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My Pleiades easy MIDI for the Simmons SDS7 was initially designed to address a common problem with this legendary instrument.

Pleiades installed in Simmons SDS7

Like so many instruments of its time, the Simmons SDS7 memory was maintained by a Ni-Cd battery. This type of battery requires regular charging. Unfortunately, if not regularly charged and left for a couple of years, these batteries leak and can cause irreparable damage. It saddens me deeply that there are far fewer Simmons SD7s in the world, simply due to the fact that they got forgotten about and bad batteries did their thing.

As well as making lithium battery conversion simple and straight-forward however, Pleiades Easy MIDI for the Simmons SDS7 also provides well, a convenient way of implementing MIDI triggering of the SDS7's voices. Pleiades has a mounting system specifically designed for the Tubbutec uniPulse MIDI to trigger converter.

Pleiades with and without tubbutec unipulse
Pleiades provides easy lithium battery conversion for the Simmons SDS7 but also support the Tubbutec uniPulse MIDI to trigger converter (not supplied).

Included with the Pleiades kit is a tiny snap-in board, that makes interfacing the trigger signals from the uniPulse with your SDS7, a breeze. Connection between the daughterboard and the Pleiades main board is via a 26-way IDC cable. Power and MIDI also come on to the Pleiades daughterboard so everything's really easy.

Pleiades interface daughterboard snap-in
Part of the Pleiades kit, is this little board which snaps into the DIP header on the SDS7 back plane making trigger connections from the uniPulse solderless.

Occupying a spare voice module slot (preferably slot 12) in your SDS7, all you need to do is remove the SDS7's front panel to access Pleiades. This makes battery monitoring and changing simple. Pleiades also has switches and an LED which, if you have uniPulse installed, provide full access to some cool uniPulse functions.Switches, LED and connectors to make uniPulse installation simple

Like all my upgrades and modifications, Pleiades doesn't require any holes to be drilled into your SDS7. You won't have to cut any PCBs or carry out any 'hacks' that will permanently change your SDS7. In fact, Pleiades can be easily removed thereby returning your Simmons SDS7 to factory. MIDI access for example, is via the pad trigger input of the voice module that's occupied by the Pleiades board. A XLR to 5-way DIN cable is included with the Pleiades kit. As I said... no holes need to be drilled! Cool, eh? 🙂

Pleiades easy MIDI for the Simmons SDS7 was designed at the same time as my Dark Matter replacement power supply for the SDS7 and it was my intention that the two products should be launched simultaneously. I wanted SDS7 users to have options and so I felt it important that Pleiades and Dark Matter should be compatible. Since Dark Matter has a separate battery board, it's easy to substitute this with Pleiades.

dark matter replacement power supply for the simmons sds7
I wanted SDS7 users to have options and so Pleiades and Dark Matter are fully compatible.

You can read more about Dark matter here.

So, you can't easily back up the memory of the SDS7 and of course, the downside of messing about with the SDS7's battery, is that you'll lose all of your patches. The only way around this problem, is if you are lucky enough to have a working original Simmons memory cassette.  I say "lucky" but to be honest, they were incredibly unreliable. I therefore decided to have a go at developing a replacement.

Unlike the memory cassette clones that we've all seen over the years, I wasn't going to copy something that already was unreliable. I figured on using modern technology to produce a memory device with an edge... or two... or three (?)

Well, I bit off more than I could chew this year and regular visitors to my website will have noticed that my on-line store has quite a few new products. My dear friend Guy Wilkinson of Super Synth Products came to the rescue and took over the design of the new 'Advanced Memory Expansion Pack' or 'AMEP'.

With four times the memory of the original Simmons MEP, AMEP will allow you back up the entire contents of your Simmons SDS7 giving you peace of mind when you install Pleiades lithium battery conversion for the Simmons SDS7. You can read all about AMEP here.

If you only have a few patches in your SDS7, it might just be easier to record the parameters of each module of each patch on to a chart. To help SDS7 owners with that, I've made a Simmons SDS7 program chart which can be downloaded here.

You'll have noticed that Pleiades has a dual AA battery holder. Indeed, the batteries are connected in parallel. If not fully depleted, changing the batteries separately means that your SDS7's memory won't be scrubbed! How cool is that!?! 😮

Pleiades has two batteries connected in parallel

Excluding the Tubbutec uniPulse, Pleiades is supplied with everything you need for a smooth install and a fully illustrated and detailed installation manual is available after purchase.

