Monthly Archives: November 2017

Walhalla Symfonie PvdM

In the early 1980’s Dutch public radio featured a program called ‘Walhalla Symfonie’. It was described as ‘an acoustical listening trip’ (translation).

The program duration was one hour, broadcasted late in the evening. Only 34 (+4) were ever made. It basically was music, sounds, quotes, experiences etc. all put together into a one hour composition. It had a strong influence of electronic music. And every one of them had a theme. The series also had a leader tune, created on a synthesizer.

I remember some of them from my childhood. It was an exciting experience to listen in the dark (sunday evening 23:00) with your headphones on to this broadcast on the radio. Recently I found all of them on the internet, downloaded them and I again enjoyed listening to them. They have a unique atmosphere to them.

This triggered me to make one myself. So here is my attempt to make a Walhalla Symfonie!
It is much shorter, around 20 minutes. And it has a different feel than the originals had, mine is less experimental, less far out there, more mainstream. But I think that it is agreeable to listen to as a listening experience. So, if you have 20 minutes to spare, take a listen and let me know what you think! (quality headphones and a relaxed listening environment are strongly advised)

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fixing DCC audio cassette tape

A box of DCC tapes

I have lying around a box with +/- 50 used DCC tapes that I purchased a while ago. DCC is the Digital Compact Cassette, invented by Philips. I have gone through them all, I listened to some of the tracks on each tape and sorted which ones I wanted to keep because of what was recorded on it. But most of them could be recorded over.

history

In my youth I had the privilege to experience the evolution of the compact cassette (CC), also a Philips invention btw. It had just made its way from dictafoon-like devices to the hifi/consumer audio market. And I witnessed its rise to a high end audio device (Nakamichi et al.). I have lots of CC tapes, probably my entire youth is recorded on those.

Then, in 1992, DCC came. But by that time, I had lost interest in recording music, or audio as a whole for that matter. So I never really noticed at that time. Also the Sony Mini-disc and DAT recorders went completely past me.

But when I rediscovered my audio hobby around 2010, I got very interested in these three now obsolete recording techniques. And fortunately you can get these devices rather cheap these days.

My Philips DCC600

I have all three devices now.

 

DCC surprised me in a very positive way. I got the same, familiar feeling playing cassettes that I had back then and that I had gotten used to. Also the deck that I got feels very solid and tape handling is direct. The DCC cassettes themselves feel very, very well thought about. Even the casing and the jewel box is outstanding well designed, even more so the prerecorded tapes.
On top of that, you get CD like audio quality. I say CD like, but I dare you to hear a difference. I was very, very impressed with the whole concept. In hindsight I wish I had used it back then.

squeaking

I noticed when I went through the lot of old tapes however, that some of the DCC tapes were making a squeaking sound when they were played. And some of those would not play at all. The deck, just kept clicking, the drive mechanism reversing a few times, before finally giving up. So I thought that these were bad tapes, or maybe they had some shedding or sticky tape or whatever and that they could not be relied upon. I was resolved to throw them away.
It was clear that it was the tapes that were the problem and not the deck, because most of the tapes would play perfectly and the problem ones would not.
I did some research into cleaning the head of the deck, but found out that this was not a trivial task, and that the fragile head could easily get damaged. The general conclusion was that you don’t clean it, unless it is absolutely necessary because all tapes play bad and it is clearly visibly dirty. So I didn’t.

forum

I researched some more and came across a post on a Dutch forum dedicated to Philips equipment. You can find the post here:

http://www.mfbfreaks.com/forum/viewtopic.php?f=5&t=10492

although I think you need to register first. And it is in dutch ūüôā

gunk

It is described there that there are actually 2 problems: the squeaking and stuck tape. The squeaking problem is related to two pieces of felt that are inside the DCC cassette, not visible from the outside. There is also a third piece of felt, this is the familiar one that presses the tape on the head. The 2 problematic felts are located near the left and right rollers located inside the cassette:

These felt pads leave behind a greasy spot on the backside of the tape when the tape is not used for a long time. The deck has trouble running the tape past these spots and finally gives up. This spot is somewhat greasy, but also a bit sticky. This can be observed by pulling the tape somewhat from the cassette and checking the backside. It is not necessary to open the tape casing for this.

