The Incredible Technics SP-10 Thread

This is very odd. You are clearly a skilled man with very good test equipment. And I love the video of you in your signature.

I use these Kenwood PSU's that I bought new/surplus maybe 15 years ago ? click here And also in the SP-10 PSU that I sell I use LM317HVT for both the 5.0V and 32.5V BUT expect about 1.0A peak when starting up on the 32.5V line.

On your bench PSU have a look at the output voltage with a scope on start up and whist it's not performing properly, this should giver you the clue ?

Let me know before we go any further ?
 
Never heard of it...

*Applies a bit of Google*
*Reads Datasheet*

Fantastic!! I had no idea there was such a device. I'll use it. :)

Here's the datasheet for those interested - http://www.supertex.com/pdf/datasheets/LR8.pdf

Hi Tim, you are most welcome !

I haven't seen it used in DIY either, but at 69 cents and as Mouser have over 8,000 in stock, it's a no-brainer for lots of applications, including -ve bias of grids ?

Dave
 
I, too, have an SP10-MkIIa, purchased off eBay years ago, and have had it in the closet since. Supposedly it doesn't run at the right speed -- yet to be diagnosed. Looking at the power supply schematic this week (inspired by this thread) I noticed that there is connection from the 5V regulator's output to the 32V regulator (TR410, R419, etc.). The VinylEngine schematic is too fuzzy to read, but I believe this may be a hold-off circuit that prevents the 32V from powering up until the 5V supply is up. I haven't gone beyond this, but it may be that incorrect sequencing prevents the rest of the electronics from working correctly.
 
there is connection from the 5V regulator's output to the 32V regulator (TR410, R419, etc.). this may be a hold-off circuit that prevents the 32V from powering up until the 5V supply is up. .

Well spotted ! That is what it would do. And only on the "A" version which I have never actually seen.................
 
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Ops ! You are right, sorry !!

I have checked all versions too, this is the BBC one, but they all have the same start sequence. My mistake.

sp10psumkii.jpg
 
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