My New Simmons SDS7

Alex-PML20 December 20233 February 2024

I often get asked, which part of my carrier was my favourite. Well, to be honest, if you’re into music, it’s a bit like someone asking which is your favourite band or song. The seventies and the eighties were very exciting times. As an electronics engineer wanting to leave defence and branch out into music technology however, the eighties were truly magic. Indeed, my time at Simmons Electronics Plc in particular, well "kid in a candy store" comes to mind! Fast, hi-tec and an amazing bunch of people, Simmons was one of the many cool electronics companies around, uniquely being the only British electronics manufacturer at the time, to have an office in Tokyo.

What used to be the old Simmons factory in St. Albans (picture taken September 2021). Above the main entrance / reception area and at the top of the stairs (to the left of where it says 'Marshall Volkswagen') there used to be a massive Simmons drum kit.

Within a few months of starting with the company, I was very familiar with machines past, present and future and working on them daily wasn’t always enough. I ended up buying a SDS9, a SDS7, an EPB, a couple of SPM 8:2s and I even bought a Silicon Mallet. And then, in 1987, 'we' released SDX and I just had to have one! Fully expanded (and costing a small fortune), SDX was capable of holding a whopping 8MB of RAM. Well stupid me, I decided that 8MB wasn't enough for drums and cymbals so I ended up buying two fully loaded SDXs, both complete with pads.

My two Simmons SDXs — Here are my two Simmons SDXs from many years ago, in a previous (life) studio. I still have them and hope I can get them back into my studio soon.

Simmons ZI pads for the SDX used FSR technology — And here's an old snap of my 'small' kit. This expanded to double-kick, a few SDX ZI cymbals and a lot more toms. Geesh... What was I thinking? I'm not even a drummer!

Young and stupid (I think I've confessed to such already), I sold my SDS7. I can’t remember why but it might have had something to do with buying the two SDXs which if memory serves me correctly, started at 13,000 GBP each for like the basic version which only had 2MB of memory and fewer pads. Little did I know that years later, selling my lovely SDS7 would be a decision I'd regret and so my long quest to find a really nice replacement began.

In recent years, I'd regularly check out the usual auction sites and scour the Internet looking for a nice SDS7. Well, over thirty years after selling the one I bought while at the company, I finally found one that looked too good to be true.

I'd heard about a Simmons tech in the US called The Simmons Guy and the unit I found was one that he was selling. That in itself, immediately made me feel comfortable as from what I've read, this dude seriously knows his stuff. The thing is that apart from being totally functional, this particular example, looked in really good condition.

So, on 11^th December I bit the bullet and today (20^th December) my new Simmons SDS7 serial number 1722 arrived.

I was recovering from my first bought of COVID but I simply couldn’t contain my excitement. It took me a while to get through the superb packaging. Of course #1722 is a US unit and therefore the transformer is wired for 120V operation. In such incredible condition, I reluctantly opened the unit and converted it to UK 240V, which included stepping down the fuse.

Simmons SDS7 arrived just as I came out of COVID — My new Simmons SDS7 on the bench and powered up for the first time and after its conversion to UK 240V.

The Simmons Guy is 'Ed Rose'. We got to know each other pretty well, while I waited for my new Simmons SDS7 to arrive. Such a lovely dude, he threw in so much with this unit including a beautifully discrete Tubbetec uniPulse MIDI conversion on a 3.5mm socket, loads of EPROMs, a patch-changer and many internal tweaks such as EPROM size selectors on each voice card and the hi-hat fast decay mod'.

Three Simmons SDS9 pads — These lonely SDS9 pads have been on the landing of the new studio for months. It's like they've been waiting for something...

Launched in 1983, the SDS7 didn't have MIDI. In fact, the first MIDI keyboards, the Roland Jupiter 6 and the Sequential Circuits Prophet 600 only appeared that year and even the MIDI Manufacturers Association wasn't established 'till 1985. Indeed this was a very exciting time.

Fitted with a Tubbutec uniPulse MIDI to CV converter which I have to say, has been done quite discreetly, #1722 can now be triggered via MIDI IN. Even the hi-hat open / hi-hat closed can be controlled via MIDI controller 18. Tubbutec supplies a configurator for Windows and OS X. With no MIDI Out though, things are a bit 'one-sided'. Having said that, the uniPulse hardware is fitted with a momentary switch which allows the system to 'learn' (and memorise) the incoming MIDI channel. A very convenient touch.

1983 Simmons SDS7 with Tubbutec UniPulse MIDI to CV.

All trigger inputs and audio outputs are on 3-pole XLRs. In the case of the audio outputs, one might be forgiven for thinking that they're all balanced. Unfortunately, that's not the case. In fact, being high-impedance as well, I've wired things to accommodate a couple of active unbalanced to balanced converters between the SDS7 and my Yamaha DM-2000 mixing desk.

