This is one of our state-of-the-art design of hybrid power amplifiers, which combines both the advantage of a transistor amps high current drive (tight bass and good speaker control) and single-ended vacuum tubes amplification (warm and sweet sound with good depth, sound stage, and air). The output transformer of single-ended tube amplifier is replaced with a super high current, high damping factor solid-state transformer, which can output max. peak music power of 140W/ch at 4 ohm loading , this amplifier can even drive down to 2 ohm with reasonable loudness. Built-in over-temperature and over-current protection for safety operation even under extreme condition. The tube section is working in an optomized pure class A single-ended operation mode to achieve the purest and most natural tonal quality.
This amplifier equipped with 5U4G as tube rectification to futher enhance the "VINTAGE TUBE" sound, which make this unit even sound better than many pure tube amplifiers made by other brands. The pre-drive tube section can even use tons of different power tubes like 6550, EL34, 6L6, 6V6, 6F6, 6K6, 5881, 6CA7, KT66,KT77,KT88...etc. Different tube models give out different tonal quality as well as texture and density, please check our FAQ Q14 for sound char from various tubes. Just change a tube model , the sonic improvement can be bigger than change 5 expensive interconnects at the same time.
Also come with input level / gain control, this feature can make this amp use as a single input integrated amplifier, or use in multiple amplifier (bi-amp / tri-amp ) mode , and can easily balance the gain between different power amplifiers..
If you were unaware of this amplifier's construction, and you judged the sound quality by listening only, you would believe it was a pure tube power amplifier and not a hybrid.You can then have both the smooth and silkiness of single-ended sound with very good punch, rich and extended controlled bass.
Upper set of photos shows regular stereo version with solid-oak chassis option , lower set of photos shows the DUAL MONO VERSION, which can use as dual monoblock and output 300Wpk per channel with 8 ohm (balanced input only) , or use them as bi-amp configuration to drive bi-ampable speaker or dual speaker setup.
Customer feedback:
Albert at STL was wonderful to deal with, and the custom hybrid integrated tube amp he designed and built for me is absolutely fantastic. Albert incorporated every feature I requested, and built it from scratch in about 3 weeks. He asked me for feedback on chassis design and components, and even sent me progress photos. When it was all finished, fine tuned and run in, I picked it up… well, the sound from this piece was simply stunning. Mesmerizing, holographic/3D, wide soundstage, dynamic, powerful, silent background, organic… all the good stuff! The music floats between my Spendor speakers, and they seem to just disappear. Plus, the amp looks damn cool - I would describe it as “elegant industrial audio jewelry”. I used to have a Naim amp, which I thought was pretty good… but this amp is on an entirely different level. It’s a revelation to finally hear what a quality stereo can actually sound like. Do yourself a favour and consider buying from STL instead of getting a ‘name brand’ amp. You’ll be glad you did!
