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Internal PSU - so space isn't the issue...

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Internal PSU - so space isn't the issue...

Postby The Elf » Wed Jun 05, 2019 9:49 am

https://www.soundonsound.com/reviews/cioks-dc7
Image

These guys get it. Fantastic job to get an internal PSU and IEC connector in there. :thumbup:

You manufacturing giants of the hi-tech world, who want to plague me with wall-warts and line lumps - are you seeing this? THIS is the way to do it.
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Re: Internal PSU - so space isn't the issue...

Postby Mixedup » Wed Jun 05, 2019 11:26 am

It does look very handy, doesn't it? But — and forgive me for saying this — given that it is in itself an external PSU, isn't it just a posh take on the in-line wart for all those devices that don't have on-board PSUs?! :headbang:
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Re: Internal PSU - so space isn't the issue...

Postby The Elf » Wed Jun 05, 2019 12:01 pm

Mixedup wrote:It does look very handy, doesn't it? But — and forgive me for saying this — given that it is in itself an external PSU, isn't it just a posh take on the in-line wart for all those devices that don't have on-board PSUs?! :headbang:
Yes, but there's a transformer and all the goodies that convert mains to something useful in there. That tells me it would take up a tiny amount of space and would fit into gear that should always have had an internal PSU and copped out.

Let's take an example - the Korg Odyssey re-issue. I've managed to get the external PSU inside the case - so they could have done it and saved me the trouble.

People always make the manufacturers excuses for them. Space is one excuse that clearly doesn't hold up.
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Re: Internal PSU - so space isn't the issue...

Postby Mixedup » Wed Jun 05, 2019 12:53 pm

I have no idea about synths these days... the newest one I currently own was built around about 1982 :mrgreen:

But for studio gear, I always thought that there were three arguments other than space for keeping PSUs external — first, it keeps the PSU away from the signal path, which significant costs (mu metal ain't cheap to buy and adds to the weight for shipping); second, you can power multiple units from a single external PSU (as with anything from guitar pedals to Chandler rackmount stuff); third, faulty PSUs can be replaced pretty much instantly (you can have a backup, and/or use a similar PSU from another device) without having to take your precious gear out of service.

But I hear what you're saying!
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Re: Internal PSU - so space isn't the issue...

Postby James Perrett » Wed Jun 05, 2019 1:06 pm

The biggest issue is complying with safety regulations. If you don't have high voltages flying around inside your device it is much easier to claim that you comply. You can then just buy in a ready approved external power supply from a specialist manufacturer.
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Re: Internal PSU - so space isn't the issue...

Postby ef37a » Wed Jun 05, 2019 1:31 pm

Hmm, a tricky one!
A really good SMPSU is expensive to design and build if you want top performance in terms of noise on the power rails and radiated crap and putting them inside gear with 60dB mic amps is fraught.
Then, in a thing like a mixer e.g. an SMPSU is likely to be THE most unreliable part (although it has to be said they are very, very good these days) and the customer will not thank you if it is not in a can and "plugged up" so it can be easily replaced*. In a mixer the most stringent measures will need to be taken with screening and earth runs. An external supply solves all that. Plus, SMPSUs are total PITA to fix.

Production is also hugely simplified if the gear just needs 48V max as it proceeds down the assembly/test line. People do not need to be trained for HV work, at least only the service guys who pull faulty units off the last stage.

Mention has been made of the World Wide mess of voltages. Linear, 50/60Hz supplies are always a compromise. Even in "civilized" Britain we get guitar amps being "cooked" because folks get 240V+.

Of course, there is plenty of audio/digital kit with internal SMPSUs and impeccable performance (RME) but it ain't cheap!

*I have stated many times, here and elsewhere. "There orta be a law!" Forcing manfctrs to make such components available as service replacements. This of course is what an external supply effectively is.
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Re: Internal PSU - so space isn't the issue...

Postby The Elf » Wed Jun 05, 2019 2:10 pm

The bottom line is that it can be done. If one can do it, they all can. Get on with it!
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Re: Internal PSU - so space isn't the issue...

Postby ef37a » Wed Jun 05, 2019 2:17 pm

The Elf wrote:The bottom line is that it can be done. If one can do it, they all can. Get on with it!

Well yes but, you NEVER see a signal to noise figure for a synth. Just getting a spec for the output voltages is a rare event!

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Re: Internal PSU - so space isn't the issue...

Postby MarkOne » Wed Jun 05, 2019 2:24 pm

Actually, I suspect putting an internal mains supply inside adds not just cost, or complexity, but the device can be a worldwide single SKU if it has a simple DC input.

And then there are the regulatory certifications required of mains powered equipment both FCC and CE requirements that probably simply go away (or are pushed down to the wall-wart manufacturer you choose).

