The Venerable Fostex PD-4 Timecode DAT Recorder

November 2, 2001 at 3:28 pm

In the world of portable timecode DAT recorders (OK, the very small world), there was first the Fostex PD-2. This was soon followed by the StellaDAT which was soon followed by the HHB Portadat which was fairly soon followed by this article’s hero, the Fostex PD-4.

To be fair, I must first voice my opinion that all four of the above mentioned DAT recorders are outstanding machines in their own right, and all have won a well deserved spot in the hearts of many professional mixers. We have sold them all, and always with a clean conscience. Like I tell our customers that are trying to decide which machine to buy: No matter which of these recorders you buy, sooner or later you will find yourself in a situation where you will wish you had one of the others. The good news is that even in one of these situations, you will still be in pretty good shape. There is no junk amongst these choices.

Fostex PD-2

From an operator’s perspective, I can tell you some of the things I like about the PD-4. First of all, being located in Nashville, we do a lot (I mean A LOT) of music videos. While I keep thinking (hoping) that maybe I’ve done my last one, I worked number 1742 (really) last month with “Usher”. The PD-4 is well suited to music video production for two reasons. First, it has a “marker” (I call it a virtual grease pencil) that can be moved to any cue point in the recording. With the touch of the LOCATE MARKER button the tape is re-cued to that point over and over… and over and over… again and again… and again… to the same place each time. You can do it in the dark with one finger without even looking up. Maybe it’s because of this feature that I’m able to read more novels during a music video than I used to with the Nagra. Second, music videos in the U.S. require that consideration be given to what is known as (or unknown as…) the “pull-up/pull-down” process. To keep from going too far into a subject that should be a full semester class in film school, I’ll just mention that the PD-4 jumps this hurdle with the optional sampling frequency of 48.048 kHz (.1% faster). As an operator who, if nothing else, thoroughly understands the synchronous playback process, this is the most useful method I’ve seen to accomplish this with DAT recorders. This sampling frequency of 48.048 also has a very useful, but seldom used, function during sync recording. It allows staying in the digital domain during film to video transfers. Look for an attempt at explaining this process in entirety and detail in a later article.

NP-1 Battery Power

The first thing that Fostex did right in designing the PD-4 was to The Fostex PD-2 was the first, and like is often the case with first children, it may have been the victim of too much attention during development. Not only was it very well made, but it had every feature conceivable at the time. This resulted in two strikes against it: It was very complex and expensive. This knocked it right out of the rental market. The setup parameters were so extensive that it was hardly worth going through each of them for a one day rental. Many of the features, including the head heater (which prevented condensation from forming) were well intended but would have been better off left out. For instance, in the case of the head heater, it used up the early NP-1 batteries more quickly and needlessly (as it turned out, DATs produce enough heat on their own in normal operation to vaporize moisture).


The StellaDAT, is probably the best recorder of the four, but to many potential customers it just did not matter. Even for the experienced and successful professional, the expense was usually not justifiable. It was, and still is, a mechanical work of art and an electronic jewel. In fact, being made in Switzerland, I think it’s fitting to call it “The Rolex of DAT Recorders”. But let’s face it, 2 o’clock is still 2 o’clock whether it’s from a Timex or a Rolex (not a fair comparison, but you get my drift). Its features, capabilities and quality could easily dominate this entire article, but if no one can afford one, why bother? I won’t even mention the front panel display that could not be read in direct sunlight. (Doh!)

HHB Portadat

Then came the HHB. It seemed to answer all of the shortcomings, or more accurately, the “overachievements” of its predecessors. It was relatively simple, user friendly, very light weight, smaller than the others and much less expensive. Because of these attributes, it did very well in this niche market (and still does). It did not, however, escape without adding some shortcomings (underachievement?) of its own. Most notable are the expensive proprietary batteries, thin wall construction, lack of gap sealing from dust and moisture, and well… wouldn’t a third input be nice?

Enter the PD-4

The Fostex PD-4 Portable Time Code DAT RecorderI think the success of the PD-4 can be explained with a single word: Balance. Fostex did a really good job of finding the happy medium between the overachievements and the underachievements of its predecessors. In fact, it may be the first of this machine category to have no overachievements at all (a good thing). It is simple, lightweight, uses the common NP-1 style battery, fairly well sealed against moisture and dust, has a rugged chassis construction, has the features and software options that most users need, and to top it all off, it has a built-in three input mixer. Oh yeah, it’s also the least expensive of them all.

