SOUND ON SOUND REVIEWS
SOUND ON SOUND magazine Vol.12 No.6. April 1997
by Chris Carter
HINTS AND TIPS ON HD RECORDING WITH THE AKAI S1100 SAMPLER
HARD DISK FOR THE HARD UP
Until quite recently the question we were asked most often by visitors to our studio was , "where's the tape machine" ? Like many musicians who record at home, we started with various Tascam and Fostex tape machines and have tried them all, cassette, Portastudio and reel to reel 2-, 4-,8- and 16 track machines. As most struggling, hard-up musicians know, the running costs on a 16 track tape machine can be a real burden and you start 'economising' by reusing tape and skimping on servicing, both big mistakes.
About five years ago our 16 track Fostex and Akai S950 sampler both desperately needed replacing and we took the decision to sell them and instead change over to a MIDI based, hard disk recording system. After months of research we concluded that what limited systems were available were far too expensive and we almost decided to stay with tape. Fortunately were were offered a new Akai S1100 and S1000 at a price we couldn't refuse, we decided to take the plunge and so began a fretful transition from tape to disk. After a couple of early catastrophes while recording vocals onto a Syquest removable disk, (quickly replaced by a more reliable optical, removable disk drive) we eventually developed an efficient, fast and very reliable system under the control of a MIDI sequencer and mixing down to DAT. While this method of recording may not be to everyone's taste we found it a pretty painless transition and if you are considering HD recording and have access to an S1100 then the following tips could help you achieve some rewarding results.
The Akai S1100 sampler was launched in 1991 as a replacement for the highly respected but ageing 16 bit, 16 voice S1000. The principal differences between the two machines are an improved audio system, with 24 bit processing, the inclusion, as standard, of a SCSI interface, a digital effects board, an AES/EBU digital output, a SMPTE interface and a hard disk recording function. Options include the IB104 S/PDIF, optical/coax digital interface and various sizes of internal hard disk.
The S1000/S1100 series of samplers are well known for their ease of use and accounts for why they have become an 'industry standard' , a cliché but true. Even so there are hidden depths to the S1100 and there are a lot of parameters to wade through, so many people just use the basic sampling, editing and playback functions. Hopefully this article will help S1100 users get even more uses out of an already versatile sampler. For the purposes of this article I will assume that most readers have a basic working knowledge of the S1100 version 4.3 operating system.
There is little , if any difference in quality when recording to either RAM and or a hard disk. However the primary reason for recording onto a HD is the increased recording time available. This could be in the form of multiple takes and retakes or a single long take.
A decent microphone will probably make more of a difference to the recorded sound than any other factor like editing or tweaking. A good microphone technique is also encouraged, try to get as high a level as you can, sung into the mic. However, if your vocalist has a soft or quiet voice then you should try to use an active or phantom powered microphone as these usually produce a higher output level. This will reduce the need to turn up the input gain to far, because while the input pre-amps on the S1100 are very good they aren't totally transparent and increasing the input levels will eventually introduce unwanted noise. If possible don't use your mic through a mixer first, as the mixer noise level, even if low, will add more noise to the S1100 pre-amps. I use an old Sony ECM56F electret condenser microphone that can be powered by a mixer or a battery but sounds particularly good when running on new batteries and plugged directly into the S1100 XLRs, no hum and no noise. Although the S1100 jack inputs have more gain available than the balanced XLR inputs they are best avoided for use with microphones as they pickup mic hum easier and (because of impedance mismatching) the tonal characteristics are not as well suited to vocals. Other options for microphone recording could be to use a high quality stand alone pre-amp or vocal processor to add EQ , valve warmth, compression, limiting or gating.
It is worth spending some time setting up the input levels correctly on the DD RECORD page; EDIT SAMPLE>DD>DREC>TAKE, before you begin recording. This is because the 'linear' level display doesn't show the correct levels while the S1100 is in DD record mode. For some reason it always shows the input levels about 30% lower than they really are and if the input level control is increased too much then serious digital clipping will occur, ouch! Make sure you know what your loudest peak is likely to be and mark the level control with a wax pencil as your absolute limit for that session.
