Messages

1

Reel to Reel Tape Machines / Re: Nagra T-i (instrumentation) for audio?

« on: July 07, 2011, 03:18:52 AM »

Hello,

As I stated on the other Nagra TI topic here, I am now restoring and converting the TI for audio.
The plan is to use external electrinics for both rec and repro, and use the TI only as transport.
However, any other experiences and ideas will be interesting to discuss.

cheers,
Tod

2

Reel to Reel Tape Machines / Re: Nagra TI Instrumentation Recorder

« on: July 07, 2011, 02:23:46 AM »

Hello,

I am also restoring a Nagra TI and will appreciate to get the manual, as well as any useful tips. Mine does not have a PS and I am considering to build one, if I cannot find the original PS.

I also plan to replace the 4 track heads with suitable 2tk (any ideas?) and use external repro/rec audio electronics. Any relevant experiences you may share will be highly appreciated.

Best regards,
Todor

3

Reel to Reel Tape Machines / Re: Studer A101

« on: January 19, 2011, 02:52:16 AM »

The better sounding is none of those as they use obsolete discrete components and a tantalum cap. Among the three, the latter version, with the larger capacitor, not epoxy-covered is better, but still way below potential.
PM me if you are interested in a better custom version.
Tod

4

General Discussion / Re: Fabric cover for Studer A80

« on: June 25, 2010, 04:36:31 AM »

Good job, Kip! I plan to do something like that, as well as an acrylic hard cover.
Enjoy,
Tod

5

Reel to Reel Tape Machines / Re: Studer A80 or A80RC

« on: June 16, 2010, 01:56:40 AM »

I guess you ask about A80R and A80RC, which are similar (the A80VU is different). Transport-wise, quite similar. However, the A80RC MK2 is the one I would go for.
Tod

6

Tape Tech / Re: using reels with different hubs?

« on: June 02, 2010, 06:27:20 AM »

Hi Laura,
You can use different hubs w/o problem, as soon as the reels are of the same size. However, refrain from using different size of reels (e.g. 7" and 10.5") with this machine, for critical recordings/playback as this will affect the stability/range of tape tension, hence tape-head contact.

In other words, what matters is that the internal diameter of the reel, where the tape rolls on, is the same on both sides.

Best regards,
Tod

7

Reel to Reel Tape Machines / Re: Would appreciate some info on Studio machines...

« on: May 31, 2010, 06:10:25 AM »

Bearings:

Upon bearing replacement, note the shims (I used the same)  and assembly order that are used for vertically aligning the guides. You will need the tool to remove the circlip holding the assembly together. Careful - these little clips are soft but have a tendency to fly away during disassembly.

The originals are precision bearings - low noise, but some new models are even better. The SKF 61900 series bearings fit all needs (spooling motors etc) and the eight smaller 3mm ID bearings are easily obtained at higher spec than the Studer originals - either normal 'ZZ' seals or ultra low friction.

NTZ also have some very smooth bearings (used in the Sony APR-5000s).

The most critical place is the large roller under the headblock cover.

Hope this helps,
Tod

8

Reel to Reel Tape Machines / Re: Would appreciate some info on Studio machines...

« on: May 25, 2010, 02:58:38 AM »

The sapfire tape guides I sourced from one-off NOS sale in Switzerland, those were used on some late model headblocks, and can still be found.

Sam, it is quite hard to find a good 15/30UPS machine, but if you can't, there is a relatively easy mod from 15 to 30 UPS (just google studer HS modification), for which you need some parts.

For location recording, I have chosen Nagra 4-S, a great machine for that purpose, running at .5/15 UPS. To be modifies along the lines of the Studers, space permitting (lots of tantal caps that must go, but a great design). My Nagra comes with a lot of ruby stones on the transport, the Swiss watch influence there, and the tape travel is remarkably stable, for the size of this jewel.
There are still quite many good Nagras fs in the US (mine came from a US studio). Very durable/reliable machines.

The A810 can also be used on location, it is "only" 35kg, and of a rather standard size, but the Nagra is way ahead in handling/size/weight, giving very similar sonic results on recording.
Best,
Tod

9

Reel to Reel Tape Machines / Re: Would appreciate some info on Studio machines...

