Nagra reel recorder maintenance and adjustments

[rstl...@gmail.com]

Hi folks
I seem to be getting back into older Nagras. Just picked up a mint condition 4.2L from the original owner's estate, with accessories etc., works flawlessly even though it was in storage for 10 years. And on the way is a IV-S from an out-of-town estate sell-off (not sure of the condition of that one, so may be DOA). I own an older well-used ex-public TV 4.2, and have over the years owned and sold two IV-Ss. I have all the service manuals, some calibration tapes, and a bit of know-how (not very strong in electronics, but I can use a volt-meter, follow a manual and decipher some circuit diagrams if necessary).

I'd like to maintain, calibrate and adjust my Nagras as a hobby (I'm now retired). I also own other reel decks (Ampex 440s, Teac, Tascam, Uher) and may work on those too. As a labor of love kind of thing, because paying money to ship and get these units repaired is no longer sensible, for a non-pro enthusiast like myself).

What would be some good tools for me to acquire, to help me in this task?

Eventually, I'd like to seek out a source of affordable NOS parts for Nagra consumables (belts, pinch roller, etc.). And maybe tools, from a shop no longer servicing these little gems.

Thanks!
--Robert

[John Williamson]

That last is going to be your major problem. The normal problems with
old tape decks are the rubber parts perishing with age and head wear.
There are places that can refurbish old parts, and they have been
referred to on this group in the past.

Other than that, for the electronics, you'll need decent multimeters
(Both a 20Kohm/ volt type for the older stuff, preferably an Avo Model 8
or equivalent, if you're working on European stuff, and a 10 Meg input
impedance type for the newer stuff) and (ideally a dual beam) 'scope,
and possibly a frequency meter.

Mechanically, apart from the normal screwdrivers, nut drivers, small
spanners, tweezers, small pliers and such, you'll need a tape tension
meter, which can be as simple as a 100 gramme spring balance or as
complicated as a dedicated unit, especially if you're repairing cassette
mechanisms. A headworn magnifier can also be very helpful.

A delicate touch is also compulsory. :-)

--
Tciao for Now!

John.

[Scott Dorsey]

<rstl...@gmail.com> wrote:
>I seem to be getting back into older Nagras. Just picked up a mint conditi=
>on 4.2L from the original owner's estate, with accessories etc., works flaw=
>lessly even though it was in storage for 10 years. And on the way is a IV-=
>S from an out-of-town estate sell-off (not sure of the condition of that on=
>e, so may be DOA). I own an older well-used ex-public TV 4.2, and have ove=
>r the years owned and sold two IV-Ss. I have all the service manuals, some=
> calibration tapes, and a bit of know-how (not very strong in electronics, =
>but I can use a volt-meter, follow a manual and decipher some circuit diagr=
>ams if necessary).
>
>I'd like to maintain, calibrate and adjust my Nagras as a hobby (I'm now re=
>tired). I also own other reel decks (Ampex 440s, Teac, Tascam, Uher) and m=
>ay work on those too. As a labor of love kind of thing, because paying mon=
>ey to ship and get these units repaired is no longer sensible, for a non-pr=
>o enthusiast like myself).
>
>What would be some good tools for me to acquire, to help me in this task? =

You will need a scope, a signal generator, and an accurate external VU
meter. You will need a set of small nonmagnetic screwdrivers. For the 4.2L
you will need a tentelometer. Everything else is pretty much your standard
electronics toolkit.

The only special tooling you'll need on any of those machines is a shorting
bar tool to remove the motor armature without damaging the magnets. You will
probably not need that unless you need new motor bearings (and if you DO need
new motor bearings, it will be easier to just send it to Dan Dugan for repair).

Download the service manuals and read them cover to cover. They describe
all the repair procedures in detail.

>Eventually, I'd like to seek out a source of affordable NOS parts for Nagra=
> consumables (belts, pinch roller, etc.). And maybe tools, from a shop no =

>longer servicing these little gems.

