Wellborne Labs PSU Squeezebox 3

[Sol]

I've just order up one:

One kit SB3 PSU Kit with optional IEC connector and detachable AC cable, Black body, Clear (Brushed Aluminium) Front Panel, Black Rear Panel. UK Spec power rating 220V.

The next DIY project

[rickcr42]

Good for you man.

ANY Welborne kit is a bargain in my opinion and would not hesitate to recommend one,no matter what the "it" is (eye balling their walnut amp chassis currently )

[Sol]

Just had confirmation they've got a paypal payment and will have evrything to me by the end of the month!

Seem like good guys base don the emai lexchaneg I've had - certainly feels like good customer service so far!

[Sol]

The PSU arrived, I built it, it works. It works fabulously well. I'm dumbfounded how well it works!

One problem! The transformer is noisy. Dialogue with Ron at Wellborne has confirmed what he's had a batch of dodgy transformers, and that they've now re-designed the board to accomodate a new transformer with a different foot print. Not able to swop out the transformer as he has none, so - he's offered that if I send him the old populated board he'll swop it out with the new one, parts to populate it, and a new transformer.

I have to send the old board back ... which pisses me off, as it's additional cost - I understand he wants to confirm the board is noisy, and he says that he can find a use for some of the parts!

Ahh well .. I'm shouldn't complain - he's a small specialised shop - in for a penny, in for a pound. At least I know the damn thing works well (apart from the buzzzzhummmm of the dodgy transformer) - and to be honest I'm not looking forward to going back to the wallwart in the interim!

[Sol]

sol said:

The PSU arrived, I built it, it works. It works fabulously well. I'm dumbfounded how well it works!

One problem! The transformer is noisy. Dialogue with Ron at Wellborne has confirmed what he's had a batch of dodgy transformers, and that they've now re-designed the board to accomodate a new transformer with a different foot print. Not able to swop out the transformer as he has none, so - he's offered that if I send him the old populated board he'll swop it out with the new one, parts to populate it, and a new transformer.

I have to send the old board back ... which pisses me off, as it's additional cost - I understand he wants to confirm the board is noisy, and he says that he can find a use for some of the parts!

Ahh well .. I'm shouldn't complain - he's a small specialised shop - in for a penny, in for a pound. At least I know the damn thing works well (apart from the buzzzzhummmm of the dodgy transformer) - and to be honest I'm not looking forward to going back to the wallwart in the interim!

Gawd damn it ... I've put up with the slight buzzing, and less than one year later the PSU has started putting out 8.5 Volts instead of 5 Volts! It did it some time ago, and I reflowed some solder into the joints and that seemed to cure it, but it's back again!

Anyone any ideas why it would suddenly work perfectly .. only at the wrong voltage? A simple on board failure or something more substantially wrong?

Here's some pictures of the board!

Top
Bottom

[leo]

Somethings not right there at all Sol! seems like bad joints around the regulator probably the resistors for setting the voltage.

How hot does the heatsink get when used wit the SB3?

With the buzzing I bet one of the laminations are loose

[Sol]

I figure its around the regulator ... the two resistors around there seem to come together - the soldering under the board there is tight, and I'm unsure whether they all should be separate or not. They are so tight, and look to be on the same track I soldered over the junction, thinking this may be the problem - however that didn't solve it. I'll have a look at the regulator ... this seems to be the most likely area.

[Deleted]

Sol
Irrespective,replace that 5V regulator,and under no cirtcumstances run at that voltage any longer than it takes to measure the voltage out.Better still, try to isolate from the load
until voltage is checked out O.K.

SandyK

[Sol]

sandyk said:

Sol
Irrespective,replace that 5V regulator,and under no cirtcumstances run at that voltage any longer than it takes to measure the voltage out.Better still, try to isolate from the load
until voltage is checked out O.K.

Will do .. thanks for the steer. I assume the regulator will have a part number stamped on it so I can go and buy one from Maplins?

So first job is run it under power ... feel regulator to see it it warms.
If it stays cool replace .. if it warms up ...it points to some other complication like a short on the resistors or somesuch?

[Deleted]

Sol
The regulator may be short circuit. It is most likely a readily obtainable (cheap!) 7805.
If it is something like a LM317T, it could also be the voltage setting resistors also, as Leo suggested .
Alex

[leo]

What value resistors are they Sol? if it uses an adjustable reg then we can tell you which resistor should go where etc.
Whats the input voltage to the reg? as Alex mentioned it could have gone short, the SB3's can need up to just over 1amp so hopefully if its using an adjustable reg they fitted a LM1084

[leo]

Just had a look at your top view piccy again and it seems the traffo has 6.3v AC secondaries? that would give just under 9v DC unloaded

[Sol]

leo said:

Just had a look at your top view piccy again and it seems the traffo has 6.3v AC secondaries? that would give just under 9v DC unloaded

Which is what I measure ... just about to have a look again so will be back ...

I guess that means there's a short around the rectifier?

[Deleted]

Sol
More likely a s/c around the regulator I.C.
Alex

[Sol]

The rectifier says LD1084V but it's rather hard to read with my super long-sight!!

