WD/WAD PSU PHONO II Choke upgrade

[bob orbell]

Well I am very pleased that a lot of you have said that the choke change has improved the sound, or shall we say changed the sound, I did find a difference, but with some music the sound became too forward and too boomy, so my conclusion was that the choke was not for me, however the two separate power supply's has really pushed my kit to top end sound, if you guy's get the opportunity to try a second PSU, give it a go, you may be knocking on Matthew's door. BOB

[John Caswell]

Hi all,
I would be very interested if members could attempt to tell me why changing or not this choke has "improved/changed/made better/made worse" the sound

John

[pre65]

Can't answer specifically John, but ever since I've been interested in valve amps the saying "bigger and better iron pays dividends" has prevailed, so perhaps a better quality choke with more henries is smoothing the ripple more ?

I know from an engineer's point of view everything has a cause, but some of us just accept that something is "better/different" without knowing why.

[david]

Hi John, I'd never thought about changing the PSU3 choke until I read about it on the Forum. Then I noticed I had a couple of Hammond clone Danburys in the parts box. I tried it and the sound is simply more natural, organic, and more solid. Phillip at Bluebell then told me the even larger 194 choke works even better, and I took a punt on this advice. The larger choke gives even more of the same, underlining Phillips' point. I did calculate optimum choke size for my Aikido current draw and it came out exactly at 40H, the rating of the 194.
David

[Richard]

How did you calculate the optimum choke size for your Aikido current draw David?

Doubling the choke size in an LC filter will halve the ripple. So will doubling the cap size.

Soon after building mine I more than doubled the capacitance in my WD3 units and noticed no difference on CD or TT but I wasn't expecting one, just filling the empty spaces on the pcb!

[david]

Hi Rich,
I used a Web based psu optimiser to do the calculation. Whilst doubling the choke size or capacitance can halve the ripple, the effect on SQ may be very different due to the tuned nature of a choke input psu.

Bearded Fiddler and I are experimenting with Shunt regulated valve psus at the moment and comparing these with different sized chokes with varying amounts of capacitance. Whilst we are a long way from conclusions, there appear to be clear differences in sound and improvements depending on the chosen combination.

At the moment I'm using the big Hammond 194 40H in PSU3, then a small hammond clone choke in my Pre case before the psu rail splits into an CRC network for each channel of the Aikido pre.

I working towards a dual mono psu, when I have some time.
David

[Richard]

Hi David, WD supply is capacitor input. Why would you want choke input?

[david]

Loose terminology, now corrected!

[colin.hepburn]

Originally Posted by Richard

Hi David, WD supply is capacitor input. Why would you want choke input?

Hi All
Well I seem to have started up a bit of a debate regarding this Hammond Choke upgrade
All I wanted to do was pass it on for the others to try, you did, and it seems you all agree with my findings Apart from BOB

I do not have the noialage on this other than the doubling of the choke and or capacitances halves the ripple
However, I have also read somewhere than some prefer the sound of a choke to capacitors i.e. more choke less caps And Richards Question why choke input

Is it not suppose to be even better than cap input I may even consider tying Choke input at some stage with the WD PSU II /Phono II and CF Pre

PS I do also recall when I rebuild the Bigger PSU for my J.E Labs Power amp I added a second choke of same Values and the sound was is bigger wider just like with the WD Psu with this combo the band is placed more in the room than before

[pre65]

Originally Posted by Richard

Hi David, WD supply is capacitor input. Why would you want choke input?

If you have the right transformer then surely choke input is preferable sound wise ?