Nest Theater Part Twenty Five ~ Willsenton R8 Push-Pull Amp For Center Channel Power 14Jun23

I know the speakers I'm building, while efficient at 90 dB/w/m, will need more power than the DRC BLHs. I studied available EL34 class AB push-pull amps, mostly Chinese for cost reasons, from Elekits & classic Dynaco kits to Line Magnetics and Prima Luna, and a relative newcomer, Willsenton. I preferred the LM34 for it's build quality and point-point non-PCB wiring, but it was price prohibitive, as was the Elekit 8600T. I chose the Willsenton R8 which is built in the same manufacturing plant as the Line Magnetics stuff and features a flexible design which takes either KT88 or EL34 power tubes and features P-P wiring and a remote control with volume. It has great reviews , but some quirks, and is better priced than many others. I bought the amp loaded with Psvane KT88 TII tubes for power & a preamp section of Psvane CV181 TII tubes & Tung-Sol 6SL7 GT tubes ~ a significant upgrade from the stock tubes. I bought direct from China and paid $1500; else I'd have to buy straight stock at a higher price in the US, and pay tax. I also even bought a quad of matched modern Mullard EL34s that I'm expecting will be my favored power tubes ~ seeking "ahhh, that EL34 sound." This is exciting new 25w/channel power for the new center channel of the NestT... and that seems almost a relegation for this killer new piece.

The new amp arrived from China in just 5 days with the EL34s still due from Amazon. The plywood cuts aren't yet made for the new speakers I'm making, so those are still in the future too. Nonetheless I tested the new power amp in COS to assure function and performance. All I can say at this point is wow. The R8 is hefty, solid, finely made, and gorgeous IMO, and it sounds fantastic even "just" with the KT88 power section. I first tested function with headphones and using my DP-X1 as a flac stream source; power up is a smooth but 30 sec long soft boot; biasing is manual and I adjusted to perfect with the simple front panel gauge; the remote works well but does not include power; the unit defaults to "CD" input independent of shutdown state; the KT88s in ultra-linear deliver more power, punchier bass and more forward high-end while triode mode delivers a fuller, rounder vocal range and less emphasis on highs & lows. But, heck yeah, the sound is excellent in either strapping,  with headphones corrected or even raw from source through amp to my head.

I took the R8 down to the Blodgett Theater and tested it driving my Paradigm Reference mains there; again I used my DP-X1 as a source. Blown away! The R8 is more musical than my Integra Research 7 AVR, making the latter premium SS amp sound clinical. So stoked to be adding this beauty to the NestT soon. If you have any inclination to try tubes, this amp is a spectacular value and musically awesome, at least with my Psvane tube upgrades.

It's worth noting that packaging from China was outstanding: double boxed with everything protected by foam. It was delivered in just 5 days by DHL, but yeah shipping and fees cost +$330. As mentioned prior I ordered mine with upgraded tubes and I received measurement placards on each tube in the mix (which allowed me to confirm the matching phase).

I lashed the R8 into the NestT audio paths to perform a shake down there as well, and complete some burn-in. I first drove the NHTs with the R8 as center channel on the NestT... holy shit, confirmed much more musicality than the NAD ~ much more dynamic with killer mid-range fidelity and much better definition in the bass & treble as well. I then swapped the ANK 300B SET amp from its spot driving the main L/R channels on the NestT and used the R8 there. I expected more of a difference, but I heard great things from the Willsenton driving the fronts though the bass wasn't as strong. The measured results without Dirac EQ were unexpectedly large, but with EQ on, the measured sweeps were very similar, and I surely could drive the mains way too loud with "all that power." The R8 is back on duty driving the center channel... all that is left now is a new pair of custom built DIY speakers, and center channel gear rack and speaker stand.

UPDATE 24Jun23... I received the four Mullard EL34 tubes and reconfigured the R8 to run them. I prefer these to the Psvane KT88s I originally bought for the for the power section. To my ear, while not as powerful (but plenty), they are more refined and dynamic in the midrange where the center channel will play hardest.