Yet another handcrafted product from QA! This is fully upgraded, prototyped and assembled locally in Singapore!
This product is essentially a 3 in 1; preamp, output buffer and headphone amp. It outputs a higher level of signal for power amplification with the added warmth of a pair of tubes from the 6J1 tube types and controllable gain. The controllable gain also allows a variable output to drive dynamic-driver headphones between 32Ω to 250Ω using the included adapter for 3.5mm input.
By situating this preamp between the source of your audio, i.e DACs and CDPs, not only can you control the signal level going to your power amp, the tube output buffer also adds a degree of sweet colouration of ‘tube-sound’ for power amplification. You need not turn up the gain of your power amp as high as before to achieve the same volume level now with this preamp, thus balancing the amplification load between this preamp and your power amp.
What goes into the formidably capabilities of this tube preamp is the choice of tube selection as well as the premium audiophile quality of the components used.
6J1 tubes are easily available but often they are presented as really basic and mediocre Chinese stock tubes. The tubes used here are premium version of 6J1; 5654W. 5654W is American version of 6J1. Not only are they more robust in construction and tube life, they are miles ahead in sound quality. By using NOS GE JAN 5654W tubes here, the sound from the tubes are already guaranteed top-notch performance.
Having one of the highest grade of tube output is insignificant if components in the circuits are not up to the standard of delivering the best signal they can. Hence QA went through the various and lengthy cycles of prototyping in ensuring we are getting the best matchings of capacitors components inside the preamp, knowing how much a difference the grade of capacitors can make.
Our faith in Vishay BC and Nichicon audiophile series of capacitors never disappoints, as they give the best audio presentation of soundstage and separation. Not surprising, Vishay BC and Nichicon have always been go-to audiophile grade capacitors and present in premium equipment no less.
To add to the grand arsenal of premium capacitors, we too used WIMA to finish the ‘Holy Trinity’ of capacitors present in this preamp. WIMA caps needs no introduction; made in Germany, they are one of the best, if not the best, film capacitors for uses in circuits. Sound depth is precise, and frequency spectrum is just defined altogether from the trio of these 3 brands of capacitors.
Knowing how important the signal paths travelled, tube sockets and RCA ports are all gold-plated components as well. Almost all parts in this preamp is as strong as they could be in their respective function, not to forget these components are all soldered with the renown and always-trustworthy WBT 4% silver content solder core. Together in tandem, these parts work within the small footprint of acrylic enclosure in the highest order to bring the sound to an audiophile performance level past its price-point.
The acrylic enclosure that house the internals are all manually hand-sprayed and ports-labelled from within, before all panels are assembled carefully. The final product is a uniformly-presented equipment in simple but sophisticated black; with even the screws and volume knob thoughtfully chosen for a wholesome match. While QA always do our best in our line handcrafted products, we do seek your kind understanding that such products are never free from imperfections. Performance are never sacrificed in anyway though.
This 5654W tube preamp can also function as a pure tube-output desktop headphone amp. Just plug the included RCAs-to-3.5mm adapter to the output RCA ports by matching the white dot to the white RCA port, and plug in your favourite headphones (32Ω to 250Ω). Sit back and enjoy the sweetness of musical notes and expanded soundstage inside your head.
12V AC adapter is included in the package. Straight out of the box, this 5654W tube preamp will perform as we intend it to be. If you think your audio system is still lacking in some way or another, this little tube preamp can almost definitely improves it. If you already satisfied with your audio turnout, we still wish you can give this a try; it might just surprise you with its abilities. Money-back guarantee with no question asked for any unsatisfactory performance of this tube preamp.
Preamp is switched on with the volume knob. Blue LED under the tube socket provides a contrasting look to the tubes orange glow.