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"dd" ‑or‑ OMNIFLOP ‑or‑ SDISKW ??? The built‑in "dd" utility on the Mac is what I use all the time now to create, copy and archive all of my 3.5" floppy disks. It's a quick, no frills solution for creating and sharing floppy disks, *.IMG and *.OUT Disk Image files for the S‑Series, W‑Series and DJ‑Series samplers Until I discovered the "dd" tility on the Mac, OmniFlop was my favorite utility on my Windows PC for creating S‑Series, W‑Series and DJ‑Series sampler disks from *.OUT files. OmniFlop is an excellent tool for creating and sharing *.IMG and *.OUT Disk Image files for use with a USB Floppy Drive Emulator (USB/FDE). Also, a required utility if you still use floppy disks with your sampler. I highly recommend using OmniFlop as a replacement for the DOS based SDISK and its Windows counterpart SDISKW. OmniFlop even has a special menu selection for working specifically with Roland sampler disks I initially had some minor hardware issues with installing a working 3.5" floppy disk drive. It turned out that only the old‑style 720KB DS/DD or 720KB/1.44MB Dual Support drives will work. The newer and (of course) less expensive 1.44MB DS/HD will only write disks for use with the S‑750/S‑760/S‑770 samplers. After solving that problem, I compiled some useful installation notes here SDISKW is a good program to use if you plan to use only 3.5" floppy diskettes with your Roland sampler and don't want to work with any advanced disk image files (*.OUT, *.IMG, *.S50, *.S33, *.W30, etc...). SDISKW might also be a better choice for you since it will work with an external USB FDD. Each of these utilities has an advantage over the other ![]() ![]()
GOTEK USB Floppy Drive Emulator (USB/FDE)
There are many methods of making a GOTEK USB Floppy Drive Emulator (USB/FDE) work with a Roland S‑50, S‑550, S‑330, S‑7xx or W‑30 sampler. The easiest way is to buy GOTEK Model: SFRM72‑FU‑DL for about $25 (USD) and simply plug it into the sampler where the floppy disk drive used to sit. The disadvantage of using this model is that there are very few bells and whistles available. The GOTEK factory firmware on this model uses a very boring 7‑segment LED display and the two buttons on the front make a clumsy user interface Luckily, there are alternatives for updating the GOTEK firmware and the best version I've seen is available for free. You can purchase a low‑priced GOTEK for about $17 (USD), a nice, crisp OLED screen for $2, a rotary encoder for $3 and update the firmware yourself using free installation software. In the past, other firmware updates required a special serial interface and a $10 software license for each GOTEK you updated The only extra hardware you need for this free FlashFloppy firmware update is a standard USB cable. When I updated my GOTEK with the FlashFloppy firmware, installed the OLED and rotary encoder, It worked perfectly the very first time I tried it. Very unusual for mods like this when trying to make 1980's technology work with modern gadgets. In fact, after all the updates went so smoothly, I thought perhaps that something had gone wrong ![]() Keep in mind that the OLED screen and Rotary encoder are optional add‑ons but... for these low cost parts, I highly recommended adding them. It's like the difference between driving a Ford Pinto and a Corvette Stingray A link to installing a GOTEK USB/FDE on your Roland sampler using the free FlashFloppy firmware is here (This firmware update requires free software installation and additional parts [optional] which requires soldering) A link to installing a GOTEK USB/FDE the easy way on your Roland sampler is here (No soldering or extra modification is required for this method)
GBS‑8200 CGA/EGA/YUV To VGA Video Converter Board DIY
This is an inexpensive way to connect your S‑50, S‑550, S‑330 or S‑7xx to a standard 15‑pin LCD Flat Screen VGA Color Monitor. This DIY project was much easier than I expected. The results are GREAT and so are the cost savings! Thanks to this tiny video board, I'm now able to use my S‑50, S‑550 and S‑760 samplers with a sharp looking, crisp and clean 17" Dell (15-Pin), Atari (13-Pin), Sharp (17-Pin), Envision (17-Pin), LCD color display. The monitors I used for testing were standard 15‑Pin VGA which were previously used with generic video boards on a PC. I am assuming that just about any 15‑pin LCD Flat Screen VGA Color Monitor will work with this DIY. I also had a cheap leftover +5V DC power supply so my total investment was less than $35 (USD)
The parts required to make this DIY work are