I agree that it's a pain to have all these lumps around the studio (or worse, live rig!) but I guess it's just become the norm for stuff in general (I've just looked around tne immediate area around my desk in our office and all the laptops, docking stations, monitors, the WiFi routers all have external supplies. Only things with a 230v direct feed I can spot from here are a desk fan, a digital signage monitor and the huge copy/print/scan Xerox thingie.
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Re: Internal PSU - so space isn't the issue...

Postby Mixedup » Wed Jun 05, 2019 2:27 pm

Well I totally garbled my words, didn't I... here's an amended version sans bloopers, changes in ital.

Mixedup wrote:But for studio gear, I always thought that there were three arguments other than space for keeping PSUs external — first, it keeps the PSU away from the signal path, which saves significant costs compared with shielding an internal one (mu metal ain't cheap to buy and adds to the weight for shipping); second, you can power multiple units from a single external PSU (as with anything from guitar pedals to Chandler rackmount stuff); third, faulty PSUs can be replaced pretty much instantly (you can have a backup, and/or use a similar PSU from another device) without having to take your precious gear out of service.

...and I note yet more reasons given by others. I'm now just imagining how much more I'd have had to pay for my collection of guitar pedals, had they all been built to accept 240V AC, when all I want to do is hook a few at a time up to a compact pedalboard supply :headbang: Just because something *can* be done, it's not necessarily always the best option.

I do wish that manufacturers would be a little more choosy about the quality and practicality of the external PSUs they choose to ship though.
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Re: Internal PSU - so space isn't the issue...

Postby ef37a » Wed Jun 05, 2019 3:12 pm

Mixedup wrote:Well I totally garbled my words, didn't I... here's an amended version sans bloopers, changes in ital.

Mixedup wrote:But for studio gear, I always thought that there were three arguments other than space for keeping PSUs external — first, it keeps the PSU away from the signal path, which saves significant costs compared with shielding an internal one (mu metal ain't cheap to buy and adds to the weight for shipping); second, you can power multiple units from a single external PSU (as with anything from guitar pedals to Chandler rackmount stuff); third, faulty PSUs can be replaced pretty much instantly (you can have a backup, and/or use a similar PSU from another device) without having to take your precious gear out of service.

...and I note yet more reasons given by others. I'm now just imagining how much more I'd have had to pay for my collection of guitar pedals, had they all been built to accept 240V AC, when all I want to do is hook a few at a time up to a compact pedalboard supply :headbang: Just because something *can* be done, it's not necessarily always the best option.

I do wish that manufacturers would be a little more choosy about the quality and practicality of the external PSUs they choose to ship though.

I would certainly like to see some form of international standard. We have it for the 3 main types of mains connector but there is a good dozen variants on length and diameter of DC plugs. At least centre positive is pretty universal now except for the daft-but-historic-and-we-ain't-gonna-change-it guitar pedal!

As I see it we only really need gear to run on 5V, 12V and around 20V for some amp systems. Output current and regulation should be to a standard as should be line noise.

"Bespoke" PSUs should be outlawed except where it can be shown that there is a good technical reason. After all, any 12V LA will start and run your car if of sufficient AH capacity.

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Re: Internal PSU - so space isn't the issue...

Postby James Perrett » Wed Jun 05, 2019 3:19 pm

MarkOne wrote:Actually, I suspect putting an internal mains supply inside adds not just cost, or complexity, but the device can be a worldwide single SKU if it has a simple DC input.

Not an issue with modern universal power supplies - you just need the right mains cable for each country.

I have plenty of gear here with internal power supplies and no noise issues (apart from the odd acoustically noisy transformer).
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Re: Internal PSU - so space isn't the issue...

Postby Rich Hanson » Wed Jun 05, 2019 4:01 pm

If the manufacturers want to stick with external PSUs, could they at least agree on a standard so that they can become interchangeable. Oh, and provide some sort of strain relief too. But if Behringer of all people can do internal PSUs, then so can others.

Many years back, we were setting up for a gig, I had an SY22 at the time which had an external PSU. Some klutz(*) stood on the low voltage cable, ripping the wire out of the plug into the synth. On that occasion we were lucky that the landlord had a universal supply that we could use.

(*) i.e. me

Ok, I'll stop grouching now.
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Re: Internal PSU - so space isn't the issue...

Postby The Elf » Wed Jun 05, 2019 4:59 pm

Rich Hanson wrote:But if Behringer of all people can do internal PSUs, then so can others.
Spot on. We need to stop making excuses for the manufacturers - they must be laughing their socks off.

All this talk of regulations, heat, space, noise... If one can get past all that, they all can.
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Re: Internal PSU - so space isn't the issue...

Postby blinddrew » Wed Jun 05, 2019 11:40 pm

Of course they can, but at what cost?
And the 'if Behringer can do it' argument doesn't really hold water, they have massive manufacturing facilities and can afford all the additional stresses of dealing with high voltages and the other challenges above. Some small boutique manufacturer may not have that luxury.
No excuse for Roland though... ;)
I agree with Dave though, it would be nice to see some standards.
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Re: Internal PSU - so space isn't the issue...

