Starfire

Custom Power Supply for mb6582

235 posts in this topic

What I am saying is that you should either familiarize yourself with linear PSU's a lot more, or just buy a switcher. Both methods can be used to get a working solution. If you're unable to design your own linear PSU (which isn't that hard!) I would not advise to use a (modified) design you don't understand fully.

Actually, there is a linear PSU noted a bit earlier in this thread that you can buy now too. It's more expensive than the switcher ($150 I think) but something to consider.

Except for a mains level electrical shock there is also the risk of fire and/or small explosion (electrolytical capacitors for example when used incorrectly) if the wrong components are used. Would you risk fire based on someone else's design? Someone you don't know all that well, and someone that might even have a bigger mouth than design skills?

I am not calling anybody incompetent, but please consider the risks a bit more before tinkering with mains voltage. If you understand what it involves: go ahead and have fun. If you don't: there are other, faster, safer solutions :thumbsup:

Where is the feeling of adventure? :P Designing a basic linear PSU isn't hard at all. Yes, you're messing with mains voltages but only on one side of the transformer and yes you need to be competent and safe but it really isn't difficult.

I am still in the "we need a PSU kit" camp or at least a standard PSU design to settle on. Even if that is something like the above linear PSU or the Mean-Well, having something that is "certified for MidiBox" would be pretty neat. I get what TK is saying about not providing information that could potentially do great harm to people. But if they are going to attempt it anyway, might as well give them a solid design - less chance they will blow up capacitors, as you say (though really, that's rather easy to avoid).

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I agree to some point with NorthernLightX - that´s why I did not add detailed build instructions for the "retro-donald" PSU in the tutorial - I just don´t want to see (or hear) someone having the electrocuting trip of his life - in that case, 150$ are the better investment... For all others willing to take the risk... just "clone" the given schematics and you will get a nice PSU... when feeling just slightly unsafe about it, buying the proposed alternative from mouser or using a high-freq switcher is the way to go...

Or... and I want to bring that up again, build the protection circuit as a standalone unit... this won´t help against age-based failure of your complete power brick (as in orange_hands case), but will protect your SIDs in case of a vreg failure.

Greets,

Peter

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I sort of view it as the celibacy versus safe sex argument that often comes up around election time here in the States :)

If there were a good, solid, PSU design that people could use, it would be safer than having them try to come up with it from total scratch. See, I understand what TK means about not being the instrument of death for a person. But if that person would have been stupid enough to ride the lightning with a kit PSU, it's highly likely they would have done the same thing building one on their own.

So, if it's about protecting people - first and foremost, being able to buy a ready-made PSU is best, second to that having a good, solid, "MidiBox Certified" PSU design that folks can use would be great.

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I sort of view it as the celibacy versus safe sex argument that often comes up around election time here in the States :)

All I said was that if you cannot tell the inside from the outside of the condom you should not f*ck around but masturbate instead, to keep with your analogy :tongue:

Anyway, to bring it up again, my MeanWell switcher works great, is virtually noise free, is pretty cheap (I guess it can be bought for under $50 including shipping), and does not involve much tinkering on the mains side of the unit. I rest my case.

Edited by NorthernLightX
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Anyway, to bring it up again, my MeanWell switcher works great, is virtually noise free, is pretty cheap

Where did you get it from ? I will consider to get one as well ....

Cheers

orange

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Where did you get it from ? I will consider to get one as well ....

Cheers

orange

See previous posts in this thread - there's an entire sub-discssion about these things, including links for where to buy.

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Where did you get it from ? I will consider to get one as well ....

I got it from a company here in NL. They only sell to other companies though. I paid €23,80 ex. VAT and shipping, shipping costs are high (€25 ex. VAT) so small orders are relatively expensive. If there's enough interest I could do a group buy. These things deliver +5v +12 and -12v, and therefore are suitable for a range of projects:

MBSID and MB6582 (with added 7809 regulator): leave -12v rail unused

MBFM: needs +12 and -12 so all rails are used

AOUT projects like MBCV: those that need a bipolar supply also benefit from the available -12v rail

Cheers.

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I have also bought the rpt-60b from Sunpower-uk, a meanwell uk supplier who also only ship to companies. I bought 4, unit price £23.40 uk shipping £10 plus vat, total £124.32 as I can think of so many projects which need digital 5v and bipolar 12v - thanks for the info NorthernLightX. But could you help me with something - what cables/connectors did you use? I know on the board you have JST B3P-VH and JST B6P-VH male headers but I cannot find the female equivalent. thanks in advance

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Hi analog monster,

sorry for the late reply, I'm having another one of those periods where I do not get to midiboxing at all.

