mastering pultec eq - gain makeup??

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matthias

Well-known member
Joined
Jun 4, 2004
Messages
768
Location
germany / frankfurt
hello,

I'm planning to build a pultec type eq for mastering purpose...
low cut , low boost and two hi boost stages in series
everything with stepped attenuators and
bigger and more detailed frequency ranges...

i want to build that all in a 2unit enclosure but without a gain makeup...

then I have an unbalanced input and output...


can I just use a G9 or another mic preamp for gain makeup ??
so I can choose, if I want tubes or transistors...

do I need transformers in the passive unit and care for the impedance??


mat
 
You might want to buffer the input stage with either a trafo or opamp circuit to help your EQ get along with whatever preceeds it in your mastering chain. A good clean opamp buffer would probably be best, in case the tranny 'sound' isn't desireable. You can use a mic amp for makeup, certainly... also gives you the ability to add variable signal coloration if so desired, depending on the preamp you choose.
 
i'd do it just to be safe, so your filter sections responds as expected all the time. it may not be absolutely necessary, maybe someone else could give a better answer...
 
Well, a Pultec type is based on a 600 ohm filters, so depending on what your makeup gain amp is going to be, you have to match the 600 to whatever, which means a stepup x-former if hitting the grid of a ax7a.
I think a mic pre would be overkill, as you are already at line level. Mic pre's are optimized for a low level input.
 
[quote author="cjenrick"]I think a mic pre would be overkill, as you are already at line level. Mic pre's are optimized for a low level input.[/quote]I wonder what a good solid state candidate would be? Can't remember who it was, but someone posted that they had great results with a 5532.
 
[quote author="cjenrick"]I think a mic pre would be overkill, as you are already at line level. Mic pre's are optimized for a low level input.[/quote]

But aren't we no longer at line level once we've made it through the filters? I thought the filters ate 40 dB or so.

-E.
 
pad the mic pre input -20db, and be careful with the gain. A preamp with seperate gain and output level controls can lend itself to some subtle tonal coloration, i often throw my Phoenix DRS2 on the mix bus outputs for a touch of sweetening. It's a cool way to use different colors for different sounds if you have a variety to choose from.
 
[quote author="cjenrick"]Don't forget the API/Melcor solution. You could trim the gain resistor to exactly match the makeup needed.[/quote]I was hoping you'd suggest that. Seemed like a good idea to me, but I'm always looking for some assurance. :wink:
 
@ cjenrick: so I need 600ohm input impedance that the passive filters work as they should ??

so for my approach I need an input stage ?? transformer or op-amp based??
 

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