dela

Although it is not a Nagra, I think that it is a really cute little thing. It is expensive, but for a device clearly meant for podcast/voice recording, it has some really innovative features, and it also has a good build quality. It has a tactile interface, like the SN, and the very mechanic control is much more intuitive than with than buttons. I probably won't buy one because I don't need one (not that it usually stops me..), but if I could imagine me needing a voice recorder, I would be really tempted. Especially since the transcription process has also been considered as an integrated part of the workflow.

Regarding the QSEF balanced input converter: I don't have QSEF right now, but I have had it opened. There is a set of input transformers, as well as a small transistor output stage for adapting the transformer output to the IV-S. I think that somewhere on this thread there is a description on the QSNES balanced/unbalanced converter for interfacing with a noise reduction unit with balanced in- and outputs. This interface basically is a QSEF and a QSSF unit built together... The QSEF is a bit "rare" in the meaning that it is not often needed by anyone. It is primarily relevant if you need a long input cable length, otherwise it is mostly dead weight (with a potential coloration of the input signal).

You can't unlock the knob and get ALC, because the ALC circuit is not installed... It could be installed later, so they installed the potentiometer and switch, but without the board, it will not do anything. I have never seen a DR IS with ALC installed, I guess DR didn't´t find it necessary after all. If you go to Nagraaudio.com and look in the historical section, you can find all manuals for it. There will be a description of the function somewhere... If you need info about the IS, I have a few of them. I have some experience with them, so feel free to contact me with questions.

And it is always nice to see an IS out in the wild (almost). I like that it is actually correctly set up to record (with an Uher mic...)

Interesting with the channel fault that moved to another channel when another bias oscillator board was installed... It could indicate that the fault is with the bias board, if that is the only parameter that was changed. I have actually had a visiting IV-S which also had problems with a missing channel, and it turned out to be a connector problem on the A16 bias board. When you get the original board back, it is worth testing the record function while manipulating the bias board and its surroundings. Regarding resoldering the contacts on the filter board, it is not that hard to get the board out (when you know how to do it). You start with removing the filter knob, that is held in place by a locking ring with a grub screw. Once the grub screw is loosened, the knob + shaft can be pulled out, and after removing the two screws in the bottom retaining the module, it can be pulled upwards and out. I would say that it is a logical place to check when a channel is missing, because the switches are a really weak point of the construction. I have a IV-SJ which had really bad switches, and that was messy... On the IV-SJ the filter settings for the two channels can be set independently, making the system even more sensitive. But the two-way knob is a little mechanical masterpiece... I feel lucky that whenever I have these weird problem, I can always borrow a known-good module from another Nagra and then use that as a somewhat primitive way of narrowing down the problem...

The Sony TC 510-1 is a remarkable recorder, in that it is a recorder that is a bit of a mystery: What is the meaning with it? Who was supposed to use it? Why did Sony, normally being masters of miniaturization, design a recorder that was larger than the Nagras? The TC 510-2 is an example of a product that was conceived more as a copy of an existing product than a result of an actual need. It seems that the brilliant Sony engineers were given the task of making merely a Sony version of another manufacturers top product. The only problem was that the designers had just about no idea about what the users actually needed, and what was important for its use. The result was a recorder that looked nice, but had some serious shortcomings (for professional use). Some of them were (in no particular order): - No balanced XLR mic inputs with phantom supply. Jack inputs? I have never seen a seriously professional microphone with a jack connector... - Only 5" reels. I know that the Nagra IV machines also had this problem, but if you took off the lid of the Nagra, it could take 7" reels. And if you needed it with a lid, you could get a 7" compatible lid. - It was larger than the Nagra, and it was very unergonomic (square form factor, sharp edges). I really wouldn't want to carry that around; I would end up with bruises all over me. - Was it easy to service? In a word: No. The drive system was difficult to take apart, and if an electronic fault occurred, you would open it up, sigh deeply and close it again. It is a very service un-friendly machine, which is a problem, because it had some serious mechanical issues after some years (f.ex. the locking mechanism for the Record-position broke). They were also prone to the sintered bearings seizing up, which is itself strange, since they were supposed to be self-lubricating. But it was much cheaper than a Nagra, you might say? Yes, but more expensive than an Uher Report recorder, that was smaller, more ergonomic and also just accepted 5" reels. Unsurprisingly the users agreed, and that is why Uher and Nagra had such a large market share (in each their part of the price range), and the TC 510-2 ended up as a bit of a rarity in the overall picture. I had a Sony TC 510-2 for a short while, and I managed to iron out a variety of quirks, and when that was done, it was a really nice machine. It sounds great, and the heads are very hard to wear down. But I ended up selling it to a friend (for the same symbolic sum that I paid for it), because although I liked it, it always ended up on the floor and being neglected there, not really giving as much joy as the Nagras. So that went to a better home...

