Review: MyST PortAMP II & PortaDAC 1704 – contrast

Sound – PortaDAC 1704

What is smooth is the 1704. Throwing it behind the PortAMP II switches things up. Frequency responses that potentially extended beyond the bounds of Redbook, fade smoothly before 10kHz. transitional stereo zones reverse, favouring smooth bass over mid-range stereo gradients. Apart from the slow low-pass filter, high transitions change little.

The 1704 isn’t as fuzzy sounding as the Porta DAC 1866. It’s nowhere near as warm as a valve amp. It keeps THD and IMD low but absolutely tops out below the limits of 16-bit audio. Test signals topping out at 144dB return SNRs of below 98dB. In hi-res systems the 1704 is a physical performance bottleneck.

Of course, NOS DACs are popular not for absolute performance but for sound signatures. And the 1704’s gentle ring, smooth high end fall off, and bass-to-mids transition zone are beautiful, and while not a totally comfy listen, return a far comfier, mature listening experience than is typical today. And today, I am all about that listen. Further, connected to the BeoLab system mentioned above, the 1704 softener the 6000’s somewhat clangy highs and warms its bass.

Sound – the combo

PortAMP II and 1704 are too different, too idiosyncratic to truly enhance one another. The 1704 is mellower, softer, and fuller while the PortAMP II shows its balls to typical hard limits. Adding the 1704 to it drastically changes its sound. The reverse isn’t true. If you were looking for a NOS DAC to feed an amp, and had the ~850$ USD for an amp, the PortAMP II, which punches way above its price, is killer. But if you love the sound of the PortAMP II and a modern DAC, the 1704 may be too drastic a change.

End words

No holds barred: my pick for amp of the year is the PortAMP II. It’s got the power, the control, and the finesse necessary for the widest range of headphones. It is perfectly balanced from left to right, and nearly noiseless. Both its and the 1704’s batteries keep music pumping through an entire day of work. And, they allow you to forgo the hassle and potential for noise and hum of the mains. Their sounds contrast rather than complement one another, but if you’re in it for NOS, adding PortAMP II is a logical decision. It is also one of the best amps I’ve ever tested.