Need upgrade to this PS

[glen]

I am getting a little buzz playing a silence track on this tube DAC. It has a 6DJ8 SRPP buffer.

I am upgrading the 100uF and 47 uF to Jensen 2 pole caps.

I am also considering replacing R35 of the CRC with a Hammond 10H choke. Would this help with the buzz even though it is before the mofset ?
How can I be sure the 10H hammond is the correct size? I have seen anecdoctal reports that it works, but

[Brik]

R35 is rated 1W at 150 ohms.

Maximum Power = 1.0 watt = V*I = (R*I)*I = R*I*I

Maximum Current = I = SQRT(1.0 watt/150 ohms) ~= 80mA

So, any choke with current rating greater than 80mA with DC resistance around 150 ohms will do.

A quick look at Hammond products yields the following candidates:

156L : 5H, 75ma, 135 ohms, 400VDC
159P : 10H, 125ma, 155 ohms, 500VDC
193B : 12H, 100ma, 155 ohms, 600VDC

/b

[glen]

Thankyou.


In your opinion will a choke in a supply like this (mofset) give an improvement ?

[Brik]

Hi,

Since the MOSFETs in this PS appear to be used as voltage controlled on-off switches (slow charging through the 2M resistor of the C63
capacitor that controls the gate causes delayed turn-on while the Zener Z3 makes sure that the gate-source voltage stays within spec),
they probably contribute little to ripple rejection once the PS achieves stability.

So, I expect using a choke will make a difference. How much difference, I don't know... Yellow_Light_Colorz_PDT_14

/b

[glen]

Brick thanks for the help, I am going to try the choke .