NeveSSL
New member
Hi all!
I am very pleased with the results of my INA217. I built it straight off of the spec sheet, except I'll be adding some audio Nichicon caps to the output to block any DC offset from going out or any phantom from coming in, just in case I do a really poor job patching at some point. I tried finding the datasheets comparing it to a John Hardy, Millenia, and an Avalon that I did for a class, but I couldn't find them. I will, though. Anyway, its flat and clean with low noise. A poor-man's Millenia, IMHO.
So, I've decided to build 6 more channels (*gulp* I need to do PCBs on these... point-to-point on vero board sucks! ) and rack them up.
Here's my question: The spec sheet calls for something ridiculous like a 1.4k reverse log pot for the gain in series with an 8 ohm resistor. That, I believe, is a bit ridiculous. So I'm debating on whether I should try to find a different, suitable replacement pot (I think someone suggested a 10k reverse log pot with another resistor across the wipers?) for the gain or should I just do the rotary switch route?
I have found some inexpensive rotary switches (total cost about $1.50 each for single pole and 12 positions) that would work. But the problem is tweaking. If I go this route, I would probably do 12 increments of around 5db from 0 to 60dB (which would require higher than 5, but you get the point). As I've experienced from Neve 1272s, this works, but its really nice to tweak the input with a "finer" control, so to speak. Maybe something that would allow me to play all the way around that 5dB range while stepping it up with the rotary switch. At the same time, that seems a bit ridiculous if I can just get a single pot that will do it all.
Also, what do you guys think about adding maybe a 10dB pad to each channel? Whats the most transparent way of doing it without adding too much extra cost or complexity? I've seen some basic pad circuits, but I am a bit concerned about significant degradation of the signal.
Last thing... should I worry about adding a balanced output to this pre? And if so, how? Diff amps? Transformers? Flux capacitors? I don't think it would be a huge deal (probably will have short runs of cable from the pre to the converters), but still may be worth doing now for longevity's sake.
Any help or insight is MUCH appreciated!
Brandon
I am very pleased with the results of my INA217. I built it straight off of the spec sheet, except I'll be adding some audio Nichicon caps to the output to block any DC offset from going out or any phantom from coming in, just in case I do a really poor job patching at some point. I tried finding the datasheets comparing it to a John Hardy, Millenia, and an Avalon that I did for a class, but I couldn't find them. I will, though. Anyway, its flat and clean with low noise. A poor-man's Millenia, IMHO.
So, I've decided to build 6 more channels (*gulp* I need to do PCBs on these... point-to-point on vero board sucks! ) and rack them up.
Here's my question: The spec sheet calls for something ridiculous like a 1.4k reverse log pot for the gain in series with an 8 ohm resistor. That, I believe, is a bit ridiculous. So I'm debating on whether I should try to find a different, suitable replacement pot (I think someone suggested a 10k reverse log pot with another resistor across the wipers?) for the gain or should I just do the rotary switch route?
I have found some inexpensive rotary switches (total cost about $1.50 each for single pole and 12 positions) that would work. But the problem is tweaking. If I go this route, I would probably do 12 increments of around 5db from 0 to 60dB (which would require higher than 5, but you get the point). As I've experienced from Neve 1272s, this works, but its really nice to tweak the input with a "finer" control, so to speak. Maybe something that would allow me to play all the way around that 5dB range while stepping it up with the rotary switch. At the same time, that seems a bit ridiculous if I can just get a single pot that will do it all.
Also, what do you guys think about adding maybe a 10dB pad to each channel? Whats the most transparent way of doing it without adding too much extra cost or complexity? I've seen some basic pad circuits, but I am a bit concerned about significant degradation of the signal.
Last thing... should I worry about adding a balanced output to this pre? And if so, how? Diff amps? Transformers? Flux capacitors? I don't think it would be a huge deal (probably will have short runs of cable from the pre to the converters), but still may be worth doing now for longevity's sake.
Any help or insight is MUCH appreciated!
Brandon