All the standard film sound guys still work on these things, they are not
hard to find parts for or get repair work done. Nagra still has pinch rollers
and bearings and belts. You can sometimes get cheaper belts from Russell
Industries.

Unlike the Uher and Teac machines, there is still good manufacturer support
for these things, it's just expensive. (There is good aftermarket support
for the Ampex machines and Saul Mineroff's kid is still doing some Uher
repair work.)
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[rstl...@gmail.com]

> "C'est un Nagra. C'est suisse, et tres, tres precis."

Indeed!

Thanks John and Scott, for the informed and detailed list of things I would need to tackle work on these fine machines. In addition to acquiring necessary knowledge and a "delicate touch", as suggested!

Anyway, both the 4.2's work reasonably well, the one I just acquired looks absolutely in mint condition. I can start fooling around with the older 4.2, which has wear and tear and could probably use a bit of a helping hand. One thing I'll need to do is setup the bias on the "newer" 4.2 to the tape stock I have here (966), I'll read up on that and hopefully that can be my first successful tweak.

We'll see in what shape the IV-S I'm waiting for will be in, it may well need some tweaking (or major surgery)... I didn't pay much for it, for that reason.
I'll let you know how I make out, and may ping the list for a few tips from time to time, if that's ok.

Thanks again for sharing your knowledge and experience!
--Robert

[Scott Dorsey]

<rstl...@gmail.com> wrote:
>> "C'est un Nagra. C'est suisse, et tres, tres precis."
>

>Anyway, both the 4.2's work reasonably well, the one I just acquired looks =
>absolutely in mint condition. I can start fooling around with the older 4.=
>2, which has wear and tear and could probably use a bit of a helping hand. =
> One thing I'll need to do is setup the bias on the "newer" 4.2 to the tape=
> stock I have here (966), I'll read up on that and hopefully that can be my=
> first successful tweak.

If it's more than a decade since it was PM'ed, it needs a new pinch roller.
You may think it's fine, but I'd get the rubber rebuilt.

I have not seen 966 for years. I have no idea if it will bias up properly.
If you mean the more common 996, it will definitely not bias up on those
machines.

The Nagra machines are also VERY touchy about slitting because of the somewhat
crude guide design. If the tape is poorly slit (and every tape Ampex ever
made was poorly slit, although I don't know about any of the 3M tapes other
than 807), the azimuth will wander. You'll see it on the scope when you
try and set it up.
--scott

--

[rstl...@gmail.com]

On Thursday, November 29, 2012 11:54:41 AM UTC-5, Scott Dorsey wrote:

> If it's more than a decade since it was PM'ed, it needs a new pinch roller.
>
> You may think it's fine, but I'd get the rubber rebuilt.
>
>
>
> I have not seen 966 for years. I have no idea if it will bias up properly.
>
> If you mean the more common 996, it will definitely not bias up on those
>
> machines.
>
>
>
> The Nagra machines are also VERY touchy about slitting because of the somewhat
>
> crude guide design. If the tape is poorly slit (and every tape Ampex ever
>
> made was poorly slit, although I don't know about any of the 3M tapes other
>
> than 807), the azimuth will wander. You'll see it on the scope when you
>
> try and set it up.
>
> --scott

I got the Scotch 966 (a couple of boxes of pancakes) some years ago when I bought a IV-S from a sound recordist at Cornell University. They used Nagras to record bird and animal sounds all over the planet, and this is the tape they biased the machines to. They were getting out of analog so I got a good deal on the recorder, and the tape supply. So I'm reasonably confident that it will bias well.

You're probably right on the pinch roller. I've seen worse, and I've seen better than the one on this 4.2. I thought I was getting out of Nagras a couple of years ago and sold off parts on Ebay, including a new pinch roller... I know there are places who will reline them, so it's probably better to go that route than source a new one ($$$)

Not sure about the slitting issue you mention, but I'll look into it.

Cheers.

[Mike Rivers]

On 11/29/2012 8:35 AM, rstl...@gmail.com wrote:

> Eventually, I'd like to seek out a source of affordable
> NOS parts for Nagra consumables (belts, pinch roller,
> etc.). And maybe tools, from a shop no longer servicing
> these little gems.