The small connector I ripped off an old PC PSU. The larger connector I found @ mouser. I do not know the exact partnumber.

Cheers, Alex.

Edited by NorthernLightX

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scrap that, made by the same company but wrong sizes, will post when I have found the correct connectors

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Thanks yeah they are the ones, the ones I ordered look identical but I must have not paid attention to the pitch - 2.5mm on the ones I ordered but 3.96 on the correct ones. Thanks again

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Hmm, very interesting. Shame I am uk based so I couldnt use it but it would be interesting to know how well these work as I am sure there are a lot of americans who would like a decent replacement

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Moonk: Could you A-B it with an orignal PSU, when you´ve completed your MB6582? I´ve still some in stock, if you are ever close to Munich :)

I´d be very interested, if these (inexpensive) switchers are really audible, or if they are of such high switching frequency nowadays, that there won´t be any audible noise...

Greets!

Peter

Edited by Hawkeye

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Moonk: Could you A-B it with an orignal PSU, when you´ve completed your MB6582? I´ve still some in stock, if you are ever close to Munich :)

I´d be very interested, if these (inexpensive) switchers are really audible, or if they are of such high switching frequency nowadays, that there won´t be any audible noise...

Greets!

Peter

hey peter!

i will definitely A/B test it. However, i burnt about 3 pads on one of the pcb's. but i found a kit where you can actually replace the burnt pad with a new one. http://www.circuitspecialists.com/pcbrepairkit.html

I'm currnetly building 3 shruthi1-s so all of my money went into sourcing chips etc, so i will go back to the mb6582 soon as i get paid :)

Edited by moonk

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Hmm, very interesting. Shame I am uk based so I couldnt use it but it would be interesting to know how well these work as I am sure there are a lot of americans who would like a decent replacement

couldn't you get a converter?

i use a euro to us convertor for some of my euro gear.

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@Monk: nice PSU that you found on eGay :sorcerer:

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@Monk: nice PSU that you found on eGay :sorcerer:

yeah yeah :pinch:

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Hi,

since im very happy with my new synth and playing it a lot,

i noticed noise in the audio.

@first i thought it was the fan making noise so i put in a 7805 for the fan and switched her power to j25,

Still the noise stayed readreadread you know

and now i think its the psu.

Well i happen to have an amiga 500 psu readread etc.should be a good alternative.

is it just possible to feed the amiga 12vdc power into the powerplug on the mb6582??

because it get's regulated anyway?

i builded it to words an c64 psu ,

or is it better to build an totally new psu?

Thanx!

ps:(its an heavy 5v/2.5 amp amiga supply so i geuss it linear)

:rolleyes: Hans

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Hi Hans,

It is well possible, that you hear audible switching noise from cheap switching PSUs...

Dunno about the Amiga PSU, but if it has old and unprotected voltage regulators, you have the same risk of frying your SIDs as with an old C64 PSU.

Antix and me have both built a linear-only PSU with a "crowbar" overvoltage protection circuit - it works great and the noise floor is even a bit lower than the original C64 linear PSU:

Cost was below 50€.

Also, orange_hand has built a linear/switcher hybrid, which is very interesting, since it is more power efficient and reportedly silent.

Greets,

Peter

Edited by Hawkeye

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Also, orange_hand has built a linear/switcher hybrid, which is very interesting, since it is more power efficient and reportedly silent.

Greets,

Peter

Any details or links on orange's design? I am always interested in other peoples designs :ahappy:

Edited by Shuriken

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Thnx Peter for the info,

As for the crowbar i made it internal in the mb6582,

Im going to read some more i geuss:)

Btw u make nice music!

peace!

Hans

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I feed 12V dc into my MB6582 where it's supposed to have 9V dc. The voltage goes through the rectifying bridge (loose some voltage) smoothing caps (no change) and finally through regulator (regulated down to 9V). It works fine and doesn't seem to generate much neat (actually I think it generates less heat than the standard 9V ac way). One thing I am thinking about though is if the dc cable is more prone to pick up noise than an ac dito.

Does strophlex means feeding it to the 9v ac input on he connector?

This because it goes thru the rectifier which should make ac dc right?

I just want to be sure before i cut the A500 cable and make it adapt the mb6582 supply socket.

still a bit wierd to make 12v dc /9v dc and the let the mb6582 add 5 v dc to make 12vdc again.

Well Confusing :)

i just dont want to open it up and rewire the mb6582.

maybe i just should go a build a new adaptor.

:rolleyes:

ps:if this is possible i geuss the cap rated 2200pf 16v ,would have a to low voltage rating right,

pff i feel noob now:P

Edited by X11

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