Stam Audio SA-V76 Tube Microphone Preamplifier
Description
A replica of one of the finest sounding preamps in the world
History:
Considered the ?Rolls Royce? of preamps, the V76 was originally developed in the 1950s by the German Institute of Broadcast Technology. It earned its reputation based on some notable features: extremely rich harmonics and massive transformers, which was unheard of at the time. The V76 design centered around two V72 circuits in series, allowing up to 76dB of gain that could be pushed further with little loss. It also featured a low shelf feature, centered as either 80hz or 120hz on different versions of the V76, a design feature intended to allow control over the rumble of microphone stands. Its four tubes provide that unmistakable clarity and color that is synonymous with the top recordings of the 50s, 60s and 70s. A studio that still contains a V76 houses a recording jewel, and we can now provide that privilege to engineers of all budgets with our own replica.
Engineering:
The SA-V76 carefully follows the original circuit. It is of common knowledge that the V76 is made of two V72 in cascade series, and therefore yields 76 dB of gain, which can be attenuated with a 12 position gain switch. The signal enters a massive Sowter 1004 input transformer (0.5 + 0:30) that gives us the option to select between standard or high impedance, and from there it goes to a pair of NOS EF86 tubes that inject the first stage of this preamp. This stage of mid gain maintains the design of the V72 utilizing a 400mh choke to secure proper filtering and linearity. Once we pass the first stage the signal enters the second stage of the preamp where the 76dB of gain are achieved with a third EF86 tube and fourth E83F tube. Another 250h choke is added on this stage to maintain perfect symmetry and linearity to finally exit the unit through a Sowter 1110 (9:1) output transformer. The output of the unit also passes through a trim pot to cut excess level and not saturate modern interfaces, as well as making micro adjustments within 6dB positions and respective 3kHz and 120Hz filters as the original
Features:
The SA-V76 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-V76 is ready to go.
Components:
We have used the finest quality NOS EF86 and E83F tubes to recreate the size and richness of the original mic pre sound. The unit has Ohmite carbon resistors, Vishay capacitors and 1% precision matched resistors. We also utilize a Sowter input and output transformers, as well as two Sowter chokes, 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-V76, we?ll refund you
If you?ve used an original before, we?re extremely confident the SA-V76 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 tube preamp is for you is to put it through its paces. That?s why the SA-V76 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
History:
Considered the ?Rolls Royce? of preamps, the V76 was originally developed in the 1950s by the German Institute of Broadcast Technology. It earned its reputation based on some notable features: extremely rich harmonics and massive transformers, which was unheard of at the time. The V76 design centered around two V72 circuits in series, allowing up to 76dB of gain that could be pushed further with little loss. It also featured a low shelf feature, centered as either 80hz or 120hz on different versions of the V76, a design feature intended to allow control over the rumble of microphone stands. Its four tubes provide that unmistakable clarity and color that is synonymous with the top recordings of the 50s, 60s and 70s. A studio that still contains a V76 houses a recording jewel, and we can now provide that privilege to engineers of all budgets with our own replica.
Engineering:
The SA-V76 carefully follows the original circuit. It is of common knowledge that the V76 is made of two V72 in cascade series, and therefore yields 76 dB of gain, which can be attenuated with a 12 position gain switch. The signal enters a massive Sowter 1004 input transformer (0.5 + 0:30) that gives us the option to select between standard or high impedance, and from there it goes to a pair of NOS EF86 tubes that inject the first stage of this preamp. This stage of mid gain maintains the design of the V72 utilizing a 400mh choke to secure proper filtering and linearity. Once we pass the first stage the signal enters the second stage of the preamp where the 76dB of gain are achieved with a third EF86 tube and fourth E83F tube. Another 250h choke is added on this stage to maintain perfect symmetry and linearity to finally exit the unit through a Sowter 1110 (9:1) output transformer. The output of the unit also passes through a trim pot to cut excess level and not saturate modern interfaces, as well as making micro adjustments within 6dB positions and respective 3kHz and 120Hz filters as the original
Features:
The SA-V76 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-V76 is ready to go.
Components:
We have used the finest quality NOS EF86 and E83F tubes to recreate the size and richness of the original mic pre sound. The unit has Ohmite carbon resistors, Vishay capacitors and 1% precision matched resistors. We also utilize a Sowter input and output transformers, as well as two Sowter chokes, 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-V76, we?ll refund you
If you?ve used an original before, we?re extremely confident the SA-V76 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 tube preamp is for you is to put it through its paces. That?s why the SA-V76 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
- Sowter 1004 Input Transformer
- Sowter 1110 Output Transformer
- Sowter 1377 Pate Choke
- Sowter 1378 Plate Choke
- 3 EF86 Tubes
- 1 E83F Tube
- Original circuit and schematic
- Vishay/BC capacitors
- Trim
- Completely discrete signal path
- 76dB of Gain
- 48V phantom power
- Impedance selection
- 120hz cut
- Phase reverse
- Assembly by hand in Chile
- 2-year warranty
- 30-day money back guarantee