Paul R
pfm Member
The original Linn Brilliant is housed in a transformer sized cylindrical aluminium extrusion. The one in my Numerik failed a year or so ago so I put it back in its box in the loft and forgot about it, using a Karik by itself as a rather fine CD source.
On the basis that my Karik was likely to fail sooner or later (it's subtly hinting...) this week I dug the Numerik out and took a look. If I could fix this then there is a chance that the Karik can be maintained, if not nothing is lost. Anyway,
This is what is inside the cylinder,
which opens up to,
and
The mains enters from the left, is filtered, rectified and smoothed. The chip is an automatic voltage sensor/selector. On 230vac the rectifier is configured conventionally and the two reservoir caps are in series. On 110vac the rectifier/caps are configured to voltage double, leading to about the same voltage on the reservoirs.
The left of the right board is the switcher, the controller chip on the other side of the board, the central yellow component a transformer, the right just contains a couple of rectifiers and some inductive filtration. There is no obvious regulation or output smoothing. Which makes sense given the conventional power supply arrangements remain in the Numerik.
David Ellwood had recommended a recap and new MOSFETs. So I ordered some bits from Farnell. Of the caps that came out only one was out of spec. The recapped boards came back to life, I've left the original MOSFETs in place for the moment. Time will tell whether we have a true fix or not but the reinstated Numerik certainly sounds OK.
FWIW if you have to ask, don't open an SMPS, and definitely don't apply mains to the open unit.
Paul
On the basis that my Karik was likely to fail sooner or later (it's subtly hinting...) this week I dug the Numerik out and took a look. If I could fix this then there is a chance that the Karik can be maintained, if not nothing is lost. Anyway,
This is what is inside the cylinder,
which opens up to,
and
The mains enters from the left, is filtered, rectified and smoothed. The chip is an automatic voltage sensor/selector. On 230vac the rectifier is configured conventionally and the two reservoir caps are in series. On 110vac the rectifier/caps are configured to voltage double, leading to about the same voltage on the reservoirs.
The left of the right board is the switcher, the controller chip on the other side of the board, the central yellow component a transformer, the right just contains a couple of rectifiers and some inductive filtration. There is no obvious regulation or output smoothing. Which makes sense given the conventional power supply arrangements remain in the Numerik.
David Ellwood had recommended a recap and new MOSFETs. So I ordered some bits from Farnell. Of the caps that came out only one was out of spec. The recapped boards came back to life, I've left the original MOSFETs in place for the moment. Time will tell whether we have a true fix or not but the reinstated Numerik certainly sounds OK.
FWIW if you have to ask, don't open an SMPS, and definitely don't apply mains to the open unit.
Paul