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The TU-8200DX comes with these upgraded parts:

  • For the four coupling capacitors: Amtrans AMCO metalized PET film capacitors (0.1µF/630V) with gold-plated OFC leadouts.
  • For the four cathode bypass capacitors: Nichikon conductive polymer aluminium electrolytic capacitors (180µF/10V).
Note: If you prefer to choose your own capacitors, make sure you follow the factory ratings outlined here.

Key specs and performance based on stock 6L6GC tubes:

  • Rated output: 8wpc ultralinear, 8.2wpc pentode, 4wpc triode
  • Rated input: 340 mV ultralinear mode
  • Residual noise: 90µV (IEC weighting)
  • Frequency response: 12 to 50’000Hz (– 3dB)
  • Dimensions: 252 x 156 x 285mm (WxHxD)
  • Weight: 6.6kg assembled (excluding AC cord)

After inserting the 6L6GC and 12AU7 stock tubes and connecting the TU-8200DX to a pair of JohnBlue JB3F and Restek Radiant CD player, I plugged in the stock AC cord and confidently flicked the power toggle to ‘on’. The filaments inside the tubes lit up but the power LED didn’t. Although the user manual advises a 30-minute warm-up without playing music for the initial test, I decided not to wait and played a CD. Phew, there was music coming out through the speakers. Then I remembered. Whilst I did set the two jumpers to ultralinear connection, I did not set the jumper for the LED, thinking that jumper was a spare. It was an easy fix. Blue light or green? I opted for blue.

The power cord that comes with the Elekit is a two-prong plug with floated ground wire that looks identical to the one for the  Triode TRK-3488. I learnt my lesson last time where floating ground silenced hum. It took me no time to reconfirm that on the Elekit. I compliantly replaced the more expensive three-prong power cord with the humble-looking stock. As a general guideline, triode mode makes less power but is more articulate and airy. Pentode is more dynamic, deeper in bass and projects a sybaritic soundstage. Ultralinear gives you the best of both worlds by compensating triode lightness with fuller body and richer tone yet avoiding the bloating images pentode sometimes verges on. In critical listening the eventual sonic outcome depends very much on the synergistic effect between tubes, loudspeakers and the music itself, i.e. the genre, instrumentation and even sound engineering of the recording. When I listened to a guitar trio on triode driving the Dynaudio Facette, I wanted richer harmonics in the mid to lower frequencies. Switching to pentode I found the three guitars grew out of proportion and overlapped too much. That made me believe that selectable mode was still not everyone’s Swiss army knife if one does not find the right speaker match to begin with.

Nevertheless switching back and forth between the three modes on the TU-8200DX is not as simple as it appears. The selection is done by manually resetting a pair of jumpers (one per channel) on the PCB inside the chassis instead of through a three-step toggle switch from the outside. Elekit does not encourage the latter modification as changing the mode setting under power might damage the output tubes and output transformers. The manual further advises to unplug power and wait 10 minutes to let residual high voltages dissipate before changing the jumper settings. A word of caution: Read the inscriptions on the PCB. Be very careful when setting the jumpers for triode and pentode. The left and right channel are not mirror imaged. A good trick is imagining yourself to be a pilot flying this amp and those jumpers are your gyro horizon.

So, was new better than old? While the TU-879S was a single-ended circuit dedicated to pentode mode, the TU-8200DX offers much more versatility. That makes it a tough case to argue ‘no’ right from the start. With both old and new amps set to pentode fitted with PAДИO 6n3c (the Russian 6L6GC equivalent), I made a quick comparison. My A/B was instantaneous with two pairs of Klipsch Synergy F2 connected to the amps sourced from the same Oppo BDP-95 through Y-splitters. No unplugging or reconnecting necessary. All I needed to do was dial up the volume of one amp and dial down the other without interrupting the music. The difference in sonic attributes was not hard to notice at all.