Retro Review: Yamaha DB50XG - Part 1
10th September 2024
This month's retro review covers a new item I recently purchased: an original Yamaha DB50XG daughterboard. Many years ago I had the opportunity to get an authorised clone of one of these but couldn't justify the price tag. That one was the NEC XR385 and I seem to recall it was bundled with an NEC sound card as well - silly me, as this bundle would likely cost a lot more today.
Anyway, I'm excited with this one for several reasons. Firstly, it's the "real thing" - any original Roland or Yamaha audio gear carries a cachet, as they were pretty much the authors of the General MIDI (GM) standard and the sample quality is known to be up there with the best. Secondly, I have a number of other GM modules with which to compare - from original 1990s external MIDI synthesizers to other WaveBlaster-compatible daughterboards and onboard GM-capable sound cards.
But before I get into the details, let's summarise what the DB50XG actually is.
The Yamaha DB50XG
Following the release of the MU80 Tone Generator in 1994, the Yamaha DB50XG launched in 1995 as their first PC product. It was a 100% General MIDI-compatible wavetable daughterboard and like the MU80 it came with Yamaha's own XG-MIDI extension, akin to Roland's GS protocol. While the original GM standard from 1991 provided 128 voices with limited capabilities to edit their parameters, XG extended this to 676 fully-editable instruments and 21 drum/percussion sets. In addition it provided over 60 effects processor types comprising 11 reverbs, 11 chorus and 42 variation effects (delays, wah wah pedals, overdrive, distortions, guitar amp simulator, etc.), and these could be applied to up to 3 individual voices at any one time.
At this time, the Wave Blaster header had been around for about three years, and many PC peripheral manufacturers including Aztech, Orchid, Terratec and Ensoniq had already come out with MIDI daughterboards of their own to cash-in on the burgeoning market for better gaming PC audio. Yamaha were certainly late to the party on the daughterboard front, but had been active in the external MIDI processor market since 1991, competing directly with Roland's Sound Canvas range.
Here's a summarised comparison of the base GM specifications, Roland GS and Yamaha XG:
| GM Level 1 | Roland GS | Yamaha XG | |
|---|---|---|---|
| Introduced | 1991 | 1991 | 1994 |
| # Instruments (Voices) | 128 | 317 | 676 |
| # Drum/percussion sets | 14 (included in the 128) | 16 | 21 |
| Polyphony | Up to 16 | Up to 16 | Up to 32 |
| Channels (Parts) | 16 | 16 | 16 |
| Effects (Reverb, Chorus, etc.) | None | 7 | 60 |
The XG can play two elements (sounds) on each channel, allowing it to play up to 32 notes at the same time if only single-element voices are used. If any notes use two elements the polyphony is reduced accordingly. The General MIDI Level 2 standard included this capability when it arrived four years later in 1999.
Being an early wavetable daughterboard the DB50XG was quite large which made it physically impossible to fit onto a lot of the shorter sound cards on the market. In 1996 Yamaha released the functionally identical DB51XG, a smaller version of the DB50XG, for this reason.
You may have read that the DB50XG has 480 available instruments and 11 drum sets - this warrants some explanation. The DB50XG has a total accessible set of 676 normal (pitched) voices and 21 drum (fixed pitch) voices. The DB50XG can run in several modes:
- XG mode - plays XG-compatible multitimbral data over 16 channels. In this mode it can access up to 480 normal voices and 11 drum voices.
- TG300B mode - plays multitimbral music data created for the Yamaha TG300B tone generator. In this mode is can access up to 579 normal voices and 10 drum voices.
So at any one time, the DB50XG can use either 480 (+11) or 579 (+10) voices. On startup the DB50XG runs in TG300B mode which maps the instruments to the standard General MIDI ones. XG mode can be switched on via a SysEx (System Exclusive) message.
Some close-up shots of the DB50XG
Software
The DB50XG came with a CD-ROM that included songs in both MIDI and audio formats, and SMF "MIDI clips" to showcase the sonic dimensions of the XG. The CD-ROM also had a demo version of Yamaha's Visual Arranger software.
