Serge power is a mess

Discussing some incredible modules that don't quite fit into the other forum categories.

Moderators: luketeaford, Joe., lisa, Kent

User avatar
metasonix
Tube Pioneer
Posts: 4515
Joined: Fri Aug 03, 2007 2:35 pm

Serge power is a mess

Post by metasonix » Sat Oct 19, 2019 1:50 pm

I've got one guy on this forum who is interested in the Serge Metasonix modules. But power supplies are an issue.....

I do the searches and STILL cannot figure out what the hell Serge-format systems use for power distribution. This was little or no help.

viewtopic.php?t=136162

I might be forced to offer a special power supply just to run the Metasonix. All the other supplies on the market are VERY anemic.

There are three different power connectors being mentioned. I still have NO idea what early Serge panels used, apparently power was an "afterthought" prior to STS.

-4 pin Molex for current STS (same connector used on older floppy drives)?
-4-pin MTA for god knows what?
-And 4-pin XLRs for Random Source (very expensive)

It would be doable to make an external power thing with all three connectors, then have Metasonix "4x4" modules equipped with MTA cables to plug into it. Running 5-amp supplies on +12 and -12 like the RKP. It will also run plenty of STS and RS at the same time. (And I mean PLENTY.) There will be power bricks and cables everywhere but evidently Serge users are already putting up with some of that mess.

But it won't be cheap. And people have to MAKE UP THEIR MINDS.

User avatar
dksynth
Wiggling with Experience
Posts: 310
Joined: Wed Jul 01, 2015 12:56 pm

Post by dksynth » Sat Oct 19, 2019 5:02 pm

:deadbanana:

I don't know what you expected from a system with 40+ years of modules built by multiple companies, innumerable DIYers with their own ideas of how best to do things, and no codified set of standards for power distribution.

User avatar
MindMachine
weekend warrior
Posts: 6897
Joined: Sun Aug 02, 2009 1:45 am
Location: Santa Susana Field Lab

Post by MindMachine » Sat Oct 19, 2019 9:41 pm

^ Exactly what I was thinking.

Custom power would be better anyway.

Folks here have stated that STS super overcharges for power that is off the shelf stuff. Lightner told me he thought that STS under powered their stuff.

For best results roll your own in this case?
FS: Pedals and Euro modules, Delta Labs
viewtopic.php?f=74&t=233636&p=3287718&h ... e#p3287718
WTT: my Mangler for your Rumour

syncretism
Morbidly self-aware and liking it
Posts: 1473
Joined: Sun Jan 25, 2009 7:05 pm
Contact:

Post by syncretism » Sat Oct 19, 2019 9:55 pm

I knew a few people who cited power as a reason they left Serge; mind, this was before Random*Source, et al, and if you weren't doing it yourself, STS was probably the only game in town.

I will say that I have had some DIY builds that were super-dodgy on my otherwise excellent R*S PSUs, but worked flawlessly with a PS2a. I don't really know what to make of that.

If I could power all my Serge panels from one big thing, though, I'd be down.

cycad73

Post by cycad73 » Sun Oct 20, 2019 1:03 am

STS Serge uses 4-pin molex connectors, but they're the keyed version (tapered to a point at one end).

This is the correct shape:
https://www.parts-express.com/molex-4-p ... gLQ-fD_BwE

Earlier Serge uses Cinch-Jones.

I was able to get both Random Source and Loudest Warning panels with the 4-pin molex connector. They work just fine off the STS PS6 supply, and don't have any issues mixing with the STS panels.

User avatar
flipper16
Wiggling with Experience
Posts: 455
Joined: Sun Aug 04, 2013 8:38 am
Location: London UK

Post by flipper16 » Sun Oct 20, 2019 7:30 am

syncretism wrote:If I could power all my Serge panels from one big thing, though, I'd be down.
What about...
http://www.hinton-instruments.co.uk/paprod/psu/

User avatar
Graham Hinton
Super Deluxe Wiggler
Posts: 3279
Joined: Fri Jul 02, 2010 6:28 pm
Location: England
Contact:

Post by Graham Hinton » Sun Oct 20, 2019 8:50 am

All modular synthesizer power systems are a mess and always have been back to the first Moog. As soon as you see wall warts and pcb distribution you know there are going to be problems.

