Stereo Overhead Preamp with EQ

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

critterkllr

Well-known member
Joined
Nov 5, 2010
Messages
311
Location
Dearborn, MI
I've been using a stereo pair of AEA R84 Ribbon mics as drum overheads. I'm planning to build a stereo preamp with some eq for them. I'd like to end up with something similar to the AEA RPQ.

http://www.ribbonmics.com/pdf/RPQ_Technical_Onesheet_6_web.pdf

It seems pretty straight forward. I'm not trying to rip off the RPQ with an exact clone, but would like to make something with similar features. The unit contains a stereo pair of preamps, high pass filters, high shelf filters/boosts. The marketing of the RPQ boasts a "No Load input impedance of 10,000 Ω" and a "Low Energy Storage circuit design that instantly recovers overloads for superior dynamic performance". I don't know if this is marketing BS or what. I have a few questions:

1) Can anybody recommend a mic pre that is low noise, clean, offers 60db to 80db of boost, and has an input impedance of around 10,000 Ω? I was thinking about an SSL 9k or Pre Grinder. Can the input impedance be changed on these to suit the mics? The extent of my experience with mic pres is Neve and API style. Any recommendations of a clean style pre for ribbon overheads would be appreciated.

2) Will a passive variable high pass filter work fine here?

3) I'd like to find a schematic for a high shelf boost with variable freq from 2.1k to 26k. Any suggestions?

I can etch a pcb from a schematic, but I'm not experienced with design from scratch. I'll need to mostly use parts from existing projects to piece this together for myself.

Thanks!
 
Bruno 2000's 9k's have a switchable variable HPF don't know what the slope of it is, but
it uses a triple section pot so not just a simple pot & cap
 
okgb said:
Bruno 2000's 9k's have a switchable variable HPF don't know what the slope of it is, but
it uses a triple section pot so not just a simple pot & cap

Thanks. I'm definitely leaning towards the 9k's. Also the Green Pre.

Any ideas on how I can figure out the input impedance and if a variable input impedance can be added?
 
Perhaps you may check my MICPRE ONE.

Input impedance is switchable between 600R and 5K but we can raise it.
70dB gain. Balanced signal path all the way from input to output.

http://groupdiy.com/index.php?topic=52443.msg668674#msg668674
 

Latest posts

Back
Top