Audionote for sale driver#

The E元4s of the Cobra are from the Russian-American Electro-Harmonix, a matched pair or a matched quartet. The original Mullard “World Series” E元4 withstood 800V anode voltage, and Siemen’s industrial version up to 1000V! Why E元4? Why not RCA 6L6 or 807, or GEC KT88, or Tung-sol 6550? Or even Mullard’s own E元7 pentode from 1950 (made to compete with KT66)? I believe the answer is purely utilitarian: the E元4 is available in large quantities, and is technically solid, sturdy valve.

The answer is purely utilitarian: the E元4 is available in large quantities, and is technically solid, sturdy valve. In this company the Cobra is more like an exception. From here up, all amplifiers are either triode or at least single-ended designs. In Audio Note’s seven-level rating, the Cobra ranks the second lowest (Level One). The succinct description picks up what’s essential to Cobra’s performance: E元4 as the power tube, pentode coupling, Class A operation, and tailor made output transformers. “28 watts per channel from a pair of E元4 valves in Pure Class A Push-Pull Pentode operation, capable of driving a wide variety of speakers thanks to its Audio Note designed and made high quality double C-core output transformers.” But the question that has haunted me ever since is this: was there something fundamentally flawed – or not – with the PP pentode/tetrode designs (for example, I cannot believe that the crossover distortion would explain everything)? So much so that whenever possible, I’ve seized an opportunity: VTL IT-85, Kondo Ouverture, Audiolici A1/25, Uraltone PP E元4 (Mauri Pännäri), Copland CTA 401 etc., not forgetting Johan Bernström’s exciting Sentec M-30 mono-blocks from the turn of the millennium.

Audionote for sale driver#

They’re great with a suitable wideband driver or for running a midrange/tweeter horn in a multi-way system, and so on. I also went with the stream, and the VTL had to go. Push-pull pentode/tetrode amps didn’t go extinct, but they became questionable, in some circles at least, and the reputational damage seemed to hit especially the ones carrying Mullard’s fantastic invention from 1955: the power pentode E元4 (the parent company Philips introduced it already in 1949). It didn’t help that some of the pentode/tetrode PP amps, like my VTL 60 Anniv., were triode strapped, or had a switch for running the amp both in a pentode and triode mode. in introduction of the Sound Practices magazine in 1992, and the European Triode Festival a couple of years later. But was that the chicken or the egg? The SET community, bringing together the best brains from France, Japan and the USA, had become more powerful and influential towards the end of the 80s, resulting eg. This was no doubt partly because markets saw a growing inflow of higher sensitivity loudspeakers. Fairly soon the interest diverted away from such (push-pull pentode/tetrode) amps toward smaller power single-ended devices, preferably with directly heated triodes (45, 2A3, 300B, 211, 845 etc.). I thought it was a fine amp but apparently not. Ei’s business collapsed in the former Yugoslavia and so on) to acquire good quality KT90s (or any other tubes for that matter), but apart from that, the VTL was a valid Class A 60 watter, and not too different from what was available at the emerging tube amp markets: pentodes / tetrodes in push-pull pairs at the output and most often operating in Class AB. Now, it wasn’t exactly the greatest time in history (eg. When I refreshed the teenage hobby in the 90s, one of my very first amps was VTL 10th Anniversary Triode 60 Stereo Integrated Amplifier a special gold plated KT90 Class A push-pull device featuring larger octal tubes (6SL7 and 6SN7) for input and the driver, Mercury Magnetics VTO-100 output transformers, and passive volume controls, one per channel (the front panel pair of RCAs went directly into the input tube grids enabling the amp to be used as a stereo power amplifier).