Suggestions on a Brickwall Limiter/Compressor

@jean-paul thanks, I had no idea modifying the mixer was an option, and just a couple of resistors.

@jaddie at least now I semi-understand the math you posted 😉 I'll for sure be adding a PAD to my F5m since it's on 2 resistors... now just need to find the time... I'll be measuring the out of my mixer output today so I can say I've done that at least once.

I'll also be playing a FLAC from a media player on the Mac to see what the DAC's output voltage is. ( compared to youtube and LogicProX )
 
Hi I suggested this in the other thread in detail. Apparently simple things need complex solutions to many.

Soundcraft max output: +21dBu = 8.7Vrms. Make it so that its maximum output level is 4Vrms/2Vrms (depending if you use XLR or convert to RCA) and you have solved your fear.

Not familiar with pads and pro stuff but please note the output impedance and drive capability of that mixer are both pretty good. Anything added behind it will not make things simpler and better but worse. Don't add, just solve stuff a good way for your custom situation. You created this by wanting a normal amplifier connected to pro gear. You can't bake a cake without breaking eggs.

Now please calculate R506 and R507 for 4Vrms/2Vrms output. Homework 🙂
 

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Don't make my words BS. It is exactly how I described. I don't care what all those professionals may or may not do and how right they all are in their beautiful pro world where we don't understand anything of. It is totally irrelevant when using "normal" HiFi stuff.
Wow. Well thanks for negating my nearly six decade career. Should I get the noose ready myself or do you want to do it?

Pros use “consumer” gear all the time, when there’s a point or advantage. We (or at very least, I) learned decades ago how to interface consumer and pro gear together properly. Its not something you can just ignore.
It is a 3V max amplifier coupled to a 9V device so a device that may damage that first device. A wolf coupled to a lamb, (dramatic music playing) ready to bite. Take away the 9V possibility and it is SOLVED. What can not occur can not damage anything. Change the wolf to a sheep or the lamb to a wolf.
That’s not a good description of the problem at all. When there is a level discrepancy between devices controls don’t operate in a convenient position, and there are often compromises in noise and headroom. Nobody’s going to damage the amp because by the time that could happen it would be so loud and distorted any user would back it off. But operating controls easily might be nice so…match levels.
 
@jean-paul thanks, I had no idea modifying the mixer was an option, and just a couple of resistors.
Per channel, and no, it’s not going to be easy.
@jaddie at least now I semi-understand the math you posted 😉 I'll for sure be adding a PAD to my F5m since it's on 2 resistors... now just need to find the time... I'll be measuring the out of my mixer output today so I can say I've done that at least once.
You don’t need to measure anything. You already have the data.

If you don’t have the time to build the pads, you sure won’t be modifying your mixer.
I'll also be playing a FLAC from a media player on the Mac to see what the DAC's output voltage is. ( compared to youtube and LogicProX )
Google macOS tone generator. Several free ones out there, plus Audacity will do it. Generate your own so you know what they are.
 
RoboDNA, please confirm:

1. the fear that the F5m will be defective by exceeding its absolute maximum 3Vrms input level.

2. also that the F5m is connected directly to the 8.7Vrms mixers outputs without having its own volume control.

Apparently my reading skills are not pro and I want to improve that. If the answers to items 1 and 2 are both "yes" then the 2 resistor change is the cheapest and most effective solution. If insecure you may even solder resistors over the existing ones. Easily modified back to pro levels.
 
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@roboDNA
Since the entire issue is caused by the Soundcraft, why don’t you upgrade that? Many mixers include a very useful and nice monitor section.

For example, Mackie 1402VLZ4.

The net cost of the upgrade, including the sale or trade in of the Soundcraft, would be minimal. And you’d be happier.
 
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@jean-paul , with all due respect ( as i've read a bunch from you and learned some things along which i thank you) this become just ridiculous: you admit you don't know habits and use of pro gear and tell you've got the answer to the issue.
It doesn't make sense. Until now i found it hilarious, the way it turns seems more pathetic to me as you seems to be yelling at clouds...

Just make some search ( or read the thread from the beginning and do some search!) about level used by synthesizers and other pro gear, learn about consoles how and why they use some references rather than others and then come back to us.

I'm sure you would learn many things and reconsider the point of view you have on people which craft the final product you listen to in your wonderful 'consummer world'...

Jaddie, should i read you don't think i learned to interface with consumer gear? Lol. 😉
 
OK. Please tell me if the situation is solved with 2 resistors or not. I focus 100% on OPs issue and a working effective solution (without any label to consumer/pro and habits as that does not interest anyone). Do you?

There is a final gain stage that can output 9Vrms connected with a straight line to a device that does only tolerate till 3Vrms. Reduce the gain of the final stage while keeping its now low Z outputs and all is good. A simple test to prove I am a total idiot or not is to solder 62kOhm resistors over the existing R506/R507 ones.

If anyone feels offended, thinks I am addressing to him or doubting professional experience or feels the need to express an opinion about me: feel free to do so. It won't change anything though 🙂 We have a 9V transformer with dimmer connected to a 3V max. lamp.
 
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@jean-paul Just read the damn bloody thread and see who did suggest a solution with 2 resistors to solve the issue... i suggest reading message 18 to be on point directly.
Then read the next message where i explained how to dial up input gain on a desk... which it seems you don't know. Audio engineering lesson 1, introduction, not even chapter1. Have you asked Robodna if he did it or known how to do it...

I tell you, it's ridiculous.

You don't want to talk about the why we suggested to do it through an external pad, that's fine to me, after all i only have 3 decades of experience in the field, i find it's insulting for Jaddie's experience.

If you want to shoot someone or community free to you but you'll loose credibility in what you can say. I find it strange and sad tbh to have to tell something like that to you, but c'est la vie.
 
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^^ I have not had time to implement the solution just yet... I'll be adding a couple of PAD resistors for each channel inside my case. I'll hard-wire them in without a switch for now until I decide on other things like maybe building a couple of new monoblock amps ( F5mX ) I also like the idea of getting the Mackie mixer with differential balance AND monitor RCA outs which I would use for the F5m amp without the need of the PAD. I may build the monoblocks with differential balanced XLR cable inputs for 4dBU level and a RCS inputs for -10dBV level. ( no need for a switch )
 
@jean-paul I'm curious, what would you suggest the best solution would be? ( if it's not the same as what I'm considering ) Other than replacing the equipment or adding the pad, is there something I've not considered that you know about? ( sorry if you already mentioned it... )

If your suggestion is to modify the mixer's 2 resistors, I do like that idea but think I may need the mixer for pro audio level uses in the future. I see what you mean about fixing the 'source' of the problem which is the mixer. The Mackie mixer does pro and consumer levels and has differential balanced XLR which my soundraft does not. That is the best solution I think, and if I did not already have the soundraft, I would have pulled the trigger on a Mackie mixer. My Mackie MR-8 studio monitors ( Class A-B ) sound amazing and they really thump, so I'm happy with Mackie..
 
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Yes, just change 50 years of established standard to something that won't be able to drive any pro gear in case you decide to use it.
Advice from someone which admited he don't know what he is talking about.

Use the two resistor to make an external pad, if it doesn't suit you sell the desk to someone doing live act ( which is the planed use for the desk because lack of monitor section) and find one dedicated to your use. You'll be glad to not have modified it as it won't loose it's resale value on advice from someone which think there is amplifier dedicated to studio gear. And did not applied his own advice to himself ( read the thread Jean-Paul! ) Lol.