« on: May 21, 2010, 02:35:20 AM »

Hello Studer fans,
I have 3 A80RC (one is 1/2" 15/30ips) in differnet stages of modification, along the following lines:
1. PS revisited:
a) All 'lytics upgraded (everywhere, not just PS) for best quality and up to 50% higher values,
b) Faster diodes (18ns)
c) Dedicated PS/regulation with Lars (former LC Audio) for the audio boards - in progress
2. Mechanics:
a) Capstan motor rebuilding, with ball bearings - in progress
b) bearings replaced on tape path
c) Sapfire tape guides
3. Audio path:
a) rebuilding the discrete opamp A101 with modern components/LN-transistors/resistors
b) use of tight tolerance metal film resistors and low noise matched transistors on audio path
c) use of film caps on signal path, where possible (stacked PE) and/or a combo of better 'lytics (Nichicon NP) and a bypass film cap;
d) rewiring with low capacitance screened cable, reducing total capacitance 50% - looooots of loooong cables inthere!
e) taking the signal before the final output stage/trafos, also bypassing the meter bridge - in progress
f) upgrading for high output tapes, as per the manual (a few caps)

Results: each mod gives small incremental improvement, adding to a very detailed, lively image, not that the stock version is bad.

Similar mods also done on my 2 A810, but the mod-freedom is more limited there - forests of opamps (replaced) and 47uF 'audio path 'lytics (replaced). My past experience in jewelry was very helpful when I had to redo the preamp in the headblock, so packed now that I wonder if a bacteria could get in there.

Bet wishes,
Tod

10

Reel to Reel Tape Machines / Re: Would appreciate some info on Studio machines...

« on: May 20, 2010, 06:09:25 AM »

Both A80 and 820 are great machines, with their own merits, and would be an oversimplification to say one is better than the other.
I said the A820 has "even better" transport, to acknowledge the unprecedented tape speed quartz/servo controls which rely on sophisticated software/electronics, and a long/elaborate tape path (just count the tape path elements).

Hence, the tape A820 speed/time stability (W&F), in principle, is unbeatable.

How does this translate into practice, is another matter, as every sophistication comes at a cost - more tings that may go wrong, hard to calibrate/maintain w/o dedicated expert (don't try this at home:). The reliance on the software to deliver that accuracy means that if it is not adequately maintained, you will go out of specs, and often out of operation. And remember, while more modern, the A820/810 are to be seen as computers, of 10+ years of age.

The A80 was built on the concept of mechanically-based stability and reliability, with more simple servo systems and no software. This makes its age less important, as soon as you refresh the mechanics/electronics, and definitely more user/service/mod-friendly. This friendliness will become more and more important, with age, and the shortage of Studer techs in your area.

My own choice is modified A80.
Tod

11

Reel to Reel Tape Machines / Re: Would appreciate some info on Studio machines...

« on: May 18, 2010, 03:34:04 AM »

My 3 cents:
1. For a combination of top transport and easy maintenance/modification (all discrete audio electronics) - A80RC. But only horizontal position, and a large size.
2. For even better transport but much harder to maintain w/o a Studer expert around - A820.
3. For compactness, vertical position, a great transport/sonics, integrated VU meters (no overbridge), but not-so-easy to maintain/modify (dozens of ICs on signal path, lots of decades old software and ICs, virtually same as with A820) - A810.
Tod

12

Tape Tech / Re: Possible replacement for 5532 opamp?

« on: April 30, 2010, 03:55:27 AM »

Indeed, the AD8066 is wideband and may require the addition of a small cap (100p) in some cases. So far I have it on the preamp in the headblock and it works great, no tweaks needed. As the opamps are on sockets, it is easy to test the change and detect eventual oscillations.

Ki, there is a small forest of 47uF l'ytics (solid aluminium) on the signal path. If someone is qualified to calculate how low we can go there (10uf?) it will be a Major improvement to use film caps, at least WIMA or better (Siemens stacked polyester caps). Otherwise I use Nichicon NP with film bypass.

Andrew, the vocals sound amazing with the AD8066.

Tod

13

Tape Tech / Re: Possible replacement for 5532 opamp?

« on: April 29, 2010, 01:19:58 AM »

Hello Ki,
I agree with Stellavox that the best resuts could be achieved if along with the opamp upgrade you would be able to reduce the values of the so many 47uF L'ytics so that you can fit film caps inthere. I am still contemplating around that (lost in calculations). So far I have successfully used AD8066 (with smd adaptors) in several A810 machines and RevoxPR99. Those are for me the best cost-effective replacements.
Let us know how it goes,
Tod

14

Tape Tech / Re: Technics 1500 series - Reinstalling the Headblock

« on: April 20, 2010, 07:35:09 AM »

Beware: moving the block in/out with the deck on can magnetize the heads
Tod

15

Tape Tech / Re: Help with sourcing part for PR99

« on: April 19, 2010, 01:20:09 AM »

You may use siver mica with better results.
Tod