Hello,
I was hoping somebody could give me some advice as to capacitor replacement in the channel strips of my mixing console, I'm not very tech savvy so am going on things I've read online, so any input/direction most appreciated as my thinking may be off.
The main thing I would like to achieve is removing or replacing with film dialectric some of the electrolytic coupling caps in the signal path as there are quite alot. The console sounds good but a little foggy, I would have thought this is at least part of the reason..
My main question is in regards to the values I could get away with before I lose any sub bass and/or get phase shift... The mixer currently uses 100uf coupling caps after/before each op amp (NE5532), and the input resistors before the op amps vary from 1K up to 56K ohms... As far as using an online calculator, it seems I could get away with using a 10uf film replacement (which fits)... for quite a few of the positions where there is 10K and above resistance.. The calculator online calculation shows that I would still have at least 15Hz optimal response or lower....
Is this a situation where there are more considerations I don't know about or could this be a move which would indeed work? The only other thing I did read somewhere is that the low end roll offs are cumulative.. so that could be a pproblem perhaps where they add up enough so I would start losing low bass and getting phase shift......
Thanks so much for your time, and please do put me right on if this is nonsense!
I was hoping somebody could give me some advice as to capacitor replacement in the channel strips of my mixing console, I'm not very tech savvy so am going on things I've read online, so any input/direction most appreciated as my thinking may be off.
The main thing I would like to achieve is removing or replacing with film dialectric some of the electrolytic coupling caps in the signal path as there are quite alot. The console sounds good but a little foggy, I would have thought this is at least part of the reason..
My main question is in regards to the values I could get away with before I lose any sub bass and/or get phase shift... The mixer currently uses 100uf coupling caps after/before each op amp (NE5532), and the input resistors before the op amps vary from 1K up to 56K ohms... As far as using an online calculator, it seems I could get away with using a 10uf film replacement (which fits)... for quite a few of the positions where there is 10K and above resistance.. The calculator online calculation shows that I would still have at least 15Hz optimal response or lower....
Is this a situation where there are more considerations I don't know about or could this be a move which would indeed work? The only other thing I did read somewhere is that the low end roll offs are cumulative.. so that could be a pproblem perhaps where they add up enough so I would start losing low bass and getting phase shift......
Thanks so much for your time, and please do put me right on if this is nonsense!
Hi, not expecting, just curious as to see if there is opportunity for improvement in clarity.. One thing a really clever guy who designed all the Jensen transformers told me, that the later Studer designs including their tape machines, are not great designs in terms of audio quality... they're very overstuffed with excessive stages, fet switching, and mostly e.caps.. Just seeing if there is any areas where they can be swapped for out for a clearer path (given the substitute isnt causing other problems!)
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Can't think that you will achieve any form of improvement as the original coupling capacitors cover the audio frequency range adequately but by all means, spend some money.
Don't believe everything you read online; some of it was written by people who know about the same as you do. The difference between you and them is that you know you don't understand circuits; they think they do. That makes you wiser than them.Fezzle said:
There is a general rule in electronics (and other branches of engineering): in order to improve something you first have to understand it better than the original designer. If you can identify a poor component choice or an incorrect value then recalculate and replace; if not, you can either leave it as it is or believe what you see online.
> still have at least 15Hz
In "long" audio systems such as consoles:
While one 15Hz cut-off is inaudible, you may have say eight stages each with a cutoff. 8 stages each -3dB at 15Hz is -4dB at 60Hz, a significant bass-shave.
A full preamp EQ record play EQ mix record play cut process may have several dozen low-cuts.
That's why you find 100uFd+10K. 0.17Hz roll-offs do not add-up so much.
Cap-jobs are controversial in studio-geek forums (which you should find). Perhaps because almost nobody takes DF96's advice: "understand". Some very old consoles clearly have old-age problems. Usually a Good Brand and grade electrolytic is fine, especially when over-over-sized (makes distortion moot). Some modern consoles are just cheap. And I see too many "upgraders" who turn working gear into non-working gear by misconnections and solder accidents.
But it is your gear.
In "long" audio systems such as consoles:
While one 15Hz cut-off is inaudible, you may have say eight stages each with a cutoff. 8 stages each -3dB at 15Hz is -4dB at 60Hz, a significant bass-shave.
A full preamp EQ record play EQ mix record play cut process may have several dozen low-cuts.
That's why you find 100uFd+10K. 0.17Hz roll-offs do not add-up so much.
Cap-jobs are controversial in studio-geek forums (which you should find). Perhaps because almost nobody takes DF96's advice: "understand". Some very old consoles clearly have old-age problems. Usually a Good Brand and grade electrolytic is fine, especially when over-over-sized (makes distortion moot). Some modern consoles are just cheap. And I see too many "upgraders" who turn working gear into non-working gear by misconnections and solder accidents.
But it is your gear.
Most quality mixing consoles have an 80 or 100HZ roll off selector switch for PA use. Saves stage rumble issues and after all, who needs to sing below that frequency? Not many of us!
> who needs to sing below that frequency? Not many of us!
I've known two. One sang Mozart. The other was the bass in the pre-WWII Russian Red Army Choir-- I was astonished at the power below 100CPS. (You don't say "Hz" when transcribing pre-WWII stuff.)
But I don't see where OP is only mixing vocals?
I've known two. One sang Mozart. The other was the bass in the pre-WWII Russian Red Army Choir-- I was astonished at the power below 100CPS. (You don't say "Hz" when transcribing pre-WWII stuff.)
But I don't see where OP is only mixing vocals?
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