Mic Pre QPP



User's Manual

Our mic pre is the most important part of your signal chain. Each QPP features four all-discrete, all-iron mic pres with a simple and powerful two stage design.


The Jensen input transformer feeds a discrete operational amplifier for up to 64 dB of gain. An interstage trim control allows you to get the right amount of coloration or drive from the amp without using an inline pad. The output line amp uses a second discrete op amp by a custom-wound Cinemag output transformer. A 20 dB pad, polarity, mute, and 48V phantom power switchbank rounds out the feature set.

The QPP comes standard with a pair of M2 op amps. These are our design with very high gain and low distortion, and produce dominant even-ordered harmonics at all levels. This gives a clear, warm sound with a soft top. The op amps are socketed in the industry standard footprint, so you can try out other op amp designs (our Flickinger inspired amp is very popular as well).

We offer a variety of input transformers, output transformers, op amps and even voltages to give you the sound you need. 


Block Diagram


Technical Specifications

Gain Range                                          28 - 64 dB (8-44 dB with PAD)

Maximum Input Level                         -3.5 dBu

Maximum Output Level                      +26 dBu 

Input Impedance                                 2300 Ohms

Output Impedance                             <75 Ohms, transformer balanced

Frequency Response                        +0.1, -0.75 dB 20Hz-20kHz

Actual Measured Noise                     -96.4 dBA

THD @ +15 dBu output                     0.002% typical

Crosstalk (any channel)                     Better than -90 dB

Power Consumption                          200 mA max

If we are out of stock and you are interested in owning one, please contact us at: contact@ironageaudioworks.com