NOOB BA and passive mixer questions

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Togril
Posts: 1
Joined: Tue Sep 24, 2013 8:10 pm

NOOB BA and passive mixer questions

Post by Togril »

hello JLM people. I thought I would make this a general post:

I am about to make my first piece of audio gear, which is a simple 8 channel passive mixer feeding 2 mic pre's.
I am an electronics noob, though ok with a soldering iron.

I intend to use the Micro Passive Mixer kit then a couple of BA's for the final stage. (which I will improve on when funds are available.
I was going to make the units self contained the passive mix feeding internally into the pre's, but thought it would be nice to make them discreet, with discreet imputs.

So before I order parts, I have some Questions:

1. If supplying +48v phantom to xlr inputs for mics, do I need anything more than the BA, SMPS power supply, xlr ins and a dpdt toggle (phantom on/off)?

2. If I want an (input) gain pot, impedance pot and JLM34mm VU, do I need anything else apart from the suggested VU buffer (and of course the pots)?

My setup will be:
Micro Passive mixer > 2x BA with JML14 transformer, and NE5532AP opamp.

Finally, how does the micro passive mixer deal / sound with less than the full 8 channels used? (ie: using 4 channels sometimes)?

Thanks in advance. Your patience is appreciated!
Will.

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Joe Malone
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Joined: Wed Jan 24, 2007 11:35 pm
Location: Brisbane, Australia
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Re: NOOB BA and passive mixer questions

Post by Joe Malone »

Togril wrote:hello JLM people. I thought I would make this a general post:

I am about to make my first piece of audio gear, which is a simple 8 channel passive mixer feeding 2 mic pre's.
I am an electronics noob, though ok with a soldering iron.

I intend to use the Micro Passive Mixer kit then a couple of BA's for the final stage. (which I will improve on when funds are available.
I was going to make the units self contained the passive mix feeding internally into the pre's, but thought it would be nice to make them discreet, with discreet imputs.

So before I order parts, I have some Questions:

1. If supplying +48v phantom to xlr inputs for mics, do I need anything more than the BA, SMPS power supply, xlr ins and a dpdt toggle (phantom on/off)?
The BA kit has the 48v phantom power switch on it. You do not have to order it separately.
2. If I want an (input) gain pot, impedance pot and JLM34mm VU, do I need anything else apart from the suggested VU buffer (and of course the pots)?
The BA kit comes with the gain pot. You will need to order a impedance pot and VU buffer kit and 34mm VU meter seperately.
My setup will be:
Micro Passive mixer > 2x BA with JML14 transformer, and NE5532AP opamp.

Finally, how does the micro passive mixer deal / sound with less than the full 8 channels used? (ie: using 4 channels sometimes)?
It works fine. The less inputs used the less makeup gain needed. Unless you ground the other inputs like when using switching TRS jacks then the makeup gain will stay the same.
Joe :-)
JLM Audio
Capturing Audio without Injury

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