3 Responses to “Studiomaster 16-4-8 latest on 13 October 2008”

1. Strangely on October 13th, 2008 at 6:37 pm

   Watson here. +15Vb relates to the second independent +15V supply. The other one should be called A but they were too lazy or they assumed that it’s obvious to most people what it means – obviously not in your case, as it’s all new to you. Like any business or work, there’s a shorthand that people use…. The same chip is used to produce 48V & 15V! It’s datasheet is here http://www.national.com/ds/LM/LM117.pdf You’ll see that the O/P voltage is set via the resistor chain, which explains the use of a 1% tolerance resistor for the larger one. Anything worse and there will be too much error. I can’t see everything at work, but the various O Volt connections are just that, I think. There is probably a bit of numbering or assumed numbering to the connectors. Maybe the connector goes A,B,C,D etc and then you’ll know which pin has the OV. ? Ultimately though, they all connect together in the PSU. Colour coding of wires is good. That’s one disappointment about the mixer loom….all the wires appear to be yellow! Ha Ha! At least they’re in order, but if you ever need to separate….. Rees Like or Dislike: 0  0 Reply

2. paul on October 13th, 2008 at 7:11 pm

   Cool thanks ive got to go over your other notes again as i dont understand the difference between the PSU ground which all the channels are connected to, plus the ground from the monitor channel to chassis, and the kettle plug groung to chassis thanks Like or Dislike: 0  0 Reply

3. Strangely on October 13th, 2008 at 7:38 pm

   Sometimes it’s to make cascading wiring easier. Sometimes it’s to make sure that there is enough capacity for the return supply feeds. Or it’s a combination of both! If there are several earth/0 Volt feeds, then care has to be taken to ensure earth loops aren’t generated – hence my personally preferred use of a big blob of an earth made from the tag-strip I mentioned earlier i.e. it’s pretty hard to generate an earth loop on something that’s only two inches long! Rees Like or Dislike: 0  0 Reply