In order to do that, you must pull back the sliding cover and pull the tape out very, very gently with a small tool and make sure that you do not damage or crinkle the tape. You can see the gunk if you look very carefully. Let light shine on the surface. Make sure that the tape is at the problem spot when you stopped the deck and pulled the tape out.

cleaning

In order to clean the tape, make sure you gently use some non residu cleaner, like IPA or alcohol or videospray cleaner 90 or whatever fits you, and gently rub the problem spot using a cotton swab. Hold the tape down while you swab, careful not to damage or wrinkle the tape. That happens so easily! Remember it’s the¬†backside of the tape.

After that, simply wind the tape back inside the housing and play the tape. Voila! It’s working again!

squeaking

For the squeaking problem:¬†I fixed this by cleaning the felt located opposite the head as well. It won’t get completely clean, but just try to clean it as much as possible. I did it with a cotton swab with IPA. After that, the squeaking was gone.

more tips

  • Always rewind the tape before you unload and store it for a longer period. The (clear) leader tape, that’s what the felt presses against when the tape is rewound, doesn’t seem to have as much problem with the grease.
  • Also don’t demagnetize the head! It will ruin it forever. The head does not require demagnetization.
  • Never ever use a¬†cleaning cassette. The head is way too fragile and it will ruin it forever.
  • If you absolutely¬†have to clean the head, use alcohol or IPA . Preferably with natural chamois leather, but a cotton swab will work as well.
  • Avoid playing normal (analog) compact cassettes in a DCC player. Normal cassettes are not as clean as DCC cassettes because they have no tapeprotection and will make the head and the drive mechanism dirty. But most of all the tape formulas used in the analogue tapes are not as good as in the DCC and will shed oxide on the head. Better safe than sorry!
  • See an other post of mine¬†http://pvdm.xs4all.nl/blog/?p=809 where I explain the tape length identification marks on the DCC cassette.

All info and the picture of the open DCC cassette are from the forum mentioned.

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Leopard 2

Training in Amersfoort

I had my training in Amersfoort. To begin we had a lot of theoretical lessons. These pictures were taken during our first encounter up close with a Leopard 2:

First encounter with the beast, parked right there in the classroomAfter weeks of training, we went riding with it:

learning to guide the tank backwards from the command hatch.And finally, after weeks and weeks, we went on exercise with it:

This was out first night exercise with the tank.Me on top of the leopard 2.
This was during our first exercise as a platoon with the platoon leader putting on his cap.

Paraat

After that period in the Netherlands, which lasted 6 months, I was stationed in Germany in Bergen-Hohne. Here are some pictures from there:

detail of the front of the wheel mechanism

This picture was taken from a tank of which the back had had a collision with a turrent.Here we are busy putting a new track on the leopard 2. Needless to say the track is very very heavy.A Eskadron 41 Tankbataljon

Field exercises

We also went into the field. A lot. Sometimes for a few days. Here are some pictures:

Waking up after a night in the field.

‘wasbord’. This terrain is formed this way with the bumps due to the tanks driving there. It gets worse over time. It is very uncomfortable to drive.Leopard 2 hidden behind a bump in the terrain.

All Terrain Vehicle. The leopard 2 has no problem with any terrain.

Full speed ahead, eeeh reverse I mean. This is a manoeuvre to withdraw, driving backwards full speed.

lolo. The leopard on a low-loader.

Parked in a ditch, this tank wasn’t coming out by itself. It had to be towed out.

What leo 2?

My driver managed to drive the tracks off of our tank, making a turn in very loose sand. It took us a while to get the track back on the cog.

Me in action. Reading the map doing a relocation during the excise. Unfortunately the picture is not very good, but the tank was moving around a lot.

My crew and my tank just after we rolled the tank from the train that had brought us to the exercise field on the other side Germany. This picture was taken in the morning, as the trainride was a night train. I am standing just behind my driver. I am the one with my back to the photographer.

Fill ‘er up! This takes long. Very long. 1100 liter.

Me giving the tank a thorough cleaning afterwards.

Shooting practice

In Bergen-Hohne is Europe’s largest and best shooting range for tanks. Of course we went there. Here are some action pics:

This actually is a small version of a Dutch shooting range where you can practice tactics, like target distribution between tanks etc.

Same small shooting range but then the view as seen from the tanks.On the big firing range. Drivers resting between sessions.

Grenades are stored right behind the shooting tanks.Me (right) and another tank commander talking to the platoon commander (middle).Alpha tank in action, ready for firing.

real world field exercise

At the very end of the tour, we did a NATO real world exercise, where you drive through the real world and drive the public road through villages and take shelter at some farmer’s place etc.

