All in one box project. Newb

[mersberg]

First time poster here.  I am trying to build an all in one circuit that will go into one enclosure. I have two questions, the first is I plan on piping a SM58 mic into the circuit and want to make sure that I understand the correct input and output impedance from effect to effect. The second, is each effect has a different supply voltage then the previous stage, +/- 15v,+/-9v and +9v. Each stage will be separated by coupling capacitors in each associated stage. The first stage was AMZ Q and D preamp/compressor to a 6 band GGG EQ to a Split band speech processor to an asymmetric audio circuit. Looking at the schematic the compressor has a 1M I/P and 100k O/P impedance, the 6 EQ has 100k I/P and a 10K O/P, the splitband has a 10K I/P and a 150 ohm O/P and the asymmetric circuit has 10K I/P and  50 ohm O/P.
The Power supply would be adjusted to +/-18 v, then have a regulator for each voltage needed.  
http://www.muzique.com/tech/2166.htm
http://www.generalguitargadgets.com/pdf/ggg_eq6b_sc.pdf?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a
http://k6mhe.com/n7ws/S_PROC.pdf
http://www.prodctodc.com/dc-35v30v-to-40v30v-positive-and-negative-dual-output-high-power-boost-converter-p-69.html#.U0VKDaj_yRi

[earthtonesaudio]

Welcome.

I guess you looked at the value of the resistors to ground to determine impedances. This is not correct, as it will only give you the *maximum DC resistance*, not the actual AC impedance of the effect while it's working (which is what matters for proper impedance matching). Look up "measuring impedance" or "impedance matching" to learn more.

If your question is "are these effects' impedances matched to each other if I put them in series?" then the answer is yes, they're fairly well matched.

I can't tell what your second question is.

[mersberg]

Thanks for the welcome, I have been researching and trying to read up as much as I can however it is still a little fuzzy ie at different frequencies the coupling cap in line creates a different reactance in conjunction with the shunt resistor. As far DC, I can match up the impedance in each stage using the 10 to 1 rule(bridging) like you said the way the AC signal reacts is what I'm still trying to nail down. My other question involves using the same power supply to run the 4 different  voltages with the effects connected in series.

[earthtonesaudio]

You can certainly power all 3 effects with one (dual) supply. Separate regulators for each voltage is fine, but maybe overkill.

If it was my project, I would just make one well-regulated and well-filtered +/- 12VDC supply and use that everywhere;
so the things that want a bipolar supply (+/- 9 or +/- 15) now get +/- 12, and the things that want +9 single-ended just get +12.

A thought experiment to get you thinking about power supplies:
In many circuits, a single power supply will provide power to multiple transistors, or multiple op-amps. No problem there. Well, multiple effects in one box is nothing special as far as the power supply is concerned. You're just connecting a couple more op-amps or transistors to it. As long as the supply is capable of providing the current you want at the voltage you want, your circuit works.

If your power supply can give 200mA at +/- 18V (I didn't actually look that closely to see what your particular power supply can do), and the sum of all the currents drawn by the effects is less than that, you're fine. Best practices dictate that you give yourself a little bit of headroom (so maybe the max current you want to draw is really 180mA) but in my experience the cases where this headroom is actually warranted are rare.

[PRR]

> The first stage was AMZ Q and D preamp/compressor

It does not have the word "preamp" anywhere on the AMZ page.

Also there is a w-i-d-e range of output levels possible from an SM58.

SSM2166 does offer gain, but only for heavy limiting.

And you might someday use another mike.

The SSM2166 chip is powered by single 5V rail. Rated max input is 1V rms. It is possible (though deafening) for an SM58 to put out more than a Volt.

SSM2166 also has input hiss of 2.4uV, 10 times more than the self-hiss of an SM58.

I really think you want an honest mike-preamp with gain control between the SM58 and any compressor.

SL1626?? Can you even find one today? And note that ham-radio audio systems are *not* optimized for hiss, because the radio path is very-very hissy, and the audience is not annoyed as long as there is speech in the hiss. Working a club is different, no matter how stoned-out the crowd is.

Your proposed voltage-converter board is rated for 0.3A-3A output current. Your chain of circuits may not be sucking 1/10th of the 0.3A minimum. While linear power supplies often have no minimum current, switchers often do. If under-loaded they may quit, or burb-burp large transient voltages while waiting for a decent load to appear. If it does run the efficiency is liable to be far-far below "70%-85%".

Rome was not built in a day. Build the separate pieces loose on the bench, work out what you really need (gains, voltages, knobs); THEN stir it all together.

[mersberg]

The voltages were what the plans recommended and I wanted to start with values with head room in mind. This is my first time building and will learn more as I go. I will use the 12 volt regulators and go from there. I've read that it is good and not good to connect signal ground to the chassis and also not connect the power supply ground to chassis, to avoid hum and other unwanted side affects of possible ground loops. I maybe wrong and I really appreciate all input as it is a great learning experience so far.  

