Peluso P-24 Stereo Vacuum Tube Large Diaphragm Condenser Microphone

The Peluso P-24 is built as a tribute to the legendary "AKG C 24" stereo tube condenser microphone.

The P-24 hosts two complete large diaphragm condenser (LDC) vacuum tube microphone systems within a single microphone body. The two capsules are located directly above each other with the upper capsule capable of rotating 180 degrees. This configuration provides for quick coincident capture in X-Y, Mid-Side, and Blumlein techniques. Both the upper and lower capsules have 9 independently selectable polar patterns controlled remotely at the microphone power supply. The two signal chains run independently through individual high impedance circuit boards and isolated custom transformers, both powered by a single vintage 6072AM glass triode vacuum tube. While the similarities between the P-12 and the P-24 (as with the C 12 and C24) run very deep, there are a few key differences.  The primary differences are subtle and come from running both circuits from the single 6072AM tube. The tube grid is biased differently with the load of both circuits yielding a better low-end response. Additionally, the anode of the tube is grounded differently providing a smoother and fuller top end.

First released in 1959, now long out of production and with only 800 units ever produced, very few original C 24 microphones exist today. It was originally designed to use X-Y and Mid-Side techniques. The subtle unique differences in the sonic quality of the microphone led many to believe it was of superior sound quality to the beloved AKG C 12 microphone. With today's advanced digital mixing tools it is possible to accurately tune the spatial aspects of a mix allowing for accurate positioning of instruments within the mix in the post production process. There are many independent sources that exist for information on the processing of a Mid-Side signal. For many years it has been one of John Peluso’s great ambitions to create a tribute to this very special microphone. Now after a few years of research and development we at Peluso Microphone Lab are very excited to release our P-24!

Our new stereo power supply comes housed in a slightly taller steel enclosure. The front panel has all of the connections and controls. In the center is our microphone input connection. On the left side is the OUT1 XLR connection and polar pattern selector. Here you can select from 9 indexed polar patterns from Omni, to Cardioid, to Figure of ‘8’, with 6 indexed settings in between. Identical controls for OUT2 are on the right side of the face panel. OUT1 is the lower capsule, and OUT2 is the upper capsule. As always, on the rear of the power supply you will find an input for either a standard IEC power supply cable for use in the US with 115V or an EU IEC cable for use with 230V. Inside this connector there is a removable fuse tray. Inside this tray is not only the power supply fuse, but also a spare fuse to use if needed.

Our other tube microphones use a rugged 8 pin connector. For a stereo tube microphone, we needed more conductors. We use the same medical systems-grade component in our new 12 pin connector. As with our 8-pin connector, this high-quality connector is built to last for a lifetime of use. The housing is equipped with a key-way that engages before any of the pins contact the receivers. This assures proper alignment of the connection before the pins are pushed into the connector. And, as for the pins, yes, they are still large strong durable pins, similar to the ones in our beloved 8-pin cabling system.

Our new 20' Heavy Duty 12-pin Connector Cable has been designed especially for this microphone. This cable has 12 conductors including 2 twisted pairs of signal wire to eliminate RF interference. The oxygen free conductors are double braided shielded and jacketed in a soft flexible PVC. This cable is designed for years of trouble-free use. As we all know, cables are prone to inadvertent damage so we offer replacement cables for purchase on our website.

Inside the P-24 microphone we find two of the same custom T14/1 historically accurate transformers we have always used in our P-12 microphone. To eliminate any interference, they are separated into two chambers within a steel can in the base of the microphone. It is historically accurate to use this transformer in the output of this microphone. Additionally, after decades of microphone experience, we have come to know and believe that the use of an output transformer is crucial to sound quality.

Our 6072AM vacuum tubes have all been burned in and thoroughly tested. The ‘M’ notation at the end of the number indicates the tube has been tested to be quiet for microphone use.

When we set out to pay tribute to the C 24, we wanted to start at the heart of the microphone and re-engineer the capsule from the beginning.  The vintage CK 12 is a very unique capsule. Like most multi pattern LDC microphones the P-24 has a two-sided capsule.  Dual edge terminated 6-micron gold mylar membranes tensioned over charged backplates are sandwiched together to create the capsule.  As sound pressure waves move the diaphragm, electrical signal passes from between the back plate and diaphragm, creating the signal. The movement of this diaphragm creates sound pressure waves within the internal volumes of the capsule backplate. The design of the venting, chamber sizes and pathways within the backplate has a dramatic effect on the responsiveness of the capsule at different frequencies.  The amazing sound quality of the CK 12 capsule comes from the unique and rather complicated design of the backplates and the extra chambers they employ. As a sound wave hits the front of the capsule, the pressure passes into the capsule, through the backplate chambers and in turn passes to the diaphragm on the other side. The capsule must be tuned so that the delay in this wave passing through the capsule matches the diffractive delay of the same sound traveling around the outside of the capsule. The intricate design of this backplate is different between the front side and back side of the capsule.  After many decades of restoring these capsules, we wanted to produce an exact historically accurate build.  This provides our P-24 with the most accurate CK 12 capsule in production today.  Additionally, in our repair department, we now stock diaphragms, and all other replacement parts for a vintage CK 12 capsule. Providing repair clients seeking vintage restoration of damaged CK 12 capsules the options to either re-skin their original capsules, replace the original diaphragms with P-CK-12 diaphragms, or replace the entire capsules with a full replacement P-CK-12 capsules.  We are very proud of the results of this painstaking process to recreate this masterpiece of condenser microphone technology.

• Dual Large Diaphragm Condenser Capsules
• 32mm P-CK-12 Edge Terminated Capsule
• Glass 6072AM Vacuum Tube Amplifier Stage
• Dual Custom-Wound T14/1 Output Transformers
• 9-Polar Patterns

Microphone kit comes as a complete system including:

• P-24 Microphone
• Stereo Power Supply
• 12-Pin Screw-on Stereo Cable Assembly
• Shock Mount
• Locking Padded Flight Case