My new Simmons SDS7 in the control room — I would normally have got this racked up but #1722 is in such amazing condition that I decided it should have pride of place.

I've also hooked up the SDS7 to a TP-Link Kasa smart power outlet and a schedule has been created which powers on the SDS7 every Monday at 12:00 mid-day for a couple of hours. That way, the NiCd battery receives regular charging.

My new Simmons SDS7 in its new home — Simmons SDS7 #1722 in its new home.

At some point, I might consider modifying the memory back-up battery circuitry so as to take lithium batteries, similar to the modification I offer as part of my external power supply package for the Cheetah MS6.

What the google hook-up also means however, is that I can say "Hey Google, switch on my SDS7" and guess what happens! 😮

LAST WORDS

How practical will my new Simmons SDS7 be for contemporary music production? Who know! Who cares!! What I do know is that I will be using it and I'll absolutely love using it. Yes, it's a huge chunk of mega nostalgia for me but I'm a firm believer in keeping the creative process fun and that's totally subjective.

UPDATE - 28th December 2023

I'm totally over COVID and #1722 is now MIDI'd up to the rest of my studio. For the time-being, stereo outputs are going directly to my Yamaha DM2000 and I AM SO HAPPY!!!!!

My new Simmons SDS7 responded immediately to MIDI and sounded just as I remember back in 1986 (ish). Oh boy! I'm gonna have some fun with this. 😀

NOTE: While I wait for my active unbalanced to balanced converters to arrive, the stereo outputs from the SDS7 are running unbalanced to my DM2000 and I have to admit that I can't believe how quite this box is. While I don't recall having any noise issues with my original SDS7 back in the day, users do refer to a noise which sits at 7.3 kHz. This particular SDS7 however, is dead quiet. The DM2000 meters will show up failing chorus chips in something like a Roland JX-8P which might not be immediately apparent on the monitors and yet the unbalanced audio outputs from my new Simmons SDS7, aren't showing anything when not played. To be brutely honest, I didn't expect that, especially from a machine that's forty years old.

First Time Positive COVID

Alex-PML18 December 202321 December 2023

After managing to stave it off for more than three-and-a-half-years, I finally succumbed; no longer a COVID virgin, my first time positive COVID test!

Both of my daughters have had COVID twice while at home and by implementing a strict quarantine regime, no one in the household got sick while they were infectious. Until the other red line disappears, the patient remains in solitary. Food and drink are brought to the patient's bedroom door. Everything that's collected is fully disinfected. Well, this time around it's my turn. 🙁

Most of my days are spent working in my own company with social exposure being minimal. On the other hand, it only takes one, as they say and a trip to the shops to get some coffee or whatever, is all it takes.

This morning I got up at 03:15 and although a little dizzy and light-headed, my nose has stopped running, my fever has subsided and my frigin' sore throat which was oh so painful, has gone. I still have a slight cough so I'm not going to do anything stupid like go down the pub!

My flavour sensitivity is still very much subdued so I'm going to stay in bed another day, probably test tomorrow and I'm definitely going to wear PPE when I can go out. I don't want to be responsible for anyone else getting this, especially just before Christmas.

My first time positive COVID hasn't been as bad as I thought it was going to be. I did have a booster vaccination about six weeks ago. Perhaps that helped to reduce the severity of the symptoms. What was weird, was that unlike flu or colds (which I can catch quite easily) this didn't seem to have any warning. When I get a cold, I tend to be a bit wheezy a few days before it breaks. Sometimes I'll be a little ackey, too. This time, I woke up with a sore throat, no warning and within a few hours, BANG... and I was in bed.

Hey, while I'm down with this, my Internet door remains open so please don't hesitate to contact me. It might take me a little while to get back so please be patient.

UPDATE - 21st December 2023

Yesterday I tested negative. After stripping my bed and putting linen and all my clothes that I'd worn into black bin liners ready to go into the wash, I opened the windows in my room while I had a shower. After that, I completely disinfected the bathroom. Paranoid? Hey, Christmas is a couple of days away.

Just before I went down, I bought a Simmons SDS7 which also turned up yesterday so I was well excited. All the way from the US, I wanted to get the 240V conversion done as soon as possible. 🙂

While I was off, I had loads of orders come in and many repair enquiries. Once my temperature and sore throat had gone and I could focus, with nothing else to do in my quarantine, I seriously managed to stay on top of customer emails.

Today I might go out later and start my Christmas shopping, fully masked up, of course. But then again.... SDS7 calls.... Play me!

