Purchased some PM1000 master modules racked as pres...

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trodden

Member
Joined
Jul 15, 2015
Messages
9
First off, thank you for this website for the wealth of info I've gathered over the last two days.  Quite a resource to have.

I purchased a four channel pm1000 pre over at the tapeop message board.  The seller is not the person who put this together so they've not been able to help me out with some (probably very stupid) questions.

After talking with someone and researching on here, I've learned that the master modules have three different amps on them, two of them of the same design from the third.  These amps are also similar to an input module, hence why they can be used as pres.

I've run some signal through them, bass guitar, mic'd with an re20.  Sounds great.  Here's my question, and it seems like it shouldn't be a question, and perhaps my amount of weed intake is the reason why I keep flip flopping on my findings.  The two pots for each channel are not marked "input" or "output".  Should be pretty easy to figure it out right?  well, not so much.  Seems they BOTH react very similar.  I'm used to other preamps where I set the output wide open and dial in my input gain… and if i'm wanting more "color" from the input gain, I turn down the output, allowing me to open up the input more..  Well, on this set up, both knobs seem to "push" or distort in a very similar matter.  Not sure if its because I'm hitting the output transformers and/or input transformers similarly depending?  Seems I get the "cleanest" when both pots are around 12:00.

This very much is a "use your ears, make a decision, hit record" situation, which I'm fine with.. but I'm also wired a way where I need to know how and why before I can go with that.  These photos are all I have right now, and I'll post more if these are obviously not enough. 

Thank you.

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Amazingly through enough internet detective work, I was able to find the person who racked these up and posed my about questions to them.

Their answer-
from what I remember those ones are made from either the echo/aux sends or the master section make up gain block

I'm not totally sure what knob is what...I think that each gain block is fixed at like 20-25 and the knobs act like a fader in between each stage like this

gain 1 / first fader / gain 2 / second fader / gain 3

since the first stage is fixed at that gain if you have a loud signal it might clip the second stage with the knob all the way up

So, yeah, its a "use your ears dummy and make a decision and record"  situation with this oddball pre.  I can't fathom what benefits there would be having its gain staging this way… unless you're recording mosquitos, but at least I understand what's going on here!  Since I mostly record LOUD AS FUCK  rock, punk, metal bands.., looks like both knobs will be "lower" most of the time.
 
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