2005年1月14日 · I can personally vouch for the ruggedness of the Ei KT90 tubes. I had them in my Jadis for 5 years, one shorted (no damage to the amp), and the others still measure a little better than "pass". However, in the past week+, I retubed the Jadis with JJ E34L tubes, and the sonics are MUCH better.

The KT90 is a vacuum tube used in audio applications. Typically, it is used in hi-fi or electric guitar amplifier applications. KT90 was developed by Elektronska Industrija Niš (EI). KT90 is designed by Blagomir Bukumira, a leading engineer at EI.

2010年7月12日 · I tried a pair of Ei KT90 in exactly that mode. They sounded good, but perhaps a bit dry. In fairness, I had them biased at a very low 50~60 mA (B+ in the mid 400s).

2014年1月29日 · I've got some Ei KT90's and trying to identify the types. These photos show two of them. They have different boxes, though I'm not sure that matters. These two look quite similar, with the square "patch". I also have two with a circle …

2008年2月18日 · In my last batches of KT-90s from Ei over 95% had that exact problem right out of the box. The type III is the only series to have the problem, the type I and II did not have it. There WERE some good type IIIs made - but after the NATO intervention in the late 90s the quality was gone.

2012年10月27日 · How do you tell the difference by just looking at the tube, if it's a Type I, II, III or IV? I know the early type I and II were great. I know that early type IIIs were good and later …

The KT90 is a beam-power pentode primarily designed for use in audio frequency power amplifier applications. Anode dissipation rate is 50W, which provides for push-pull amplifiers utilization up to 110W output per pair, with 550V on the anode. Up to 160W per pair may be achieved with anode voltage of 750V and screen grid voltage of 600V.

For your consideration - a beautiful matched quad of Ei KT90 Type II! This version of the KT90 (easily identified by the numerous spot welds on the plate structure) is widely regarded as best sounding and most reliable KT90 ever made. For amps that call for 6550 / KT88 / KT120, these tubes are the gold standard.

2025年2月4日 · Offered here is a very rare matched octet of EI KT90 Type II power tubes made in Yugoslavia. These tubes were a joint venture between EI and Manley Labs in the early 1990's. The type two are identified by the many spot welds on the plates and are known to be the best sounding of the KT90 variants.

The Electro Harmonix KT90-EH tube is a drop-in for any KT88 or 6550 tube... bias your amp just as you would a KT88 and you're good to go! Sonically they are true to the Electo Harmonix brand; clear top end that is open but not bright or tizzy, tight bottom end, and a …