Phono II Tweaks - a summary -

[LSfarzo]

Hi,
I was looking around on the forum and on the net as I would tweak my Phono II. I tweaked my kat 6550 and I had amazing results so I decided to tweak the other unit, too. I found many useful things expecially from the last threads on this forum and so I would try to make a brief summary of the expecially reccomended tweaks for this item. as all the info are quite a bit "scattered" all around..

I would ask you all if you're so kind to help me to complete this listing:

1) PIO caps for the 0.1 uF and 2.2 uF capacitors, the C12/13 and C22/23 on the latest electro diagram from WAD.
The 0.1uF cap seems to be "one of the most critical component as it is the only coupling cap". Successfuly reported used brands (in descent order) Audio Note Copper Foil (more expensive), Jensen Copper Foil, Hovland Music Caps, Dynamicap, Russian teflon (PTFE) caps. All them would do their work, some other brand (i.e. russian PIO caps on ebay) have been successfully tested. A major improvement has been reported though they're quite expensive;anyway it is worth the price. Rating: A+

2) Silver Mica capacitors for the other two couple of caps: 220pF (C22/C23) and 8.2pF (C16/C17). 1% tolerance caps are needed. Some general improvement, anyway those components seems to be quite cheap so they're worth the effort. Rating: B+

3) Tantalium Resistors.Some users experiencies report they're fine anyway it is not clear where they've been used (all resist. have been swapped??) and wich brand has been used.. Do AN resistors perform the same as many other common brands (which are really less expensive)?. This item has to be completed with the resistors ID to be swapped and with the brands. Rating B+

4) ECC83: which brands to look for? Are the substitution really worth the effort? Rating:?

5) The internal wiring: the wire for the input from the arm cable (the original one is a braided one) seems to be very critical though no info have been found about some other types which would have been successfully tested. Rating ?

6) Phono II 1st stage battery bias. A good tweak but it requires you to change the hardware and not only a component swapping.. Seems to result in a very good improvement. Rating: A-

Please if you have some other suggestions, improvements or if you have comments please report so we could try to organize a list of modding to be tried.

Thank you
Luca,
Italy

Hi Luca

I've mod'ed my Phono II as follows....

1) I changed the orange drop caps (C14 & 15, C18 & 19) with Auricaps form Partsconnexion. Beware that the leads on these caps are thick - I would advise fitting pegs on the PCB and soldering the leads onto these rather try to enlarge the wire holes.

2) Changed the two elec caps (C12 & 13) with std Blackgates from Partsconnexion.

3) Carried out the 3.18uS RIAA time constant correction by inserting parallelled 75k and 18k resistors on left and right channels between C16/17 and junction of R31/32 and V4b/a.

The most significant improvement came from mod number 3 and cost pennies!

Hope this helps?

I have a KIT 6550 and would be interested in hearing about your tweaks.

Steve

Luca

Meant to mention that I'm using Brimar ECC 83's and found these to be v good and an improvemet over the originals supplied with the kit. I got them off eBay.

Steve

[KennyK]

steve, could you expand on what improvments you found with the brimars?


my own tweaks to the phonoII are:

3.18us Mod, using the second resistor option (75k / 18k)
1k Vishay resistors replacing the first and last resistors in the signal path
10k vishay resistors for cartridge loading
orange drops(C18/19) 2.2uf and (C13/14) 8.2uF replaced with PIO 'military' grades (courtesy of Stuart)

is it worth replacing C10/C11 with something better?

Rob also recommended to me bypassing the psu electrolytic with tiny value polypropelenes. I'm not sure whether to do the HT or the Heater supply (or both)

I've also fitted XLR connectors to the rear of my phono, as I'm running long leads from the turntable, I've gone 'balanced' into the MC stepups.

Hi Kenny

The biggest difference I noticed with the Brimars was in the bass - tighter and clearer. Of course, as with any tube rolling, it takes time to change 'em over and get the hot.... but of all I've tried to date I stuck with these for now.

Steve

[colin.hepburn]

Originally Posted by KennyK

steve, could you expand on what improvments you found with the brimars?


my own tweaks to the phonoII are:

3.18us Mod, using the second resistor option (75k / 18k)
1k Vishay resistors replacing the first and last resistors in the signal path
10k vishay resistors for cartridge loading
orange drops(C18/19) 2.2uf and (C13/14) 8.2uF replaced with PIO 'military' grades (courtesy of Stuart)

is it worth replacing C10/C11 with something better?

Rob also recommended to me bypassing the psu electrolytic with tiny value polypropelenes. I'm not sure whether to do the HT or the Heater supply (or both)

I've also fitted XLR connectors to the rear of my phono, as I'm running long leads from the turntable, I've gone 'balanced' into the MC stepups.

Hi All
I have been following you posts with grate interest
I am about too start my Wad Phono II just waiting for my pbs too come thought the post so i will be starting from a blank sheet It would be very much helpfully if you guys can Post a list of all the parts and value's in one list thanks
Cheers
Colin

[KennyK]

I've been looking at replacing the coupling caps C10 & C11, as that seems to be a critical component.

are Audio Note Silvers worth the money, or should I stick to the cheaper copper ones?

[Clive]

You should definately put in capacitors you like the sound of at C10/11. You need these to be balanced in sound with C18/19.

Greg uses Russian teflon for the 10/11 and I think some PIOs for 18/19. The alternative approach is to use the same in both positions if you've found the perfect cap for you.

For 10/11 you could consider silver mica from diyhifisupply, they do them for $56 for a pair. AN Silver are very good, probably close to sliver mica but they are very different to AN Copper. Silver's are very neutral and revealing, Coppers are warmer and slightly coloured in the mid (in a very pleasant way). So many capacitors to chose from v-caps etc too.

[KennyK]

Thanks for that, Clive. the Audio Note Silvers are £76+vat each
what I'm wondering is if they are that much better than the special silver mica.

will changing C10/11 for anything better lower the noise floor or will it colour the sound?

I've got Russian PIO in C14/15 and C18/19 already, and vishay resistors at R15/16 and R35/36

[Clive]

I suspect that sliver mica will be just as good, if not better that AN Silver.

Changing C10/11 is just the same as changing any other coupling cap, more/less detail, different sound.

Different caps are all about synergy with other caps and the rest of you system, you might find the sound too analytical with silver/silver mica, you might find it just right. Hard to say.