A Busy MKS Winter 2023

Alex-PML9 December 20233 February 2024

It's already been a busy MKS Winter 2023 as for some crazy reason, I'm getting a lot of MKS-70s and MKS-80s in at the moment. Hey, my favourite synths but seriously?!?!?

Yes, I love 'em. I know them really well but still relish the challenges that they throw at me. Some of those pictured above are from overseas which makes me feel quite humbled to have that kind of reputation.

For those interested and starting from the top...

Roland MKS-70 requiring full service and ALL upgrades.
Roland MKS-70 that needed a new power supply (like Guy Wilkinson’s P0004) and replacement front panel switches.
Roland MKS-80 which had two duff voices. The customer also wanted Aurora replacement modular switched-mode power supply installed.
Roland MKS-70 with a serious CPU-board issue (which might take me a while).

The JX-10 module-board just caught to the left of the picture above but fully shown below, has been sent from a local (UK) customer and has some serious audio issues.

It's funny how things go from amps to synths, then back to amps with the odd 59kg piano thrown in there somewhere! 😀

Almost up to date, I've had a lot of orders for AT-D-50, AT-JX-8P, AT-AJ-2 and AT-JX-10 replacement aftertouch sensors, as well as other stuff and a busy MKS Winter 2023 has got me working all hours, right now.

Search for Plasma Music Limited or just hit the link above.

Roland HP-3700 Keyboard Service

Alex-PML4 December 202311 January 2024

A couple of weeks ago, I insanely agreed to take on this Roland HP-3700 keyboard service job. “A couple of duff keys” I thought. “Hey, no problem” I thought. Well, I use the word ‘insanely’ because I’d forgotten just how big and heavy these things are. Last time I saw one of these was about fifteen years ago and you know how sometimes your memory of the size of things is just WRONG? Well, this was a good example of just that.

Anyway, I only got around to working on this a few days ago. One problem with getting old, is that our parents are getting older and there comes a point when those who sacrificed so much and looked after us, now need a little attention themselves. Hence, I feel as though I have two jobs at the moment.

The HP-3700 was launched in 1990. A stunning example of Roland’s precision engineering, beautiful craftsmanship and a level of sonic excellence we take for granted with the name 'Roland', the HP-3700 was indeed the company's flagship full-sized piano a the time. Anyone who’s had experience with one of these instruments, will appreciate that it’s not just about the sound. As I often comment, the smooth, transparent connection between your fingers and the sound, is simply magic and in my opinion, it what makes these machines feel so gorgeous.

Roland HP-3700 has simple controls — Unlike some big 'workstation' digital pianos, the Roland HP-3700 has very simple controls; volume, brilliance, transpose, temperament, sound selection, chorus / tremolo selection and reverb selection You can just sit down and play, without having to read a manual.

I have to confess, that I find it incredibly sad that this generation of instruments simply doesn’t receive the recognition it should. Anyone who brings me one of these old pianos and is willing to spend more than what it’s worth to have it renovated, receives my utmost respect and admiration. In fact, any service tech’ will understand that you simply can’t charge for the actual time and effort it takes to service something like this and the expression, ‘labour of love’ indeed, comes to mind. If the instrument is in really nice condition, a complete Roland HP-3700 keyboard service could easily take a couple of days or more.

At 59kg, I needed some help to move this beast and take it apart. My helper elves were on the ready and between us, things were eventually good to begin.

Elves (daughters) Katana (left) and Tsunami (right) — My helper elves, daughters Katana (left) and Tsunami (right)... not misbehaving, for a change.

It took me a while to get this thing open but once I had, I realised why. At some point in its thirty-three-year life, a fluid spillage had occurred on the front left of the keyboard. Left unattended for years, this had the effect of ‘sticking’ the left-hand panel to the bottom-case. 🙁 The laminate (artificial wood-effect veneer) on the front of this panel had also come away slightly, presumably from the spillage. Fortunately, the laminate hadn't split so this could easily be reglued. At the moment however, this was the least of my worries. For now, I’ll just tape it up so that it doesn’t rip off when the piano is moved.

Extensive fluid damage on the left side of the keyboard in the Roland HP-3700 piano — Extensive fluid damage on the left side of the keyboard in this poor ol' Roland HP-3700.

Performing a quick internal inspection and then switching on the piano to test all functions, I noticed that the bottom-A key was dead. Hmm… In fact, it was quite apparent that the left side of the key contact strip and the contact PCB weren’t in great condition at all.

Thirty years of dust, dirt and loads more interesting stuff inside this Roland HP-3700 — Rubber key contacts off and check out over thirty years of dust, dirt and loads more interesting stuff.