Build Procedure 1) Take the white 8‑pin connector that came with the GBS‑8200 video board and move the grey wire in Slot "S" over to Slot "HS". To remove the grey wire, use a needle to press down on the metal connector then gently pull the wire up and out (see Figure 1). The reason for moving this wire from Slot "S" over to Slot "HS" is because an HSYNC signal is required for S‑50, S‑550, S‑330 and S‑7xx RGB video output. The grey wire by default on the GB‑8200 video board is connected to an "S" video signal (CSYNC), not HSYNC 2) Solder the six wires on the white 8‑pin connector that came with the GBS‑8200 video board onto the 8‑pin male DIN connector S‑50 / S‑550 8‑PIN DIN MALE PLUG GBS‑8200 VIDEO BOARD 8‑PIN WHITE CONNECTOR (P11) VIDEO SIGNAL PIN# PIN# WIRE COLOR VIDEO SIGNAL GROUND 2 <----------------------> GD BLACK GROUND VSYNC 5 <----------------------> VS YELLOW VSYNC HSYNC 4 <----------------------> HS GREY HSYNC [AFTER MOVING WIRE] BLUE 8 <----------------------> B BLUE BLUE GREEN 7 <----------------------> G GREEN GREEN RED 6 <----------------------> R RED RED +5V 1 DO NOT USE - NO WIRE DO NOT USE OPEN 3 DO NOT USE S NO WIRE DO NOT USE Because these wires are supplying video signals, I opted to shield them by wrapping three layers of aluminum foil around the entire six wire cable assembly. I then took some black electrical tape and wrapped everything tightly. I'm not sure if the shielding is necessary but I did it just to play it safe 3) Connect all the cables and power on all the devices... Make sure the power supply you are using is "center tap" positive!) ![]()
Another S‑550 owner with this same video board has put together a great overview of how it works including the menus. For more details check out freudelheim
![]() ![]() Issue: Screen shaking or rolling around TROUBLESHOOTING
If you end up getting lost and venture into the cryptic Chinese menus by mistake, the quick route to get English displayed is made by pressing: MENU > UP > MENU > UP > UP > MENU > MENU Other menu button functions (with no OSD menu showing on the monitor) Auto‑Scan: DOWN/AUTO Reset The Board: Press and hold DOWN/AUTO for 5 seconds Video Mode‑Select (RGBS / RGBHS / YPbPr): SW (RGBS = 15‑pin VGA connector) This video board is very easy to use. If you need additional menu info and technical specs, download the GBS 6800 Operation Manual at this link ![]() If this video board will be used with an S‑50 or S‑330, an inexpensive metal housing is recommended to keep the static sensitive components safe. I use a Hammond 1599DD aluminum enclosure (normally used as a guitar pedal case). If this is to be used with an S‑550 and there is no HD5‑IF SCSI Interface Card installed, you can do what I did and take advantage of the empty space on the underside. Place the video board inside the sampler like so... ![]() $20 (USD). Now that's the kind of DIY I like... nice and inexpensive! If needed, here is some more detailed info; I tested the GBS‑8200 video board with a Sharp LL‑T15A4‑B 15" LCD Flat Screen VGA Color Monitor (manufactured in 2003 ‑ specs) and a Dell E176FP 17" LCD Flat Screen VGA Color Monitor (manufactured in 2006 ‑ specs). In addition to a standard 15‑pin VGA Out connector, there is also a 12‑pin socket (P12) on the GBS‑8200 video board which provides a video output signal for R, G, B, VSYNC, HSYNC, and GROUND. If you have an older style monitor like a CGA, EGA, or RGB, this extra 12‑pin connector might be able to adapt to those older style monitors by using a different connector arrangement. For this DIY, the included 8‑pin connector (P11) with six wires was used. You might be tempted to use a tap off of the main S‑550 circuit board to supply power for the GBS‑8200 video board. Don't do it. Ordering a replacement circuit board for vintage gear like the S‑550 is not an option. Play it safe and stick with a cheap external power supply. An external power supply will also help to isolate any hum the GBS‑8200 video board might introduce into the S‑550 audio circuit Old RGB Monitors Some of the older RGB color monitors that work with the Roland S‑50, S‑330, S‑550, S‑750, S‑760 and S‑770 use an oddball 8‑pin rectangular female connector (the official name for this connector is "SMK EIAJ 8‑Pin Female VTR Connector"). The color monitors distributed by Roland were P/N#: CC‑121 and P/N#: CC‑141. Similar RGB monitors were Amdek Color-II, Taxan RGB Vision-I, II & III and Sony Trinitron KV-1311CR. The cable needed for use with these old monitors is very difficult to find. Roland manufactured this cable with a rectangular male connector as P/N#: RGB‑25N If you want to build your own cable, the cost to get all the parts (not including shipping) is about $40 (USD) ![]() ![]() Two popular RGB monitors of days gone by were the Atari SC1224 and SC1435. These monitors used a strange 13‑pin connector. If you want to build your own cable, the cost to get all the parts (not including shipping) is about $35 (USD) ![]() How To Share 1 Monitor With 2 Or More Roland S‑Series Samplers If you have 2 or more Roland S‑Series Samplers, this inexpensive DIY is for you. Complete plans are contained in this PDF file ![]() ![]() Using A Non‑Roland Mouse With The S‑550, S‑330 And S‑7xx Samplers ![]() NOTE: The S‑50 will not work with any type of mouse. The EXT CONTROLLER port on the back of the S‑50 will only work with the optional DT‑100 Digitizer Tablet. If you plug a mouse into the EXT CONTROLLER port, you run the risk of causing a short circuit in the sampler. Likewise, if you plug a non‑Roland mouse into the EXT CTRL port on the S‑550, S‑330, S‑750, S‑760 or S‑770, you run the risk of causing a short circuit. If this happens, see info about replacing the PICO® fuse at the section on this webpage called Mouse Or RC‑100 Is Unresponsive, Intermittent Or Not Working After losing bid after bid on expensive MU‑1 