caps and has actually won shootouts with stock ATR-100s. It's a very simple design compared to their later models and the heads and transport were really good compared to most machines in the late '60s.
Many thanks Bob. Appreciated! I dont feel confident enough to perform the mod but the guy who serviced the A700 will most probably have the knowledge to do it. I'd be afraid of upsetting something in the process and not knowing how to rectify it. The guy who repaired the A700 said that it did have a bit of head wear but not to any great detriment of the sound. I treat it with 'kid gloves' as the original caps smoked twice and had to be replaced with new ones. I only use it for tape compression of selected parts, out and back into DAW but i'm so curious to hear how much of a difference the mod makes... who knows, one day i may feel brave and venture inside with a soldering iron!

Regards.
Old 21st August 2011 | Show parent
  #24
Gear Addict
 

Quote:
Originally Posted by Bob Olhsson View Post
The EMI mod was simply re-connecting the inputs to the record pots thus bypassing the mike preamps.

You'd also need to replace the caps, the alignment trim pots can be loose and there's a problem with the head connections getting pinched and broken by the front panel. Finally, the high speed two tracks were commonly used as part of broadcast automation systems which means lots of used ones are going to have heads and bearings in pretty rough shape.

My machine was only used occasionally at home, has all high-end film caps and has actually won shootouts with stock ATR-100s. It's a very simple design compared to their later models and the heads and transport were really good compared to most machines in the late '60s.
that's a nice mod. i'll have too look out for one of those.
Old 21st August 2011 | Show parent
  #25
Here for the gear
 
Kid_Baldon's Avatar
 

I have a very good friend who has used an A-77 for years. A beautiful machine, if it's serviced and on top form. The transport certainly doesn't suck. It's all a matter of opinion.
Old 22nd August 2011 | Show parent
  #26
Quote:
Originally Posted by Kid_Baldon View Post
I have a very good friend who has used an A-77 for years. A beautiful machine, if it's serviced and on top form. The transport certainly doesn't suck. It's all a matter of opinion.
it sux if you stop comparing it to Ampex, 3M and whatever there was... compare it with a80, a800...
Old 23rd August 2011 | Show parent
  #27
Gear Head
 
BertilAlving's Avatar
 

The Revox A-77 didn't have very good electronics, but it was not too difficult to modify the input and output stages and thus getting top performance.

In 1976 I used my modyfied 15 ips A-77 and two mikes in A-B configuration when I made the quite famous classical recording of "Cantate Domino" (for the Swedish label Proprius).

Best regards,
Bertil
Old 23rd August 2011 | Show parent
  #28
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pqlia's Avatar
Quote:
Originally Posted by BertilAlving View Post
The Revox A-77 didn't have very good electronics, but it was not too difficult to modify the input and output stages and thus getting top performance.

In 1976 I used my modyfied 15 ips A-77 and two mikes in A-B configuration when I made the quite famous classical recording of "Cantate Domino" (for the Swedish label Proprius).

Best regards,
Bertil
Would i be right in saying that you are he who this has been quoted of:
Quote:
''Cantate Domino, recorded by legendary sound engineer Bertil Alving in 1976, is widely regarded as one of the greatest audiophile masterpieces ever recorded'' {www.hdtracks.com}
If so, I can't wait to hear it over my monitors!

I'm amazed at how all this is relative! To me my A700 is the best sounding 2 track recorder i've used - which certainly more than anything only shows my inexperience with decent sounding recording devices. (I'm not a pro, certainly not these days)

Obviously you have a great deal of experience so i'm wondering if you can quantify ''not very good'' electronics. - Why were the electronics poor (in laymans terms) and how did this failing manifest itself in terms of sound. poor signal to noise? poor frequency linearity? Also, how did the modifications benefit the sound quality. . . did the mod give a very subtle improvement or was it quite noticable?

I'm getting very curious about this mod. although i've been advised against modding it by those 'in the know' - due to it being consumer level and antiquated.

Many thanks in anticipation for your help.
Old 23rd August 2011 | Show parent
  #29
you caught me in the wrong time dimension... I can not reply as dr. bill right now.. lack of time.

simple things to check why the Revox line was poor:
transport
unbalanced input
input gain stage was kinda.. toysRus
headstock
tape speed

I agree, that you can record with those.. you may even record a fantastical piece of music with it. but to be honest.. something like the one mentioned with a stereo pair of mics into a machine, hit record... you can't go wrong (if you know the mic placement issues.. which I don't... ).

Quote:
Originally Posted by pqlia View Post
Would i be right in saying that you are he who this has been quoted of: If so, I can't wait to hear it over my monitors!

I'm amazed at how all this is relative! To me my A700 is the best sounding 2 track recorder i've used - which certainly more than anything only shows my inexperience with decent sounding recording devices. (I'm not a pro, certainly not these days)

Obviously you have a great deal of experience so i'm wondering if you can quantify ''not very good'' electronics. - Why were the electronics poor (in laymans terms) and how did this failing manifest itself in terms of sound. poor signal to noise? poor frequency linearity? Also, how did the modifications benefit the sound quality. . . did the mod give a very subtle improvement or was it quite noticable?

I'm getting very curious about this mod. although i've been advised against modding it by those 'in the know' - due to it being consumer level and antiquated.

Many thanks in anticipation for your help.
Old 23rd August 2011 | Show parent
  #30
Gear Head
 
BertilAlving's Avatar
 

Quote:
Originally Posted by pqlia View Post
Would i be right in saying that you are he who this has been quoted of:
Quote:
''Cantate Domino, recorded by legendary sound engineer Bertil Alving in 1976, is widely regarded as one of the greatest audiophile masterpieces ever recorded'' {www.hdtracks.com}
If so, I can't wait to hear it over my monitors!
Yeah, that's me and my recording...

This is many years ago and I don't remember in detail all the modifications I made with the A-77 (and I don't have the schematics anymore). But the low quality input cards were removed and I connected the line level from my custom built mic preamp directly to the potentiometers (as already mentioned in this thread). The stage between the potentiometers and the record head was of bad design and had quite high distortion, so I rebuild that stage to get lower distortion. The playback output stage has very high noise level in original (more hiss than from the tape, if I remember correctly) so that stage was redesigned for a much lower noise.

In my opinion the tape transport of the 15 ips speed A-77 was not too bad regarding wow/flutter and scrape flutter (modulation noise), but the quality of fast wind/rewind was terrible... it was necessary to brake the supply reel a little bit with a finger or the thumb when spooling for getting an acceptable tape cake... Today I would probably go for a Studer B-67, it's a much more pro machine (however, today I'm a happy owner of an Ampex ATR-102).

It's worth mentioning that if the 15 ips A-77 has NAB equalization it should be modyfied to use CCIR/IEC equalization for getting a better signal-to-noise ratio (I went yet further and used an unorthodox equalization beyond CCIR and therefore I got a very low tape noise).

Here is an excerpt from the record "Cantate Domino" (the end of track 1: choir, organ and brass ensemble) recorded in 1976 on the A-77 (no Dolby) with only 2 microphones. In 1993 I made this digital transfer (a number of transfers have been made over the years without my supervision).

Cantate Domino, the end.mp3

EDIT: I uploaded a new slightly longer file with possibly better mp3-conversion.
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