Review : Stellar Labs DA-250 class D amp / Nobsound HiFi Alps 27 passive preamp

Budget Esoterica Review Magazine
May 2020 Issue

Stellar Labs /  Nobsound Alps27 tweakers delight

Today i will be singing the praises of another gem from the wizards at Stellar Labs. This time i will be reviewing the Stellar labs DA-250 class D amp. The amp is rated at 50 watts x 2 . So why do i like this piece so much? This is the amp that will finally prove to audiophiles that power cords indeed make a difference! If you like experimenting with power cords, then this amp is for you. I tried two very differently priced power cords with this amp, and i could clearly tell that the more expensive power cord made the amp sound better. The first power cord i tried,  was the inexpensive Burtman power cord weighing in at $50. The second, and much improved power cord i tried was a $300 plus Mad Scientist power cord. To keep this system in the budget realm, i added a Nobsound Precision passive preamp with Alps27 volume control to the mix. 

The Stellar Labs DA-250 class D amp measures 8.5" wide x 10.5" deep x 1.75 inches high. It weighs a solid 3.32 pounds. The amps are bridgeable at 8 ohms with less than 0.1 % THD. There is  a volume gain adjustment on the rear panel. Price is just under $75 at the Newark store. This amp is very easy to review. It is dead neutral and anything that you use with it, such as preamplifier, cables and cd player that has any character that deviates from that neutrality you will hear. The amp has a good ability to be tweaked as noted by the different results from trying two different power cords. I believe this can be a sign of a good amp.

Power amplifiers need to be used with preamplifiers and the Nobsound High Precision passive volume controller with Alps27 potentiometer and CMC pure copper rca jacks is an excellent place to start. This is known as the HiFi version, which has the upgraded volume pot and specialty rca jacks. It can be found at for under $50. You would think that all passive preamps sound exactly the same, but i don't think this is the case. I have 4 different passives , and they all seem to have slight differences. In the case of the HiFi version Nobsound passive, there seems to be a slight enhancement to the sound. Maybe a slight added smoothness, richness and liquidity to the sound, if that is possible. After all, passive preamps use different designs and parts just like amps do, which could justify small differences in sound perception of different components. Anyway, i do know that the preamp is a joy to use. The volume knob turns very smoothly and you can just feel the quality of the piece oozing out of its pores. This is a very solid preamp built like a small brick house. The finest i have used to date. 

I heard fairly good dynamics with the Stellar Labs / Nobsound duo hooked up to a  pair of Boston Acoustics speakers. While listening to the Neil Diamond song, "Soolaimon", from the best of Millennial collection, the bass dug considerably deep with a woody and textured sound. "Song Sung Blue", sounded slightly rich and pretty smooth. 

There is a song i liked to listen to from the very best of Darryl Hall and John Oates titled, "Method of Modern Love". The vocals had a good sense of rhythmic flow and a slight sense of bloom. I also heard a little bit of tube tonal color from the percussion instruments. The song, "Maneater". has the bouncy  and thick bass that i really like. I also noted a snappy textured sound. The horns were seductive and velvety.

Overall, i am pretty excited about the Stellar Labs / Nobsound HiFi preamp combination, and would have no problem recommending it to any budget audiophile. I have used the Stellar Labs amp on and off for the past several months and have had no reliability problems whatsoever. The Nobsound preamp, of course, looks like it could last a lifetime.
Two thumbs up! Move over, Parasound Zamp ?

Associated Equipment

Boston Acoustics VR-M50 speakers
Target speaker stands
Sony Dvd player
Musical Fidelity DAC with Mt. Fuji Tuning Blocks
Supra power strip
Audiomagic xstream power cord
Mad Scientist power cord
DH labs White Lightning x 2 stereo interconnect
Morrow Audio digital entry level interconnect
16 gauge speaker cable