and MSX mice at eBay, I decided to purchase a KMTech PS/2 to MSX mouse adapter instead. It works flawlessly with my S‑550 and S‑760. The adapter is very small at 63mm x 19mm x 13mm. Compared to the price of a used MSX mouse, this clever adapter board is a bargain at $31 (USD) + shipping. The overseas shipping to the USA was amazingly fast at only 6 business days! The seller is kevinmount* who has a 100% Feedback Rating on eBay * The item was PS/2 to MSX Mouse Adapter and was purchased from kevinmount Ship time: 6 days from United Kingdom to the USA The big advantage this adapter has over an MU‑1 mouse is that if the PS/2 mouse goes bad, a replacement is inexpensive as opposed to finding another expensive MU‑1 mouse on eBay. Plus, every MU‑1 or MSX mouse I've seen for sale on eBay is being sold as a used item and is already 30+ years old. I've had excellent results using a WYSE PS/2 (P/N: 770510‑21L / LED Optical Type) and a DELL (P/N: M-S34-6MD / Ball Wheel Type). It's recomended that when using a LED Optical Type mouse, do not use a mousepad with complex patterns. Use one with a solid color or the mouse pointer will jump around the screen
My only complaint about the board is that it needs some type of a cover. My solution was to wrap everything with black electrical tape. I can't stand to have an exposed circuit board with static sensitive components glaring at me. It goes against everything I was taught about electronics ![]() ![]()
2‑Prong Power Cable Replacement DIY Tired of always looking for that oddball 2‑Prong AC power cable? Do something about it. Here's a super simple mod that will let you use the more common 3‑prong AC cable with your Roland sampler. The cost for parts was less than $1. In addition to always being able to find the right AC cable, this mod adds ground circuit protection. Why is that important? Just ask several S‑50, S‑550 and W‑30 owners who connected their sampler to an ungrounded mixing board. The audio output transistors on their samplers were toasted!!! The mod is so simple that all it needs is a picture to explain. It's easy as 'connect the dots'. If you buy the correct sized AC power adapter (P/N: 703W‑00/03), it's a 1 for 1 swap, no case modification and no sheet metal to cut. There's even a pre‑drilled hole in the case for the ground wire. Just piggy‑back onto one of the screw holes used for the serial number plate. Easy! The DIY image shows the mod for an MKS‑70 but this will also work with an S‑50, S‑550, W‑30, MKS‑50 and a bunch of other Roland rackmounts and keyboards. If you are using a sampler with something running other than 110/117V AC, please note... this mod has NOT been verified to work on a sampler running 220V/240V. This mod is only for those with electronics experience. Author accepts no liability if you damage your synth or hurt yourself. Always keep one hand behind your back when working with live electrical circuits. It's the best way to stay alive ![]() If you just want to buy a 2‑prong AC replacement cable, don't pay the ridiculous high prices at eBay or elsewhere The 2‑prong replacement cable is Hosa P/N: PWC-178 and is available at sweetwater.com + always FREE Shipping / NO Minimum! W‑30 LCD Replacement DIY Detailed instructions for replacing your old LCD. Not the easiest DIY in the world but the good news is for under $30 (USD), you can get rid of that annoying high pitched shrill in the process * * * Update: December 2021 * * * A new version of this DIY manual is now available. Feedback from others report that a 100 Ω / 1W resistor works best with the Blue, Black and Monkey Vomit Green displays. Also, most people agree that cutting off the existing LCD wiring harness and reusing it is easier than assembling a new Hirose connector so this has been added as Option #1
W‑30 Backlight Replacement Over time, the W‑30 backlight will begin to fail and get dimmer. It takes a while to disassemble the W‑30 to gain access to the LCD, but installing a new Electroluminescent Panel (ELP) segment is quick and easy. The old ELP slides out easily after unsoldering two leads There are several vendors on eBay selling ELP's the price range of $8 to $20 (USD). The most common colors available are Blue or White When soldering in place, use a heatsink (a large coin also works well) and touch the leads with the soldering iron for only very brief moments and use a lower than normal temperature for the soldering iron. I had to trim off about 1mm from the top and bottom edges to make it fit. However, it's not an issue because this flexible ELP may be bent or cut into any shape. This ELP also works with Roland S‑750, S‑770, AKAI, Kurzweil and EMU samplers. The Roland W‑30 Blogspot has some good before/after pictures about this replacement. A green ELP is shown on that webpage but the instructions are valid * * * Please Note * * * If your W‑30 has a high pitched and incredibly annoying shrill, that sound is caused by a failing high voltage inverter circuit which drives this ELP. Replacing the ELP will not stop this annoying sound. Your best course of action would be to replace the entire LCD assembly as detailed at this link ![]() ![]()
W‑30 LCD Contrast Pot Replacement
