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WP: What are the main principles, technical reasons, construction details and such which distinguish this amp?

AS: As is well known, even slight variations in audio equipment can affect the sound, sometimes dramatically so. The Preciso incorporates solutions that work together to achieve the best results with the given parts and circuitry matched up to result in what we think is the best sounding amplifier possible for the size and price. This is crucial for our smallest model.

Past this general premise, some of the characteristics are:
  • Point-to-point wiring: We find that this is how to build up circuits that satisfy more of our requirements. It is far more expensive than printed circuit boards but leads to far superior results. How we affix the parts also is done in such a way as to shorten the wiring as much as possible and the wiring itself is accomplished with specifically selected cabling.
  • Optimization of amplification stages and reduction of their number: This requires careful design and control but makes better sound.
  • Use of pure triode tubes: Triodes are more linear and pure triodes are better than pentodes or tetrodes configured as triodes.
  • The chassis is made of aluminium in automotive paint with a broad scope of possible colors. The footers are solid brass and this combination makes for good mechanical and electromagnetic behavior.
  • Blend of right components: We chose our parts based on their performance in specific circuit junctures. We don’t pursue boutique parts for their own sake but rely solely on verifiable performance. What works well in one place might work less well in another.
  • Proprietary transformers: We design all our transformers and chokes which are custom wound for us and assemble them using special cores.

WP: Why did you pursue push-pull over SE?

AS: A good question. We favored push-pull because at this price it delivers better sound. A single-ended circuit in this application would be far more expensive.

WP: You mentioned two tubes in the final version while maintaining the same number of stages. Do the tubes work in SRPP?
AS: Previously we used both halves of the tube is a slightly different configuration. But the circuit with two different tubes sounds better. Now we only use one half of each tube so the input stage remains single-ended and is not SRPP.

Sound - discs used during the listening sessions: Stereo Sound Reference Record. Jazz&Vocal, Stereo Sound, SSRR4, SACD/CD;  Stereo Sound Reference Record. Nobu’s Popular Selection, Stereo Sound, SSRR5, SACD/CD;  Tron. Legacy, OST, muz. Daft Punk, Special Edition, Walt Disney Records, 9472892, enhanced CD + CD; Cassandra Wilson, Silver Pony, Blue Note, 29752, CD; Depeche Mode, Hole To Feed/Fragile Tension, Mute Records, CDBONG42, MS CD; Donald Byrd, The Cat Walk, Blue Note/Audio Wave, AWMXR-0009, XRCD24;  floating.point, Free Falling, self-made by Piotr Sczepaniak, CD-R; floating.point, State of Denial, self-made by Piotr Sczepaniak, CD-R; Jun Fukumachi, Jun Fukumachi At Steinway (Take 2), Lasting Impression Music, LIM DXD 038, silver CD; Linda Ronstadt, ’round midnight, Elektra/Asylum Records, E2-60489, 2 x CD; Linda Ronstadt, What’s New, Elektra/Lasting Impression Music, LIM PA 046, gold CD; Santana, Abraxas, Columbia/Mobile Fidelity, Collectors Edition, No. 06452, UDCD 775, gold CD;  Suzanne Vega, Close-Up, Vol 1. Love Songs, Amanuensis Productions/Cooking Vinyl, COOKCD521, CD; Laurie Anderson Big Science, 25th Anniversary Edition, Nonesuch, 79988, enhanced CD.

I received the loaner from Warsaw audio salon Audiofil where it was burned in, listened to and where something regarding the power switch was noticed. It has three positions and the sequence of settings is important. Mr. Andrzej Sztechman explains:
  • The switch is off in the middle position.
  • Push the switch down for a few minutes to warm up.
  • Then push the switch up to listen.