Hot Heads

Mic Pre/ Instrument DI/ Headphone Amp

Downloads:

Hot Heads Specifications

Hot Heads came about after a remote session where I needed a box that would let a performer do overdubs without necessitating a console. Hot Heads is that and so much more. Two channels of premium mic preamp/DI and a high power headphone amp with a monitor mixer serve a number of studio functions. Adding the Dante option turns Hot Heads into a complete audio interface. The mic preamps are premium quality, transparent, with a large gain range controlled by a small processor that sets the gain, monitors and controls the phantom power, and checks for defects in the mic line. The instrument DIs have variable input impedance and gain, to best match your instrument. The headphone amp senses headphone impedance and sets it's drive accordingly. It is able to drive headphones of low and high impedances to impressive levels. The monitor mixer mixes the mic, DI and line inputs to give each performer a mix of their own. It can accept balanced or unbalanced inputs, low or high levels and has modes to allow stereo, left only, right only, mono, mix-minus (left minus right) and reverse stereo (in case you get your ears on backwards).

Price:tbd

Overview

  • Mic Preamp:
    • THAT 1580/5171/1606 low noise, high headroom chipset featuring digital gain control, dc servos and transformer like balanced output.
    • The chipset is managed by an internal computer, allowing gain to be varied in 1 db steps from -8dB to + 73dB by integrating the pad control and gain control using a single knob.
    • The signal path is fully differential input to output, with a unique dc coupled front end.
    • Phantom power is monitored by the computer and turned off if an unbalance is detected, to protect the microphone.
    • When an external preamp is selected, external phantom is monitored and the mic is isolated from the preamp if an unbalance is detected.
    • The phantom power defaults to the off state to protect ribbon and dynamic mics from being accidentally plugged into a live circuit.
  • Instrument Preamps (DI):
    • Input impedance is variable from 125k to 3MΩ to best match your instrument.
    • Gain is adjustable from to 0dB or 30dB.
    • Compatable with Audio Simplified Amp Link to drive long line to amp without HF loss.
    • High headroom, transformer like, line level balanced output.
  • Headphone Power Amps:
    • High dynamic range, low noise, low distortion headphone amps.
    • 3w @30 Ω/chan
    • 150 mw at 1500 Ω/chan
    • dc servoed, dc coupled output
    • Power level is switched by computer to match headphone impedance
    • Output DC protection & turn on delay
    • ¼” & ⅛” jacks.
  • Low noise universal power supply built in. (No wall wart!)

Specifications

Line Inputs:
Nominal Level : +4dBu
Maximum Input level: +24dBu

Line Outputs:
Nominal Level : +4dBu
Maximum Balanced Output level: +27.5dBu into 600Ω
Maximum UnBalanced Output level: +22dBu into 600Ω

Frequency Response:
20hZ to 20kHz +0.01dB,-0.11dB

Noise level:
-90.5 dBa

Distortion:
THD: .00847%
IMD: .011%

Power:
Voltage Range: 80-246vac
Frequency Range: 47-63Hz
A/C Current:1.5A @115VAC

Dimensions:
width: 375mm , height: 42mm, depth: 100mm
width: 14.75", height: 1.75", depth: 4"

Possible Usage Scenarios

  • Practice Amp:
    • Mic to mic input.
    • Instrument to Instrument input.
    • Mobile device or computer to unbalanced stereo line input.
    • Headphone mode to L-R removes most vocals on practice track.
    • Musician can sing and play to track with ability to balance headphones to taste.
    • If desired, track can be passed to second PMA for another musician via buffered stereo line out.
  • Studio:
    • Mic to mic input, Mic output is passed to board at line level. (Alternatively, unit can be switched to Mic thru mode. The Internal mic preamp becomes monitor only, the board supplies phantom power and recorded mic preamp.
    • Instrument to instrument input, instrument output is passed to board at line level, eliminating the need for a mic preamp.
    • Instrument loop output can be patched to remote amp.
    • Studio monitor system feeds balanced inputs, can be stereo, mono, or dual mono.
    • Performer hears latency free voice and instrument, could also be mixed with full mix from board for “more of me approach”.
    • Stereo Monitor loop feeds additional units for complete studio system via buffered stereo line out.
  • Studio Drummer:
    • Room mic to mic input for good communication with band.
    • Mic output is passed to board at line level, if desired.
    • Metronome to instrument input allows drummer to set his own click level.
    • Metronome output is passed to board at line (or mic) level to print to track, if desired.
    • Metronome loop output can looped to other PMAs via unbalanced loop output.
    • Studio monitor system feeds balanced inputs, can be stereo, mono, or dual mono.
    • Stereo Monitor loop feeds additional units for complete monitor system.
  • Live:
    • Mic to mic input, mic output is passed to board at line level.
    • Instrument to instrument input, instrument output is passed to board at line level.
    • Instrument loop output can be patched to amp, buffered signal allows longer line.
    • Monitor system feeds balanced inputs, can be stereo, mono, or dual mono.
    • Performer hears latency free voice and instrument, could also be mixed with full mix from board for “more of me approach”.