Hi all. I am making a Passive mixing console that was in a past tape ot (Hamptone) design. I'd like to make it a 6 buss line level. The schamatic has a attenuator followed by a 150K resister for each channel then all of the lines are tied together. It only shows a 1 buss. If I wanted to make 6 buss could I use 1 attenuator per channel, then split that into 6 with six 150K resisters leading to each of the 6 busses. I was just going to put a on/off switch on each of the 6 lines before the resister. Does this seem correct? Thank you.
Question about passive mixer from tape op?
- Thread starter Coldsnow
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Milkmansound
Well-known member
yeah - the mixer looks like with 6 channels you get 8dB of gain - and if you want stereo you'll need 2 JFP gain stages - which will make it more like +12db gain since its only 3 channels per side. Nice! Are you going to put in an output transformer? This is a project that I have been interested in myself for a while.
I also notice that this is an unbalanced input according to the mag - will you want a balancing circuit on the input?
I also notice that this is an unbalanced input according to the mag - will you want a balancing circuit on the input?
Actually I'm not looking at a 6 channel mixer but a 6 buss mixer with 16 input channel. Two busses going to the JFET stage, two going to Neve line and two open ended so I can patch in what ever. So each of the 16 input signals will go through the attenuator then split 6 times to six 150K resisters then each compine with the 16 other channels to go to the busses. Prior to each 150K resister, I plan on having a on/off push button switch to sellect or not select that paticular buss for that signal. I hope this sounds correct.
synthetic
Well-known member
I've been considering a project like this. Which issue was it in?
Milkmansound
Well-known member
TO #37
sorry, I do not know why I said 6 channel - need to read sometimes! Anyway - it sounds like a great project and your concept gels with what the schematic calls for, so I do not know why there would be a question.
sorry, I do not know why I said 6 channel - need to read sometimes! Anyway - it sounds like a great project and your concept gels with what the schematic calls for, so I do not know why there would be a question.
funkydiplomat
Well-known member
the taper will be screwed up slightly towards the clockwise end of the channel volume control pot. there will be more channel to channel interaction also. input z of each channel will lower (*probably not a big deal depending on what's driving it). you could make the 150k resistors bigger... but they form a voltage divider with the input of the gain stage too. so you'd need a few extra dbs of gain. or if you're going to be feeding the input of this mixer with something beefy, you could try lower value channel attenuater pots. 5k or so*.
just some thoughts.
joe
just some thoughts.
joe