Throw them away and start again. Serge is not difficult to fix and Metasonix not difficult to supply.

Image

User avatar
lumin
Common Wiggler
Posts: 238
Joined: Wed Apr 20, 2011 10:05 am
Location: Miami
Contact:

Post by lumin » Sun Oct 20, 2019 9:10 am

:love: :love: :love: :love:
Tonight I'll dream that my easel had one of those power supplies

User avatar
levelhead3
Wiggling with Experience
Posts: 312
Joined: Mon Jun 11, 2018 8:53 pm
Location: Olympia

Post by levelhead3 » Sun Oct 20, 2019 4:14 pm

definite power supply porn. but it's a dream we can make real.

User avatar
luchog
Crazy Pony
Posts: 1104
Joined: Sat Nov 21, 2015 2:57 pm
Location: The Emerald City

Post by luchog » Sun Oct 20, 2019 4:23 pm

I would love to have some of those Metasonix panels in my Serge system; and having a single power supply that can handle the whole thing would be ideal; especially if it's a good linear supply with a better, busbar-type, distribution system that what either R*S Serge or Eurorack currently has.

As for connectors, I'd probably go with the current STS 4-pin keyed Molex with 18g wire, but there's probably some better solution I'm not aware of. It's easy enough to make adapters for all of the existing formats (I'm currently making one for a R*S PS to STS panel power connection).

I really do not like the current R*S boat power distribution, very cheap and chintzy.

User avatar
ndkent
Super Deluxe Wiggler
Posts: 3658
Joined: Tue Dec 23, 2008 5:59 am

Post by ndkent » Sun Oct 20, 2019 5:40 pm

Seems obvious and is probably known to many but Serge philosophy was to build modules into full panels. So you would wire it to the power system or you you get new power. Earliest stuff - "Paperface" "73-75" needed +6v but later stuff did not and started using the mentioned Molex 4 pin for whole boats.

As soon as you hit the lets do Serge as separate modules, yeah, it's everyone has their own connector and maybe just as importantly boat specs in terms of spacing and holes. So basically you have STS half boat M-odules with the power dist thing in the middle. You have quarter boat sized Random*Source. You have the indy DIY Loudest Warning doing a different thing. Finally you have people building CGS into panels, 5U etc. stuff, maybe even +-15v powered.

User avatar
Graham Hinton
Super Deluxe Wiggler
Posts: 3279
Joined: Fri Jul 02, 2010 6:28 pm
Location: England
Contact:

Post by Graham Hinton » Mon Oct 21, 2019 4:51 am

There are four mistakes that nearly all modular power systems fall down on:

1) No consideration of the voltage drops in the power system and the common impedance coupling associated with them.

2) No consideration of the 0V resistance between different modules or frames within the system and establishing a common 0V within it and between other systems. A banana plug connection does not cut it and is usually connected in the wrong place anyway.

3) No consideration of proper audio earthing for safety and screening and compatibility with other audio equipment.

4) Inappropriate choice of connectors. Just because a module has a certain connector does not mean that it has to be on the other end of the cable too and making pcb splitters makes 1) to 3) worse. You can't beat a ring terminal screwed to a busbar and it costs less.

I wouldn't be mentioning these problems without knowing a better way of dealing with them.

User avatar
cebec
Super Deluxe Wiggler
Posts: 1162
Joined: Thu Mar 08, 2007 9:20 am
Location: Virginia

Post by cebec » Mon Oct 21, 2019 7:10 am

Been using STS Serge and PS4s since 2005 and never had an issue with noise, underpowering, overpowering. It just works.

User avatar
hongaars
Common Wiggler
Posts: 108
Joined: Mon Jan 04, 2010 3:30 pm
Location: Utrecht

Post by hongaars » Mon Oct 21, 2019 9:23 am

I have never had any problems with the STS PS2 and PS4.

But that Molex cable & PSD look poor.

syncretism
Morbidly self-aware and liking it
Posts: 1473
Joined: Sun Jan 25, 2009 7:05 pm
Contact:

Post by syncretism » Mon Oct 21, 2019 1:24 pm

I have read in the past that the Obelisk's black input jack is a 0v common. This doesn't bear out in testing for me, though - the behavior differs dramatically from when I use the 0v common jack on my PSU. Was I misled?

