Hello all,
I've decided to embark on the project of creating a pair of these amps for the purpose of embarking on a long arduous journey of exploration into audio equipment.
I did a lot of digging through Kevin Gilmore's pages and archives and have found the carbon v5 schematics and a couple of power supply schematics - attached. There's just a series of questions that I have before I wade deeper into this:
1: Are servo V1 and servo V2 jumpers meant to be connected when the amplifier is in operation, or just voltage testing points, or both?
I've found out they're meant to be a DC bias correction feedback system.
2: The boards that I've found seem to point that most resistors can be 1/4W, but are there any that can be substituted for 1/8W? (I haven't modeled the entire thing in SPICE to see current/voltage/power of each resistor; if there is one out there that would be a godsend)
3: Is it correct to assume that doubled resistors (R31 and R32, R33 and R34, R20 and R3, R21 and R4) are done to meet voltage ratings of ~400V? (in which case, forces them to be 1/2W or so?)
4: I've heard rumours of resistor inductance being able to affect sounds noticeably. Are these concerns legitimate or mostly unfounded?
5: If I were to lay out my own board (to use a custom thermal management solution), will I run into copyright issues?
6: Assuming I can lay out my own board: apart from the 10m90s and the c2m1000 that require heatsinks in the amplifier section, and the transistors in the PS section, do the other transistors dissipate enough power to warrant spacing from other parts? (bunch of PZTA's and the STN's in the preamp, the PZTA's below the c2m1000's, and the DN2540's).
7: I reverse-engineered a PCB board for the blue hawaii's power supply and found it to be almost the same as the KGSSHVPS3 schematic. Considering that this power supply is used in the blue hawaii, I'm presuming this is a proven through-and-through power supply. How does the PS8G improve upon this, considering its greatly increased complexity? - As in, is there a large audible difference?
Found my answer in the thread - Zener diodes in the KGBH power supply (KGSSHVPS3) have not insignificant (~1%?) thermal drift over time, and the PS8G has a lot less ripple (range of microvolts instead of millivolts). However, I'm still curious about the auditory difference.
8: Is D1 in the KGSSHVPS3 schematic in error? It seems like it would restrict the biasing output to a maximum of the DC rail.
Update (3/5): I've went and put everything into Micro-Cap; this answers a lot of the questions I have. However, I'm encountering some errors from the C2M1000170D model that I got from CREE's website - some very large (and very wrong) voltage values are being generated, I believe most of this is due to the thermal modelling included in the subckt that Micro-Cap is having troubles with.
kgsshvcarbonv5.pdf kgsshvps3.PDF kgsshvps8g.PDF
