ART TubeOpto 8

Controls: Per-channel input gain, per-channel variable output level, pad, phase flip, low-frequency roll-off switch, LED meters and clip indicators per channel

I/O: 8-channel ADAT lightpipe digital I/O (24-bit, 44.1/48kHz); 8x balanced 1/4" TRS analog outputs; 2x front-panel high-impedance instrument inputs; wordclock in/thru for multi-unit sync

Notable use: 8-channel ADAT expander built around 8 Class-A discrete tube mic preamps (2nd generation); supports up to 70dB clean gain plus deliberate tube-driven warming/soft-clipping character

Notes: LEGACY/DISCONTINUED: this product lives under ART's own '/legacy/' URL path, meaning ART itself categorizes it as discontinued/no-longer-current; source set to 'researched' rather than 'catalog' for this reason. It is included in this batch anyway because it is explicitly named in the task brief as a well-known classic ART preamp. phantom_power left blank: not explicitly stated on the fetched ART page even though the unit is described as having 'mic preamps' — leaving blank rather than assuming +48V per the no-guess rule. frequency_response, impedance_ohms, power_watts, driver_config all left blank: ART's own legacy page does not publish these specs and no manufacturer figure was found, so nothing was fabricated. analog_or_digital set to 'hybrid' as a judgment call: the preamp stage itself is analog tube circuitry, but the unit's primary output path is digital ADAT lightpipe (the analog 1/4" TRS outputs are a secondary path). rack_units set to '1' based on description as 'housed in a single rack space unit.' price_usd is uncertain: secondary-market figures varied widely, from a completed Reverb used-listing price of $340 to an Equipboard aggregator 'starting from' figure of $877.59 (which may include new/rare/inflated listings); used the lower, more concretely-sourced $340 figure as the reported price_usd but flag that this is a rough secondary-market estimate, not an MSRP, since the product is discontinued and no longer sold new by ART or mainstream dealers (B&H listed it as 'No Longer Available'). year_intro and country_of_manufacture not stated anywhere found, left blank.