WTB : SMPS for a Linn Classik Media Di

[DonaldStott]

As the Title suggests, I'm looking for a replacement SMPS for a Linn Classik Movie Di.

It looks like this and the only references on the board I can find are 'DESIGN: IW, AW 08/02/02' and 'PCB254/L4' : -

 

[nyatt]

Hi. I have one or two Chakra power supplies that were pulled from perfectly working Linn amps for upgrading to Dynamik power supplies (I used to work at a Linn retailer in the S.F. Bay Area). I will pull them from storage if you are interested. I am in California. They look pretty much like what you have there.

 

[DonaldStott]

Thanks for your response.

I am in the UK (Scotland).

 

[nyatt]

I know I have a couple more somewhere, but I did find this one, that looks a lot like yours. They used these in a number of different amps.

 

[DonaldStott]

Thanks - it does look very similar but of course the PCB numbers are different.

I do know that the SMPS in the Linn Classik Movie Di has this Output Stage: -

The +V and -V are (I believe?) +30V and -30V respectively.

I can't make out clearly the labels associated with the the 8-pin output at the top left of your first picture.

Apologies for all the questions but I don't want to risk anything going BANG!

 

[nyatt]

I can certainly understand your concerns! I don’t see any writing near the 8 pin connector except “To amp board and then P301. Also, this one clearly says “April 08”. As for voltage out, I seem to recall V+/- being higher than 30. We might be at the head-scratching moment…

 

[blucreativo]

Hi,
regarding the dual output voltage it's depend of the amplifier. For example an AV 5125 the output is +-50 volt. From a LINN Chakra 3200 is +- 40 V (more or less). I know that because I have to replace my amp supply on an AV5125. This is very simple to recognize if you see the specifications of the amp on the vice "peack out. voltage"
Ciao
VV

 

[androa76]

Hi, I also look for solution for half a year with no success. If someone can help with schematic to repair it? Linn don*t care about help or support.

 

[DonaldStott]

I can certainly understand your concerns! I don’t see any writing near the 8 pin connector except “To amp board and then P301. Also, this one clearly says “April 08”. As for voltage out, I seem to recall V+/- being higher than 30. We might be at the head-scratching moment…

Thansk nyatt - the corresponding 8 pin connector on my amp board is shown as P700 on the circuit diagram?

As your PSU is 'April 08' and mine is '08/02/02' there will have been a lot of changes and improvements in those six years!

You'll appreciate why I don't want to send +/-40V to my amp board when it's only designed for +/-30V - or am I being over-cautious?

As you say we " ... might be at the head-scratching moment… " and of course Linn will provide no help or support whatsoever! Maybe there is a helpful Linn Retailer on this Forum?

Despite COP26 being held here recently in Glasgow, Linn's approach is still 'If it's broken, then buy a new one' !!!

Hi,
regarding the dual output voltage it's depend of the amplifier. For example an AV 5125 the output is +-50 volt. From a LINN Chakra 3200 is +- 40 V (more or less). I know that because I have to replace my amp supply on an AV5125. This is very simple to recognize if you see the specifications of the amp on the vice "peack out. voltage"
Ciao
VV

Thanks blucreativo - not sure what you mean by 'This is very simple to recognize if you see the specifications of the amp on the vice "peack out. voltage"'

 

[blucreativo]

The PSU of an AMP Linn AV 5125 has a double 50V in output. So, this information it's possible to find in two ways:

1. vith an multimeter directly on the PSU

2. in an indirect way (if the PSU is broked) for example from the specification of the amp. because the "peack output voltage" is ugual or minor of the DC voltage in output from the PSU. From AV 5125 you find:

and 46 Volt is indicative of the output (50 Volt).
Ciao
VV

 

[DonaldStott]

Thanks blucreativo - as the PSU is broken I cannot measure the output voltages directly using my multi-meter.

I note your comment about the Peak Output Voltage for the AV5125 but what I need to know is the internal voltages from the SMPS to the main amp board via the 8 pin connector - this detail is not listed in any public Linn documents for the Linn Classik Movie Di.

https://docs.linn.co.uk/wiki/images/c/c7/Cms_Di_info_rev0.pdf
What would be ideal would be is if someone that has a working Linn Classik Movie Di could measure the output voltages from the SMPS using a multi-meter.

@nyatt - don't know if you are able to measure the output voltages from the SMPS you have?

 

[nyatt]

OK, I wired 2 of these units up. The first PS is the first unit I did pictureS of. Obviously, this is not a 30/30V unit,but closer to 50/50V. The second unit has essentially the same V out. They clearly work, but Donald, I don’t have a +30/-30V unit.

 

[androa76]

+-50V is to high because lm3886 (lm4780) one of them don"t remember now, is on output. I think around +-30 is much closer to what we search.

 

[blucreativo]

....for my curiosity what is the purpose of the signal "DEAMAND"?

 

[nyatt]

I found that it is like a switch. Applying +5V turns the amp on. I don’t have the technical knowledge to know exactly how, but empirically testing and checking voltages in working units over a decade ago gave me the guidelines to make these work outside of a LINN amp.

 

[blucreativo]

@nyatt would you sell your power supplies Linn in IItaly?

 

[nyatt]

Hi Blucreativo. I would be happy to sell you a power supply, but I am not sure how much shipping charges will be.

 

[blucreativo]

Hello nyatt. Please check the delivery cost and tell me the total cost for the 2 PSU. Is it possibile to pay with PayPal ?
ciao

 

[DonaldStott]

+-50V is to high because lm3886 (lm4780) one of them don"t remember now, is on output. I think around +-30 is much closer to what we search.

To what extent will the DEMAND circuitry 'control' the output voltage?

I know a little about how an SMPS works but as usual my limited knowledge is a dangerous thing!

@nyatt - Message Sent.

 

[rynoshark]

My AV5125 is having hard time turning on these days, I'm wondering if this might be the PS or something else. Every once in a while I can get it to power up, but usually the blue light flickers and then goes out. Any ideas?