Pleiades lithium battery conversion kit for the simmons sds7

IMPORTANT: If you require  a Tubbutec uniPulse, please order here, specifying that you require the Pleiades Simmons SDS7 kit.

I joined Simmons a couple of years after the SDS7 was launched but it has always been my favourite kit, next to SDX. I know that many favour the SDSV which remains an iconic analogue drum system but the SDS7 was just so much more 'me'.

The SDS7 I bought while working for the company was sold to fund the purchase of my first SDX. It was a decision I always regretted but last December, a SDS7 came up on a well-known second-hand music gear site and I just had to have it. You can read all about that here.

Pleiades is handmade in Hemel Hempstead, Hertfordshire, United Kingdom, only a few miles from St. Albans where Simmons used to based and where I used to work.

I do not keep Pleiades units in stock and each Pleiades is built to order.


Vintage Simmons Technical NetworkAnd finally, my Pleiades lithium battery conversion for the Simmons SDS7 would have taken much longer to develop and might not have even happened at all, if it wasn't for the help, support and encouragement that I received from my Simmons Vintage Technical Network friends and colleagues. THANK YOU Ed Rose, aka The Simmons Guy, Michael Buchner and Patrice Jacquot.

tubbutecPleiades features extensive uniPulse integration and being a firm believer in partnerships, I'm very proud to mention the special relationship between Tobias of Tubbutec and myself. I see too many people now-a-days thinking that they can do everything themselves... and failing!

I first got to know Tobias while developing SDSM, my uniPulse adapter for the Simmons SDSV. Both Ed Rose and I had a couple of ideas for uniPulse and Tobias kindly updated the uniPulse firmware, implementing those ideas. AWSOME!

Pleiades is available to purchase here:

My Pleiades lithium battery conversion for the Simmons SDS7 was initially designed to address a common problem with this legendary instrument.

Pleiades installed in Simmons SDS7

Like so many instruments of its time, the Simmons SDS7 memory was maintained by a Ni-Cd battery. This type of battery requires regular charging. Unfortunately, if not regularly charged and left for a couple of years, these batteries leak and can cause irreparable damage. It saddens me deeply that there are far fewer Simmons SD7s in the world, simply due to the fact that they got forgotten about and bad batteries did their thing.

As well as making lithium battery conversion simple and straight-forward, Pleiades also provides a convenient way of implementing MIDI triggering of the SDS7's voices. Pleiades has a mounting system specifically designed for the Tubbutec uniPulse MIDI to trigger converter.

Pleiades with and without tubbutec unipulse
Pleiades provides easy lithium battery conversion for the Simmons SDS7 but also support the Tubbutec uniPulse MIDI to trigger converter (not supplied).

Included with the Pleiades kit is a tiny snap-in board, that makes interfacing the trigger signals from the uniPulse with your SDS7, a breeze. Connection between the daughterboard and the Pleiades main board is via a 26-way IDC cable. Power and MIDI also come on to the Pleiades daughterboard so everything's really easy.

Pleiades interface daughterboard snap-in
Part of the Pleiades kit, is this little board which snaps into the DIP header on the SDS7 back plane making trigger connections from the uniPulse solderless.

Occupying a spare voice module slot (preferably slot 12) in your SDS7, all you need to do is remove the SDS7's front panel to access Pleiades. This makes battery monitoring and changing simple. Pleiades also has switches and an LED which, if you have uniPulse installed, provide full access to some cool uniPulse functions.Switches, LED and connectors to make uniPulse installation simple

Like all my upgrades and modifications, Pleiades doesn't require any holes to be drilled into your SDS7. You won't have to cut any PCBs or carry out any 'hacks' that will permanently change your SDS7. In fact, Pleiades can be easily removed thereby returning your Simmons SDS7 to factory. MIDI access for example, is via the pad trigger input of the voice module that's occupied by the Pleiades board. A XLR to 5-way DIN cable is included with the Pleiades kit. As I said... no holes need to be drilled! Cool, eh? 🙂

Pleiades lithium battery conversion for the Simmons SDS7 was designed at the same time as my Dark Matter replacement power supply for the SDS7 and it was my intention that the two products should be launched simultaneously. I wanted SDS7 users to have options and so I felt it important that Pleiades and Dark Matter should be compatible. Since Dark Matter has a separate battery board, it's easy to substitute this with Pleiades.

dark matter replacement power supply for the simmons sds7
I wanted SDS7 users to have options and so Pleiades and Dark Matter are fully compatible.

