pvision

MOOG MKPE 3-band parametric equaliser power supply
« on: April 16, 2018, 12:16:37 PM »
Looking for a schematic for the power supply in a MOOG Equaliser. There are plenty of schematics for the EQ but I haven't located one for the PSU yet

I am chasing a fault with the PSU. I have recapped it and created a fault then exacerbated it by shorting two pins of the TIP30 whilst probing the PSU

The PSU uses a TIP30 / TIP29 combination with a handful of resistors and a 14-pin DIP chip marked 1468 or 7717. It's not a PSU design I've seen before

Looking for a schematic, an equivalent for the TIP30 and a clue as to what the IC is

Nick Froome
« Last Edit: April 16, 2018, 12:28:27 PM by pvision »


JohnRoberts

Re: MOOG MKPE 3-band parametric equaliser power supply
« Reply #1 on: April 16, 2018, 03:29:02 PM »
Looking for a schematic for the power supply in a MOOG Equaliser. There are plenty of schematics for the EQ but I haven't located one for the PSU yet

I am chasing a fault with the PSU. I have recapped it and created a fault then exacerbated it by shorting two pins of the TIP30 whilst probing the PSU

The PSU uses a TIP30 / TIP29 combination with a handful of resistors and a 14-pin DIP chip marked 1468 or 7717. It's not a PSU design I've seen before

Looking for a schematic, an equivalent for the TIP30
tip30 probably still available
Quote
and a clue as to what the IC is
7717 is probably a date code (year 1977-week 17)

1468 is some kind of hall effect chip so probably not your PS.

good luck

JR
Quote
Nick Froome
Visit https://circularscience.com to hear what properly "cleared" drums sound like.

pvision

Re: MOOG MKPE 3-band parametric equaliser power supply
« Reply #2 on: April 16, 2018, 03:47:25 PM »
Thanks, John. I'll do my homework and draw out the circuit

Nick Froome

PRR

Re: MOOG MKPE 3-band parametric equaliser power supply
« Reply #3 on: April 17, 2018, 09:41:43 PM »
If this is +/-15V supply, then it is SG / MC 1468 dual tracking regulator:
https://www.silicon-ark.co.uk/datasheets/mc1468r-datasheet-silicon-general.pdf

Those old dual-reg chips were flaky and could be killed. I would just use any generic +/-15V supply.


JohnRoberts

Re: MOOG MKPE 3-band parametric equaliser power supply
« Reply #4 on: April 18, 2018, 09:45:24 AM »
If this is +/-15V supply, then it is SG / MC 1468 dual tracking regulator:
https://www.silicon-ark.co.uk/datasheets/mc1468r-datasheet-silicon-general.pdf

Those old dual-reg chips were flaky and could be killed. I would just use any generic +/-15V supply.
Good find, my searches were unsuccessful.

JR
Visit https://circularscience.com to hear what properly "cleared" drums sound like.

pvision

Re: MOOG MKPE 3-band parametric equaliser power supply
« Reply #5 on: April 18, 2018, 01:38:11 PM »
Brilliant - thanks chaps.

I have traced enough of the circuit to work out the psu has ± regulated and ± unregulated to the main board. My thought was to dump the existing setup and replace it with a generic supply with regulators, so it looks like its the right approach

I'll draw out the psu anyway in the hope it will help someone else in the future!

Nick Froome

pvision

Re: MOOG MKPE 3-band parametric equaliser power supply
« Reply #6 on: January 07, 2019, 07:55:33 PM »
An update on the Moog EQ. Connector pinouts. There is a PSU connector that feeds a loom with a multipin that connects to the audio board. It also has a separate two-pin connector for the front panel bypass switch

multipin on board -----------------------------------------power plug
9 - orange - to bypass switch connector
8 - grey - to bypass footswitch socket
7 - blue - blue power --------------------------------------------5
6 - coax - audio OUT
5 - red - red power ----------------------------------------------4
4 - green - to bypass footswitch socket
3 - black - black power -----------------------------------------2
2 - coax - audio IN
1 - green - to bypass switch connector ---------------------3

More updates later

Re: MOOG MKPE 3-band parametric equaliser power supply
« Reply #7 on: January 12, 2019, 09:57:28 AM »
Thanks for the update.  I have one of these that doesn't turn on so your info is helpful.  Please keep us posted.

pvision

Re: MOOG MKPE 3-band parametric equaliser power supply New
« Reply #8 on: January 13, 2019, 05:19:52 PM »
I finally bit the bullet and finished the new psu. The final piece of info I was looking for was found by reading the schematic again. The +23 Volt supply is just rectified DC straight off the bridge, not regulated in any way. Which means that it's a very ordinary ± 15 supply at its heart

I stripped the old transistors & resistors off the psu pcb and left the diodes & caps. I then fitted - with a bit of lead bending and judicious choice of mounting points - a 7815 & 7915  to existing holes & tracks and fitted two jumpers. I didn't cut any tracks

This meant I could retain the pcb and the multipin connection to the loom. Final parts count was two regs. I had already recapped the psu

Critical to getting this right is the correct orientation of the plug that goes on the main pcb. It's not keyed so it is possible to insert it incorrectly. I didn't make the mistake but could see it was possible

There's a non-standard yellow jumper on the main pcb where I have jumpered out the CMOS switch used for the bypass switch





Nick Froome
« Last Edit: January 13, 2019, 05:23:49 PM by pvision »

 

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