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crimson Elektrik 610 Preamp 520 Power Amp schematics?

neiljadman

neiljadman

Senior Member
Does anyone have them available? I just pick up a 610 and a 520 power amp. I've always wanted to hear some Crimson amps and the prices were right. I need to build a power supply for the 610 so need voltage and polarity info at the least. The 610 battery harness is missing so I intend to build a small CRCRCR supply and a couple of TeddyRegs to power it.

Thanks

Neil
 
A friend of mine has some of these. He put them back to someone in the know for a PSU as you are describing Neil and other mods. I think it was possibly a designer or original manufacturer of the actual amps, it certainly cost him a few quid!

Whether you can find them and ask for a schematic I'm not sure.

Nice design though!
 
As the original designer of the 610 circuit board I suppose I ought to be able to remember more than I can!, but I can tell you that the original psu was a board with + and - 9v nicad batteries. The board can also be powered with a greater voltage, but should be current limited as there are shunt regulators on board.
Seem to remember the alternative psu was to use + and - 12v with 100R limiting resistors.
I could ask my brother who currently fixes them, but it will only make his head bigger!
The pinouts for the polarity i cannot recall but it is easy enough to work out... follow the tracks with the smoothing caps to ground from the cathodes of the TL431's to the edge connector.
CJ
 
I was responsible for all the circuit topologies for Crimson and on the 610 PCB Clive Powell did the track layout.

The early 610s had a PCB marked "610/35-B" and was on a blue substrate. The tracks lift easily when heated unfortunately. The circuit does not have massive power supply rejection due to it being generally battery powered. Sometimes the power supply and signals were carried via a 5 PIN 180 deg DIN cable from the stereo power amp. There were dropper resistors of value 680R which fed the on-board zeners D5,D6 12Volt with about 30 mA (less 10 mA for the active parts of the circuit).

Later 610s had a PCB marked "Crimson CPR2" which had TL431 shunt regulators on board with a total current feed of 20-30 mA. The regulators were set to between 10 to 15 volts according to when the PCBs were made.

All the 610 PCBs had this pinout:-

Pin 1 Left disc output
Pin 2 VCcc+
Pin 3 Vcc-
Pin 4 Left disc input
Pin 5 Right disc input
Pin 6 disc stage ground
Pin 7 Right disc output
Pin 8 Line stage output right
Pin 9 Balance pot right channel
Pin 10 line stage in right from volume pot slider
Pin 11 Line stage ground
Pin 12 Line stage in left from volume pot slider
Pin 13 Balance pot left channel
Pin 14 Line stage output left

Voume pots were all 47(50) K log dual. Balance pots were single gang and were 1k linear.

I have been working on the original "610/35-B" schematic and when I have it in electronic form, I shall be adding it to my webspace
http://homepage.ntlworld.com/bepowell/schematics/

Mail me on [email protected] for any specific information.

Brian Powell
 
Thanks Brian, I will open her up this weekend to see - she's been sitting on the shelf awaiting attention for the last year - this may be just the prod I need to undertake the restoration.
 
bepowell said:
Sometimes the power supply and signals were carried via a 5 PIN 180 deg DIN cable from the stereo power amp.
Click to expand...

That would explain a lot - mine appears to be one of these. The signal leads are disconnected from the DIN pins 3 & 5, and there are three candy stripe wires connected to pins 2, 4 and 3, I'd hazard a guess that pin 3 is 0v, but I'm having trouble tracing the connections through the amp.
 
Hi just use a continuity checker to find which wire goes to pin 2 on the PCB (+ve) and so on. The switch will need to be in the "on" position. I seem to remember the centre pin being 0 Volts. The supply line rejection ratio is not that great (batteries being the preferred PSU option) so a quiet supply is important, particularly on disc. I would not try to use the on-board zeners they are noisy and the slope resistance is not that good.You could feed the PSU in via the DIN and use the phonos a signal inputs.
 
Finally getting around to resurrecting this pair.

520 Power Amp
A quick re-wire of the trafo and she's set for 120v...bring her up on a variac and she's singing sweetly. I've been running it for a couple of weeks now with no issues, so a quick recap will be all that is in order.

610 Preamp
  • I bodged together a suitable 15-0-15 volt power supply with a small trafo, a hacker generic power board and a couple of TeddyRegs set to +/- 15v. Wired up an old DIN lead and fired her up - nothing - except the regs started to melt down
  • After cooling, disconnected the board header and checked the voltage at the pins - all good.
  • Extracted the board and she's gonna get a recap anyway but D5 & D6 are both shorted -shorting the power rails to 0V - so I'll rebuild without them - don't need them anyway.
Hopefully that'll see her working again.
 
So spent the afternoon listening the the pair. The preamp board was fine bar the Zeners, so wit the regulated PS they are not needed anyway, so she's running at +/- 15v off the TeddyRegs. I also made the recommended mods to the high pass filter

All I need to do now us put the power supply in a box and we're done. It'll make a nice little system for one of the kids.
 
I think dropbox has changed, anyone can view via the above link on my Sept 17 post.
"You can share files with anyone, even non-Dropbox users, by getting a link to any file or folder. Once you get the link, you can send it by email, Facebook, Twitter, instant message, social networks, wherever you want. You can share these links with anyone, even if they don't have a Dropbox account."
There are schematics for the preamp PCBs as well as many others.
Let me know if the link does not work.
 
Looks like the Dropbox area doesn't exist anymore after following the link.

Would be great to have it available as at some point my Crimson Pre and Power will be brought out of hibernation and I'm guessing will need a bit of work!
 
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