Any S1100 HD recording works best when running in parallel with a MIDI sequencer. The S1100 DD record mode defaults to note C3/60 on MIDI channel 16 for it's HD/DD record/playback trigger. This note should be placed a couple of seconds in front of where the S1100 will drop into record or playback. This forward-delay is in addition to the default S1100 pre-delay of 500 ms and allows the hard disk plenty of time to jump into action before the recording begins. The MIDI note, or the track it is on, should be locked or isolated so that any successive playbacks always remain in sync. If you intend to play back multiple takes then different MIDI note numbers can be assigned to each take on the DD PLAY page; EDIT SAMPLE>DD>SONG>S.ED, but remember only one take (either mono or stereo) can play at once. An alternative way of playing back multiple takes simultaneously is outlined below
TRANSFERRING DD TAKES TO RAM
If you are playing back a lot of different takes that need to be butted very close together or overlap each other then it becomes impossible using the HD/DD recording feature alone. Over the years I have developed a technique for transferring S1100 DD takes into the sampler RAM for better manipulation and control. To achieve this at the highest quality with no loss and no noise then an IB104 digital audio interface must be fitted to your S1100. Using this interface it is possible to save DD takes to DAT and then digitally load them back into the sampler RAM for editing and key grouping. A lot of memory is essential for this procedure with 8 Mb RAM the minimum, 16 Mb recommended and 32 Mb an ideal configuration.
The first thing to do (particularly if you only have 8 Mb of RAM) is choose only the takes that are essential and save these to DAT, either one at a time or in bulk. This is accomplished using the ONE or ALL buttons on the TAKE BACKUP page; EDIT SAMPLE>DD>PLAY>BU.S. Connect a DAT machine to the IB104 interface, using the coax or optical connectors and begin the back-up (see Stick to 44.1 kHz box). As the back-up proceeds mark your DAT tape with ID numbers to help guide through it when you play the tape back later.
Next go to the DIGITAL INTERFACE page; EDIT SAMPLE>REC1>DIGI and set the source to DIGITAL and the input to either ELECTRICAL or OPTICAL, depending on the type of connections your DAT machine has and leave the receive rate at AUTO. Now go to the sample RECORD page; EDIT SAMPLE>REC2 and set the parameters as you would normally for; NEW NAME, STEREO or MONO, SAMPLE LENGTH and PITCH etc. The input level doesn't need to be adjusted as you are recording from a digital source and the S1100 display should indicate: receiving - 44.1 kHz or 48 kHz depending on the output of the DAT machine. Play back the DAT tape and record the previous DD takes into the sampler RAM a section at a time. At the beginning of each take you will hear a very short burst of digital data, this is irrelevant information that can be edited out on the sample TRIM page, EDIT SAMPLE>ED1. The takes can also be edited into shorter blocks, deleting any silences or pauses in the process to save RAM space. Once the vocal takes have become samples then a wealth of editing is open to you, retuning, stretching, squeezing, reversing, combining looping etc. and if you have access to a Mac or PC sample editor then other functions such as EQ and level re-scaling and special effects are available.
RAM BACK TO DISK
When you have assembled your resampled takes they can be put into key groups and if you have the RAM it's possible to have 20 or 30 vocal phrases spread across a keyboard. Using a MIDI sequencer you can now arrange and rearrange the vocal takes with ease on a keyboard. Vocal takes can be cut and pasted on screen if you are using a computer based sequencer, timing can be adjusted and shifted and takes can now be overlapped and double tracked.
If the S1100 is a major part of your set-up then it could be pretty inconvenient having the sampler RAM full of vocals. One of the most useful features of the S1100 is the ability to playback samples and stereo HD takes simultaneously. An often overlooked part of this duality is the ability to mix down the contents of the RAM, samples, key groups etc. onto the hard disk. To achieve this prepare the MIDI sequencer to playback the rearranged and edited vocal takes and include a separate note (C3/60) on MIDI channel 16 to trigger the S1100 DD record/playback function, as mentioned earlier. Put the S1100 into DD record mode, play the sequencer and record your samples onto the hard disk (for more details see box).
