Overview

Roland’s Quad-Capture UA-55 (2011, discontinued) is a compact USB 2.0 interface marketed as “4-in/4-out,” realized as two analog inputs with VS preamps plus coaxial S/PDIF I/O[1]. It supports 24-bit/192 kHz (note: 192 kHz operates at 2-in/2-out) and includes AUTO-SENS auto gain, VS Streaming low-latency drivers, USB bus power, and MIDI I/O[1][2].

Scientific Validity

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Manufacturer specs report 104 dB A/D and 109 dB D/A dynamic range, reaching a transparent baseline for project-studio work. Frequency response is 20 Hz–22 kHz (+0/−2 dB) at 48 kHz and 20 Hz–90 kHz (+0/−8 dB; +0/−2 dB to 60 kHz) at 192 kHz[1]. Independent, comprehensive third-party benches (THD+N, crosstalk) are limited, so this is a provisional assessment based mainly on catalog data[1].

Technology Level

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Solid for its era (VS preamps, AUTO-SENS, stable low-latency drivers) but ordinary by today’s standards where USB-C, built-in loopback, and higher converter performance are common. Still, packing S/PDIF and MIDI in a small bus-powered chassis remains practical[1].

Cost-Performance

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Using 349 USD as the UA-55 price basis, we select PreSonus Studio 1810c as the cheapest equal-or-better current comparator: it provides stereo S/PDIF I/O, MIDI I/O, four mic preamps, 24-bit/192 kHz, and specs of 110 dB (mic pre DR) / 112 dB (line DR)[3][5]. Official store price is 299.99 USD[4].
CP = 299.99 USD ÷ 349 USD = 0.86 → 0.9 (rounded to one decimal). As a pure price-for-capability metric this is strong, even though its measured performance trails recent interfaces[1][5].

Reliability & Support

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Build quality and driver stability were historical strengths, but support is limited now that it’s discontinued. Roland’s page indicates Intel-only macOS coverage (Apple Silicon not supported), constraining long-term usability on modern Macs[2].

Rationality of Design Philosophy

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A rational focus on measurable transparency (flat FR, adequate DR, stable drivers) is evident[1]. The “Quad-Capture” name can mislead buyers into expecting four analog inputs; the fourth pair is via S/PDIF—worth clarifying at purchase time[1].

Advice

If you need S/PDIF and MIDI in a compact unit, the UA-55 still works; for new purchases, Studio 1810c offers better value and current support with equal-or-better specs[3][4][5]. Existing UA-55 owners can keep using it on compatible systems and plan an upgrade if moving to Apple Silicon Macs[2].

References

[1] Roland, “QUAD-CAPTURE UA-55” product page (specs including DR/FR; 192 kHz = 2-in/2-out): https://www.roland.com/global/products/quad-capture/
[2] Roland, “QUAD-CAPTURE Updates & Drivers” (Apple Silicon not supported): https://www.roland.com/global/support/by_product/quad-capture/updates_drivers/
[3] PreSonus, “Studio 1810c” product page (features incl. S/PDIF/MIDI): https://www.presonus.com/products/studio-1810c
[4] PreSonus Store, “Studio 1810c” listed price 299.99 USD: https://www.presonus.com/products/studio-1810c
[5] PreSonus, “Studio 1810c” technical specs (e.g., Line DR 112 dB / Mic DR 110 dB): https://www.presonus.com/products/studio-1810c

(2025.8.21)