Take a look at the head alignment adjustment. If it looks
like a gear underneath the head you'll need a special
alignment tool. They're scarce. It looks like a stubby
screwdriver with a (mating) gear cut along the shaft and a
pin sticking out of the end that holds it to the top plate
while you're adjusting the head.

--
"Today's production equipment is IT based and cannot be
operated without a passing knowledge of computing, although
it seems that it can be operated without a passing knowledge
of audio." - John Watkinson

http://mikeriversaudio.wordpress.com - useful and
interesting audio stuff

[rstl...@gmail.com]

On Thursday, November 29, 2012 1:12:16 PM UTC-5, Mike Rivers wrote:
> Take a look at the head alignment adjustment. If it looks
>
> like a gear underneath the head you'll need a special
>
> alignment tool. They're scarce. It looks like a stubby
>
> screwdriver with a (mating) gear cut along the shaft and a
>
> pin sticking out of the end that holds it to the top plate
>
> while you're adjusting the head.

Thanks Mike. I took a picture of one head on my 4.2 which I loaded up here:

http://i1077.photobucket.com/albums/w477/rstl99/Nagra/nag42headadjust.jpg

Looks like a small Allen socket, and the instruction manual refers to using a demag'd 2.5mm Allen key. Are we talking about the same thing?

[rstl...@gmail.com]

In looking at the interior of my two Nagra 4.2's, I notice a short piece of frayed copper wire soldered to a plate, the open end of the wire resting on the rubber belt above and to the right of the motor. What is the significance of this wire, and is there a reason it's making contact with the belt? Should it?

http://i1077.photobucket.com/albums/w477/rstl99/Nagra/nag42copperbelt.jpg?t=1354223418

[Scott Dorsey]

<rstl...@gmail.com> wrote:
>In looking at the interior of my two Nagra 4.2's, I notice a short piece of=
> frayed copper wire soldered to a plate, the open end of the wire resting o=
>n the rubber belt above and to the right of the motor. What is the signifi=
>cance of this wire, and is there a reason it's making contact with the belt=
>? Should it?

Read the manual. It discharges static.

[Scott Dorsey]

In article <k988i6$g8r$1...@dont-email.me>,

Mike Rivers <mri...@d-and-d.com> wrote:
>On 11/29/2012 8:35 AM, rstl...@gmail.com wrote:
>
>> Eventually, I'd like to seek out a source of affordable
>> NOS parts for Nagra consumables (belts, pinch roller,
>> etc.). And maybe tools, from a shop no longer servicing
>> these little gems.
>
>Take a look at the head alignment adjustment. If it looks
>like a gear underneath the head you'll need a special
>alignment tool. They're scarce. It looks like a stubby
>screwdriver with a (mating) gear cut along the shaft and a
>pin sticking out of the end that holds it to the top plate
>while you're adjusting the head.

That's for the III models, not the IV ones. If you need one of those,
it's not all THAT hard to make one out of brass stock by hand.

[rstl...@gmail.com]

On Thursday, November 29, 2012 4:27:54 PM UTC-5, Scott Dorsey wrote:

> Read the manual. It discharges static.

Oops, sorry Scott (RTFM indeed!). I had a feeling it was for static. Nagra engineers thought of everything didn't they? I just spent a few minutes staring at the innards of my two 4.2's. Interesting small differences here and there, reflecting improvements done over the years, different components used, etc. I wonder how these machines were put together, mostly by hand I would imagine. How many sets of hands and how many hours would have gone into making a single Nagra IV, then testing it prior to shipping... No wonder they cost what they did, new. And now their chinese assembly plant is pumping out small digital handhelds in a fraction of the time, how the industry has changed over the years...

[Mike Rivers]

On 11/29/2012 3:40 PM, rstl...@gmail.com wrote:

> Thanks Mike. I took a picture of one head on my 4.2 which I loaded up here:

> Looks like a small Allen socket, and the instruction manual refers to using a demag'd 2.5mm Allen key. Are we talking about the same thing?

