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Elekit TU-8600S 300B Single Ended Triode Power Amplifier/HPA Kit

  • 1,95000


>>> Please note that tubes are not included in this kit <<<

"A world-class, four-star 300B tube amp that should cost $20,000 but will cost you only about $2,000 because you've assembled it yourself"
Herb Reichert Stereophile Magazine March 2019

The TU-8600S is a 300B single ended audio power amplifier kit, replacing the old TU-8600R model.

We are selling a special edition for the diyAudio store. This special edition includes:

  1. Lundahl LL 2785B transformers, PCB board and HV connector 
  2. 81 x 1/2W 2% REX50G Takman resistors
  3. TKD 2CP601S potentiometer with conversion kit

The 8600S has been reviewed by Stereophile and is now a Stereophile recommended component.

TUBES ARE NOT INCLUDED, but are readily available. Here's starter, premium, and ultimate variations from a trusted diyAudio partner.


      Power circuit enhancement

      • High efficiency, low magnetic flux leakage R-core transformer
      • Schottky barrier diodes for shorter recovery time
      • Individual windings for the filament heater (A power), high voltage (B power), and bias to stabilize the negative feedback circuitry (C power)
      • All power stabilized to reduce residual noise as much as possible, resulting in a noise level as low as 1/10th of the TU-8300R

      Stable NFB circuit for high quality audio

      • Improvement to various parts and circuits including OPT to make the most of 300B tubes
      • NFB applied to cathode of 300B by the third winding of the OPT as well as to the voltage amplifying stage
      • NFB is minimized as well as transient response

      New active automatic bias adjustment

      • Bias power is supplied separately
      • New "Active automatic bias" used where the amp detects plate current and automatically adjusts the grid voltage, rendering the TU-8600 both self-biasing as well as having fixed bias.
      • Current detecting circuit moved from cathode side to the B power side for better sound quality

      Full power use of 300B tubes

      • Orthodox voltage amplification stage to make the most of the 300B's outstanding sonic characteristics
      • 12AU7 (ECC82) used in parallel for 2nd stage to drive the 300B tubes to full power resulting in 200Vp-p without clipping

      Tube friendly design

      • Warm up times for directly heated and indirectly heated tubes differ. Most designs warm up both at the same rate.
      • The TU-8600 heats up the directly heated 300B tubes after the indirectly heated 12AU7 / 12AX7 indirectly heated tubes have warmed up. 
      • This is a very tube friendly design that will not overload tubes that have not warmed up fully 

      Output level section for headphones

      • There are jumpers on the board to allow for headphone impedance matching

        DIY friendly design

        • The TU-8600 comes with high quality polymer hybrid electrolytic caps and polypropylene film caps, however extra space has been designed into the PCB for audiophiles to add (larger) after market caps


        • The TU-8600 operates at very high voltages, and includes a safety cover


        • Tubes: 300B x 2, 12AX7x1, 12AU7x2 (TUBES ARE NOT INCLUDED)
        • Rated output: 9.2W + 9.2W (10% THD)
        • Rated input: 320mV
        • Residual noise: 36uV (IHF-A)
        • Frequency response: 7Hz-40kHz (-3dB)
        • Input impedance: 50kΩ
        • Output impedance: 4-6.3Ω, 8-16Ω selectable
        • Input: Line1 (2 x RCA)
        • Output: Gold plated speaker output terminals (banana plug compatible)
        • Power input: 100/115/200/230V 50/60Hz (IEC inlet)
        • Power Consumption: 90W
        • Dimensions: 385x217x325mm (including projections)
        • Weight: ~12.6kg assembled

          Customer Reviews

          Based on 7 reviews
          My last amplifier..
          I built one. Thank you Herb Reichert!!!!!!
          Lundahl Upgrade
          A kit that is a joy to build, and to listen to...
          What a vacuum joy

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