One of the most common failures on the W‑30 is a broken LCD Contrast Potentiometer which is located on the back of the sampler. This knob has a tendency to break easily during transport because Roland used a sub‑standard plastic part. Symptoms are a wobbly, unreliable knob or worst case scenario, a blank LCD. You can replace this one using an Alpha brand 9mm B10KΩ potentiometer. The cost is only 67¢ (USD) and is available from taydaelectronics.com. The part number is SKU: A‑1850 This part is not a direct "drop‑in" replacement. Replacing this one is a little tricky because of the tight quarters and the case alignment. I had to cut off a small section at the end of all three pins and bend them at a right angle to make it fit into the PCB holes. I cut two 25mm sections from a strong paperclip, sanded off the outer chrome and soldered them to the ground frame of the pot. I then soldered the other ends to the empty GROUND trace holes on the PCB for stability (the empty GROUND trace holes were leftover from the old potentiometer). The result was a perfect fit. The old potentiometer I removed was a B5KΩ so I'm not sure if the previous owner of this sampler replaced it sometime in the past or if Roland changed the value to a B5KΩ on later production models?!? The schematics in the W‑30 Service Notes say this part should be a B10KΩ pot so that's what I used Don't get your potentiometers locations mixed‑up like I did LCD CONTRAST is on the MAIN BOARD and Silkscreened as VR1 INPUT GAIN is on the ANALOG BOARD and is also Silkscreened as VR1 Note: This replacement part from taydaelectronics.com is also a plastic part just like the Roland original. A metal shaft potentiometer is too large to fit through the opening in the case unless you drill it larger. You can take your replacement one step further and cut the plastic shaft off flush with the back of the case and add a flat‑blade screwdriver notch for adjustment. This way, if the back of the sampler gets knocked around during transport, the recessed knob will be unaffected. The drawback is of course, it's not very easy to adjust the contrast knob while you are on stage The INPUT GAIN Potentiometer is also a part which breaks easily but this potentiometer is much harder to replace because of it's odd‑ball value which is C5KΩ (Anti‑Logarithmic). To date, I've been unable to source an equivalent part number for this potentiometer S‑50 And W‑30 Control Jack Templates I designed these templates after being frustrated time and time again by having to move my S‑50 and W‑30 away from the wall to locate where certain audio and control jacks are located. This makes it easier to plug cables in and out without having to always face the back of the sampler... or use a mirror. There are four template variations with different fonts and color schemes for each sampler ![]() ![]() File Format: PDF Document Mouse Or RC‑100 Is Unresponsive, Intermittent Or Not Working (S‑550, S‑330, S‑750 & S‑770) I always thought the mouse interface on the S‑550 sucked due to a poorly designed operating system. It turns out those claims were unwarranted. I didn't know it at the time but the problem was always with the EXT CTRL 9‑pin connector on the front panel. I opened up five S‑550's and all five had broken or loose solder connections at this PCB location. Due to age, excessive pressure on the case, strain on the 9‑pin connector or a combination of all three, these solder connections break off or become loose. Some of the symptoms include
If you are still having problems with the mouse or RC‑100 after extensive troubleshooting, be aware that there is a 1/6W PICO® fuse resistor which may have blown. I remember back in the 1980's when a rash of Atari computers had a similar problem. If a device other than an Atari mouse or joystick was plugged into the 9‑pin jack, it would sometimes create a short and blow a PICO fuse because one of the pins carries a +5V signal. A similar situation may exist here with the S‑550, S‑330, S‑750 and S‑770 (Note: The S‑760 does not use a PICO fuse in the EXT CTRL circuit) Miscellaneous Fuses ![]() This Fast Blow PICO Fuse (P/N: 0251.750NAT1L) manufactured by Littelfuse has nearly the same resistance as the original of 150mΩ. This one (P/N: 0251.630MXL) will also work in a pinch. It has a lower blow point (630mA vs. 750mA) and a higher resistance (200mΩ vs. 150mΩ). The differences are so minimal that it should not be an issue (i.e. only 50mΩ so... as long as the blow point is lower and the resistance is somewhat close, you're covered ▶ SPECIAL NOTE: If you replace the PICO fuse, take extra care to observe how Roland installed it! This fuse sits far above the PCB and away from other components, about 25mm. This is on purpose so that if this fuse does blow, it won't scorch other nearby components or traces on the PCB from the excess heat it generates during failure. Since this is a "Fast Blow" fuse, use a heatsink when soldering it in place. Use a slightly lower than normal soldering temperature (less than 350℃ / 662℉) and don't let the soldering iron make contact for more than five seconds at a time. Otherwise, the performance may be deteriorated or the fuse may open
The original PICO fuse installed by Roland was a Panasonic P/N#: ERQ16NKR15E ‑ Original Panasonic datasheet: here
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Mouse schematics for the S‑550 (Left), S‑330 (Middle) and S‑750/S‑770 (Right) showing fuse resistor locations
![]() RGB Video Output Not Working (S‑550, S‑330, S‑750, S‑760 & S‑770) If your sampler is having an issue with no video output, it is possible that a fuse in the video circuit has blown. Just like the mouse circuit, the same 1/6 Watt PICO® Fuse Resistor is used. This Fast Blow PICO Fuse (P/N: 0251.750NAT1L) manufactured by Littelfuse has nearly the same resistance as the original of 150mΩ. This one (P/N: 0251.630MXL) will also work in a pinch. It has a lower blow point (630mA vs. 750mA) and a higher resistance (200mΩ vs. 150mΩ). The differences are so minimal that it should not be an issue (i.e. only 50mΩ so... as long as the blow point is lower and the resistance is somewhat close, you're covered ![]() One important thing to know is that Pin #1 of the 8-pin DIN connector in the video circuit is connected to the PICO fuse and +5V DC. Pin #1 is used by some monitors and some external video boards but not by others. SCART external video boards and some older RGB monitors require a connection to Pin #1. The GBS‑8200 external video board and some older RGB monitors like the Atari SC1224 and SC1435 do not use a Pin #1 connection. If you have no video output with the latter, replacing the PICO fuse will not help so look elsewhere for the problem. If you have no video out and are using an external SCART video board, check for a fried PICO fuse
The original PICO fuse installed by Roland was Panasonic P/N#: ERQ16NKR15E (Original Panasonic datasheet: here}
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RGB video circuit schematics for the S‑760, S‑330 and S‑750/S‑770 showing the PICO fuse resistor locations
Note: A large view of the S‑760 OP‑760‑1P Video Expansion Board showing the location for FUSE1 is shown at this link. To replace FUSE1 on an S‑760, the top and bottom OP‑760‑1P PCB's need to be removed along with the S‑760 Main PCB. This repair is a MAJOR operation involving a lot of work! ![]() ![]() No Sound Output Or Scratchy Sound Output/Input (S‑550, S‑220 & MKS‑100) Broken traces on the Switch Board are a common point of failure with the S‑550, S‑220 & MKS‑100. Over time, moving the sampler around will place too much strain on a particular section of the Switch Board and it will eventually crack. This usually occurs when the module is shipped from Point A to Point B. Broken traces on the board will set the total output volume knob to zero which renders the sampler useless. The problem area is located near the REC LEVEL and VOLUME potentiometers (VR1 and VR2). I was able to fix my S‑550 by using epoxy on the broken PCB then soldered some jumper wires to reconnect the traces which were snapped ![]() Scratchy sound or no sound at all can also be related to the REC LEVEL or VOLUME potentiometers (VR1 and VR2). If you are experiencing scratchy sounds when using either of these potentiometers, you can replace them using an inexpensive one manufactured by Bourns. Just like the original potentiometers, this replacement part has a very short Flatted/D shaft. The pins need to be bent slightly to fit into the PCB holes but it works perfectly S‑550 VR1 and VR2 are both 10K potentiometers with a Linear Taper - Mouser P/N#: 652-PTV09A-4015FB103 S‑220 VR1 and VR2 are both 10K potentiometers with an Audio Taper - Mouser P/N#: 652-PTV09A-4015FA103 MKS‑100 VR1 is a 50K potentiometer with an Audio Taper - Mouser P/N#: 652-PTV09A4015FA503 VR2 is a 10K potentiometer with an Audio Taper - Mouser P/N#: 652-PTV09A-4015FA103 Distorted Sound Output (S‑550) If your S‑550 is experiencing distorted sound output, it's possible the previous owner was careless and connected one or more of the 1/4" output jacks to a non‑grounded mixer or some other type of non‑grounded equipment. Since the S‑550 is not grounded by default, this can easily damage one or more of the nine output transistors on the Analog Board (this board is located in the compartment underneath the sampler). It's an easy fix if you are handy with a soldering iron. Replace all nine 2SC2878A transistors at locations Q1 through Q9. As of January 2022, there are a few vendors on eBay and AliExpress selling replacement 2SC2878A transistors. Even if you've isolated only one or two outputs as the culprit, take some extra time and replace all nine transistors while you have the board out. It's possible that other transistors were damaged and are ready to fail soon. Detailed information about this fix is available in this thread over at gearsz.com. This is another reason why it's a good idea to ditch that stupid 2‑prong Roland power cable and add a three‑prong AC power outlet to your Roland samplers/synths to ensure proper grounding! If you are in a jam and can only find 2SC2878-B transistors, they will work but... you will need a transistor tester to measure and select only those with an hFE less than 700 ![]() ![]() S‑50 Noise, Static And Distortion Issues If your S‑50 is experiencing noise, static or distorted audio then join the crowd. Over time, the S‑50 can start to experience a problem with