Oracle Delphi MK II Mods - diyAudio
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Old 4th August 2014, 07:32 AM   #1
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Default Oracle Delphi MK II Mods

I have been modding my Oracle Delphi Mk II for years. I while ago I modded the control electronics, the motor mount and the bearing. BTW, the Oracle bearing system is not new. It has been used in optics for precise laser mirror rotation. There is a patent for it 6 point bearing system.

I am going to redo the sub-chassis so I will share this info later.

I will start with the power supply. I have the most current, but non turbo supply. The exorcise was to fit a supply in the same box because I think it looks cool.

I had a lab style supply laid out, but then found an Acopian supply on eBay for 40 bucks. I went with the Acopian and added a filtered power entry module, design a PCB for a DC blocker which would fit the block and finally a ground loop breaker for which I added a perf board for the resistor and capacitor.

Next I plan to replace the local regulator with one using the new TPS7A4701. It's specs look really good, especially in the low frequencies compared to the LM317 used.

I do have schematics of the original electronics and my modded ones if anyone is interests. They were made by tracing out the old PCB's.

one more thing, I will be replacing the caps and resistors on the motor PCB. There is a schematic out in the internets GS 38.09 Ver 02. It is more extensive than the Ver 01 which I have. If anyone has experience with the difference and can give some pointers, it would be great.

The following PSU will be running between 27.04 and 28 Volts. The GC 38.09 is spec't for 27 +/- 20%. Steady state current draw is 45 mA, transient is 240 mA. The light bulbs and LED suck up less than 100 mA more. The Acopian I a using can provide 1/2 Amp.

Last edited by canyoncruz; 4th August 2014 at 08:29 AM.
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Old 4th August 2014, 07:41 AM   #2
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I laid out the parts in solidworks so I could place all the components and they would fit. This mechanical layout was also used to determining the size of the DC blocker PCB.

mod to the box are as follows:

1) Punching out the three weldnuts for the old PCB mounting

2) Drilling 8 through holes for the Acopian and DC blocker

3) in the area of one of the cable entries, a cut out for the IEC was made

4) In the area of the Fuse holder (the center hole) a spot face was made for chassis ground contact.

Machining time was about an hour. this would mean a cost for $60 to $85 depending on your machinist.



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Old 4th August 2014, 07:52 AM   #3
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First I assembled the DC blocker. It also has a small bridge, cap and resistor to drive the LED. I didn't want to have its wires traverse across the box.

The PCB was $33 (x a minimum of 4) plus tax and shipping. The components were another $20 or so.



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Old 4th August 2014, 07:54 AM   #4
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Next a connector was added to the LED and plugged in.

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Old 4th August 2014, 07:57 AM   #5
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Next the wire with spade connectors for the DC blocker were measured, assembled and added.

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Old 4th August 2014, 08:00 AM   #6
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next the wired for the ground loop breaker were cut and assembled, using lug connectors along with the perf board foe the resistor and capacitor.


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Old 4th August 2014, 08:03 AM   #7
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Using aluminum hardware, the ground loop breaker and IEC were attached. These have to go in together because of the short power entry ground wire. The aluminum hardware serves to canct as chassis ground point and also the home the bridge rectifier. The screw has a large flange for good contact.




Last edited by canyoncruz; 4th August 2014 at 08:09 AM.
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Old 4th August 2014, 08:08 AM   #8
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Finally the Acopian was attached along with the Ac in from the DC blocker, the ground loop breaker and the DC out cable, which is the same one that came with the original box. it is foil and wire grounded and this was tied to the case. There is no continuity at the phono connector end.




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Old 4th August 2014, 08:11 AM   #9
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I will be running a few tests at work after I enlist the help of one of our test engineers. Will post the results.
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Old 4th August 2014, 08:14 AM   #10
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Here are pictures of my Delphi MK II with the current round of Mods. As mentioned, the sub-chassis is next.




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