The keyboard construction on these pianos differs from that of Roland synthesisers from the same period. Being a piano (and not a synthesiser), the keys are obviously weighted and I have to say, are beautifully balanced. Unlike its synthesiser brothers and sisters, the HP-3700’s black keys can be removed without having to take out adjacent white keys. With a small flat-headed screwdriver, a gentle push in the right place and a nudge to the rear, the black keys pop out. With a similar action, the white keys slide out forwardly. An amazingly elegant design!

After removing a bunch of keys, cleaning the respective key contact strips and surrounding areas, I replaced the contact strips and keys and then tested. Everything played fine, except that bottom A key, of course.

Roland HP-3700 after initial fluid damage cleaning — Here's what the left side of the keyboard looked like after an initial clean. Not quite new but a lot better than it was.

I explained my findings to the customer and even sent some pictures. Well, he soon got back to me and we agreed a price for a full service. I explained that I probably wouldn’t be able to fix the bottom A key as the connection between the carbon pads on the contact PCB and the tracks, had been damaged. He accepted this and asked me to proceed anyway.

I’d already got wind of what was underneath the keys and indeed on stripping the entire keyboard, I found dust, dirt, round bits of paper from a paper punch, Christmas tinsel, cat hairs (a lot) and even a small stone. This was going to be quite involved, I thought.

TAKE HEED... Just like an acoustic piano, these instruments had beautiful keyboard covers which conveniently slide backwards and into the body of the piano to expose the keyboard when you want to play. If you have a Roland HP series piano or something similar, PLEASE use it!!! When not in use, the piano's keyboard cover (or lid) should be pulled forward to prevent contaminants falling in between the keys. Protecting the keyboard in this way also reduces the discolouring effect of ultraviolet light on the white keys so they’ll stay white for longer and won’t slowly fade to a beige yellow colour.

Roland HP-3700 keyboard cover (lid) — If your piano has a cover like this, USE IT! And please don't think that the cat can play an Elton John song. IT CAN'T!

I did my usual hot soapy water bath thing for the rubber key contact strips and indeed removing them half-an-hour or so later, revealed their original grey colour and not the dusty light brown that they were before. They all needed a very light scrub after which I left them to thoroughly dry for a couple of hours.

Roland HP-3700 contacts before and after cleaning. No, please don't make me tell you which is which!!!! Of course the important parts (the carbon nipples) are on the underside of the bubbles.

While the rubber key contact strips were drying after their bath, I continued with phase 2 of cleaning the inside of the piano.

I continued with scraping off loads of crap, vacuum cleaning, dusting and then cleaning the area where the key contact strips will go. Yes, it took ages and while I was doing it, my mind drifted back to my days at Roland UK. Sometimes we’d be short of stock and would buy a load of big HP pianos from Roland Benelux. I’d come in with the service team on a Saturday and we’d convert them from 220V to 240V, also swapping out the 2-pin IEC C10 socket for a 3-pin C14 type. Three or four of us worked on one piano. Today I only have a couple of (small) elves!

Right, so the inside of the piano looks a lot better. The fluid spillage ensured that it’ll never be as good as new but pretty much all the crap that shouldn’t have been inside, is now gone.

Reinstalling rubber key contacts and keys into Roland HP-3700 — After a second round of cleaning, I reinstalling some of the rubber key contacts and keys. Suddenly things started to look and sound a lot better.

Okay, so now that everything's starting to look good, I decided to have a closer look at that bottom A key again. Yeah, I know but this is exactly the kind of challenge that I was put on this earth for! 😊

There are three contact PCBs that are linked and that run the length of the keyboard, sitting underneath the keys. In between the bottom of the keys and the top of the contact PCBs are rubber contact strips. One strip will run under several keys. A pair of ‘bubbles’ in the contact strip will fall under each key and in each of those bubbles is a carbon nipple. In the rest position, there's a gap between the carbon nipples and four carbon pads on the contact PCB.

When a key is pressed, the rear two carbon pads on the contact PCB are shorted by one of the carbon nipples in the respective rubber bubble. The action is followed by the shorting of the front two pads via the second carbon nipple in the respective rubber bubble. The time between the first nipple shorting the rear contacts and the second nipple shorting the front contacts, is converted into velocity by the instrument's on-board computer. This is how the piano ‘knows’ how hard you’ve hit a key.

Measuring the continuity between the four carbon pads on the contact PCB under the non-functional bottom A key, revealed that the integrity of three of the four pad / track connections was good and that only one pad / track connection was broken. That wasn’t as not as bad as I thought it would be and so I figured on trying a little liquid carbon to fix this.

Repairing broken carbon contact to track connection on Roland HP-3700 keyboard contact PCB — Repairing the broken carbon pad / track connection on the keyboard contact PCB requires a lot of patience.