Looks like the mating gear is already there on that model,
so you'll be fine using a hex key to adjust the head
alignment. Maybe the assembly I'm thinking of is for the
Nagra III. I used to do some maintenance for a facility that
had several Nagras and one of the alignment tools. When they
decided to get rid of the recorder, I stole the tool just in
case I needed it some time.

[rstl...@gmail.com]

On Thursday, November 29, 2012 5:31:35 PM UTC-5, Mike Rivers wrote:

> Looks like the mating gear is already there on that model,
>
> so you'll be fine using a hex key to adjust the head
>
> alignment. Maybe the assembly I'm thinking of is for the
>
> Nagra III. I used to do some maintenance for a facility that
>
> had several Nagras and one of the alignment tools. When they
>
> decided to get rid of the recorder, I stole the tool just in
>
> case I needed it some time.

>

> "Today's production equipment is IT based and cannot be
>
> operated without a passing knowledge of computing, although
>
> it seems that it can be operated without a passing knowledge
>
> of audio." - John Watkinson

Thanks Mike. One can't have too many tools!! I like your footer quote, by the way. Based on AES report, I liked the old-school tube console, quite a contrast with the touch-screen virtual iPad-esque console... What a transitory world we're all living in, and some things occasionally seem to flow backwards, oddly enough (recent resurgence of vinyl records, for ex.).

[Marc Wielage]

On Thu, 29 Nov 2012 13:48:40 -0800, rstl...@gmail.com wrote
(in article <a628ace8-1a27-4e8f...@googlegroups.com>):

> Oops, sorry Scott (RTFM indeed!). I had a feeling it was for static. Nagra
> engineers thought of everything didn't they? I just spent a few minutes
> staring at the innards of my two 4.2's. Interesting small differences here
> and there, reflecting improvements done over the years, different components
> used, etc. I wonder how these machines were put together, mostly by hand I
> would imagine.

>------------------------------<snip>------------------------------<

Yes, Stefan Kudelski's engineers in Switzerland did essentially machine,
build, and assemble all the parts by hand, plus each one had to be carefully
aligned and tested before shipping. It was almost literally done with the
precision of a Swiss watch -- which is one reason why they cost about $10,000
back in the day. Great, great machined.

About the only bad thing I could say about a Nagra 3, 4.2, or a 4S is that
they were really, really slow to rewind. The AC-operated studio model, the
Nagra T (which was closer to $20,000) could rewind tapes like a bat out of
hell -- just an amazing machine. I've come very close to buying those over
the years, but never followed through.

The Nagras are not used at all for dialogue these days, at least in
Hollywood, but there are sound effects people who like them for very loud
sounds like cannon fire, explosions, and stuff like that. The analog Nagra
preamps are really great, and the precision of the controls and workmanship
were just second to none.

--MFW

[Robert St-Louis]

On Nov 30, 4:21 am, Marc Wielage <mwiel...@yahoo.com> wrote:
>
> Yes, Stefan Kudelski's engineers in Switzerland did essentially machine,
> build, and assemble all the parts by hand, plus each one had to be carefully
> aligned and tested before shipping.  It was almost literally done with the
> precision of a Swiss watch -- which is one reason why they cost about $10,000
> back in the day.  Great, great machined.
>
> About the only bad thing I could say about a Nagra 3, 4.2, or a 4S is that
> they were really, really slow to rewind.  The AC-operated studio model, the
> Nagra T (which was closer to $20,000) could rewind tapes like a bat out of
> hell -- just an amazing machine.  I've come very close to buying those over
> the years, but never followed through.
>
> The Nagras are not used at all for dialogue these days, at least in
> Hollywood, but there are sound effects people who like them for very loud
> sounds like cannon fire, explosions, and stuff like that.  The analog Nagra
> preamps are really great, and the precision of the controls and workmanship
> were just second to none.

