Ys Audio Balanced A1
Dual Mono Valve Preamp

At the core of most high-end systems is a dual mono preamp and a pair of mighty monoblocks. Further serving the goal of total channel separation, fully balanced XLR-terminated cables typically feature throughout. The entry price of such a no-compromise system architecture is typically formidable but the benefits are undeniable. If only there was a way to do this on a smaller budget . . .

Well, now there is. Take one XLR equipped DAC (starting from as little as £270), connect via a modestly priced balanced interconnect to this stunning A1 Preamp, then XLR out to a pair of £175 Pop Pulse amps that now function as 70W x 2 Tripath monoblocks: a fully balanced system for little more than £1000. Just add a PC and speakers.

We searched high and low for a high specification (preferably tubed) preamp to provide the warm, full blooded heart of our budget balanced system, and found it in spades in the shape of the Ys Audio A1 Preamp: a truly hand-made labour of love point-to-point hand wired by designer Chui Yat Sang in Hong Kong.

Innovative problem solving in the Balanced A1’s Class A, + wave auto-balance circuitry offers wonderfully realistic, dynamic, open-sounding music that will please the ears and stir the soul of even the most discerning listener. The gain stage of the main circuit is a fully balanced design, each channel using one 12AT7 and one 12AU7 vacuum tube to form zero negative feedback (0 NFB). The A1 line stage employs specialized tubes to project a clean, fresh soundstage while effectively preventing RF and vibration interference. The low impedance output stage is defining yet truthful to each note.

The Balanced A1’s application of a highly efficient solid-state regulator in the HVB+ power supply produces a sonic quality that is completely stable, lively, and rhythmically true to its source. At the heart is an extremely quiet power supply comprised of a fast, large current, R-core transformer. The shortest possible cable connections inside are the signature of the Mr. Chui ’s master craftsmanship.

The best independent testimony to the excellence of this preamp, and Ys Audio's other products, is perhaps found in Audiogon's customer feedback pages here >

Specification:

• Frequency response: 8Hz - 230KHz (-0.5db)
• THD: < 0.03% (20Hz - 20KHz / 2V)
• Gain: 17db (Balanced), 12dB (SE)
• S/N: > 99dB
• Channel balance: < 0.2db (20Hz - 10KHz / max output)
• Channel separation: > 90db (2Hz - 20KHz)
• Input impedance: 100K ohm
• Output impedance: 650 ohm (balanced), 325 ohm (SE main)
• Recommended load: 18K ohm or greater (balanced)
• Phase mode: normal
• Max output: 46V
• Line stage tubes: 12AT7 x2 / 12AU7 x 2
• Four inputs via XLR or RCA
• 12 month UK warranty / 240V