Regular visitors to my site may recall my post of 19^th November 2020 which featured an Alesis MMT-8 refurbishment. I used liquid carbon to repair the switches on that sequencer which three years later, are all still working. At between 35 - 40 GBP for a small kit, the good stuff is quite expensive but for this Roland HP-3700 keyboard service, I figured it was worth it.

Well, my first attempt with the liquid carbon wasn't successful. Remember; I didn't really want to touch the duff carbon pad itself but repair the connection between it and the copper track that it's connected to. Despite having cleaned the area thoroughly with IPA (avoiding the carbon pad, of course), the liquid carbon wasn't adhering too well to the copper track. I tried again but with a slightly different application technique and this time I got lucky. After fully reassembling the piano’s keyboard, the bottom A key sprang to life. Oh wow! RESULT!!! In fact, the whole piano now sounded and felt amazing.

I know what you're thinking and I didn't forget about the laminate that had come away from the left cheek. Being on the point of putting the piano back together that evening, I held back and decided to let the glue dry over night. Yes, it was really frustrating!

The fluid damage meant that this particular Roland HP-3700 keyboard service ended up taking three days to complete. I also needed help to move and even dismantle this thing. As I’ve already intermated however, there’s just no way I could charge for that amount of time and... don't forget the cost of the elves (yes, they're expensive). Fortunately, for my customers who I care about dearly, I love what I do and I want to do what I can to keep these beautiful instruments going for a little bit longer. Sometimes that means taking a bit of a hit but what the hell.

My only regret about this job, is that I didn't get to see this HP-3700 fully working piano back on its stand. 🙁 or did I...

The day that Peter collected his beloved Roland HP-3700, he couldn't find the cable. I advised to get one off Amazon but he messaged soon after asking if I could order it and send it to him. That evening was quite nice particularly after all the rain we've recently had. It was also mild and warm so I decided to take my Jag out for run. Well what-the-hell, seeing as Peter only lived twenty miles away, I decided to run over an IEC C14 mains cable for him. While I was him, he offered to take a snap. 🙂

And I finally got to see the Roland HP-3700 complete on its stand.

At the beginning of this post, I sang the praises of the HP-3700 and other similar pianos of the same era but perhaps I should reiterate the point; these pianos are very underrated instruments. Unlike many synthesisers from that time, some of which are now established classics, these pianos haven’t been able to hold their prices but don’t let that fool you. These are beautiful instruments and lovely pieces of furniture which have lasted decades. If maintained, these pianos could keep on making music for decades to come. If you have one of these, please keep it! Oh and do think about getting it serviced.

Occasionally Weird Things Happen…

Alex-PML27 October 202316 March 2024

A few weeks before Christmas 2020, I was contacted by someone who’s Cheetah MS6 had not just blown up but had also tripped the electricity supply in his house! The upset MS6 owner sent me his unit and to cut a long story short, I ended up building an external power supply for the MS6, prior to repairing it.

The customer was then reluctant to pay for the repair and the power supply. Being quite amicable, we agreed that I could keep the MS6 to sell. To be honest, I just wanted to get my money back on the power supply and the repair.

While the Cheetah MS6 is a lovely little (British made) synth module, the power supply is well, crap and so I thought it a good idea to document the build of my external power supply in a post of 27^th January 2021. I couldn’t believe how many enquiries I received and although frightfully expensive, I've lost count of how many of these things I’ve built now.

Anyway, after five minutes on ebay, that ol’ Cheetah MS6 got snapped up and indeed someone picked up a bargain. As I recall, it ended up travelling in the Manchester direction.

Well, last July, I was contacted by this dude who, it would seem, ended up with this particular MS6… but without the power supply!

The guy who bought the MS6 off me via ebay, must have eventually sold it and sadly, it would appear that the next owner passed away. The current owner (Charlie) then bought it at a house clearance auction.

I really couldn’t believe that this was the same MS6 but Charlie sent me pictures and indeed, it was the very same unit on which I prototyped my external power supply for the Cheetah MS6.

Charlie wanted his new MS6 up ‘n’ running and so he sent me the unit last August with a view to build another power supply.

It feels quite strange, virtually doing the same work twice on exactly the same piece of gear but like the post heading reads 'occasionally weird things happen'.

The Cheetah MS6 is an enigma. Launched in the late eighties by a small British computer manufacturer, this rather unassuming, multi-timbral, six-voice (twelve-oscillator), analogue synthesiser module is loaded with CEM 3396s and sounds amazing. It's such a shame that it doesn't have a couple of frills like chorus on stereo outputs, for example. On the other hand, the range of sounds is extensive and the quality of lush analogue sound is just so beautifully vintage. 🙂

UPDATE - 1st November 2023

This morning I received the most lovely telephone call from Charlie. He'd called to confirm receipt of his Cheetah MS6 including my external power supply and just wanted to express his gratitude and amazement at the build quality of the system. 🙂

I’m Back (2023) !

