Stam Audio SA-V72 2-Channel Tube Microphone Preamplifier

Recreating a classic German tube preamp

The Stam Audio SA-V72 is a faithful two-channel replica of the vintage German V72 tube preamp.

History:
The V72 was originally developed in the late 1940s for German radio broadcast as a fixed gain microphone preamplifier. It?s big, rich sound led to it being incorporated into recording studios around the world, most notably used by the Beatles in the famous REDD 37 console, as well as by companies like EMI and Decca in their house studios.

The original unit has an appearance consistent with its times, being a solid metallic block with little in the way of interface. The Stam Audio replica, the SA-V72 combines the classic sound of the original with a modern interface for the best of both worlds for the user, without any compromise in sound.

Engineering:
Strictly following the original design the SA-V72 uses a Sowter input transformer with the original ratio (50+50/47K) with the option to select HI-Z 50 ohms (1:20) or 200 ohms (1:10), after passing through the input transformer the audio signal is amplified by two NOS EF86 tubes that in conjunction with high quality passive components provide us with an authentic tube sound and extremely rich harmonic distortion (THD), finally the audio passes by a Sowter output transformer with the same frequency response and ratio as the original (76k/600ohms) with everything being filtered by a critical Sowter choke which provides the necessary linearity for the correct functioning of the V72 preamp. The unit delivers a whopping 52 dB with a design capable of delivery the necessary voltage e in a convenient 500 series format.

Features:
The SA-V72 is a 1U rack standalone chassis. It features an adjustable gain control, an output trim pot, 48v phantom power, reverse polarity and a high impedance switch, all of which add to the versatility of the original. There is also a front mounted DI input. The original unit was also not configured for modern connections and required further components to interface with modern audio connectors, however the SA-V72 is ready to go.

Components:
We have used the finest quality NOS EF86 tubes to recreate the size and richness of the original mic pre sound. The unit has Ohmite carbon resistors, Vishay capacitors and 1% precision matches resistors. We also utilize a Sowter input and output transformers, as well as a Sowter choke, handmade in the UK. Although the most expensive transformers available, they are also by far the best sounding ones. It is on these points that other replicas choose to make savings or utilize more commonly available components, however our extensive research and testing has found our own approach to produce the finest sonic match to the original.


100% satisfaction guarantee ? if you don?t love your SA-V72, we?ll refund you

If you?ve used an original before, we?re extremely confident the SA-V72 will put a big smile on your face every time you use it.

However, if you?ve never touched the original before, as gear-lovers ourselves we understand that the only way to really know if this preamp is for you is to put it through its paces. That?s why the SA-V72 comes with a 30-day money back guarantee. This allows you to get it into your studio and see how it impacts upon your recordings. If you love it (and we think you will!), great?keep the unit and create amazing music with it. If not, no problems. Just send it back to us and we?ll fully refund your purchase. Don?t worry, whichever way you decide to go we will remain friends.


Technical Specs

• Original circuit and schematic
• Sowter input transformer
• Sowter output transformer
• Sowter choke
• NOS EF86 tubes
• Vishay/BC capacitors
• Completely discrete signal path
• 52dB of Gain
• Trim
• 48V phantom power
• Impedance selection
• Phase reverse
• Assembly by hand in Chile
• 2-year warranty
• 30-day money back guarantee