Originally Posted by PinkFloyd I haven't ordered the parts yet but found some of them kicking about so have fitted a few resistors, the 100K trimpots and the BD140 transistors. Will come back to this thread once I have fitted the rest. So far, so good
What type's / manufactors of resistors use you?
My first look - the schema of the splitter is the same of MK II?!
Originally Posted by PinkFloyd Here are the differences Fritz:
MKll rail splitter: vs .MKlll rail splitters:
I have study the PCB - the difference is position of the capacity-booster transitors - MKII at input - MKIII at output.
Originally Posted by PinkFloyd Note: MKlll uses constant current diodes throughout the amp, no standard diodes at all just 3.5mA & 5.6mA CRD's across the board (and splitters)
Which values of CRD's are used in rail splitter - 3.5mA or 5.6mA?
which values of CRD's are used in diamond buffer - 3.5mA or 5.6mA?
On my understanding, the trick to use different values of CRD's to flow the difference into the output of the OP (for Class-A) did not work with diamond buffer! For this feature we must use an additional CRD.
What the values of the feedback network resistors?
- input of OP to ground (1k in MKII) / - input to output of OP (330k in MKII - local feedback) / - input to output of diamond buffer (3k3 in MKII - overall feedback)?
What the values of the ZOBEL net? And the resistor in series to the output?
I calculate a 100 nF about 20 kHz - it haves ~ 80 Ohm / 100 kHz ~ 16 Ohm.
Which type of caps I should use for my Senn - polyester (MKS) or polypropylene (MKP)?
I remember Mike has written about this here ..... but where?
Today I use in MKII no input cap (4,7 uF), no Zobel, no local feedback (330k) and a Holco H2 15 Ohm plus 1000uF BG in series to my Sennheiser HD600 headphone - the sound is very clear, very rich in details, analytic ....
I did not test - what's the difference in sound by use the local 330k feedback and/or the ZOBEL net?