Alex-PML25 September 202329 November 2023

THANK YOU to all my customers for your support! I didn't have a 'holiday' as such but simply had to make time to finish off my new premises. Now I feel like a holiday!!! 😀 This week though, I'll be jumping repairs and order-builds that have come in recently so rest assured that things are back to normal.

As many will know, I hate DIY mainly because I don't think I'm very good at it. Having said that, this final phase of the project has taught me a lot of patience. Being fussy, I've learnt when to draw the line. The property is a self-build house from the seventies and no adjacent walls are quite perpendicular and no opposing walls are exactly parallel. Kind of good for a recording studio but a pain to paint, decorate and build stuff in. Of course I also learnt a lot about paint, LOL.

as you can see in the picture above, I still have a couple of things to finish off like the recoat of the other side of the door that's behind me and most obviously, I need to mount a TV screen.

I'm delighted that my sub-bass enclosure is almost finished. A couple more coats of paint and I can think about putting in the hi-fi. I'll be doing a feature on the build of this soon. Of course it's the front that most people will be interested in.

Furniture has been ordered and while the seating will be here in a few days, I'm not expecting the bespoke coffee table before the end of the year! 🙁

UPDATE - 23rd October 2023

Last week I received an e-mail informing me that my teak root coffee table was ready to be delivered. WOW!!! That's like several weeks before I expected. On the day of delivery, I received another message saying that the delivery van had broken down. 🙁 Oh boy... Anyway, to cut a long story short, it got delivered today and I'm delighted to announce that my lounge is now F I N I S H E D which means that the whole place is now presentable and just the best place for me to work.

Apart from being a place to receive guests, I'm look to resume my video exploits very soon. Of course the area just isn't big enough to host bands, not even solo artists, really. I am however, looking to do kinda podcast things, chat shows and stuff like that. Let's see how it goes...

JUST A QUICK REMINDER...

So back in 2021, I had just moved in and the task of getting this space together seemed really quite daunting. Anyone who loathes DIY as much as I do, will understand. It wasn't just a case of a few licks of paint. There was repair work to do, I had to fix things to keep out the rain, doors needed to be recut, repaired and in one case, a new door had to be fitted. I built a shelf unit in the lab. That was after I installed an 800mm worktop. There were rack enclosures that I had to build for the studio. Oh boy. And of course I was rebuilding my business and was determined not to let down my customers.

New premises for Plasma 2021 — I ripped out the old kitchen with a view to make the kitchen / diner into a kitchenette / office.

Office Kitchenette done — Of course, my Marshall fridge / freezer got installed ahead of any office equipment! Well, you have to, right?!?!?

I had a lot of EMS rack cases but they were meant for the road. In the studio, I wanted something a bit classier and decided to build my own 19-inch rack enclosures. 'Glutton for punishment' comes to mind.

Building 19-inch rack enclosures — It took a long, long time to build the 19-inch rack enclosures I needed. Waiting for paint to dry, oh boy!

I was so busy with repairs and designing stuff so getting the lab up 'n' running was an obvious priority. Working in the lab was such a relief and fixing gear and designing peripherals for vintage synthesisers in my kitchen at home, soon seemed like a distant memory. The only problem was that I still had all of my IT at home so I was dashing between the new place and my home, fixing stuff and then doing admin. A no-brainer, the office was the next area to be completed after the lab.

Lab and office open for business — After the lab was done, I had to get the office operational.

One thing visitors don't see are cables. I H A T E C A B L E S and planning just how everything was going to talk to everything else without cables hanging all over the place, was a challenge I took on while I was, well... waiting for paint to dry, LOL.

Gear in place — With equipment roughly where I wanted it to be, the next task was to connect it all up... discreetly. I also had to consider sound treatment and ended up making my own acoustic panels (not shown).

Planning and then implementing all the cabling in such a way as to keep it discrete, was a big deal but my work wasn't over by a long shot. I was well aware of the 'sound' of the studio. Hard, plastered walls gave all the important rooms a lot of reverb and that had to be addressed.

The walls of my previous studio were covered with foam acoustic tiles. While perfectly adequate, I wanted something a little more cosmetically pleasing and embarked on making my own acoustic panels. Like I said; glutton for punishment!

DIY acoustic panels — A long job making these but well worth it. Not only did the panels address the reflections but they also had the effect of dimming down the brightness and making things feel a little more cosy.

