Expansion Port Sound Module (EPSM) (Previous Batches)

Description

IMPORTANT NOTES PLEASE READ

• • This listing is for remaining units from previous EPSM batches. These units use the older modified connector, not the newly manufactured connector used on the current EPSM listing.
  • Only a small number of these previous-batch units remain available.
  • This is a brand new product without much software that uses it yet. The goal is to get these units into the hands of people writing homebrew, tools, music, and testing software so the EPSM can become more useful to a wider audience.
  • The connectors on these modules were made by processing existing connectors with many tools. Because of this, the fit and finish differs on each unit. Some units slide in with a loose fit and others with a tight fit.
  • If you are looking for the current EPSM listing with the newly manufactured connector, you can find it here.
  • An enhanced version of the EPSM, called the EPSMPlus, is also planned. If you are interested in being notified when that version becomes available, you can follow the enhanced version listing here.
  • A Famicom version is also being considered. If you are interested in a Famicom version, please register your interest here.

1st Batch Notes

• • • The first batch can be identified by a black PCB with a green LED.
    • Although EPSM output is available through the RCA and RF jacks, the audio levels are incorrect through this route. Using the 3.5mm audio jack is recommended for the best quality and experience.

2nd Batch Notes

• • • The second batch can be identified by a black PCB with a blue LED.
    • There was a small issue affecting some units in this batch. Some areas of the solder mask were too thin and were removed during cleaning. To prevent corrosion, these areas were plated with solder. These units are functionally fine.
    • EPSM functionality is only available through the 3.5mm jack and not through the RF or RCA audio jacks.

Expansion Port Sound Module (EPSM)

The Expansion Port Sound Module, EPSM for short. Is a new device made for the NES Expansion Port that has never really been used.
This device started with the idea to make something useful for the never used port.
The basic idea is to add a lot more audio capabilities to the NES without having to add expensive hardware to each and every cart,
while also adding support to listen to the already existing carts with expansion audio.
Using game carts with expansion audio on an unmodified NES will only output the audio into the void, the EPSM solves this.
It’s cheaper to get a slightly pricier expansion adapter than adding audio hardware to multiple games.
The EPSM would have been possible to make as early as 1985 though in a bulkier version since the slimmed down version of the chip did not come as early.

Features:

• • • Genuine Yamaha YMF288 FM Synth Chip
    • Adds 15 new sound channels to the NES for future homebrew support
      • 3 Square wave channels, also capable of noise
      • 6 FM Synth channels with Hard Panning Stereo support
      • 6 Rhythm channels featuring 6 different ADPCM Drum Recordings with Hard Panning Stereo support
    • Forwards expansion audio from supported gamecarts
      • Original Famicom expansion audio games with compatible adapter
      • PowerPak
      • EverDrive N8 or Everdrive N8 Pro
    • 2 different Addressing modes
      • Direct/Mapper assisted
      • Fallback mode
    • 3.5mm Jack for Stereo Output

Cartridge Support

Direct mode addressing requires an Everdrive N8 Pro with this mapper pack is required for EPSM support. Special EPSM specific cartridge boards using direct addressing mode is planned. You can sign up to be notified of the first one planned here.

Source and Support

Please note that although this is an open source noncommercial project Muramasa Entertainment has received permission to manufacture the EPSM from Perkka the creator of the EPSM. Please note that support is limited and before purchasing please check the Github page to see more information on the product. Also please feel free to ask questions on the NESDEV Discord on the #chiptuning or #hardware channels.

Example

If you would like to see some examples of what is possible you can listen to this playlist from how2Bboss here.