You can read more about Dark matter here.

So, you can't easily back up the memory of the SDS7 and of course, the downside of messing about with the SDS7's battery, is that you'll lose all of your patches. The only way around this problem, is if you are lucky enough to have a working original Simmons memory cassette.  I say "lucky" but to be honest, they were incredibly unreliable. I therefore decided to have a go at developing a replacement.

Unlike the memory cassette clones that we've all seen over the years, I wasn't going to copy something that already was unreliable. I figured on using modern technology to produce a memory device with an edge... or two... or three (?)

Well, I bit off more than I could chew this year and regular visitors to my website will have noticed that my on-line store has quite a few new products. My dear friend Guy Wilkinson of Super Synth Products came to the rescue and took over the design of the new 'Advanced Memory Expansion Pack' or 'AMEP'.

With four times the memory of the original Simmons MEP, AMEP will allow you back up the entire contents of your Simmons SDS7 giving you peace of mind when you install Pleiades lithium battery conversion for the Simmons SDS7. You can read all about AMEP here.

If you only have a few patches in your SDS7, it might just be easier to record the parameters of each module of each patch on to a chart. To help SDS7 owners with that, I've made a Simmons SDS7 program chart which can be downloaded here.

You'll have noticed that Pleiades has a dual AA battery holder. Indeed, the batteries are connected in parallel. If not fully depleted, changing the batteries separately means that your SDS7's memory won't be scrubbed! How cool is that!?! 😮

Pleiades has two batteries connected in parallel

Excluding the Tubbutec uniPulse, Pleiades is supplied with everything you need for a smooth install and a fully illustrated and detailed installation manual is available after purchase.

Pleiades lithium battery conversion kit for the simmons sds7

IMPORTANT: If you require  a Tubbutec uniPulse, please order here, specifying that you require the Pleiades Simmons SDS7 kit.

!!!! WARNING !!!!

There's a post that's been on the Internet for a while in which some guy slaps a lithium battery into his SDS7, wires it up to the memory board and claims that it works. PLEASE DO NOT DO THIS.

When powered up, the SDS7 will try to charge the battery. This will not be good and could even lead to a fire. Pleiades has been designed to do the job properly. Yes, it requires a small modification to the memory board but Pleiades won't destroy your SDS7 and definitely won't catch fire.

I joined Simmons a couple of years after the SDS7 was launched but it has always been my favourite kit, next to SDX. I know that many favour the SDSV which remains an iconic analogue drum system but the SDS7 was just so much more 'me'.

The SDS7 I bought while working for the company was sold to fund the purchase of my first SDX. It was a decision I always regretted but last December, a SDS7 came up on a well-known second-hand music gear site and I just had to have it. You can read all about that here.

Pleiades is handmade in Hemel Hempstead, Hertfordshire, United Kingdom, only a few miles from St. Albans where Simmons used to based and where I used to work.

I do not keep Pleiades units in stock and each Pleiades is built to order.


Vintage Simmons Technical NetworkAnd finally, my Pleiades lithium battery conversion for the Simmons SDS7 would have taken much longer to develop and might not have even happened at all, if it wasn't for the help, support and encouragement that I received from my Simmons Technical Network friends and colleagues. THANK YOU Ed Rose, aka The Simmons Guy, Michael Buchner and Patrice Jacquot.

tubbutecPleiades features extensive uniPulse integration and being a firm believer in partnerships, I'm very proud to mention the special relationship between Tobias of Tubbutec and myself. I see too many people now-a-days thinking that they can do everything themselves... and failing!

I first got to know Tobias while developing SDSM, my uniPulse adapter for the Simmons SDSV. Both Ed Rose and I had a couple of ideas for uniPulse and Tobias kindly updated the uniPulse firmware, implementing those ideas. AWSOME!

Pleiades is available to purchase here: