IWISTAO Blog is the official platform of IWISTAO HIFI MINIMART, dedicated to high-fidelity audio and DIY electronics. We focus on tube amplifiers, output and power transformers, speaker enclosures, and Bluetooth audio technologies, including HiFi Bluetooth speakers, headphones, and tube-based acoustic systems. The blog shares product insights, technical knowledge, and practical guides for audiophiles and audio builders worldwide.
IWISTAO Tube Amp FU50 2x13W Triode Connection Class A Signal-ended MM Phono Headphone USB Decoder
FU50 Tube Integration Amplifier + Transparent Speaker 3 Inch Full Range.
Advantages of single-ended class A tube amp are that sound is pure and delicate, high-frequency extension of natural human voice, strings are very attractive, especially in triode connection was the most prominent. Because the operating point is selected on the linear characteristic curve segment, nonlinear distortion is relatively small, even harmonic content is high, but also very good sound effects, sound quality is beautiful moist, sweet and pleasant, like as the taste of multi-harp. The unit adopts shuguang tubes KT100 as power stage, this tube is an improved version of famous tube KT88 sounds fine, natural and smooth, mellow voice, has a very strong tube taste with expectations.
Designed with a switch for 5 signal inputs, they are MM phono, CD / DVD drive, USB decoder, AUX line, MP3/PC. And designed independence channel to exclude interference between different inputs to ensure no matter what audio input, the unit will not be impacted by other audio input and sound. And you can choose the different signal source according to individual needs.
IWISTAO Mono FU50 Tube Amplifier Singal-ended Small 300B with dual 6J4P Preamplifier
The unit used the power tube stage FU-50 (or rY-50), it is an original high-frequency emission control, her sister possession of the same series is famous 805 (FU-5), 807 (FU-7), 845 (FU-45), 813 (FU-13) and so on. After it is transplanted to Hi-Fi stereo, its middle and high frequency is transparent bright, airy, grainy good. When connected to a triode connection output, frequency response curve is closer to the famous king tube 300B, so called "small 300B". Suitable for the performance of the human voice, strings and so on. This tube looks simple, but was called extraordinary refined, is also being used in multiple tube amp manufacturers product.
This mono FU50 tube amplifier is positioned as a desktop sound system, which adopt a power adapter as power supply to save the space and reduce the weight to compare the traditional tube amplifier.
Whole casing of the power amplifier adopted aluminum alloy chassis and wooden panel, large gold-plated output and input terminals; mono design with class A single-ended output, the sound is bright and warm. And its preamplifier used 2pcs 6J4P that can be replaced by tube 6H4C, 6AC7.
The actual listening experience, sound neat, vivid and elegant, thick warm quality! High frequency delicate and elegant, quite expensive! Midrange sweet round, warm, aura! Low-frequency strong, dive deep, Tri-band balance, have strong tube taste, reduce grinding most of the digital sound, so that the sound more rounded and it don’t tire to listen sound.
