• 2UBES VTX-1 Push-Pull Dual Triode Tube Microphone Preamplifier with WiFi Remote Control •

The 2UBES VTX is a modern adaptation of a classic 60's push-pull microphone preamplifier design from a vacuum tube recording console. It uses custom designed audio transformers, is managed by a microcontroller and controlled remotely via WiFi if desired. It has two modes, "Clean" and "Glow" which changes the first stage plate load from passive to active. "Clean" is a classic honest Triode sound. "Glow" mimics a Pentode tube for something more retro. Two useful sounds. Push-Pull design also sounds different than the more common single-ended tube mic preamp designs out there. Different harmonic content as Push-Pull tends to cancel even harmonics and sum the odd harmonics..


Motorized Potentiometer provides smooth, transparent remote gain adjustment via slider control.

sweepGreat Frequency Response:  -.38dB at 41.2 kHz.  Low Distortion: .018% THD + N @ 1 kHz

• Bar Graph level metering or Classic OG analog VU meter on OLED screen.

• Clear, visible illuminated pushbuttons.

• Remote AC power transformer puts the hum far away.

• Front panel Direct Input jack loves bass and guitars.

• Extra +15dB JFET Boost Stage up front brings those low level ribbon mics out of the mud.

• Highpass filters are 60, 120 and 240 Hz.

• -15 dB pad tames hot sources and allows use as line amp.

• 10 dB Output Pad allows front end to be overdriven for effect.

• Silent 48 Volt Phantom Power switching. 


Hand Crafted in Small Batches with loving care in Fort Lauderdale Florida USA.


Remote Control from Literally Anywhere:

• Connect with WiFi  directly or via your router to the 2UBES VTX's browser-based interface with your PC, phone or tablet for full remote control operation. In the studio or remotely from any spot on earth! Perfect for Streaming or Remote Sessions.  •


Optional WiFi Gateway/Router allows local or distant remote control of up to 8 mic preamp channels from one screen.

Subscribe to Home

VTX Vacuum Tube Microphone Preamp Features:

•  Fully Balanced 2 Tube Triode Push Pull Design.

•  Ample headroom of greater than +27 dBu output before clipping.

•  Custom-Designed AMI Audio Transformers based on Classic Vintage UTC A10 and A24. 

•  Clean/Glow switch which mimics a pentode tube in "Glow" setting.

•  Motorized Gain Potentiometer and relay control of functions allows full remote operation.

•  Remote Operation lets you to place the VTX Tube Mic Preamp near the mic and return to the control room at line level for a shorter mic cable,  better signal integrity and less noise.

•  All control changes are always written to memory so the unit always powers back up just as you left it. 

•  Full WiFi Connectivity for remote smartphone operation and DAW control and recall directly or via optional Gateway/Router.

• Two output levels: normal +4 dBu, and a -10 dB output attenuator for flexibility and ability to overdrive the input, if desired. 

•  +15 dB FET Gain Stage for ribbon mics and other low level sources.

•  1/4" Direct Instrument Hi-Z Input.

•  -15 dB Mic Input Pad. 

•  60Hz, 120Hz, 240Hz Low Cut Filter

•  Signal Polarity Reverse (Phase).

• + 48 Volt Phantom Power with muting function on output during switching.

•  External Low Voltage 12 VAC power source for safety and hum reduction.

•  Bright, crisp OLED display with both bar graph and classic analog meter simulation.

•  Optional Multi-Preamp Gateway/Router allows up to 8 VTX preamps to be operated from a single phone screen.

•  Full storage and recall of your favorite session settings by name with optional Gateway.

•  One Year Full Warranty, Materials and Labor.

•  Made right here in the USA. 


VTX Vacuum Tube Microphone Preamp Specifications:

Dimensions: 9"x 5"x 2"

Max Gain: 57 dB Typical

Tubes: (2) 12AX7 / ECC83

Max output at 1% THD: +27.5 dBu

Signal to Noise: 81 db Unweighted.

Maximum Input Level: +12 dBu padless.

Total Harmonic Distortion + N: .021% @ +4 dBu

SMPTE Intermodulation Distortion (IMD): .02% @ +4 dBu

Frequency Response: 20HZ -.5 dBr, 40 kHz -.3 dBr Referenced to 1 kHz.

Microphone Input Impedance: 1900 Ohms

Direct Input Impedance: 50k Ohms

Output Impedance: 600 Ohms

Low-Cut Frequency: 60, 120, 240 Hz

Power: 120 VAC .12A


Price: $2499 USD MSRP

For Sales Inquiries, please contact:

avn sys

AVN Systems

390 Cambridge St Rear

Allston, MA 02134

508-341-3499 | avnsys.com

Email: office@avnsys.com