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February 20, 2026Colotube triodes vacuum tube amplifiers 300 B monoblocs
RRP 24,000 CHF / £24,000 after taxes, Our trade-in set price: £12,000
*** WE will ship WORLDWIDE ***
We have for sale a super rarity, a pair of Colotube 300B monoblocks. Those are only made to order, fully prepaid. No dealers, price drops, etc. We came into their possession as a trade-in, and they are truly among the best 300B amps we ever heard. Everything is Premium there and screams quality, from the smallest details, through the parts selection, to a premium set of Emission Labs tubes, which come with the amps. Best to come and listen to them. If you are 300B aficionado, you will immediately understand what I am trying to say here.

Below are some details extracted from the manufacturer’s website: ( https://www.colotube.ch/en/reviews/ )
Colotube vacuum tube amplifiers are 300 B triodes monoblocs with a sinus power output of 9 watt. They are the result of many years of R&D. Both devices are built mirror-inverted – for the most sophisticated demands on design. Each amplifier is hand-wired and hand-assembled in our family business. Handmade in Switzerland – in its purest form.
Only components of the highest possible standards have been used, to optimize acoustic performance. Most obvious is the lasing 3 mm stainless chromium steel cabinet and its side parts in heartwood Wenge. The Pole Terminals and the RCA sockets are made by WBT, a German specialist. They are 24-carat multi-layer gold-plated and – as everything in and on a colotube – of highest quality. The tube sockets are made of Fluorpolymer (like Teflon), absorbing the vibrations coming from the transformer and the acoustic waves from the speakers. The Inox volume control with 26 positions has been improved by the Swiss jeweler Stefan Rüthy. Exclusivity and Design in the smallest detail.
All tubes are handmade today at Emission Labs in Prague. Built true to the original of the legendary Western 300B, but with the latest and highest quality material, each tube is numbered and has its test certificate. Pairs with similar test results are put together so that for both, the right and the left channel, we have similar conditions.
To bring amplification to its perfection, colotube uses one driver tube and one output tube. Handmade silver wire with a purity of 999.99 embedded in (like Teflon) builds the signal path. The Munddorf condenser with a dialektrikum from gold and silver only lies in-between, so that the auditory spaciousness
and the richness of the music shall not be lost.
The output tube EML 300B is comparable to the WE 300B. Thanks to their great experience and today’s highest quality material, Emission Labs produces this unique 300B tube. Thanks to the new heating, we have the lowest possible distortion.
The driver tube EML 20A Mesh is a DHT triode with an amplification of 20. The much wider plate distance guarantees lowest possible distortion. Due to the perfect interaction between the output tube 300B and the DHT triode driver tube 20A, odd distortions are nearly annihilated! What stays are the even distortion that you find warm and soft. In this development lays the secret of the unique sound of a colotube amplifier. You are warmly welcome
to test it. You will be thrilled. Promised!
We recommand that you use loud speakers with a high sensitivity of around 93 db.
Please note that you do not need a preamp when you have High Level (2V rms) equipment.
Below are some pictures of the actual amps,