User avatar
metasonix
Tube Pioneer
Posts: 4515
Joined: Fri Aug 03, 2007 2:35 pm

Post by metasonix » Mon Oct 21, 2019 4:33 pm

cycad73 wrote:STS Serge uses 4-pin molex connectors, but they're the keyed version (tapered to a point at one end).
Someone sent me a photo of the connector on his recent STS panel--same kind
Image
That is the old 1490 series. Still available, reliable, and cheap, but there's no PCB-mount version for making a busboard, and the pins only come in crimp-on form.
https://www.mouser.com/ProductDetail/Mo ... %252BUFiFL
https://www.mouser.com/ProductDetail/Mo ... 8NgOSuZ9ty
https://www.mouser.com/ProductDetail/Mo ... H7n5b1B2Di
https://www.mouser.com/ProductDetail/Mo ... T3NT%252B9

I've been told that some older STS panels used the other Molex connector--the nontapered one that supplied power to floppy drives. "Original" early Serge "usually" used Jones plugs, whatever that means. The XLR plugs that RS uses are rated for 0.5 amps maximum and so not really suitable for Metasonix. Making everyone happy will be impossible.

Screw it. I'm going to put 0.156 MTAs on our Serge-y modules. Mostly because I've got the connectors handy, they were commonly used for MOTM/Frac/etc, and mating plugs are PCB mount.

Get an MTA busboard. Please don't try to run Metasonix from a Random Source or STS power supply or you will be sad. Sorry. (Maybe I should just buy MTA busboards and attach good quality power bricks.)
You can't beat a ring terminal screwed to a busbar and it costs less.
Of course. Sadly, most people "can't be bothered" to pick up a screwdriver.
Serge is not difficult to fix and Metasonix not difficult to supply.
Graham, you would not believe the whiny emails I get......the smart, experienced people can solve these problems and now we are getting a big crop of noobs. They commonly DEMAND idiot-proof products. (Better be cheap too.)

User avatar
revtor
Dialing it in..
Posts: 1680
Joined: Sat Nov 29, 2008 10:31 am
Location: North Jerz

Post by revtor » Mon Oct 21, 2019 11:03 pm

syncretism wrote:I have read in the past that the Obelisk's black input jack is a 0v common. This doesn't bear out in testing for me, though - the behavior differs dramatically from when I use the 0v common jack on my PSU. Was I misled?
NOT a 0v common. The black jack in the obelisk is a voltage indicator. The led will change based on the voltage that jack receives.

User avatar
Graham Hinton
Super Deluxe Wiggler
Posts: 3279
Joined: Fri Jul 02, 2010 6:28 pm
Location: England
Contact:

Post by Graham Hinton » Tue Oct 22, 2019 5:32 am

metasonix wrote: That is the old 1490 series. Still available, reliable, and cheap, but there's no PCB-mount version for making a busboard, and the pins only come in crimp-on form.

"Original" early Serge "usually" used Jones plugs, whatever that means.
Cinch-Jones, the flat bladed rectangular ones like you will find on the back of a Minimoog, VCS3 or ARP 2600. And are best left there.
The XLR plugs that RS uses are rated for 0.5 amps maximum and so not really suitable for Metasonix.
I don't recommend using XLRs for more than 250mA and preferably not. They are too limited by contact resistance and the size of cable that can go through the boot. Trident Ringlock are better.
Screw it. I'm going to put 0.156 MTAs on our Serge-y modules. Mostly because I've got the connectors handy, they were commonly used for MOTM/Frac/etc, and mating plugs are PCB mount.
Still not a good idea. For new designs have a look at my module power standard connector specification and PM me.
Get an MTA busboard.
You can't get enough copper on a busboard and IDC connections are not good for power. If you must use that connector use Molex KK 0.156", but again preferably not.
Graham, you would not believe the whiny emails I get......the smart, experienced people can solve these problems and now we are getting a big crop of noobs. They commonly DEMAND idiot-proof products. (Better be cheap too.)
I get them too. If you make idiot proof products a bigger idiot will come along and break it. Not that you shouldn't try, but don't be surprised when one does.