the relay coil which is located on the Jack Board. The relay coil is there to temporarily delay an inrush of current to the Audio Out circuit so that any annoying loud pops are avoided when you power on the sampler. The Audio Out circuit is essentially turned off for a couple of milliseconds The three solutions I know of are to Replace It, Clean It or Bypass It SOLUTION #1 - Replacing The Coil Tom Arnold, another S‑50 owner, has supplied an excellent solution which has been verified by several online visitors here. He designed a very small PCB which is used to replace the single relay coil by using three inexpensive, low current and easy to source relays. The big advantage to this solution is these new relays are easily swapped out when they fail. According to Arnold, the S‑50 design is prone to failure because the original single relay coil and replacement relays will eventually fail over time. Since it's very difficult to remove and clean the factory installed relay coil, swapping out three 0.85¢ relay coils makes more sense because they are socketed on this new PCB "This is a 3DPDT relay board to replace the 6PDT relay in the Roland S‑50. Two holes in the middle are for hold‑down screws. I recommend putting in sockets so you can replace the relays more easily as they will go out again the way they are being used." The best price I've seen for these new relays is only 0.85¢ each from Allied Electronics. You'll need to buy three 16‑pin IC sockets and three 5V relays (Zettler P/N#: AZ822‑2C‑5DSE) The bad news is that OSHPark has a minimum purchase of three PCB's. The good news is they only cost $3/each ![]() ![]() UPDATE (November 2018) : Open Mirror from Australia was able to install this new PCB and Relay setup into his S‑50 before I was able to (it's still on my To‑Do list). He reports excellent results. The distortion he was experiencing has completely disappeared ![]() ![]() SOLUTION #2 - Cleaning The Coil Jim Atwood Of Japan has a step‑by‑step solution for cleaning the relay coil at this link; ![]() SOLUTION #3 - Bypass The Coil Some online visitors have reported they have bypassed the coil completely and just remember to keep the volume slider at zero when powering up. Since this will significantly alter the original circuit design, I won't provide any info about that fix. It seems risky, IMO The S-50 Or S-550 Front Display Panel Is Blank / Freaking Out / Intermittent ![]() ![]() Q: I have an S‑50 / S‑550 and the display screen is blank or acts weird. What can I do? A: Some owners have reported failures with bad solder connections on the FIP display. Use a magnifying glass to inspect for hairline cracks and reflow NEW solder if needed. The FIP driver coil for the display panel is also a common point of failure with the S‑50, S‑550, Super JX‑10, MKS‑70 and other Roland synths. The cause is a manufacturing defect which has been traced to the Sumida Corporation, the only supplier of this coil (P/N: 12449251). Unfortunately, sources for replacement coils are very difficult to find. A supplier on eBay has some redesigned replacements which sell for $75 USD. Another hope is to find an old coil from a cannibalized Roland product which uses the same part number. The JX‑10, JX‑8P, GM‑70, GR‑1, DDR‑30, S‑50 and S‑550 synths/samplers all use the same part number. However, be aware that these coils may also be defective. There seems to be no rhyme or reason as to when or if a coil will fail. Guy Wilkinson has a webpage with detailed troubleshooting of the FIP display and FIP coil at this link Note: The image on the right shows the coil on an S‑550 Main Board as denoted by the silkscreen label T1. The coil for an S‑50 is located on the Panel Board Assembly and has a silkscreen designation of L1 even though these are the same part number. Also, the MKS‑70 synth uses a nearly identical coil but the windings are slightly different. The coil from an MKS‑70 will most likely work in a pinch Tact Switch Replacements ![]() After time, some of the buttons (tact switches) will start to act intermittently or fail. The best solution is to replace all of the tact switches at the same time because if you only replace a few, others are bound to fail soon after. eBay and other vendors sell complete sets of tact switches and these range anywhere from $30 (USD) to $92 (USD). Ouch! You can save a lot of money buying them instead from an electronics supplier such as mouser.com. You can get a complete tact switch replacement set from Mouser for less money. Also, ALWAYS buy a few extras because... shit happens! I try to list two types of replacement tact switches to choose from. Why? I prefer a harder press Operating Force of 2.6 Newton because I like to hear that solid 'Click!' whenever I make a selection (S‑50 / S‑750 / S‑770 / W‑30 Tact Switches) ![]() 1) Brand Name: ALPS Manufacturer P/N: SKHHAMA010 Mouser P/N: 688-SKHHAM Operating Force: 1.6 Newton (Black) Operating Life: 500,000 cycles Size: 5mm (H) x 6mm (W) x 6mm (D) [ Alternate P/N: OMRON B3W-1000S ] 2) Brand Name: ALPS Manufacturer P/N: SKHHARA010 Mouser P/N: 688-SKHHAR Operating Force: 2.6 Newton (Red) Operating Life: 200,000 cycles Size: 5mm (H) x 6mm (W) x 6mm (D) [ Alternate P/N: OMRON B3W-1002S ] SAMPLER / QUAN