Fostex had a tough sell ahead of them when they introduced the PD-4. Mixers were just starting getting comfortable with the idea of timecode DAT recording in the field, and most were using the HHB Portadat at the time. It seemed that everyone was wondering which machine would be the next “Nagra” in the DAT world. We were so used to having a chicken in every pot and a Nagra on every set, that we assumed there could only be one model of recorder. In fact, we were so used to this idea that we wanted there to be just one, and it was looking like the HHB was it. After all, it took long enough to become confident with the PortaDat, why go through that painful process all over again with another Fostex? So when the PD-4 came out, there was some sentimental resistance.

Well, that was then. Now, the Fostex PD-4 is widely accepted in the professional world. In fact, seeing one on a film or television set has almost as much of a calming effect as a Nagra. In the four years or so that the PD-4 has been in use, it has earned a respectable track record in terms of reliability. It is simple enough and now familiar enough to be on the rental shelves (sadly, in the same spots formerly held by fewer and fewer Nagras).

The Operator’s Perspective

Keep the same internal battery that was used for the earlier PD-2, the NP-1. By now, there are nearly as many NP-1 batteries to be found on a movie set or media event, as there are D cells. They have increased in capacity and decreased in price, as have their chargers. The NP-1 battery was a very good choice.

Sealed Against the Elements

Since field recorders are often used in the field, sooner or later they will encounter dust and moisture. Dust ruins transports and moisture prevents recordings and causes rust. That’s why it’s a big plus that the PD-4 is fairly well sealed from these elements. The clear plastic lid over the transport is very well sealed with an O-ring gasket. All of the buttons, switches and controls are sealed with foam gaskets. While not sealed quite as thoroughly as its big brother, the PD-2, a nice effort was made towards keeping destructive dust and moisture out the PD-4.

Built-in Mixer

When I first saw a PD-4 at an NAB show, I looked at its built-in mixer and said “big deal”. Well, at least I’m willing to admit when I’m wrong. The HHB is a very nice size, but I would never head out on a documentary shoot without a mixer. By the time I add an ENG mixer to the package the combined set up has become bulkier than the PD-4. The mixer portion of the PD-4 has three inputs, mic or line level, 48V Phantom powering, three pad choices (0, 15, 30) and a three position channel assignment switch (left, center, right). Another very cool feature on each input is a sweepable low cut. It is so nice that I used to wonder why it’s not found on more sophisticated equipment until I realized that it is functionally identical to the infamous Schoeps CUT1 low cut filter. Anyway, the mixer does, indeed, add a lot to the PD-4’s utility, and, therefore, its value.

Confidence Monitoring

No doubt influenced by the Nagra, the PD-4 allows the user to select “confidence monitoring”, which means you are actually checking playback while recording. While in confidence mode, the signal is delayed slightly to remind you that you are indeed hearing playback. While this delayed sound is disconcerting to the novice, it is certainly confidence inspiring for those who have run out of tape or thought they rolling when they weren’t. Personal opinion: Always record in the confidence monitor mode (I know…I know…but get used to it). I’m so used to monitoring this delayed signal that when I watch playback on video assist, my brain thinks that the words are coming out before the mouths move. Interestingly, the original production Nagra, the Nagra III, would only record in this confidence monitoring mode. The “BA” switch (for Before/After) that can be seen on most Nagra III’s, came later and even then allowed the operator to only momentarily monitor the input signal. It was the right way then and remains that way today. It is the only way to know that you are actually recording.

Nobody’s Perfect

In general, the PD-4’s “short comings” can be appreciated as adding to the machine’s simplicity, but there are a few that are a nuisance. Here’s a few, along with some suggestions on how to deal with them.

The first one that many notice is the absence of the ability to power “T Powered” microphones. While it would have been nice, I suppose its absence is reflected in the machine’s lower cost. Well, maybe it’s time to let the “T Powered” technique die (I know, I know…I own some too). Your T powered mics can still be used with the PD-4 by using an outboard microphone power supply. My favorite is the Denecke PS-1T ($135). It runs all day on a single 9 volt and if you can break one, I’ll give you an honorable mention.

The next absent feature was definitely a shortsighted mistake. The headphone monitoring allows stereo monitoring only…i.e.: you cannot choose left, right, mono or mid-side monitoring functions. If the PD-4 was only a recorder, I could see the logic behind this feature. However, since it is also a mixer, selective monitoring should have been included. The good news is that a very nice “after market” monitor selector modification, made in Germany, is available for the PD-4. This “monitor matrix” is available at Trew Audio for $300 plus $50 for the installation. We have installed quite a few, and everyone is happy so far.

The last shortcoming that I sometimes regret is the PD-4’s inability to be locked to an external sync source. This is rarely a problem, but it would be nice to be able to “stack” machines if additional tracks are needed. The machine will, of course, lock to an AES/EBU digital input source. So, while it is conceivable that multiple machines could be sync locked together in this manner, would it really be worth it? To my knowledge, it never has.

True to its minimalist approach, the PD-4 comes with nothing more than a strap and a manual. Not even the power supply is included. In fact, the PD-4 simply will not work until you buy more stuff. Once you buy a method or two for powering the recorder, the next investment has to be the Portabrace case. If the recorder never comes out of this case, it will be very difficult to accidentally scratch or damage it. The case fits nicely, and allows easy access to connectors and controls. Used with the suede padded strap, it is not too hard on the shoulders. For the adventure documentary however, I highly recommend…no, I insist…that you use the Portabrace AH-2 Audio Harness. It consist of two pieces – an over the shoulder strap brace, and a waist belt. It is infinitely adjustable and does a great job of distributing weight and keeping the recorder from flapping around. Recently, on a documentary film I was working on for the Great Smoky Mountain National Park, the AH-2 harness pretty much made the difference between being able to do the job and not. At $94, it more than pays for itself in reduced doctor bills and career change counseling.

I could go on and on about this machine, but hopefully you have a pretty clear picture of what it has, or doesn’t have, to offer your type of work. If there are any specifics you’re still unclear about, please give us a call.


Software Version 2.30 & 2.40

Fostex has once again improved the versatility and user friendliness of their venerable PD-4 Timecode DAT recorder with the refinements available in the latest software: Version 2.30.

The most needed improvement this version offers is the option to have the delayed “confidence” monitoring on the balanced outputs (XLR connectors). This allows easier confidence monitoring through the tape return, now found on most field mixers. Until now, this could only be done with the PD-4 by using the headphone jack. While using the headphone output for monitoring through a mixer is acceptable if set up properly, confusion in setting levels, etc., caused some problems. Personally I had no real problem using the headphone output for tape return monitoring, but it was, at best, inconvenient. Since I prefer using a multifunction umbilical cable (L/R send and L/R return) and the headphone jack is located on the opposite side as the inputs, I will gladly switch to monitoring the confidence output on the balanced XLR connectors.

The other changes in the software allow yet another “Date User Bits” Option (YY/MM/DD/Reel#) and the ability to jam sync both timecode & user bits or timecode alone or user bits alone. Something really useful would be to have the ability to have user bits be external timecode. This would allow, in playback situations for example, to record both the recorder’s timecode and the timecode from the playback track (the HHB Portadat has always been able to do this).

Fostex will soon be shipping Software Version 2.40. This version is identical to V2.30 except for the added feature that allows the battery warning tone sensitivity to be adjusted for different types of NP batteries. This was finally deemed necessary when Lithium Ion batteries triggered the warning tone at about five seconds before shut-down. It was actually needed when 13 volt and 14 volt NP batteries were introduced.

It is a good idea to upgrade your recorders to the most current software. Trew Audio is an authorized FostexService Center and we can perform the upgrade at minimal cost. Or, if you’re feeling lucky and you’re handy with tiny screws and EPROM chips, you could just order the EPROM and operator’s manual addendum from us and perform the upgrade yourself.

Selective Headphone Matrix

Another of the few items remaining on PD-4 owner’s wish list can be checked off:

There is now a good after market upgrade that gives the operator the ability to monitor Stereo, Mono, Left only, Right only, or Decoded Mid/Side Stereo. The internal modification consists of a splicing in a small circuit board with a knob that mounts through the plugged hole on the right side next to the input connectors. The same 1/4″ jack is used for monitoring.

The result has the look of a factory original installation and adds a much needed feature to the recorder. The cost at Trew Audio is $300 plus $50 for the installation. Someone handy with doing things at their own risk with a soldering iron, cutters, heat-shrink and a jeweler’s file could expect to install it themselves in about two hours.

“Panel Lock” Tip

Once you have the PD-4 strapped on (or on you cart) it is highly recommended that the “panel lock” be used. The PLAY, STOP, FAST FORWARD, and REWIND buttons are located on the top of the deck instead of on the front panel. Because of this location, the Portabrace case can, and often does, push these buttons. This becomes a real problem if, say, the REWIND button gets pushed between takes. If this happens (and it has), the next time you go into record, everything previously recorded on the tape can be destroyed.