User avatar
drewskee
Wiggling with Experience
Posts: 431
Joined: Wed May 06, 2009 12:33 pm
Location: Swamps of New Jersey

Post by drewskee » Wed Oct 23, 2019 2:32 pm

cebec wrote:Been using STS Serge and PS4s since 2005 and never had an issue with noise, underpowering, overpowering. It just works.
And I've been using them since 1999 without issue as well. Note that a PS2 really cannot power more than 1 panel reliably, maybe two if the modules don't require that much juice. I have two panels each with a separate PS2 and that works quote well. YMMV...
Last edited by drewskee on Sat Oct 26, 2019 8:24 am, edited 1 time in total.
Things should be as simple as possible but not one bit simpler - Albert Einstein

User avatar
MechaSeb
Super Deluxe Wiggler
Posts: 1502
Joined: Fri Apr 02, 2010 7:21 pm
Location: France

Post by MechaSeb » Fri Oct 25, 2019 5:14 am

Mostly depending on what your panels are made up of though.
Had good enough experiences with Animal + TKB on a single PS2a for example.

Same with 4 M-Class (two panels) & one PS2a. However it's clearly the limit, and what it's been designed/advertised to be used with.

I used to try powering 3 panels (+/- the TKB) with one PS2a. The oscillators was drifting a lot and DSG's was wonky. Clearly not good ! Stopped after seconds and ordered a PSU delivering more juice.

But rahter thant number of panels, it may be wiser to look at which modules you want to power. I seems to remember that basically NTO, PCO, WAD & FRS are the most juice eaters modules in Serge paradigm. Maybe DSG as well but in different proportions.

Also bear in mind that PS2 & PS2a ain't the same PSU.
PS2a is the so called "medical grade" (<- Rex words) small black box with the penrose triangle on it. PS2 is the slightly larger grey box. Don't know specs of the PS2...

PS2 : https://3.bp.blogspot.com/-opB_IKehMm0/ ... 1600/2.jpg

PS2a : https://images.reverb.com/image/upload/ ... 3o2kd0.jpg
https://images.reverb.com/image/upload/ ... k6xzsp.jpg

User avatar
drewskee
Wiggling with Experience
Posts: 431
Joined: Wed May 06, 2009 12:33 pm
Location: Swamps of New Jersey

Post by drewskee » Fri Oct 25, 2019 10:01 am

MechaSeb wrote:Mostly depending on what your panels are made up of though.
Had good enough experiences with Animal + TKB on a single PS2a for example.

Same with 4 M-Class (two panels) & one PS2a. However it's clearly the limit, and what it's been designed/advertised to be used with.

I used to try powering 3 panels (+/- the TKB) with one PS2a. The oscillators was drifting a lot and DSG's was wonky. Clearly not good ! Stopped after seconds and ordered a PSU delivering more juice.

But rahter thant number of panels, it may be wiser to look at which modules you want to power. I seems to remember that basically NTO, PCO, WAD & FRS are the most juice eaters modules in Serge paradigm. Maybe DSG as well but in different proportions.

Also bear in mind that PS2 & PS2a ain't the same PSU.
PS2a is the so called "medical grade" (<- Rex words) small black box with the penrose triangle on it. PS2 is the slightly larger grey box. Don't know specs of the PS2...

PS2 : https://3.bp.blogspot.com/-opB_IKehMm0/ ... 1600/2.jpg

PS2a : https://images.reverb.com/image/upload/ ... 3o2kd0.jpg
https://images.reverb.com/image/upload/ ... k6xzsp.jpg
All true and excellent points...agreed. Also a Random Source pulls a decent amount of juice and one of my panels has a rare Dual Random Source so I know it's not an easy load.

I should have been more clear that I was referring to the black lump PS2a. I tried one powering both panels I have with a PSD and it got real hot. Using the two PS2a's is much better though not cheap.

