[Swarkybubble]

I have always used fixed gain on my Piccolo but have just had the load switch taken out of the circuit too leaving the load at 560 ohms. Is this OK ? I just get the impression that the sound has hardened a bit. 

[poty]

Are you shure you connected the right load resistor? It is possible that either before you use different resistance or now you connect different resistor.

[Swarkybubble]

Hi,
Yes, the others have been removed leaving just the 560 ohms Schinkohs.

[poty]

Could you post pictures of the places of the load resistors and the connections for load switch substitution?

[Swarkybubble]

Sorry, What I meant was that I soldered the Schinkoh load resistors, 560 ohms for my troika cartridge,  direct to the back of the RCAs and there are no resistors in place for the switch to feed. In other words it makes no difference which position the switch is placed in. Its presence is purely cosmetic.
In any case, the Piccolo seems to be now back on song  again, I think it was down to a phase mix-up on the mains connection to my Bugle power supply which I use with it.
By the way I am building a Shunt Mosfet regulated power supply for my "tubesforever" type souped up Piccolo, based on the Salas Simplistic circuit and R-core transformers, all in one box. If I notice any improvement/changes I  will let you know.

[poty]

Experimenting with the Piccolo board I found out that the most compromise part of the build is the DC-DC converter. I tried to use highly filtered storage batteries for the two voltages the Piccolo uses and this is greatly improves the noise floor and overall sound (for me, because this topic is highly subjective). I like this changes more than use boutique caps and eliminating switches (I use relays) - the second place I hear noticeable differences. Until now I haven't had any luck with building a power supply that saves this achievement.

[ptmconsulting]

Here's a tweak to the battery power supply that will improve dynamics a bit. Put a 1000uF electrolytic cap (or something of similar size) across the + and - leads where the battery supply connects to the board. The voltage of this cap doesn't have to be large. Or alternately you can use a non-polarized film cap of at least 1-2 uF if you've got one lying around and it fits in the case.

Enjoy

[poty]

It's only half-measure.

[Swarkybubble]

Well, here it is. I haven´t heard it yet but someone who has assures it will be worth the wait.

http://s524.photobucket.com/albums/cc328/VantheManspeakers/Piccolophotos/Piccolo%20regulator/?action=view&current=Piccolo.jpg

[poty]

Using such power supplies you can feed many power amplifiers, not only Piccolo! Great!
Why do you use two power supplies? Does it mean you eliminate switched DC-DC convertor and powering the circuit directly?

[Swarkybubble]

Precisely,  the converter was eliminated and the Piccolo fed directly at 6.0v and  -3.0v  if I remember rightly.
It has survived a soak test and is sounding good. The transformers are oversized (120mA at 9.0v and 12.0v so there is absolutely no background noise)
All I need now is a way to run in my FT3 Russian teflons in my MM valve stage. They are really hard and will need a few hundred hours, I fear. Still, it can only get better.

[poty]

Great! I hope I can copy this config to try. Very good improvement really!

[Swarkybubble]

Good luck. Just in case you don´t know about it  The PCB is from the Salas LV Shunt Regulator on DIYAudio Group Buy.