I started off this post by thanking my customers for their patience and understanding but I must also acknowledge friends and family, for their unwavering support. The new place is just an awesome work environment and my daughters both commented that the studio actually sounds better than what I had at Area 51, my previous studio on the local industrial estate. 🙂

Not impressed with Amp Wiring

Alex-PML22 August 202331 August 2023

I'm taking a few weeks off next month so that I can complete my new premises (yes, it's more than two years) and I'd like to get as many units back to customers as I can before 1st September. Things like this dodgy amp wiring seriously don't help.

This Vox AC15HW came in smelling bad and the customer saying that it had started smoking. It was evident that the power transformer had fried. While doing the swap-out, I noticed the little fella (diode) pictured below, sitting uncomfortably close to a fuse. This just looked really bad so I decided to put a jacket on it (bottom picture). Better safe than sorry, eh?

I have a feeling that this amp had been repaired before so I'm reluctant to point the finger at Mr. Vox, on this occasion. 🙂

DON'T TAKE ANYTHING FOR GRANTED

Another Busy week at Plasma Music

Alex-PML18 August 202318 August 2023

So far August has been well, a bit crazy. On top of an insane amount of repairs poring in, I've been busy building stuff and next week I have a meeting about a complete studio revamp. What the hell has happened?

Pictured below are 'some' of this week's builds which will all be fully tested over the weekend ready to go out on Monday.

At the back in red is a Supernova modular switched-mode power supply for the Juno-106.
In front of that and also to the left are two of Guy Wilkinson's P0004 modular switched-mode power supplies for the Roland MKS-70.
In front of those is the dual-stacked Nebula balanced outputs jack-board for the Roland MKS-70.
And In front of the Nebula and also the small PCB to the right, is an Aurora modular switched-mode power supply for the Roland MKS-80.

Not pictured because they're already boxed up, is an Eclipse bounce eliminator, a couple of my new CR2032 battery adapters and a PML-TX01 redesigned power transformer, all for the Marshall JMP-1.

Yamaha RX5 Repair

Alex-PML11 August 202320 March 2024

The Yamaha RX5 is one of my favourite drum machines and when I acquired an example that wasn't 100% working, it seemed like my next rainy Sunday afternoon would be occupied with a Yamaha RX5 repair (or two).

Every once in a while, I receive a mysterious parcel, sometimes from as far away as Japan. It took me a while but I eventually sussed out that my ex-frontman / singer, Rob would occasionally get the urge to buy me something. Anyway, a couple of years ago, one of those parcels contained a Yamaha RX5 drum machine (yes, you read correctly) that indeed had come all the way from Japan.

Being a die-hard Sisters of Mercy fan and like many, wanting to get those big Doctor Avalanche drum sounds, it was quite obvious where Rob was coming from. He'd given the game away, LOL! 😀

While much appreciated, the RX5 wasn’t in great cosmetic condition and outputs 10, 11 and 12 were dead. This wasn't a pad problem as I was getting MIDI. It was defiantly an analogue signal path problem. The machine had been opened before and on close inspection, the membrane cable that connects the main-board to the output board for example, didn't look in great shape.

Despite the issues however, this RX5 came in really useful for testing my Nebula balanced outputs jack-board for the Roland MKS-70. I made a special lead that connected four outputs from the RX5 to the audio inputs on Nebula, where the outputs from the MKS-70’s voice-boards would go. It worked like a charm but to be honest, I would have preferred to have a Yamaha RX5 in my keyboard room.

So, as you do, every once in a while, I’d check out the Yamaha RX5 action at the usual on-line places. Well, a few weeks ago, a RX5 popped up. Cosmetically in great condition it did have a fault and so the auction started at 50 GBP. To cut a long story short, I ended snapping it up for 108 GBP. On top of that, collection was only twenty-five minutes away from where I live. GEEEERATE!!!!!!

Yamaha RX5 on ebay — My patience paid off and I finally found a nice condition Yamaha RX5 for a very reasonable price.

When I went to pick up the unit, the seller showed me the fault and indeed as described, it simply wouldn’t boot properly, with garbled characters cycling randomly on the display and LEDs also randomly coming on and going off. It wasn't even possible to reinitialise the machine so something was clearly very wrong.

Having sussed out that the fault on the RX5 that Rob bought me, was down to a couple of faulty op-amps on the jack-board and that the fault on the unit I’d just bought was on the main CPU-board, I did the obvious thing and just swapped out the main-board in my machine with the one I’d just bought. Okay, so now I have one pretty good condition, working Yamaha RX5. That can now go upstairs into the studio. Yippee!

I put the main-board from the unit I’d just bought into the case of my old unit. Of course, it still didn’t boot properly.

