Roland S-10 Sampler Refurb

Introduction In February 2018 I bought a Roland S-10 sampler for £50, which looked in reasonable condition on eBay but with the usual QD drive failure. My plan was to re-use the 4 octave keyboard in another project, as S10’s often have had a hard life! However once I had cleaned up the sampler at home, I found it worked well except for the drive, so I decided to keep it as a sampler in my workshop and restore it back to the best condition I could by replacing the worn out components. The sampler may have been bought and used by J-M-J originally, so it seems a good idea to save it.

This post details the refurbishment work that has been done.

History The 12-bit S-10 keyboard sampler was introduced in May 1986 at an initial price of £1099, and sold strongly in 1986/7 with over 8000 manufactured before it was phased out with the arrival of the 12-bit S-330 in early 1988. In February 1988 the S10 was was being blown out at £699 and the S10 was one of the cheapest ways of getting into sampling, albeit just 4 seconds and with a really unreliable storage drive. The S10 and its rack mount brothers the MKS100 and S-220 have fallen out of favor with musicians and can easily be found secondhand for under £100, they are actually quite usable and immediate.

Old LCD Display

LCD to OLED The 16×1 blue back lit LCD had faded significantly (as expected) with the EL reaching end of life and the inverter whining. Take a look at the picture, hard to use a sampler with a faded display with just 16 characters!

This was the first component to be replaced on the S-10. I used a modern OLED display which provides a much clearer display and wide viewing angle. There is no need for a contrast adjustment.

The OLED I fitted is the Vishay O016N001AGPP5N0000, which is the correct overall size of 80mm x 36mm and has a green character colour. I bought it from Mouser for £13. It is an easy fit once the main front panel has been removed, and the LCD holder unscrewed. The inverter cabling to the power supply and inverter are removed, and the LCD cable desoldered from the old display and moved to the new display. The contrast cable wire is not required and should be removed (it did go to Pin 3 on the display).

New OLED

The new display works fine but only displays the first 8 characters, just like the Alpha Juno displays upgraded to 16×1 OLED’s. The solution is to hack the operating system which is fortunately on a separate ROM chip. All the 2nd line display commends have to be revised to use 8h in addressing rather than 40h.

I want to keep the OLED, so a firmware hack has to be done! The OS code can be downloaded as a binary and I now need to reverse engineer it. The firmware for the Alpha Juno has been successfully hacked to use a modern OLED, so I will follow the same route and disassemble the binary into the source assembler code. Then make the change , assemble and create a new ROM.

I will post progress on this and the final ROM code.

Old (L) and New (R)

Panel Switches Some of the button switches were a little unresponsive after 33 years, so I bought a complete new set of 30x from Mouser. This is much cheaper at just £5 than using eBay. The Alps part number you need is: SKHHAMA010.

I clipped off the old switches, desoldered the legs and removed the old solder, then soldered in the new switches making sure they are flat against the PCB’s. I removed and cleaned the PCB’s along with button caps. If you need switches for the MKS-100 or S-220 they are Alps SKHHBSA010, also available from Mouser.

Panel Buttons Two of the buttons were badly damaged, still usable but I may replace them with NOS items, if I can find them.

Keys A couple of the white keys had minor damage, a visible cigarette burn melted into the top surface and a black spot of corrosive paint to mark the upper split point (why?). I was able to tidy these up with a craft knife and some sandpaper, so I did not need to buy replacement keys. All the keys had to be thoroughly cleaned with soapy water, as they were filthy, I use shower glass cleaner.

Two of the keys did not work, so the whole keyboard has to be removed and the contacts cleaned.

Slider Dust Cover The S-10 has a dust cover for the 3 slide potentiometers to the left of the keyboard. The dust cover had perished and looked awful sitting in front of the sliders and visible through the plastic bezel. I cleaned the slider and bender plastic bezel after removing it from the sampler, and removed the bend lever (to clean it) along with the PCB. I could then remove the old dust cover, which is a push fit, and copied the outline onto a new one cut out of 2mm neoprene sheet. Quick refit of the parts and… Perfect and it looks much better!

In August 2019 I went back and used Dexoit to clean out the sliders and added Fader Lube to make them all smooth again, well worthwhile.

New Lithium Battery

Battery The 3V lithium battery needed replacing after 30+ years, as on power on the Performance Data was lost, and a message came up on the LCD requesting the Bender range be entered. The battery is on the main PCB but tucked under the keyboard, so that had to come out! The old battery measured 3.29V, whilst the new one measured 2.94V, do not be fooled, a 30 year old battery needs to be replaced!

A new battery was bought off eBay and soldered in. The old and new battery soldering can be done (carefully) with the PCB still mounted in the casing.

PSU Recapped

Power Supply All the large and small electrolytic capacitors on the power supply PCB were replaced with new high performance versions with the same pin out and dimensions. I use Nichicon and Panasonic electrolytics and I will probably go back and upgrade the caps in the main board as I have done on the S-220’s.

August 2019 Update The recap of the PSU caused all 3 power rails to fail, possibly due to the transistors being weakened by moving the board about. I replaced the regulator, power transistors and one rectifier bridge with new items.

Disk Drive  The disk drive was in good condition with no motor whining but it failed to load QD disks. I took the drive out and it was immediately obvious that the belt had perished. I ordered a new drive belt from eBay (Germany) and in the mean time removed the old belt goo with isopropyl alcohol and cotton buds. The new belt was fitted and the drive worked perfectly after a few issues reading, it settled in and worked ok.

Disks The S10 sampler came with 16 Quick Disks in various conditions but only the 3 newer disks were readable and the rest were thrown away.

S10 Manager I downloaded this software onto a Windows 7 PC and soon had it working well with the S-10 (and S-220’s), making sample transfer easy. I spent an evening working through the factory library, the JP8  Brass & Strings is the high lite!