Photos: impressive! Looks very accurate.
Couple of questions
1. Power for the small board with time constants/ratio etc. Does this come from the 3 points at the top of either audio PCB just above the sym trim pot?
Yes, take the power for small PCB from one of audio boards. 3 wires can be soldered directly,
or with use of Phoenix 2.54mm pitch screw terminals, or with use of 3-pin 2.54mm pitch Molex connector.
Don't crimp, solder!
2. My relays have coil resistance of 360 ohm each. So the resistors R98 and R87 should be 60 Ohm right?
I couldn't get any .5watt 60R so I ordered some 60R4 0.6 watt. Now this is going to sound dumb, but they look physically small, like the rest of the 1/4 watt resistors. I guess as their resistance is low they aren't are physically big as say the .5watt 2K resistor in R89.
Does that sound reasonable or are these not right?
I used relays with approx. 1kOhm coil. Less power consumption, etc. 12V relays cost is almost same for
different coil resistance, BUT why spent additional milliamperes, especially in case of Lunchbox?
It comes up as 15-20 ma per slot difference. I'd like to spent them to OPA2604's
and quad (eight in case of 202X etc) VCA's.
However, 360 Ohm is OK, within the specs for power supply consumption.
Use regular, carbon, cheap, 1/2W, 10% 62, 68, or even 75 Ohm resistors, it is fine.
99% of relays have working range within 30% of specified coil voltage at least.
1/2W resistors will be about +30 deg C at home temp +25 C.
I think yours 60R4 will work fine as well.
BTW, thanks Igor, the PCBs are excellent to work with.
Thanx
I love those little beasts too
I had ordered all WIMA caps for the polys, and I could only get 100v rated ones, which it turns out are physically too big to fit in the sidechain filter part of the PCBs Doh!
No need for cool audiofoolish capacitors in sidechain filters!
5mm pitch, 50-63V film capacitors.
Farnell have all values for up to $0.7/cap.
Mouser/Digikey should have the caps too.
Parametric search, pick nice looking ones in normal price range. Like:
http://il.farnell.com/jsp/search/browse.jsp?N=500004+1000229+5087885+5087887+5087944+5087945+565143+565129&Ntk=gensearch_001&Ntt=capacitor&Ntx=mode+matchallpartial&No=0&getResults=true&appliedparametrics=true&locale=en_IL&catalogId=&prevNValues=500004+1000229&filtersHidden=false&appliedHidden=false&originalQueryURL=%2Fjsp%2Fsearch%2Fbrowse.jsp%3FN%3D500004%2B1000229%26Ntk%3Dgensearch_001%26Ntt%3Dcapacitor%26Ntx%3Dmode%2Bmatchallpartial%26No%3D0%26getResults%3Dtrue%26appliedparametrics%3Dtrue%26locale%3Den_IL%26catalogId%3D%26prevNValues%3D500004%2B1000229