You can certainly power all 3 effects with one (dual) supply. Separate regulators for each voltage is fine, but maybe overkill.

If it was my project, I would just make one well-regulated and well-filtered +/- 12VDC supply and use that everywhere;
so the things that want a bipolar supply (+/- 9 or +/- 15) now get +/- 12, and the things that want +9 single-ended just get +12.

A thought experiment to get you thinking about power supplies:
In many circuits, a single power supply will provide power to multiple transistors, or multiple op-amps. No problem there. Well, multiple effects in one box is nothing special as far as the power supply is concerned. You're just connecting a couple more op-amps or transistors to it. As long as the supply is capable of providing the current you want at the voltage you want, your circuit works.

If your power supply can give 200mA at +/- 18V (I didn't actually look that closely to see what your particular power supply can do), and the sum of all the currents drawn by the effects is less than that, you're fine. Best practices dictate that you give yourself a little bit of headroom (so maybe the max current you want to draw is really 180mA) but in my experience the cases where this headroom is actually warranted are rare.

[mersberg]

Going over each of the links once more, I then went to the datasheet and found where they called it a preamplifier.
http://www.analog.com/static/imported-files/data_sheets/SSM2166.pdf
In my first post I tried to avoid throwing to much on the plate to avoid confusion, mainly on my part, however what I'm trying to do is create a box that I will run into a CB radio. I been trying to get the "HIFI" sound I hear some of the Ham radio guys use over on the Voodoo Audio website.
http://www.wz5q.net/index/audiocrew.htm
I chose the SM58 because of recommendations from other CB guys using it for their HIFI stations and its durability. I have modified the audio portion of my radio to bypass the internal audio circuit and drive the the RF portion with external audio. I am not a power guy and I am just focused on quality.

SL1626?? Can you even find one today? And note that ham-radio audio systems are *not* optimized for hiss, because the radio path is very-very hissy, and the audience is not annoyed as long as there is speech in the hiss. Working a club is different, no matter how stoned-out the crowd is.

I built the Split band board without the compressor because I figured I could use the AMZ board to take care of that portion. I am open to building extra circuits that i would need to make my audio sound good.

Your proposed voltage-converter board is rated for 0.3A-3A output current. Your chain of circuits may not be sucking 1/10th of the 0.3A minimum. While linear power supplies often have no minimum current, switchers often do. If under-loaded they may quit, or burb-burp large transient voltages while waiting for a decent load to appear. If it does run the efficiency is liable to be far-far below "70%-85%".

I double check the site, output current has a max rating of .3 A and my proposed draw would be somewhere in the 237 milliamp range. I think I should be good there but maybe some sort of load resistor to maintain a steady load would be needed?

As I said in the earlier post I really appreciate your input and i value the information I have received so far. Thanks once again.

> The first stage was AMZ Q and D preamp/compressor

It does not have the word "preamp" anywhere on the AMZ page.

Also there is a w-i-d-e range of output levels possible from an SM58.

SSM2166 does offer gain, but only for heavy limiting.

And you might someday use another mike.

The SSM2166 chip is powered by single 5V rail. Rated max input is 1V rms. It is possible (though deafening) for an SM58 to put out more than a Volt.

SSM2166 also has input hiss of 2.4uV, 10 times more than the self-hiss of an SM58.

I really think you want an honest mike-preamp with gain control between the SM58 and any compressor.

SL1626?? Can you even find one today? And note that ham-radio audio systems are *not* optimized for hiss, because the radio path is very-very hissy, and the audience is not annoyed as long as there is speech in the hiss. Working a club is different, no matter how stoned-out the crowd is.

Your proposed voltage-converter board is rated for 0.3A-3A output current. Your chain of circuits may not be sucking 1/10th of the 0.3A minimum. While linear power supplies often have no minimum current, switchers often do. If under-loaded they may quit, or burb-burp large transient voltages while waiting for a decent load to appear. If it does run the efficiency is liable to be far-far below "70%-85%".

Rome was not built in a day. Build the separate pieces loose on the bench, work out what you really need (gains, voltages, knobs); THEN stir it all together.

[earthtonesaudio]

PRR's advice about starting small is very good.

Most people have a better time if they start simply before attempting something larger. 3 effects in one box, adapted to a non-standard input source, with multiple power requirements, would be considered by most to be well beyond a suitable project for a beginner.

A regulated power supply is a good start because:
* you need one anyway for your ambitious project
* lots of opportunities to practice using your voltmeter (you do have one, right?)
* cheaper to blow up a few LM317s while you learn, than a SSM2166