I started this thread over 1 and a half years ago.
Since then, my amp and speaker settings have changed.
The purpose of this update is to explain some of my current tube choices and to highlight the 2nd stage of amp breakin that comes from owning this amp for over 1 year.
My current Audio Chain consists of:
Oppo BDP 95
-> Soundsilver Symmetry Interconnects
-> Torii MK 4
-> Clearday Double Shotgun Speaker Cables
-> Zu Audio Soul Superfly 16 Ohms speakers
Final Tubes Used:
Input Tubes : Holland Made PCC88/7DJ8 Pinched Waist -> ( see Joe's Tube lore; IMHO these have 95% of the Pinched Waist 6922s but at 1/2 the cost)
Rectifier : Brimar 5R4GY "D' Getter -> Provides Warmth to the mids with excellent tight bass
VR Tubes : STC/GEC 0A3 "D" Getter - > more warmth then RCA OA3s,
RCA 0C2 "0" Getter -> provides sonic clarity
Output Tubes : Philips EL34 MetalBase NOS tubes -> I prefer EL34s with the Hazen grid mod which sounds more transparent/sonically clear than KT66 tubes ( e.g. NOS GEC Grayglass)
Torii Switches :-
(a) Bass tightening switch "on"
(b) Treble switch in middle 12 "O'clock" position
(c) 16 Ohms speaker impedance
(d) Volume normally 5-6 clicks on the stepped attenuator
When I first bought the amp ( and even after a few hundred hours of initial burn-in), I had preferred to leave the positive feedback switch in the "off" position because the sound became too diffuse sounding.
After another extended burn-in from normal usage ( I lost count!) which took over 1 year, the amp actually sounds much better with the positive feedback switch activated.
The soundstage seems wider but the sonic images are now still focused.
So for those who have just bought this wonderful amp and are still in the breakin process ( even after the initial few hundred), please continue to be patient.
You will definitely get to this final stage of the burn-in process whereby every piece of music is natural sounding, makes you tap your foot in delight and pulls you into the music.
The holy grail, IMHO, is the natural recreation of recorded music.
In no particular order :-
Piano notes have a natural and extended decay.
Bass is nice and tight.
Cymbals have a natural shimmer.
Stringed instruments such as violin strings have "air".
With my current setup, for every piece of music that I listen to, I am instantly transported to the venue where the recording took place.
All the ambient sounds are reproduced.
This could be either an intimate jazz nightclub ( ala Barbara Streisand One "Night Only") or a Concert Hall ( ala Adele's Live concert at the Royal Albert Concert Hall) or even a cathedral ( with classical music).
The natural ambience of the setting is just "there".
The movie soundtack from the "Untouchables" just makes me want to cry like a baby.....
Any piece of Yo Yo Ma's music could probably crack the heart of any Greek/Roman/Italian Stone statue out there.
Enough said.