Regarding the GDAN newsletter: On the sound forum gearspace.com there is a user (Plush), who once mentioned that he was somehow involved in the newsletter. It was created by the late Al Swanson, and it seems that at that time it wasn't´t distributed digitally. But you might sign up on gearspace.com and ask him directly, he seems to still be active there. If you succeed, please write back, if it is possible to get them too. I have attached a link to the thread where he mentions it: https://gearspace.com/board/all-things-technical/515237-nagra-4-s-nagra-4-2-a.html

Unfortunately the IV-S does not have individual mic preamps, it has a stereo preamp assembly, so it is not possible to switch modules between channels... Normally the module connectors does not fail, but you could start with reseating the signal processing modules (no need to involve the A22 motor board behind the battery compartment. I have attached a block diagramme of the IV-S, so that you can see the signal flow. As you can see, in REC mode (and MIKE In enabled) the output of the mic preamp is on the middle pin of each level control, which is quite easy to find. So if you follow the signal path from the input, it should be possible to find out where it disappears. And as always: Look out for contact problems, intermittent switch problems etc.

Do you have line input cables for it? If you record using the line input and there is no fault, it is easier to locate the fault. A perhaps trivial suggestion: The IV-S is a great recorder, but the rotary switches used in it are not as durable as the Elma switches in the mono machines. Have you tried giving the switches a bit of exercising? Both in the mic power selectors, the filter selector and all other switches? on www.nagraaudio.com you can download the service manual, and in it are some good overviews of the signal paths.

I have been talking to Joseph Parys from SQN about a somewhat problematic SQN-3C (bought from Richmond Film Services), and it has been fascinating trying to piece together the documentation for the SQN-3C. He is working on trying to complete an archive with all the technical documentation for their products, and when I got the info on the SQN-3C, it was like opening an ancient treasure trove: Hand drawn schematics, hand written notes about the SN plug box scribbled on yellowed paper and still with missing pieces of information. I think that mine is working now, but I am actually afraid to test it with a Nagra SN mounted. And it has been a really interesting tour round some classic designs... I have most of the types, and they are extremely well built and with a high sound quality. And every bit as well designed and rugged as the Nagras,

I absolutely love his enthusiasm! You really feel his love for it (which I can easily relate to).

Or talk to Mike Harris (mikesfilmsound.com); he can help you with spares and/or do the actual repair. As you write the belt size is not critical, but it will have to be completely smooth, or it will be very noisy when the Nagra is winding.

It is the (ex-)rubber coating on the tacho disc, where the winding idler makes contact. I have one that had the same problem... You can buy belt sets for Nagra III, and in that set there are three belts: Two belts for the reels, and one that can be fitted on the tacho disc wheel. Here is an example: https://www.ebay.com/itm/284563609320 If the reel belts are the grey neoprene type, I wouldn't replace them; they rarely fail. It is not exactly easy to replace the belt/rubber coating; to do it you have to remove the motor and the motor chassis. The worst part is the removing of the motor from the capstan/tacho shaft. On the gearspace forum (reel-to-reel part) there is a description on how to change the bearing on a 4.2; you don't have to disassemble the motor, but it is described how to take out the screw holding the shaft. Be certain to pay attention to every single part; if you do that and you have some sense of mechanics, you can do it in an hour or two (or faster, but that is not advisable).

I would guess that one of the largest "disruptions" in sound work was the introduction of portable location recorders (especially the Nagra III in the early 60´ies). Before that it took a sound team and very heavy machinery to record any kind of location sound. After the advent of portable recorders it became possible to work with 1) hand held cameras, which came at that time, and 2) a much smaller sound crew, perhaps even just 1 person. The next big shift came with the flash/hard drive recorders (and better wireless microphones), which made it possible to easily record more tracks/microphones. So the portable recorders made hand held recordings possible, and the multiple tracks made it possible to be even more flexible, once the boom mic wasn't´t (about) the only source when out recording. My background is in danish film post production (now TV), and one of the things that we saw with the advent of multiple track recorders was that more work was given to the people doing the recording. Before that their main task was making the recording and handing in the tapes. Since there was just 1 or 2 tracks available, all attention could be given to record these 1 or 2 tracks optimally. With the new recorders, not only did it take more time to mic the actors up, but since the editing department was pressed for time (the budgets, again...), the recordist now also had to make a temp mix on site, so that he/she could deliver a 2 track mix for editing. That was quite stressful for some, and I remember several occasions where the recordist had to redo the 2 track mix for delivering it to replace the first mix in the editing department on a daily basis. In some ways it was like the proverbial washing machine: When you get the washing machine it makes it faster to wash, but that just means that you are washing more...

I know that it not exactly the area that you are working in, but there might be some inspiration in this paper from 2020 about the changing role of sound engineers/technicians in the BBC: https://pure.royalholloway.ac.uk/portal/files/33017740/2018heathtphd.pdf It is aimed at describing the changes for TV sound people (in broad terms) more than Film production, but I guess that some conclusions will be the same. And in any case, it might be an inspiration, or you can checke sources of the paper... I have been working in film post production (currently I am working with broadcast technologi), and I would say that one of the most important technological changes for the last generation has been moving from tape based recording to file based systems. Not only did the new(ish) digital recorders allow faster turnover, but they also made it possible to record ever more simultaneous tracks. And transfer the material to the editing department much faster, so that editing could start almost immediately after the recording had ended. One thing to notice, is that the changing roles and working conditions for sound production has also been influenced (a lot) by ever increasing workload and ever smaller budgets...