The sampler RAM is now free to load in instruments and/or percussion etc. With this arrangement it is possible to have a stereo mix down of vocals (or instruments) playing back from the hard disk on outputs 7&8
with individual outputs 1 to 6 and the stereo L/R outputs available for more instrument samples, without any loss of polyphony.
A lot of my comments on vocals can also be applied to other recordable sources, acoustic and electronic and if carefully recorded there is little difference between a DAT recording and an S1100 HD/DD recording. Also with it's real-time stereo digital output the S1100 is ideally suited to digitally recording your work into any S/PDIF equipped source such as DAT, digital mixer or digital sound card (PCI, NuBus etc.). Second hand S1100's seem to hold their prices quite well and are not seen in classified ads as often as the S1000, as satisfied users appear to hang on to them longer. Current prices for an S1100 are about £1000 to £1300 depending on it's condition, the amount of RAM and whether it has a IB104 card. Points to look out for are what operating system it has, currently v4.3 and preferably in ROM for much faster booting. The display should be nice and bright and a copy of the revised instruction manual is also pretty essential to get the best from the machine.
When you consider that the Akai S1100 is a superbly specified 'industry standard' sampler with probably the largest sample base in the world AND a stereo hard disk recorder then you begin to appreciate what a bargain it is.
ADDITIONAL TEXT / INFO BOXES
If you own, or find, an S1100 which doesn't have the software with the HD option, an approved Akai service centre can supply a new EPROM with the latest software. Panic Music (UK: 01954 231348) charge £45 for this service.
DIGITAL MIX DOWN EXCLUSIVE
Here's a , never before revealed, exclusive Chris Carter tip for users with the IB104 interface fitted. The S1100 manual tells you that to perform a mix down from RAM to disk you must connect the two rear analogue L/R outputs to the front L/R inputs. A better way, that keeps everything in the digital domain, is to connect the real-time stereo digital output to the IB104 S/PDIF coax input and configure the S1100 as follows (for XLR pin connections see Welcome to the RSDO box).
Go to the DIGITAL INTERFACE page; EDIT SAMPLE>REC1>DIGI and set source to: DIGITAL and input to: ELECTRICAL. Next go to the DD RECORD page; EDIT SAMPLE>DD>DREC and set source to: DIGITAL, d.rate to: AUTO, start to: M.NOTE+DEL, stereo mix to: OFF and mode to either STEREO or MONO. Now go to the TAKE page; EDIT SAMPLE>DD>DREC>TAKE and name your mix down and set the length to a suitable figure. At this stage you may find the mix down level is too soft or loud and although it seems as if there is no way to adjust the input level because you are in the digital domain there is a workaround. Go to the DIGITAL STEREO OUTPUT page; MASTER TUNE>Dout, which sets the level for the real-time stereo digital output socket. You have a choice of 0 dB (default), -6 dB or +12 dB, make your adjustments and return to the TAKE page. Set your MIDI sequencer as described earlier and record a digital mix down. One of the benefits of this digital mix down method is that, in theory, an endless number of DD mix down sessions can be performed without any loss of quality.
Unusually S1100 doesn't use a time code to stay in sync while in DD mode, unless you use the internal (or an external) SMPTE generator to play takes from the QLIST. Instead the S1100 relies on the timing accuracy of the connected hard disk and MIDI sequencer. I've used various sequencers from different manufactures, software based and hardware versions and on the whole they stay in sync to the same degree, as do hard disks. While writing this I tried an experiment with a drum pattern recorded from a MIDI sequencer onto the S1100 HD with the DD record function triggered by a MIDI note at the beginning of the pattern. I played back the sequencer, and the S1100, triggering the DD take from the same note and apart from some slight phasiness, the rhythm patterns were still in sync after 8 minutes. Pretty impressive!