S‑50 / 34
S‑750 / 21
S‑770 / 21
W‑30 / 29
* * * Please Note * * *
I do not own an S‑750 or S‑770 so the P/N's for these two samplers are speculative and I'm relying on feedback from other owners (S‑550 Tact Switches) ![]() Command Keypad (SW2 through SW15 - Quan: 14) Brand Name: ALPS Manufacturer P/N: SKHHBSA010 Mouser P/N: 688-SKHHBS Operating Force: 2.6 Newton (Red) Operating Life: 200,000 cycles Size: 9.5mm (H) x 6mm (W) x 6mm (D) Alphanumeric Keypad (SW16 through SW28 - Quan: 13) Brand Name: ALPS Manufacturer P/N: SKHHARA010 Mouser P/N: 688-SKHHAR Operating Force: 2.6 Newton (Red) Operating Life: 200,000 cycles Size: 5mm (H) x 6mm (W) x 6mm (D) [ Alternate P/N: OMRON B3W-1002S ] Main Board PCB (SW1 - Quan: 1) File this under the category, "If it ain't broke... don't fix it!". This switch is located inside the case on the Main Board PCB and is rarely or never used. It is a reset switch only used for testing purposes. It most likely will never need replacing. The original ALPS part number is no longer available but the dimensions and functionality are identical to ALPS SKHHARA010 shown above. If you must replace this switch, use Mouser PN: 688‑SKHHAR Brand Name: ALPS Manufacturer P/N: SKHHAD039A Operating Force: 1.6 Newton (Dark Gray) Operating Life: 500,000 cycles Size: 5mm (H) x 6mm (W) x 6mm (D) (S‑760 Tact Switches) Tact switch leads for the S‑760 are mounted extremely close on top of the Panel Assembly PCB and using diagonal flush wire cutters to remove them (as explained above) is not the best method for this sampler. I recommend using the combination of an Exacto razor knife and a stainless steel hollow desoldering needle (or a solder sucker) to remove these small tact switches from the PCB. Heat the solder trace on the backside of the PCB and use the Exacto razor knife to gently pry the tact switch up and out of the PCB via. Use a stainless steel hollow desoldering needle (or a solder sucker) to remove any excess solder from the PCB vias. I found working with the S‑760 Panel Board Assembly to be a real challenge. After soldering the switches in place, two of them did not work because the solder did not make a good connection. I suspect that using a very low temperature setting was the culprit. After reflowing solder on these areas, a good contact was made. I used a very low temperature setting because the 30+ year‑old Roland PCB's and traces are quite brittle and fall apart easily. Also note that the Panel Board Assembly and Encoder Assembly are incorrectly labeled in the S‑760 Service Notes The total number of tact switches needed for the S‑760 is 13. Do yourself a favor and buy a couple of spares because... shit happens There are two types of tact switches to choose from. The original Panasonic tact switches installed by Roland had a light touch Operating Force of 1.3 Newton* ![]() 1) Brand Name: OMRON Manufacturer P/N: B3F-6022 Mouser P/N: 653-B3F-60223 Operating Force: 1.5 Newton Operating Life: 300,000 cycles Size: 5mm (H) x 6mm (W) x 6mm (D) 2) Brand Name: OMRON Manufacturer P/N: B3F-6020 Mouser P/N: 653-B3F-60203 Operating Force: 1.0 Newton Operating Life: 1,000,000 cycles Size: 5mm (H) x 6mm (W) x 6mm (D) Note: These switches will also work for the Roland JV‑80, JV‑90, JV‑880, JV‑1080, JV‑2080, U‑20 and XP-50 The original switches I previously recommended were manufactured by Panasonic but these have been discontinued. You may still be able to find some of these from other electronic supply houses like AliExpress Manufacturer P/N: EVQ-21405R* (This part was marked as obsolete at mouser.com in August 2019) Manufacturer P/N: EVQ-22705R (This part was marked as obsolete at mouser.com in August 2019) ![]() S‑760 Rotary Encoder Replacement Although it's not exactly a "Drop-In" solution, this rotary encoder replacement works extremely well. It requires an inexpensive custom PCB, a low‑cost commonly found rotary encoder and little bit of soldering. I have also supplied an alternate method which does not require a PCB. It takes a little more work but if you are miserly to the extreme... that's the one for you ![]() SP-700 LCD Replacement
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EV-5 / EV-7 EXPRESSION PEDAL
This foot pedal is a variable resistor for controlling different parameter functions on the W‑30. Depending on how the EV‑5 control jack is assigned, this pedal can modify Control Changes in real‑time. The W‑30 Control Change parameters which can be changed using an EV‑5 are
#1 = Modulation #2 = Breath Controller #7 = Volume #64 = Hold/Sustain