Sadly the XG extensions were only officially used in a single PC game, Final Fantasy VII (there is also an unofficial patch for Quake II that uses XG), so these days you're not going to be buying a DB50XG to provide anything new if you already have another GM wavetable. What you will get are its incredibly high quality instrument samples.
It is worth bearing in mind that for most GM-compatible DOS games their music was composed on a Roland Sound Canvas, so playing games with one of these is going to provide music exactly how the original composer wanted you to hear it. The Yamaha however, does offer a different flavour - sometimes quite dramatic with drums and percussion especially sounding more pronounced than with the Roland. We'll explore more of this later as we compare the DB50XG to others.
Yamaha's Other General MIDI Cards for the PC
While the DB50XG was their first card for the PC market, they released others which are listed here.
(For information on their external MIDI devices, see the main Yamaha page):
| DB50XG | SW60XG | DB60XG | DB51XG | |
|---|---|---|---|---|
| Introduced | 1995 | 1996 | 1996 | 1996 |
| Type | Daughterboard | 16-bit ISA card | Daughterboard | Daughterboard |
| Part # | XQ791 | XR394 | XR385 | XV176 |
| Polyphony | Up to 32 | Up to 32 | Up to 32 | Up to 32 |
| Sample ROM | 4 MB (XQ731 / MX25866A) | 4 MB (XQ731 / MX29018A) | 4 MB (XQ731 / MX28277A) | 4 MB (XV721 / MX C003364) |
| Microcontroller | Hitachi H8/3002 | Hitachi H8/3002 | Hitachi H8/3002 | XU947 |
| Synth/DSP Chip | XQ036 / XQ730 | XQ036 / XQ730 / YSS205 | XQ036/XQ730 | XU947 |
| Effects Processor | XR253 | XR253 | XR560 | XU947 |
| Firmware ROM | - | XR795 | - | - |
| DAC | 18-bit (NEC D63200) | 18-bit (NEC D63200) | 16-bit (Asahi AK4510) | 18-bit (NEC D63200) |
| Analogue Input | No | No | Yes | No |
Functionally, these are all very similar with no significant differences in capability or audio quality.
From left: Yamaha MU10, SW60XG, DB60XG, and DB51XG
The DB50XG also came in the form of both an external MIDI tone generator called the MU10 and an ISA card, the SW60XG, both of which launched 10 months after the DB50XG. The SW60XG has a few extra ICs not found on the DB50XG: an ISA bus controller (Yamaha XR393) and another DSP/DAC/ADC chip (Yamaha YSS205).
The DB60XG was only sold in Japan, and was essentially the same as DB50XG but added an analogue input. This means the DB60XG got a different CODEC and a different Hitachi microcontroller firmware. The NEC XR385 was an authorised OEM version of the DB60XG.
The DB51XG was introduced later as a smaller daughterboard with a lot of the individual chips from the DB50XG now embedded on a single ASIC, the XU947. The only other major ICs external to this were the sample ROM, DAC and a 1MB static RAM IC. The Korg NX5R was sold with a Yamaha DB51XG daughterboard fitted from factory. Buyers of the lower-end NS5R could purchase the DB51XG as an optional upgrade.
In 1998, they released their first PCI MIDI card, the SW1000XG. This supported up to 64-voice polyphony and six separate audio buses (compared to three on all their older PC units mentioned above). It had a 15-pin proprietary daughterboard expansion connector on the top, to which you could optionally add a PLG100V or PLG100VL synth, or the pricier PLG100DX FM synth ("PLG" was Yamaha's abbreviation for "Plug-in"). It also had an S/PDIF digital output socket as well as MIDI In and Out.
In Part 2 (coming soon), we'll get it installed and start testing - being a wavetable daughterboard, it uses no separate memory address, IRQ, or DMA channel, as it channels everything via the sound card it is installed onto.