Officially Licensed Circuits Eclipse Valve


Officially Licensed Circuits

The Eclipse Valve is the first circuit to be offered exclusively by OLC, meaning that you won't find it anywhere else online. This circuit was developed by, yet OLC is the sole licensee. Please keep in mind that, as stated on the home page, OLC does not focus on sales pitches - but on customer service instead. The other kits have sold themselves and I think that these will, too. However, please don't hesitate to ask questions.

The Eclipse Valve is a low-voltage, all-tube, clean booster (approximately 16 - 20 dB of boost) using both halves of a 12AU7 / ECC82. This is a limited kit, although this is not intended to incite interest or affect pricing in any way. If it's popular, I'll make more available.

Purpose: To boost the signal and overdrive the input of your amp (or the next pedal in your chain). Keep in mind that boosters are best suited for tube preamps / amps, but people often use them to get different tones from other pedals in the chain, too.


  • Unlabelled switch: this is unlabelled for a reason. It is an input cap switch to make it a treble booster, but you can make it a "fat" boost. The caps are included to make it flat/treble, "fat"/treble, "fat"/flat, or two ranges of treble/treble, etc. I went with flat/treble in my prototype, but you can make this switch your own.
  • Tone: This is more than a low-pass filter. Counter-clockwise, the treble is rolled off -11 dB @ 2.5 kHz. At 12:00, the response is flat. Fully clockwise, the treble is boosted by approximately 3dB @ 2.5kHz and 8dB @ 10kHz. Simply put: it goes from dark to sparkly.
  • Volume: Ouput volume.


  • All-tube (no transistors or opamps)
  • unique
  • great tonestack
  • low-voltage (for your safety)
  • Operates on 12 VDC power adapter (included for US customers, see this FAQ for specs and a recommended Maplin unit for international customers)
  • Input / output / DC jacks are on the rear side of the pedal.
  • Power supply and tube included.
  • True-bypass, as usual.

Most recent forum threads

Where to find one?

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