Tube Console Preamps – Racked / Serviced / Modified
Racked and ready to rock! Found throughout Gates broadcast and recording consoles of the 1950s and 60s, the M5215A preamp is a popular two-stage design employing EF86 tubes. In addition to racking, these preamps have been recapped, serviced and modified. Negative feedback manipulation recently popularized by industry-leading tube preamp manufacturers has been implemented, provides recording engineers with additional functionality and versatility implemented through modifications to the stock circuit. Powered via custom external linear power supply using a Hammond power transformer with DC heaters.
$2795 + Shipping
CONTROLS:
- INPUT – Variable stepped input padding, pre-input transformer.
- POL – Standard polarity / phase switch
- NFB – Negative feedback control. Functions similar to gain with clockwise rotation increasing gain, but also altering the harmonic content of the preamp, with more THD present as the gain increases
- LF – Manipulates the low frequency inside the negative feedback loop. Counterclockwise is stock, while switching clockwise provides low end boost. The amount of boost is impacted by the NFB knob, in that with the NFB control fully counterclockwise, the LF switch has the most impact on frequency response.
- O/P TERM – Terminates the output transformer with a 600 ohm load, which is required for stability purposes. If linked to equipment with 600ohm inputs, the switch can be flipped down to avoid loading down the output section, but with interface inputs the termination is required.
**With both NFB and LF at counterclockwise position, the preamp operates in stock configuration**
