Oracle DIY DC power supply upgrade

[Gaucho]

I have constructed a power supply for my Delphi MKII. The new power supply resulted in better sound stage depth, sharper focus and deeper more powerfull bass. The difference in bass can be felt as well as heard!

The supply as I built it is just a slight rework of Mr. Pass's BOZ powersupply. I used a single Avel-Lindberg D4007 (30VA) transformer with the secondaries in parrallel to give full capacity at 30 volts AC. Refering to the BOZ PS schematic I used three 9.1 volt zener diodes plus a (green) 2.1 volt LED to replace the six 10 volt zener diodes to create a new reference voltage of 29.4 volts. For C2 I used 220uF instead of 100uF. I used 1.5K for R1. I removed R2,R3 and C4 from the circuit. For Q1 I used a D718.

Under load the new supply is with in a tenth of a volt of the stock Oracle supply which BTW meaures higher then its rated 27 volts. I strobed the table and both supplies run at the same speed.

I first built the supply at a little lower voltage with just the three 9.1 volt zeners and no LED and although I could still get the correct speed just by adjusting the pitch contol on the table the sound was worse than the stock supply. What the h*ll?

Warm regards,
Gaucho

[Bill Fitzpatrick]

Originally posted by Gaucho
I have constructed a power supply for my Delphi MKII. The new power supply resulted in better sound stage depth, sharper focus and deeper more powerfull bass. The difference in bass can be felt as well as heard!

Color me a skeptic.

[Daniel-A]

your new power supplu is better than witch one from oracle, regular or turbo?
Daniel

[Gaucho]

The new supply performs better than the stock MkII DC supply. The MkV motor is a synchronous type and thus requires an AC supply.

I ordered some of the upgrades from Oracle and will report any improvements. I am getting the acrylic hard mat, suspension upgrade, MkV clamp and replacing the acrylic arm board with the newer type.

Cheers,
Gaucho