 

Here we’re waiting to get out of the gate at the barracks.

Through the village.

Some of these roads are very narrow.

There were also other military vehicles involved. In fact it was a complete exercise, where multiple countries collaborated.

Taking a stand in a field.

A moment of rest, parking in a small town by the side of the road.

Getting supplies like fuel (jerrycans) in the late evening.

Loader in action. He is in charge of the flashlight.

Queuing to return to the base. The exercise lasted about 3 days.

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Dolby 363 rack with model 350 cards

recording

Since I was very young I was intrigued by recording studios and the equipment therein. Can you tell?? (cue Studer A80 blog entry). A few years ago I had the opportunity to visit the famous Wisseloord studios here in Holland and needless to say that that was a thrilling experience. I am intrigued by the recording process, and mainly the tape part. But recording techniques in general have my interest. Like how to record a solo acoustic guitar, or how to record a symphonic orchestra. And as pure as possible. In order to do that, in the old days, you need a tape recorder, and there lies the base of my fascination.

tape hiss

Tape has a very nasty flaw: it introduces tape hiss into the signal. Tape hiss is clearly noticeable when you play around with consumer decks, giving a nasty hiss in quiet sections when you replay your recordings. This wasn’t so much of a problem when recording from LP or FM radio, which has a background noise that would make the tape hiss less noticeable. It became a bigger problem since CDs came around and the source of the recordings were becoming quieter or even dead silent.

If you wanted to minimize the tape hiss, you had to resort to quieter, and more expensive tape. You had to use the more high-end decks, and have them calibrated properly to that tape. Thorough maintenance became even more important.

studio – multitrack

If you thought that you had a problem with tape hiss at home, imagine the problem professional recording studios had with it. They have to conform to the very highest of standards because they are at the very beginning of the audio path, a path that would result eventually with you playing the record or CD at home. So they want to introduce as little noise (in general) to the signal as possible. Adding to the problem was the fact that multi-track recorders had 16, 24 or 32 tracks that all brought their hiss to the final 2 channel stereo end-mix.
Without proper noise reduction, even in the most expensive studio with the high end tapemachines and studiotape running at high speed the end result would suffer quite substantially from tape hiss.

noise gate

To circumvent this problem, studios often reverted to using devices like noise gates. When the audio level of a track would drop below a certain level, the noise gate would kick in and mute the channel on playback. This was of course done so that the downmix to 2 tracks would be more silent in the quiet parts. There is an interesting article on the use of Kepexes used by Alan Parsons on Dark Side of the Moon by Pink Floyd:

I remember extensive use of Kepex noise gates. I think part of the sound is these Kepex gates. They had a certain sound rather similar to tape compression. We were not just using them to reduce tape noise, they had a sound as well.

Read the article here: http://daily.redbullmusicacademy.com/2015/11/interview-alan-parsons

Dolby A

But, toward the end of the 60’s a new technology came around. Invented by Ray Dolby, Dolby (“A”, as it was later renamed) promised a reduction in tape noise level of around 10-15 dB. It was targeted at the professional market, and it was also used in the recording of optical sound on films for motion pictures, improving the audio quality significant.
In music studios it was an instant hit. Much of the music of the 70’s would not sound so great on CD’s as we know it now if Dolby A would not have been around.

Dolby SR

Without going too much into the history of Dolby, (you can look that up on Wikipedia for yourself) suffice to say that in 1986 Dolby introduced its best performing professional noise reduction system to date: Dolby SR.
Dolby SR stands for Spectral Recording, and it utilizes different techniques to achieve an increase in dynamic range of 25 dB. Professional tests conducted using a studio environment (link) concluded that a recording made with Dolby SR was indistinguishable from a digital recording.
So, my fascination with professional tape recording equipment would not be complete without some noise reduction and/or compression units. I purchased a Dolby Model 363 rack with 2 cat. 350 modules.

The test

My intention was to test these out with my Studer A80. But, as I was preparing some test material, I found out that my A80 was actually too silent and my source material too noisy to test this properly. I had a vocal track that was almost super silent as far as noise is concerned.
So I took out my most ‘noisy’ deck, which I think is my Teac A3440, and recorded some vocal track on it. With, and without Dolby SR.
To be fair, this was a quick and dirty test, and in no way this was an exhaustive test. I tried to find a noisy tape as well. I found that using the SR unit I was able to push the A3440 to a level where it was rivaling a CD as far as noise and dynamic level was concerned. You have to hear it to believe it.

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