Hi Marc,
Would be nice to have a photo of the Nagra room(s) where these fine
instruments were caringly put together years ago. Might not be that
much different from what Nagra office-factory looks like now, in this
very interesting photo-tour done recently, showing off some of the
newer gear (audiophile components) being designed and put together.
Some of the older guys in the photos were possibly around when they
were building the 4.2s and IV-Ss back in the 70s and 80s.

http://www.6moons.com/industryfeatures/roadtournagra/1.html

Yes, the Nagras are not the speediest to rewind. But as some have
said, their main job is to RECORD, and editing/rewind/forward
functions can more readily be performed on another machine (and also
saving additional wear and tear on the Nagra - I treat mine like all
old things I respect, with kid gloves!). I use my TEAC 3440 to whizz
the tape around after I've got the sounds on it through the Nagra. I
just demag'd and thoroughly cleaned the tape path on the nice 4.2 I
just bought, and did a test recording of guitar and voice. The
quality and naturalness of the recording is so pleasing to listen to
(even in mono), compared to what I get with my H4n or other consumer
digital recorders. One day, I promise myself to get a Sound Devices
recorder (or the USBPre2 to feed into my laptop audio software) to get
better quality digital recording. But for the sheer fun and pleasure
of it, no other machine comes close to a Nagra reel recorder for me.
Yes, the Nagra T would be a lovely machine to own, but I'm not sure
I'd be up to the care and maintenance it may need (looks a lot more
complex than a 4!).

I just called a supplier to price out a replacement pinch roller, and
was reminded how costly Nagra parts are ($177 canadian). At that
price, I'll probably rather get one rebuilt by Terry's Rollers (http://
www.terrysrubberrollers.com/)
--Robert

[William Sommerwerck]

I'd always wanted a Nagra, and they've become quite reasonably priced in the
past decade. But I realized I'd never use it (I have a pocket DAT), so I
didn't buy it.

I remember a review in Audio (I think) about 40 years ago. The reviewer,
while making a recording, deliberately dropped the machine from waist height
onto a concrete floor. He said that, during playback, you could not tell
when the drop occurred. If this is true, it says a lot about the transport's
stability.

[Scott Dorsey]

William Sommerwerck <grizzle...@comcast.net> wrote:
>I remember a review in Audio (I think) about 40 years ago. The reviewer,
>while making a recording, deliberately dropped the machine from waist height
>onto a concrete floor. He said that, during playback, you could not tell
>when the drop occurred. If this is true, it says a lot about the transport's
>stability.

I have a recording made with a III that dropped about 20 feet and indeed
you cannot hear any flutter. It is staggering.

My drop was not deliberate, it was caused by a gaffer.

[Robert St-Louis]

On Dec 1, 10:06 am, klu...@panix.com (Scott Dorsey) wrote:

Truly amazing stories. Kudelski and his engineers certainly knew what
they were doing when they designed these machines.
When I got my "new" 4.2 home this week, I was cleaning it on the
kitchen table, and put it on the chair for a moment. All of a sudden,
something happened and it fell to the kitchen floor (luckily, vinyl
cushion-floor). I swore at my carelessness but when I picked it up
and looked it over, I could not see a mark anywhere on it. I suppose
if a III can survive a 20 foot drop while recording, a 2-3 foot drop
to a kitchen floor shouldn't matter too much! :-)

On a related note, I found a pair of Nagra equipment being sold off on
an out-of-town Craigslist, among a bunch of other audio and film
paraphernalia and old cameras, by the nephew of a man who had
collected and cherished this equipment and had recently died. When I
looked at the grouped pics on his ad, I spotted a Nagra IV-S, and a
Nagra DSM monitor, about which he had no knowledge nor interest.
According to his aunt, his uncle's equipment was all in running
condition. Anyway, I offered him a relatively low price (due to
uncertain condition) which he accepted and the equipment is on its way
to me by the post. I'll be curious to see if the IV-S and DSM run, if
so they will be welcome additions to my resurging Nagra "collection".

[William Sommerwerck]

> My drop was not deliberate, it was caused by a gaffer.

Great joke, even if you didn't intend it.