NEW GIESELER ENHANCED PSU
Well I thought it was time to re look at my PSU range. The current range IMHO is still competitive & up to date with current tech but I did think the Gold Tune Enhanced version could be improved a bit in terms of sound & more competitive pricing. It was a bit of a struggle to hear a sound difference between say the Gold Tune & Gold Tune Enhanced versions so the $100 price jump was not really justified.
So far all my PSU’s use high quality/low noise LDO (low drop out) monolithic regulators. This is the area where the most development is happening with new regulators. Now looking critically at LDO regulators they do have one aspect that is not the best for audio quality – output impedance. To minimise the voltage drop all LDO regulators run the regulators series device (Mosfet or Transistor) in a common base arrangement, that is the collector (or drain) is the output. This gives the lowest voltage drop but also has high output impedance which is not good for a PSU. This new enhanced PSU is running the series device (Transistor) in “Emitter Follower Mode”. This gives very low output impedance but it needs more voltage at the input due to the bigger voltage drop across the transistor. Also there has been talk on some UK forums that the usual monolithic regulators using lots of negative feedback do tend rob the sound/music a bit.
In light of all of this I have come up new design using all discrete components & the pass transistor is now running in “Emitter Follower” mode hence nice low output impedance. Also it is a non feedback design based on a very low noise red LED string voltage reference being fed with a constant current source. The raw DC front end of the design is the same as the Kraftwerk Gold Tune which is well optimised IMHO. It does not have the thermal cut-out, short circuit protection & huge 4 Amp rating of my other designs but these options are not normally required when running Klein/Gross/Fein DAC’s which only draw a few hundred milliamps.
Does it actually sound any better? Well I have only done a few brief comparisons against a standard Kraftwerk PSU & it definitely sounds better than that. After Christmas I will try some critical comparison with the Gold Tune version & old Enhanced versions & report back.
The current rating is 2A & so plenty for Klein III/Gross/Fein DAC’s. Also with the Gross/Fein DAC’s it is best to use the 16v 2.5A transformer (in photos) as they draw more current. The Klein III will work fine with the usual 12v transformer. The 16v transformer has another nice option which a direct mains earth connection so when using this PSU negative side is now at mains earth. John Swenson of Uptone Audio fame is a big fan of having a PSU negative output connected to mains ground.
Well there are few SNA’s members who are already using this PSU so maybe they can add some comments. Due to the massive amount of Nichicon Gold Tune capacitors the red LED’s run for quite a while after the PSU is switched off – see photos.
They are currently in stock & the cost is $500 including shipping.