HappyHourStudio
Active member
I revised and rounded out the schematic for this tube console I’m building to be the workhorse mixer in my studio. I’ve got all the parts and I’m slowly approaching the time where I’m gonna start cracking at it. As that time creeps up, I wanted to try and wrap my head around it as much as possible. Curious what you guys think and if any of you have the knowledge and time, would love to hear your thoughts on the following questions…
•Do the resistor values on the 11 summing resistors of Bus 1 & 2 need to be 50K instead of 100K so that the total value = 100K at that juncture instead of 150K? To match the break away point between the Tone Control Stage and Direct Out Cathode Follower?
•Would the echo send need to be unbalanced? If not, where would the (-) and ground run to for the return into bus 1 & 2? (I’ve left that part of the schematic blank until I figure out where that’s running)
•Are there any easily identifiable improvements to the circuit that might improve the overall quality of the audio? Be it frequency response, etc.
•At the input stage of the preamp, I have a line level switch that will have 10K resistors running in parallel and a 240K resistor bridging the two right after. Are these values standard for that kind of level switch? Are there other methods? Are there values that might be better suited for a line level switch?
•The power supply I’m using is actually just an old Heathkit power supply where I can choose the precise voltage I want. This worked really well for the first rendition of this console I built; however, it was only 5 voltage amplifier/tone control channels running into a two bus much like the one in the schematic I posted. I’m wondering if the Heathkit will be able to power an additional 5 channels. It’s essentially 20 12AY7s & 13 12AU7s.
•I was told by a buddy that often times output transformers don’t really help in any way when dealing with a circuit utilizing cathode followers in this manner. I’m sure that might be generalizing a bit, but is there any truth to that? Out of curiosity, why?
Anyway, thanks ahead of time!!! Love reading all of your thoughts and input. I’ve attached a photo of the schematic, the loose block diagram, and one of the channel strips.
From top to bottom: Direct Out Volume/Bus 1 & 2 Volume/Treble/Bass/Phase Switch/Mic&Line Level Switch/Gain/Echo Send
Mucho Love,
-Kyle
•Do the resistor values on the 11 summing resistors of Bus 1 & 2 need to be 50K instead of 100K so that the total value = 100K at that juncture instead of 150K? To match the break away point between the Tone Control Stage and Direct Out Cathode Follower?
•Would the echo send need to be unbalanced? If not, where would the (-) and ground run to for the return into bus 1 & 2? (I’ve left that part of the schematic blank until I figure out where that’s running)
•Are there any easily identifiable improvements to the circuit that might improve the overall quality of the audio? Be it frequency response, etc.
•At the input stage of the preamp, I have a line level switch that will have 10K resistors running in parallel and a 240K resistor bridging the two right after. Are these values standard for that kind of level switch? Are there other methods? Are there values that might be better suited for a line level switch?
•The power supply I’m using is actually just an old Heathkit power supply where I can choose the precise voltage I want. This worked really well for the first rendition of this console I built; however, it was only 5 voltage amplifier/tone control channels running into a two bus much like the one in the schematic I posted. I’m wondering if the Heathkit will be able to power an additional 5 channels. It’s essentially 20 12AY7s & 13 12AU7s.
•I was told by a buddy that often times output transformers don’t really help in any way when dealing with a circuit utilizing cathode followers in this manner. I’m sure that might be generalizing a bit, but is there any truth to that? Out of curiosity, why?
Anyway, thanks ahead of time!!! Love reading all of your thoughts and input. I’ve attached a photo of the schematic, the loose block diagram, and one of the channel strips.
From top to bottom: Direct Out Volume/Bus 1 & 2 Volume/Treble/Bass/Phase Switch/Mic&Line Level Switch/Gain/Echo Send
Mucho Love,
-Kyle