Beamer Pentode Preamplifier
Instrument (DI) input on both channels. XLR Line inputs and input line transformers are omitted on the standard version.
The line inputs can be very handy on the Beamer, though. They give you a chance to run balanced line signals through the preamp. Add color to recorded tracks. Plug a mic into the Channel 1, then feed a compressor with it, and then in turn feed the second channel from that compressor. If you put the 2nd channel into the pentode mode and drive it just below the clipping point, you’ll get a very saturated, in-your-face sound that’s about to explode! Try this on a rock or blues vocal.
You can add the XLR line inputs with dedicated transformers as an option on the Beamer’s shop page for $200.
Design concept: (tube) pentode hybrid preamp, transformer input and output
2 channels: 1 Berliner’s and 1 Creamer’s channel
Switchable input impedance (for mic input only): 900Ohm, 10kOhm, 2.4kOhm
Instrument (DI) input impedance: 3.9MOhm (Berliner side) and 2.2MOhm (Creamer side)
Output mode: Transformer or solid state balanced driver
Low/high frequency shelving boost, corner frequency varies (see manuals)
Frequency response: 10Hz-50kHz +/- 3dB
Maximum gain: 76dB/50dB (mic/instrument), Berliner side; 74dB/48db (mic/instrument), Creamer side
Gain control range (Berliner side only): 36.7dB (for mic input, Pad switch adds another 10dB)
Harmonic distortion: <1% before clipping level (Berliner), <2% (Creamer), quickly decreases if driven less.
Maximum output level: 32dBu
Minimum output load: 600Ohm
Connectors: XLR mic and output, balanced only
Instrument input: 1/4” unbalanced, mono
Power consumption: 40W
All supply voltages regulated (including heater)
285V Plate voltage for huge headroom
Gold plated printed circuit boards with a double copper layer.
Gold plated tube sockets
The Beamer can be ordered with Ni-Fe alloy or pure Steel output transformers:
Beamer A: 2 Ni-Fe alloy core output transformers
Beamer B: 2 pure Steel core output transformers (the choice of most people)
Beamer AB: Ch1 with Ni-Fe transformer, Ch2 with pure Steel.
Please specify mains voltage when ordering: 115VAC or 220-240VAC.
Different input impedances available on special request, please call or email.
We give a one year warranty on parts and labor.
Here’s the SOS’s Sonic Farm 137th AES booth report: