Audiophilepure

After multiple dedicated listening sessions over many weeks, with dozens and dozens of albums, the amplifiers never rose more than a few degrees ambient room temperature. These will happily drive whatever speakers you might choose to use. These could very well be the last amplifiers you’d ever need to buy. I’d be hard pressed to find a need for more power than these can offer and the ability to upgrade the sound stage in years ahead makes this a no-brainer.

Final Thoughts

Testing the preamplifier by itself and using the RCA digital input jack, the results of activating the three available digital filters on the frequency response with 16/44.1 sampling are shown below in Figure 21. The digital input was 0 dBFS which means full DAC analog output into the preamplifier section, The Volume was set to 48. Each filter delivers a different roll-off response at 20 kHz. You just need to try them all to see which one you prefer. Filter 2 gives the most high-frequency roll-off, and this will make the sound a bit smoother. Since this Class D amplifier has quite a bit of high frequency distortion, start with Filter 2, and then switch to the others, using music that has a lot of high frequencies, such as violins.

https://www.stereophile.com/content/primaluna-evo-300-hybrid-integrated-amplifier

The PrimaLuna EVO 300 Hybrid disrupted my preconception that pure tube amps are superior to amps with a solid state component. From the first note, the EVO 300 established itself as a modern classic, reproducing music fresh-scrubbed, juicy, spatially adroit, dynamically adept, and powerful. It possessed the liquidity and richness of a good tube amp, never crossing over into syrup or schmaltz. It boasts an undeniable aliveness that grabs you from the first note and never lets up. It’s got drive. It engaged me in the music for many blissful hours.

I’m no longer agnostic regarding hybrid tube/solid state integrated amplifiers, let alone committed to the all-tube approach. At least when it comes to the PrimaLuna 300 EVO, I’m a hybrid believer.

https://www.stereophile.com/content/ta-r-2500-r-multisource-receiver

While the R 2500 R was situated in the office, I tested it as a USB-connected computer audio interface, with my aging Lenovo desktop PC. I downloaded and installed the T+A Windows USB driver with no problems, and the R 2500 R was immediately recognized and worked as expected with no further tweaking. I did some production editing and CD authoring using the T+A amp instead of my regular RME soundcard, and everything worked as expected. Based on all the listening I did from the computer, I’d say the R 2500 R’s DAC is pro-grade as far as neutrality and the smooth operation of its USB driver. I also plugged a bus-powered Western Digital hard drive into the USB socket of the R 2500 R. Using the phone app, I was able to navigate the file menus and play anything I desired. It was in this mode that I first experienced the R 2500 R’s excellent DSD DAC, playing files ripped from SACDs. My ears perked up, because I heard a clarity and naturalness that not all DACs seem able to convey from DSD material.

https://www.soundstagehifi.com/index.php/equipment-reviews/1868-chord-electronics-ultima-integrated-amplifier

It’s been some time since I’ve had a Diana Krall album on repeat play. But knowing how dependable her recordings are, I thought I’d give in to my hidden desires and listen to “Dancing in the Dark” from The Look of Love (24-bit/96kHz FLAC, Verve Records / Tidal). This choice was rewarded, as the Chord Ultima Integrated bathed me in a smooth, sweet, and detailed presentation that felt effortless. The rasp of the shaker positioned to the right sounded distinct and present, yet had a velvety texture. Krall’s unmistakable voice was ever so real, her expressive intonations and varied tone beautifully rendered by the Chord amplifier. Double-bass plucks were full and tuneful, well endowed with instrumental timbre. I was most impressed with the realism of the woody strikes on the slit drum. The Ultima Integrated laid out the images across a dark, elegantly lit soundstage. The images possessed soft contours—no cookie-cutter outlines here. These images appeared on a black backdrop, with nothing in between to detract attention from them. The soundstage width remained within the outer edges of my loudspeakers, though it stretched out more deeply than my front wall.

https://www.stereophile.com/content/octave-audio-mre-220-se-monoblock-power-amplifier

Pre-measured tubes arrive in a separate box, with amplifier positions labeled for the power tubes. If you use these, you’re golden. If you want to roll tubes, manual bias adjustment is necessary. Turn the front-panel bias selector knob to the tube you wish to bias, then use the supplied small screwdriver to adjust the trimmer screw next to the tube. Yellow and green LEDs located between tubes V2 and V3 indicate if bias is too low, correct, or too high. Combinations of yellow and green allow you to tweak bias higher and lower according to tube choice and loudspeaker type. Sayeth the manual, “Certain loudspeakers may benefit from the higher bias current, as it will increase the damping factor and provide slightly better control of the speakers.” BIAS Low corresponds to a plate current of 33mA, and BIAS high to a plate current of 40mA.

The low end side of the spectrum is an easy bit to explain. Most powered subwoofers utilize class D amplifiers internally, and the application here seems to exemplify why. The bass response through all speakers demoed was tight and detailed. If you are looking for bass control, are a self-proclaimed bass head or find yourself with a proclivity towards dance or electronic music, you might find yourself in favor of the Naim Uniti Nova PE vs. the Star. There was slightly more bass energy overall, and things were much more controlled across the scene. Subtle nuances in low end instruments could be picked out easier, and there was just more low end information to ingest. Of all the bits and bobs about the listen, this was perhaps the clear winner for the PE version. If you are struggling to get the most out of your low end, check out the PE in the all-in-one category. The 150 watts is really able to provide the necessary shove for big drivers in that regard.

In terms of the big picture, the PE really seems to provide a lot of that same dynamic shove across the frequency spectrum. There is a palatable energy to the sound that could be viewed as more than the sum of the parts here. Compared to both the Naim Uniti Star and the 300b Woo Audio WA5, there was just a bit more thrust and metaphoric “crackle” to the picture. In one of my partnered listening sessions a friend played a very solid, relatively simple track featuring female vocals, some light backing instruments and no percussion. Upon switching back and forth between the Nova PE and Star the impact was noticeable and echoed confidently by the company. An experimental success of sorts from an enthusiastic, but relatively un-HFi-educated outside observer. This distinction took place despite the usual “Rage Against The Machine” track or high-drama electronia typically used to showcase this genre of sonic clout.

https://www.stereophile.com/content/triode-lab-2a3-evo-integrated-amplifier

Another EVO, the PrimaLuna 400 EVO tubed integrated ($5995), is capable of outputting a whopping 38Wpc into 8 ohms. It produced a bigger soundstage, but it lacked the bloom and sweetness of tone the Triode Lab produced. The PrimaLuna was more energetic and produced more detail, yet somehow I felt less connected to the music—and that is something the PrimaLuna excels at. Compared to the 2A3 EVO, the music kept its distance. The PrimaLuna on paper has more to offer: It can drive a wider variety of speakers and power tubes, includes a headphone amp, a MM phono stage, remote, triode/ultralinear switching, more inputs, subwoofer, and tape outs. Nothing comes free!