Postby ef37a » Thu Jun 06, 2019 6:05 am

blinddrew wrote:Of course they can, but at what cost?
And the 'if Behringer can do it' argument doesn't really hold water, they have massive manufacturing facilities and can afford all the additional stresses of dealing with high voltages and the other challenges above. Some small boutique manufacturer may not have that luxury.
No excuse for Roland though... ;)
I agree with Dave though, it would be nice to see some standards.

Ta. One big beef is the captive DC cable? I bet 90% of PSUs get chucked because of a cracked conductor where it leaves the blob. Some PSUs (Christmas lights!) come with a detachable cable which of course can be replaced.

Laptops for instance often use a specific DC socket that excludes all other plug types for no other reason than to do just that! The warning that "Only a bona fide Ripsuoff power supply must be used or damage could result" is b****s. It is easy-peasy in this day and age to make gear that can accept a wide range of voltages, many sort the polarity and a few don't care if it is AC or DC!

Jusfort. When a mnfctr tells you that any but their own PSU could cause damage to the gear you should OF COURSE heed that advice. My point was it should not be the case.

In many cases it is not true but unless you have the means to test out the situation, play safe.

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Re: Internal PSU - so space isn't the issue...

Postby The Elf » Thu Jun 06, 2019 7:35 am

blinddrew wrote:Of course they can, but at what cost?
This has been put to the lie too. KT76 - 150 quid with an internal PSU? Moog One at 8 grand with an external PSU?

The bottom line is that external PSUs save money for manufacturers, and they like it that way. Every time one of us makes their excuses for them they get away with it. One more line lump with a cotton-thin cable to get lost, get forgotten and get tripped over and snapped at the next gig.

And let's be clear - this is a keyboard forum - I'm not including guitar effects pedals here.
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Re: Internal PSU - so space isn't the issue...

Postby ef37a » Thu Jun 06, 2019 8:26 am

I will concede Elf that for things the size of keyboards it is hard to justify the line lump.

There is a "breakpoint" however? A keyboard controller such as my Evo Ekeys49 is powered from USB and has an optional 9v input. It would be quite ridiculous to incorporate a mains supply in such a device even though there would be adequate space.

I also have an old Yamaha (PSS sommat) "Portasound" that needs batteries or a few watts from a rat. Where does the line get drawn as to the economical point at which to include mains power?

I have thought of a "half way house" solution? The unit is lump powered but said lump clips into a recess in the keyboard exposing an IEC connector. Thus the device can go through production powered from LT and then the appropriate PSU clipped in for the destination country? All that adds cost of course but it would just be a one-off case re-design and we should all be looking to make stuff last longer and be repairable.

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Re: Internal PSU - so space isn't the issue...

Postby Folderol » Thu Jun 06, 2019 8:41 am

These days I rather agree with Elf.

Universal SMPSUs are now cheap as chips.

Noise effectively ceased to be an argument once switching frequency exceeded 100kHz. It's usually about 150kHz these days.

It is relatively simple to keep the mains voltage area (and indeed the entire PSU) very small and enclosed - including the socket (which ideally should be the internationally recognised IEC one), on the back of the equipment itself . The only thing that needs to be region sensitive is the mains lead itself.

Any synth with a processor in it (i.e. all of them!) will be generating a lot of noise itself, and will almost certainly need local voltage regulators - which may themselves be switch mode. It is quite likely that the entire kit would still need EMC certification for this reason alone.
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Re: Internal PSU - so space isn't the issue...

Postby ef37a » Thu Jun 06, 2019 8:59 am

Folderol wrote:These days I rather agree with Elf.

Universal SMPSUs are now cheap as chips.

Noise effectively ceased to be an argument once switching frequency exceeded 100kHz. It's usually about 150kHz these days.

It is relatively simple to keep the mains voltage area (and indeed the entire PSU) very small and enclosed - including the socket (which ideally should be the internationally recognised IEC one), on the back of the equipment itself . The only thing that needs to be region sensitive is the mains lead itself.

Any synth with a processor in it (i.e. all of them!) will be generating a lot of noise itself, and will almost certainly need local voltage regulators - which may themselves be switch mode. It is quite likely that the entire kit would still need EMC certification for this reason alone.

That is all generally so Will but the batch of about ten 9V 1A supplies I load* and noise tested about 5 years ago were a very varied bunch!

Re EMC, yes my Ekeys has processor in it but the whole thing cannot pull more than 2.5 watts. A bigger synth needing 10W or more is a more difficult thing to keep quiet!
There is always 400V+ in an SMPSU no matter how wee and so the production line objection is still valid IMO.

I would like to see the end of captive DC leads.

*The hash frequency was load dependant which makes filtering a leeetle more tricky plus it is modulated by 100Hz ripple so harmonics are everywhere!

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