The BFK9000.
Loaded with New Old Stock JAN(Joint Army Navy) stamped 6CB6 pentodes designed to meet the high quality and reliability standards of the United States Military.
Manufactured by Sylvania, Philips, Radio Corporation Of America, and General Electric in the 1960’s-1980’s.


Switchcraft jacks and Alpha potentiometers flown on wires and firmly bolted to aluminum enclosure to avoid stress applied to circuit board.

Circuit board attached to enclosure with standoffs again to reduce stress and tension being applied to circuit board.
IC's are socketed, NOT soldered directly to circuit board to make easy replacement later if/when needed.
High quality long life high temperature low impedance electrolytic capacitors from Rubycon and United Chemi-Con.
5% NP0 capacitors in the power section and audio path.
5% metalized polypropylene in the PLL sections.
1% metal film resistors.
High quality 2A/25W medical grade 12v center postive DC power adapter is included. Only use 12v DC center positive power source included.
Engraved enclosure(NO STICKER!!!!)

The BFK9000 is an effects processor designed to process audio signals from your modular synthesizer.
VCO waveforms are an ideal source.
Guitar will also produce interesting results. It is recommended that you patch your guitar into a preamp with an envelope follower before the BFK9000. Crank the gain and then patch the envelope out into the CV input of the BFK9000.
The more gain you hit the audio input with the better the PLL's will track.

The higher the frequency the better the tracking.

Try cranking the PLL frequency to max then patching the output of the BFK9000 into a divider or pitch shifter down an octave or two.
Patch LFO's, audio rate VCO's, envelopes, envelope followers, sequencers, random voltages, rhythmic pulses into the CV input.

Signal flow of the BFK9000 is 2 6CB6 pentodes providing gain to drive 2 4046 Phase Locked Loop chips behaving as primitive oscillators in parallel, but not wired up like a traditional PLL you may be familiar with.
There is some conversation going on between the 2 4046's.....Something about an alien transmission of unknown origin scrambled with intermodulation and beating.

Frequency of PLL pitch and amount of PLL influence level for each 4046, 1 set on the left and 1 set on the right.
Tube gain is maxed at full gain, no knob.
1 switch for each PLL that controls the behavior characteristics of each PLL.