Hello everyone,
First of all thank you to all those who contributed to devellop the original version of this project (@khstudio @peterc @Harpo and i don't remember the other
) and nourished 70 pages of info that I finished reading.
I wonder about designing a stereo version of this eq with input and output transformers, a kind of mastering, bus oriented version.
Potentiometers:
The idea would be to do it with a rotary switch that would allow to act on the L/R at the same time.
From what I understand the biggest difficulty is to find a potentiometer and the trouble of mounting the resistors on it.
With this stepper pot things might be easier for soldering by creating a small pcb. With a 2 deck 12 poles we can easier control the L/R with stepped and precise control. Obviously by having calculated what is needed with the @Harpo spreadsheet.
With 12 steps, we could have +-2 db of boost and cut by increment of 0.5db. I dare to think that for bus or mastering it would be enough.
There is a version of this stepper pot with 4 poles but still 12 steps, we could imagine 2 poles with increments of 0.5db and 2 others with increments of 1db via a switch.
In the end Switch Up increments of 0.5 db for +-2db boost and cut, Switch Down increments of 1db for +-5db boost and cut.
I think it's not very advantageous to go through a 4 pole solution. From what I've read the +-2db seems to be suitable.
-For all those who have it in a similar configuration could you tell me if this margin is enough for you?
-For all those who are with normal potentiometers, do you often use more than 2db of correction?
I talked to this potentiometer supplier on Alibaba, she can also custom make C500K dualgang with center detent 10%. I think for 200MOQ (to see).
This could also be a solution with 1 knob per frequency band, with Harpo's method to adjust everything independently.
However, I find that this solution offers less precise control with the aim of using it on a BUS.
Transformers:
To make things more interesting, gain warmth and colors always with a view to BUS, Mastering use. I personally find the idea of the transformer welcome.
For the input transformer, I had thought of a Neutrik NTM4.
-Do you think that in this configuration this transformer will be suitable or is it better to go for something else?
-What are the "rules" for choosing an input transformer?
-Could you enlighten me on this question?
For the output transformer, I would go for something like a Carnhill VTB-2280 for example.
I think i will need a little circuit to correctly drive this transformer to.
I saw that Igor had a UTM transformer company, which seems to have a good reputation and is not very expensive to compare to the other.
-Do you have any advice for an output transformer?
-Have you ever tried UTM transformers?
1u or 500:
The next point concerns the casing, 1U or 500 format.
In a 1U case there would be plenty of room to do all this, but it adds the cost of the xlr, the power supply, and all the things inherent to the 1U format. I'm talking about drilling, alignment, wiring etc... Which increases the cost and assembly time. On the other hand, the design is a little easier because there is more room to house everyone.
On a 500 format it would cost less. I think that on a stereo format, it could fit with a little elbow grease (French expression).
The design would be more complicated but possible.
I started to look and find some information on this format with various PDFs, I think I can do it.
-In your opinion, what would be the most suitable format?
-For those who have already done 500 stereo format, do you have any advice on things to pay attention to when doing 500 stereo format?
There you go, even if this project never sees the light of day, the idea has been running through my head for a week, and I had to put it somewhere.
So my last questions are:
-Reading this post, is this a project that you find interesting?
-Is it worth it in 2025 (as we could read just above) to start on a machine like this?
-Do you have any suggestions regarding this project?
Thank you to all those who took the time to read this post and also to those who took the time to respond.
Cheers
PS:Yes Google was my friend to write all this in a comprehensible and readable way.
First of all thank you to all those who contributed to devellop the original version of this project (@khstudio @peterc @Harpo and i don't remember the other
) and nourished 70 pages of info that I finished reading.I wonder about designing a stereo version of this eq with input and output transformers, a kind of mastering, bus oriented version.
Potentiometers:
The idea would be to do it with a rotary switch that would allow to act on the L/R at the same time.
From what I understand the biggest difficulty is to find a potentiometer and the trouble of mounting the resistors on it.
With this stepper pot things might be easier for soldering by creating a small pcb. With a 2 deck 12 poles we can easier control the L/R with stepped and precise control. Obviously by having calculated what is needed with the @Harpo spreadsheet.
With 12 steps, we could have +-2 db of boost and cut by increment of 0.5db. I dare to think that for bus or mastering it would be enough.
There is a version of this stepper pot with 4 poles but still 12 steps, we could imagine 2 poles with increments of 0.5db and 2 others with increments of 1db via a switch.
In the end Switch Up increments of 0.5 db for +-2db boost and cut, Switch Down increments of 1db for +-5db boost and cut.
I think it's not very advantageous to go through a 4 pole solution. From what I've read the +-2db seems to be suitable.
-For all those who have it in a similar configuration could you tell me if this margin is enough for you?
-For all those who are with normal potentiometers, do you often use more than 2db of correction?
I talked to this potentiometer supplier on Alibaba, she can also custom make C500K dualgang with center detent 10%. I think for 200MOQ (to see).
This could also be a solution with 1 knob per frequency band, with Harpo's method to adjust everything independently.
However, I find that this solution offers less precise control with the aim of using it on a BUS.
Transformers:
To make things more interesting, gain warmth and colors always with a view to BUS, Mastering use. I personally find the idea of the transformer welcome.
For the input transformer, I had thought of a Neutrik NTM4.
-Do you think that in this configuration this transformer will be suitable or is it better to go for something else?
-What are the "rules" for choosing an input transformer?
-Could you enlighten me on this question?
For the output transformer, I would go for something like a Carnhill VTB-2280 for example.
I think i will need a little circuit to correctly drive this transformer to.
I saw that Igor had a UTM transformer company, which seems to have a good reputation and is not very expensive to compare to the other.
-Do you have any advice for an output transformer?
-Have you ever tried UTM transformers?
1u or 500:
The next point concerns the casing, 1U or 500 format.
In a 1U case there would be plenty of room to do all this, but it adds the cost of the xlr, the power supply, and all the things inherent to the 1U format. I'm talking about drilling, alignment, wiring etc... Which increases the cost and assembly time. On the other hand, the design is a little easier because there is more room to house everyone.
On a 500 format it would cost less. I think that on a stereo format, it could fit with a little elbow grease (French expression).
The design would be more complicated but possible.
I started to look and find some information on this format with various PDFs, I think I can do it.
-In your opinion, what would be the most suitable format?
-For those who have already done 500 stereo format, do you have any advice on things to pay attention to when doing 500 stereo format?
There you go, even if this project never sees the light of day, the idea has been running through my head for a week, and I had to put it somewhere.
So my last questions are:
-Reading this post, is this a project that you find interesting?
-Is it worth it in 2025 (as we could read just above) to start on a machine like this?
-Do you have any suggestions regarding this project?
Thank you to all those who took the time to read this post and also to those who took the time to respond.
Cheers
PS:Yes Google was my friend to write all this in a comprehensible and readable way.