STICK TO 44.1 kHz
The sampling frequency of the real-time stereo digital output and analogue HD/DD recording are fixed at 44.1 kHz. Unless your DAT machine will only record at 48 kHz then always transfer or back-up at 44.1 kHz. Because although the S1100 can convert from 44.1 kHz to 48 kHz when making back-ups the pitch of the take will be affected when you load them back, your vocals will be out of tune. It also makes things simpler when performing a digital mix down.
WELCOME TO THE RSDO
The wonderfully named 'real-time stereo digital output' is more than it appears to be. Although it uses the professional XLR balanced AES/EBU configuration don't let this put you off, it is compatible with the more popular consumer version S/PDIF. I have two leads for use with the RSDO, a long one with a phono plug for connecting to a DAT machine and very short one with a 1/4" jack plug for connecting to the IB104 digital coax socket for performing digital mix downs as mentioned elsewhere in this article. It is very easy to make your own S/PDIF digital lead, just follow these directions.
Looking at the rear of both the XLR and phono or jack plug connect the pins as follows:
XLR pin 1 to phono/jack centre tag or tip. XLR pin 3 to phono/jack case or shield tag.
TAKE IT FOR A SPIN
To get the most from the S1100 a hard disk is essential, especially if you want to try HD/DD recording. For some reason Akai have a formatting limit of 500 Mb max, no matter what size the hard disk, so Jaz drives are out! But even a relatively small hard disk can store hundreds of samples, key groups and programs and loading and saving times are reduced to seconds. Most types of SCSI drives can be used but beware of old slow models, these can cause a stuttering or chopping effect when stereo takes are played back.
An option endorsed by Akai is the use of 3.5 inch optical media. The most popular and cost effective is the 230 Mb format, the original 128 Mb format is being phased out and the newer 640 Mb type are still expensive. Optical disks are very cost effective, extremely reliable and immune from stray magnetic fields. A good buy at the moment is the dinky 'Olympus MO230' drive (without a fan, so ideal for audio work) at £230 (incl. VAT), with disks about £40-£50 for a pack of ten. A cheaper, if slightly smaller option is a Zip drive (with a 100 Mb capacity), although the disks work out a lot more expensive than optical in the long run.
Formatting a hard disk for use with the S1100 can be very slow, in excess of 20 minutes for a 230 Mb optical, it all depends on how the disk is partitioned. When formatting for HD/DD recording the disk can be partitioned entirely for DD takes, in which case 230 Mb optical would give about 22 minutes of stereo recording. Alternatively the disk can be divided into two or more partitions, with one partition for DD takes and one or more for samples, key groups and programs. A disk partitioned for DD takes and samples takes the longest to format. But here is another exclusive tip. If you are about to start a session recording to HD and you suddenly realise you haven't got a formatted disk and can't wait 20 minutes then try this. Go to the S1100 FORMAT page; DISK>FORM and set the parameters as follows: partition size: 1 Mb, max: 1. Now press: ARR, followed by: YES. 20 seconds later you will have a fully formatted disk, ready to roll. The only downside is that the disk can only be used for HD/DD recording, but it's probably best to keep separate disks for samples and HD/DD recording anyway.
AKAI S1100 SAMPLER
16-bit linear sampling at 32 kHz, 44.1 kHz, 48 kHz
16 voice polyphony
24-bit internal processing
Stereo Hard Disk Recording
Realtime DSP effects
32 Mb RAM, maximum
Stereo out, 8 assignable outputs, digital output
320 character display
HD Hard Disk (or hard drive).
DD Digital Disk, Disk Drive or possibly Direct to Disk ?
TAKE Default term for a single DD recording, takes can be renamed.
DSP Digital Signal Processor (used for effects and HD recording).
S/PDIF Domestic version digital interface, as used on most DAT machines.
Two varieties, OPTICAL and COAXIAL.
AES/EBU Pro version digital interface.
XLR Professional heavy duty 3 pin connector.
Copyright © 1997 Chris Carter / SOS Publications.