And both of my panels have a single power cable unlike an Animal that has dual cables and requires the PSD with the PS2a
Things should be as simple as possible but not one bit simpler - Albert Einstein

User avatar
MindMachine
weekend warrior
Posts: 6897
Joined: Sun Aug 02, 2009 1:45 am
Location: Santa Susana Field Lab

Post by MindMachine » Sat Oct 26, 2019 12:13 am

cebec wrote:Been using STS Serge and PS4s since 2005 and never had an issue with noise, underpowering, overpowering. It just works.
Here since 1999. :boat:
FS: Pedals and Euro modules, Delta Labs
viewtopic.php?f=74&t=233636&p=3287718&h ... e#p3287718
WTT: my Mangler for your Rumour

User avatar
MindMachine
weekend warrior
Posts: 6897
Joined: Sun Aug 02, 2009 1:45 am
Location: Santa Susana Field Lab

Post by MindMachine » Sat Oct 26, 2019 12:13 am

cebec wrote:Been using STS Serge and PS4s since 2005 and never had an issue with noise, underpowering, overpowering. It just works.
Dual post - glitch on single click.

Happy sailing.
FS: Pedals and Euro modules, Delta Labs
viewtopic.php?f=74&t=233636&p=3287718&h ... e#p3287718
WTT: my Mangler for your Rumour

User avatar
MindMachine
weekend warrior
Posts: 6897
Joined: Sun Aug 02, 2009 1:45 am
Location: Santa Susana Field Lab

Post by MindMachine » Sat Oct 26, 2019 12:16 am

MindMachine wrote:
cebec wrote:Been using STS Serge and PS4s since 2005 and never had an issue with noise, underpowering, overpowering. It just works.
Here since 1999. :boat:
... w/ STS. 1990 w/ Serge.
FS: Pedals and Euro modules, Delta Labs
viewtopic.php?f=74&t=233636&p=3287718&h ... e#p3287718
WTT: my Mangler for your Rumour

User avatar
metasonix
Tube Pioneer
Posts: 4515
Joined: Fri Aug 03, 2007 2:35 pm

Post by metasonix » Fri Nov 01, 2019 9:28 pm

Graham Hinton wrote:Cinch-Jones, the flat bladed rectangular ones like you will find on the back of a Minimoog, VCS3 or ARP 2600. And are best left there.
Fun fact: did you know that the Jones plug standard is one of the oldest connector systems in the electronics world? Jones plugs first appeared in the 1920s, for use on primitive early aircraft radios. They are close to a century old.

On Gearslutz there is a guy who claimed that his grandfather invented them. I'd like to hear more about his account. The original Jones patent was filed in 1929.
Still not a good idea. For new designs have a look at my module power standard connector specification and PM me.
I'd go with that, but here we are with this lack-of-standards business.

Since people had warned me that RS and Loudest Warning/CLee panel dimensions were slightly different, and I already made panels to fit RS boats, I decided to buy a CLee boat to measure it. Sure enough, they are very close, but just different enough to drive people up the wall. Mr. Lee (the LW guy, whoever) offers some slightly-tortured logic for his panel design here. He can do whatever he wants, although I can't help thinking that he is losing some possible customers.

STS/Serge and RS panels are 7" high (178mm and change) while CLee/LW panels are 175mm. RS panels are 4.25" wide, LW ¯\_(ツ)_/¯

RS mounting holes at least TRY to conform to the old Serge 1" grid, being 6.5" (~164mm) by 3.5" (~90mm) center to center. LW has 167.5mm by 101.5mm. He did that to use Euro rails. Understandable; but then why bother getting special boats made, that don't use Euro rails? And now I'm told there are 4 or 5 other companies making LW style panels.
Image

I have to say this for Craig's boat: it is a MASSIVE slab of black powder-coated steel. The RS boat I had here for Ricardo's custom setup was nicely made aluminum, but wasn't something one could use to beat a pro wrestler into unconsciousness. Problem being with getting power into the thing and distributing. Drilling extra holes in the RS boat is easy, but adding holes to the LW box will be difficult.

The LW boat came with a bare, unstuffed busboard. Unlike everyone else (?) he's using 4-pin MTAs with a 0.1" spacing. It is not compatible with dotcom modules. Sorry Craig, it might be okay for your solid-state modules, but ours need MOAR PWER.

Perhaps we should go with a half-wide RS-sized module using an RKP and a few MTA connectors added with a daughterboard. Or mount it in the bottom of an RS boat. Decisions.
Last edited by metasonix on Sat Nov 02, 2019 3:09 pm, edited 3 times in total.

Post Reply

Return to “Buchla, EMS & Serge”