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

  • 1,87400


>>> 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-8600R is a 300B single ended audio power amplifier kit. This is a special edition for the diyAudio store that includes upgraded 2% REX50G Takman resistors. 

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

We are currently offering it in these configurations:

  • Deluxe Special Edition (SE). This is the TU-8600R, upgraded Takman resistors and a pair of Lundahl transformers for ($1,874)
  • A "Super Deluxe SE" version which additionally upgrades to a Japanese TKD 2CP601S stepped attenuator ($1,899)
  • The Lundahl Transformers (Pair) are also available for purchase by themselves, and are compatible with both the original TU-8600 and the current model TU-8600R ($650)
  • 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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