Before switching on loads of test gear, I always do a quick visual inspection. If the item in question will switch on, then I switch it on. On this occasion something was definitely not right as I noticed that an analogue-to-digital converter was getting rather warm. In fact, after half-an-hour or so, it was about 50°C while adjacent devices were only a little over ambient temperature.

A quick check of the power supply revealed that everything was good.

On a side-note, the RX5 power supply puts out +5V derived from a 7809 positive voltage regulator and -4V via a 7905 negative voltage regulator. The configuration is rather clever and unusually allows the heatsink on the 7905 to be connected to 0V.

So, normally associated with the DX range, the Mitsubishi M58990P 28-pin ADC can be found in many early Yamaha digital instruments from that period. Now-a-days it’s not too easy to source but I managed to find one that was unused and for a decent price.

Faulty components removed from Yamaha RX5 repair — The Yamaha RX5 main-board. To the right are the components that I removed; a M58990P and two M5218L dual op-amps.

Unfortunately, IC 12 (the M58990P) wasn't what was causing the malfunction. This ADC is simply for the data and tempo sliders. While it had to be replaced anyway (because it was cooking), I knew it wouldn't fix the problem as it doesn't have anything to do with the computer side of things. This RX5 still wasn't booting. Damn!

I had to dig a little deeper. Code just wasn't running on the processor and data line D3 was definitely duff. Checking connections and realising that the seller I bought this from had swapped out the 63XX series processor, I then discovered two broken tracks. Technically, there were actually three as there was also a break under two linked pins on one of the ICs. After fixing them, I still had a non booting RX5. 🙁

Yamaha RX5 track repair — The guy I bought this off, tried to fix it by changing the HD63B09EP processor. While doing so, he managed to break a couple of tracks.

The signal of the FIRQ into the processor seemed to be playing up, looking like it was only running at about half the speed of what it should be and it kind of looked modulated. A lot of back-tracking and things were becoming quite challenging. I thought that the counter clue in conjunction with the symptoms, would point me in the right direction but intermittently, things like not all 'Chip Enable' lines for the three SRAM devices would come up. In fact, things reached a point which made me concerned that perhaps the firmware had become corrupted or perhaps the voice ROMs had been damaged. Even the SRAM wouldn't be straight-forward to change as there are three TC5564PL-20 devices.

Indeed I ended up changing a lot of logic and even burned a pair of new firmware ROMs.

Interestingly, this RX5, actually had three seemingly unrelated problems; the ADC, two (or three) broken tracks and some duff logic. Hmm... The guy I bought it off, threw in a GliGli RX5 USB card and I'm wondering if that screwed things up somehow. In his attempts to repair it, I'm sorry to say but it looked like he made the situation worse. Those tracks for example, didn't break by themselves.

All in all, my Yamaha RX5 repair took me a couple of days. While I was at it, I also changed the battery and replaced the cheep processor socket with a proper turned pin type. After putting everything back together, reinitialising the unit and restoring factory data, I switched it on and YES, life and.... SOUND!

Yes, of course ICs fail. That's a big reason why I do what I do! While accepting the ADC going down and even a couple of logic gates, I have to admit to being quite surprised at the failure of the two M5218Ls. Remember that these were technically out of my first RX5. These humble single-in-line dual op-amps are used extensively in equipment manufactured during this period and are amazingly reliable, with a pretty good specification for the time. In fact, I can't remember the last time I had to change one of these, let alone two in the same machine.

Being ex-Roland, you wouldn't be blamed for thinking that I should almost have a natural affinity towards machines like the TR range and even the R-8 but I have to confess that the solid, punchy feel of the Yamaha RX5, was more my cup of tea than the rather traditional, rounded, perhaps even 'jazzy' sounds associated with Roland, at the time.

Yes, I know the RX5 is only 12-bit at 25kHz but just put the specs away for a moment and LISTEN! 😀

Busy weekend

Alex-PML31 July 202331 July 2023

Had a busy weekend just gone building a load of stuff:

1 x Aurora replacement power supply for the Roland MKS-80
2 x Supernova replacement power supplies for the Roland Juno-106
1 x AT-JX-10 FSR- based replacement aftertouch sensor for the Roland JX-10
1 x AT-D-50 FSR-based replacement aftertouch sensor for the Roland D-50

Hmm... I guess I do look a little tired!

Despite a busy weekend building stuff for customers, I managed to find time to renovate this now gorgeous Yamaha RX5 drum machine.

Yeah, I know what you're thinking... being ex-Roland I should instinctively favour classics like the TR-808, TR-909 and TR-707. To be honest though, I've never been a big fan of Roland drum sounds. The Yamaha RX5 on the other hand, well... I just love it.