The video bleepbit posted above has info on his webpage which states, "...the trick is to set the EV‑5 to receive the Control 2 (Breath Controller) and the Breath Controller to the Aftertouch (to do it press Config 2 / F4 in the Performance Mode) and save your preferences to the System Disk (Save / F1): Now, you can manage the cut‑off in your sounds by the real‑time filter." The EV‑5 retails for the outrageous price of $119 USD and the EV‑7 retails for even more at $279 USD. It is a very simple circuit and it is quite easy to make an equivalent tabletop hand controlled input device using a couple of inexpensive potentiometers, a 1/4" stereo plug, an enclosure and some 2‑conductor shielded cable Instead of buying the 1/4" stereo plug and 2‑conductor shielded cable separately, I suggest that you buy an inexpensive, ready‑made cable on eBay and snip off one end. That way, you'll have a 1/4" plug already soldered onto a cable which will eliminate extra work on your part. I have found this to be the least expensive route. I was able to build one for under $11 ‑ and that includes the shipping charges! Granted, it's not a true foot controller but, it's still a useful real‑time input device for the W‑30 and other samplers/synths, as demonstrated in the video above by bleepbit The EV‑7 and EV‑10 expression pedals are identical to the EV‑5 except they are housed in a metal case, not plastic. The EV‑10 had an extremely brief production run before it was replaced by the EV‑5. Recently, the EV‑7 seems to have been removed from the inventory of most online retailers ![]()
Notes:
❖ Also works great with other samplers/synths including the Roland Alpha Juno‑1/2, HS‑10, JX‑10 and the MST Expressor Eurorack module ❖There is an optional add‑on polarity switch mod which enables EV‑5 compatibility with non‑Roland gear. Details for adding this optional switch into the circuit are here ❖The image shown on the right is a dual EV‑5 hand controller. This variation on the original design uses one 1/4" stereo output jack and one 3.5mm stereo output jack (hidden from view). Using output jacks instead of hard‑wiring the output cables was preferred since I already had several existing ready‑made cables. The knobs on top are the Main Controllers (VR1) Adjusting the EV-5 Minimum Volume Knob |
EV-5 DIY Parts List (Hand Controller Version) Tayda P/N: A-1982 - 10KΩ Linear Pot Tayda P/N: A-1983 - 50KΩ Linear Pot Tayda P/N: A-5081 - 1/4' Stereo Plug Tayda P/N: A-5166 - 1590A Enclosure 2 Conductor Shielded Cable (Shield = Ground) taydaelectronics.com ![]() Variation: DIY Dual hand controller with optional out jacks |
Ver # disp MT25 ROM. Ver. 2.01 05 AUG/88 (This Line Displays The EPROM Firware Version#) S‑550 SYS. Ver 1.13 26 OCT/88 (This Line Displays The Floppy Boot Disk O/S Version#)
MT25 ROM. Ver. 2.00 11 SEP/87 MT25 ROM. Ver. 2.01 05 AUG/88 MT25 ROM. Ver. 2.02 01 FEB/88Through extensive testing, I have been unable to find any differences between these three versions. My best guess is that some minor changes were made to improve timing on the SCSI chain
W‑30 ROM Ver 1.03 [01/21]Note: Binary files for creating your own W‑30 EPROM's may be downloaded for free at the Synth & Sampler Binaries Webpage
v1.10 (Only 3.5" FLOPPY or GOTEK) v1.07 (SCSI2SD / HARD DRIVE / CDROM / ZIP DRIVE) v1.06 (Only 3.5" FLOPPY or GOTEK - Fast Boot) v1.01 (Only 3.5" FLOPPY or GOTEK - Old School Version)
Replacement Power Switch [ MKS‑100, S‑220, S‑550, S‑750*, S‑770* and SP‑700* ] | |
* * * SPECIAL NOTE * * *
117V AC Models S‑750, S‑770 and SP‑700: The USA/Canadian models use this Power Switch P/N: 1312924 (ALPS SDGA3P) 110V / 230V / 240V AC Models S‑750, S‑770 and SP‑700: The Europe / UK / Latin / Asia models use Power Switch P/N: 1312939 (ALPS SDL1P-D) |
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ALPS P/N: SDGA3P
Sony P/N: 554‑880‑12 Power Rating: 5A @ 250V AC Type: ON/OFF w/Four Solder Lugs |
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If your old S‑550 switch is experiencing problems, don't bother trying to repair it. Some of the parts inside are sealed in plastic and other parts are wired in place. Repairing it is a lost cause. This power switch works with the S‑550, S‑220, MKS‑100 and a wide selection of other Roland synths and samplers including the D‑110, D‑550, GM‑70, JV‑880, MKS‑20, MKS‑50, MKS‑70, MKS‑80, and U‑220. In the 1980's and 1990's, this power switch was also used with a variety of Sony/JVC/Panasonic TV's and component stereo devices. This power switch is quite robust and therefore more expensive than most. Replacements can sometimes be found on eBay for about $10 (USD). Do a keyword search for "ALPS SDGA3P" | |
Replacement Power Switch [ W‑30 / S‑330 / S‑750* / S‑760 / S‑770* / SP‑700* ] | |
* * * SPECIAL NOTE * * *
110V / 230V / 240V AC Models S‑750, S‑770 and SP‑700: The Europe / UK / Latin / Asia models use this Power Switch P/N: 1312939 (ALPS SDL1P-D) 117V AC Models S‑750, S‑770 and SP‑700: The USA/Canadian models use Power Switch P/N: 1312924 (ALPS SDGA3P) |
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ALPS P/N: SDL1P‑D
Power Rating: 5A @ 250V AC Type: ON/OFF w/Four Solder Lugs |
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If your old switch is experiencing problems, the outer shell is removable and the inner workings can most likely be repaired by cleaning the contacts only if you have the skillset and patience of a watchmaker and you like puzzles. Use caution if you attempt to repair this switch! My experience with this one proved they explode like a hand grenade because they are spring loaded. Use eye protection and only open the outer case while holding it inside a Ziploc baggie to keep the parts inside from flying across the room! Replacement switches can be found on eBay for only $2.50 (USD). Do a keyword search for "ALPS SDL1P‑D" or visit the jk_parts storefront on eBay |