Double Triode Limiter

Where the great sound begins?

The Double Triode Limiter (DTL) is more than classic tube triode microphone preamp. The old-fashioned design was upgraded with a musical opto-limiter. The limiter is based on circuit used in 60’s and 70’s.

Tube amplification in your hand.

The Preamp.

The DTL is a tube microphone preamp adapted to work with any type of microphone. A wide range of amplification makes it possible to record drums as well as the quietest ribbon microphone. DTL does a great job of recording tracks from external devices such as synthesizers or drums machines (like Akai MPC). Great results are achieved with reamping tracks from DAWs. The DTL adds a nice tube saturation to the sound. The high impendance inputs (HiZ) allow for connecting an electric or bass guitar directly into the grid of the first step of tube amplification (Typical HiZ solution).

Legendary opto-compression as well.

The Limiter

Additional device capabilities are activated by the Limiter section. This can be used to limit peak levels of the input signal. The component in charge of compression is an IGS Audio custom designed photocell. When the limiter is working it is indicated by a LED labeled “Limit” on the front panel. The limiter controls the louder parts of the signal and prevents from the digital clipping at the inputs of you ADC. Another trick could be using the DTL as a drum compressor or mix buss compressor. It can improve the overall dynamics of the mix and give it a brighter sound. This is a very versatile device for audio processing.

Full of features.

The audio path of the preamp is a two stage tube amplifier with individual drive on both steps. The saturation at the first step depends on the input signal level (with possibility to use Pad -20dB). The saturation of the second step is dependent on the Output regulator. Inputs and outputs are balanced with Sowter (UK) and Edcor (USA) transformers. The anode voltage is set close to 300V DC. For each of the channels Output and Limiter threshold can be regulated smoothly. The featured switches are: GAIN, +48V, Mic/HiZ, Phase, Pad -20dB. Hi-Z inputs are located on the front panel. The meters show output signal level.

More dBs? No problem.
  1. Download
  2. Specification
  1. Device type
    Optical Compressor Yes
    Input & Output
    Input Pad Yes, -20 dB
    Input Impedance (balanced) 300 Ohm, Carnhill transformer or 1M Ohm for Hi-Z instrument input
    Phantom Power Yes
    Output Impedance (balanced) 600 ohm, Carnhill transformer
    Audio transformers Yes
    Levels
    Operating Level +4 dBu
    Max output level +22 dBu
    Max. gain 60 dB
    Max Gain Reduction 18 dB
    Bandwidth
    Frequency response 20Hz to 20kHz; +/- 0.3dB
    Distortion (@ 20 Hz - 20 kHz)
    THD+N <0.1%
    Front Panel
    VU Meters Yes, output level
    Power
    Voltage 115/230V AC, 50 - 60Hz
    Power consumption 40W
    Power supply internal
    Packing box
    Dimensions 70x50x30 cm
    Shipping weight 7kg
    Others
    Tube set 6N1P, 6N2P
  2. Files
    DTL manual v1 pdf.pdf