Phono II advice Please!

[bob orbell]

To many people change things like coupling capacitors, valve etc, and ignore the power supply, the power supply is very important to the sound of any system and sadly is taken for granted, any amplifier, phono stage etc needs the best clean power supply to give of its best, the amplifier is simply a modulator and the best designed amplifier with a poor power supply will sound ****. The change to non inductive resistors in the power supply will improve small detail sound and you may even hear things that you have never herd before, try the Mills, you should be quite surprised, and even better low ESR capacitors will improve things. Bob

[Lyndon Johnson]

Thanks Bob , I'll give that a go. It's cheaper than paper-in-oil capacitors!

[Lyndon Johnson]

I have fitted the Mills resistors at R1 and R6 in my PSU II and reckon I can hear a subtle improvement in sound staging and smoothness in the details.

I'm keen to keep working on the power supply and read elsewhere on the forum that a 30H choke was a good upgrade. Is that still the view and does anyone know of a UK supplier? I have found USA suppliers but was hoping to avoid the higher delivery charges.

[bob orbell]

I think the supplier of the choke in question is in Scotland, PM Colin Hepburn (moderator) he should have the details, I did the choke mod but found no improvement, others have, the Phono on its own draws very little current about 10 mA I think, so the choke may not be doing much or any work, also better capacitors (low ESR type) improve further, if you are only using Phono you only need C1-2-4, keep the values the same, you could even try bypassing these three capacitors with smaller values such as 10 uF and 100nF, soldered underneath the board, all rated at the same voltage. Bob

[colin.hepburn]

Hi Lyndon
Yes I did the choke mod first then posted it up here for the others. I found it made big difference to the sound staging but as I have said before I am using the older WAD CF conversion.

I got from bob and my WAD Phono II with my single ended JE labs 6SL7/KT66 and back loaded Horns so the amp and speaker may have contributed the differences I hear but I like it

Here is the choke details model 157G 30H @ 40ma 595R if you want to try it for yourself hears the link to Philips site http://www.bluebellaudio.com/
Hope this helps
Colin

[Lyndon Johnson]

Great, thanks both of you. I will get the choke ordered.

I'm keen to change the capacitors too but again would appreciate a steer in terms of where to go. I can se Evox Rifa PEH169 advertised as low ESR types but can't find them in my value (100uF). 220uF seems to be the lowest.

Lyndon

[bob orbell]

RS Components, part no. 174-0522 you can only buy min. of 2, £5.21 each. I think they may be what Matthew now supply's. Bob

[Phil Y]

Hi Lyndon,

A couple of us have recently had good results with Mundorf Mlytic caps in PSU positions.
They might be worth a look.

http://www.world-designs.co.uk/forum...ead.php?t=7785

Phil.

[Greg.]

Yes, having used both Rifa and Mundorf mylitics, I’d pay the extra and get the mylitics. I found the choke benificial sound wise. Philip Ramsey sells Hammond chokes. You can buy direct from Hammond (just google) but I would check postage. Philip might be cheapest.

[bob orbell]

The capacitors that I mentioned from RS are Vishay, the data sheet says ESR is 1.12 ohms, now this is low and important, do we know the data of the Mundorf ? Bob