It was running compleetely cool so it's now off the board ... if it wasn't dead it is dead now ;o)

So where does one get one from as a single unit

[leo]

the 1084 is the regulator, basically the LM1084, wasn't a bad guess eh
The normal ones are LM317T which can handle about 1amp, the LM1084 can do about 5amp
We need to be sure it is actually an adjustable one rather than a fixed 5v as the 1084 types are marked the same, going by the resistors in that supply I'd say it is an adjustable one

Farnell part number 7610087 sometimes these regs come on ebay , none on there at the moment though as I've just checked

uk.farnell.com/jsp/Semiconductors/power+control/NATIONAL+SEMICONDUCTOR/LM1084IT-ADJ/displayProduct.jsp?sku=7610087

[Sol]

Thanks Leo .. perfect.

Can anyone remind me of the regulators in the X-CAN V3 ... I'll order some of those while I'm on, as my X-CAN V3 needs some TLC as well.

... while I'm on (sorry for the barrage) any tips on removing the pin ends left in the through hole after I removed the regulator from the PSU? I'm guessing some heat, and a suction pump. It looks like I've lifted a pad on my first attempt at removing the damned regulator I should be banned from using a soldering iron.

[Deleted]

Sol
Voltage regulators, if properly heatsinked, are normally very reliable devices.
I like "Gootwick" desoldering braid for cleaning up PCB holes etc. It is worthwhile paying a little extra for the much higher quality treated braid. The wider version is best for normal work, and the less wide version for I.C.s
Alex

[Sol]

sandyk said:

Sol
Voltage regulators, if properly heatsinked, are normally very reliable devices.
I like "Gootwick" desoldering braid for cleaning up PCB holes etc. It is worthwhile paying a little extra for the much higher quality treated braid. The wider version is best for normal work, and the less wide version for I.C.s
Alex

My X-CAN V3 killed a one of the three - "Tip15"? My memory isn't what it once was ... Mike repaired mine, I rolled in some tubes (which proved to be dodgy) and kille dit again! Most annoying - I'm assuming it the same fault thet developed last time that Mie repaired. It's been out of action for a few months now .. and Mike was going to have another look for me once he got over the hump of orders he'd had on the Pinkie - though we never got organised, and I'm loath to ask him right now, or when he's back from hospital, for obvious reasons.

So I figured (for the little money they cost) if I need one for the Wellborne PSU I may as well buy a regulator for the X-CAN V3 as well - spreads the cost of the P&P!

[Deleted]

Sol
I was referring to normal I.C. voltage regulators which have built in overload protection. Discrete voltage regulators usually don't have too much protection designed in their circuitry.
Internal valve "flashovers" may sometimes kill transistors when used as voltage regulators. Short of a circuit redesign, it is very hard to protect power transistors when used in this mode, from "rogue" valves. A few spare TIP devices probably wouldn't go astray as you suggested.
Alex

[leo]

Be worth adding fresh solder to those stuck legs and try desoldering again, once the old solder has been heated a few times it goes manky with less flux so can be much harder to remove, I find a bit of fresh solder usually makes it easier.

I don't know the X-can V3 circuit but it sounds like it uses darlington transistors if they are marked as TIP***
Did Mike mention the TIP number in any of his posts?

[Sol]

leo said:

Be worth adding fresh solder to those stuck legs and try desoldering again, once the old solder has been heated a few times it goes manky with less flux so can be much harder to remove, I find a bit of fresh solder usually makes it easier.

Nice tip thanks

I don't know the X-can V3 circuit but it sounds like it uses darlington transistors if they are marked as TIP***
Did Mike mention the TIP number in any of his posts?

I'll have a search ... ISTR a post where he mentioned it - had a quick look, but could find it. He'd suggested a change from the standard to these TIP#### as an easy available find. Best bet is I open up the X-CAN V3 tonight and go from there - they should be numbered. I can satisfy myself that they remain cold.

[Sol]

Well she's finally fixed ... Leo managed (quite simply it appears) to spot some damage (my ham fists again) and she's up and running again!

Jeesh, you don't realise what you are missing until you've lost it, and it comes back. The bass is smuch better controlled, the highs are sweeter, and the music is room filling at normal volumes.

Leo ... thanks so much for your efforts .. if I can ever return a favour just ask .. it would be my pleasure.

So 'back in Audio Heaven [1] again'

[1] relatively obviously ... and I'm off to read more on whhat can be done with a Squeezebox ... while I don't mind swopping vinyl ... CD is no replacement for the instant select of the SB3

[Sol]

Apr 30, 2008 0:28:54 GMT mrarroyo said:

Sol, is the unit you bought ... www.welbornelabs.com/squeeze.htm

Indeed it is ... though if you are thinking about it .. it was way too much money, and Leo is currenlty investigating an alternative that sits between the SMPS and apparently provides lots of benefits.

If you wantt o replace the SMPS with linear then you need a linear PSU with a 5V output and a 2A capability. I'm sure there's a kits about on the web that offer a linear PSU with 5V 2A!

If you have a SB3 and are using the digital out, there's also stuff tha tcan be done with digital output (Red Wine offer a service) again it's expensive, and I've not tried - and I suspect that the SB3 would be beyond my hamfistedness even with a paint it by numbers explanation to go the DIY route.

[leo]

Glad it arrived ok