Retro Instruments OP-6 Portable Amplifier
Portable Tube Mic Preamp
PreampPrice not published
Specifications
- Type
- Preamp
- Description
- Portable Tube Mic Preamp
- Topology
- all-tube/valve, transformer-balanced input, choke-loaded transformer-balanced output; recreation of the RCA OP-6 remote-pickup amplifier
- Signal path
- Analog
- Channels
- 1
- Channel format
- mono
- Form factor
- Portable carry-case chassis (not rackmount)
- Powered
- IEC inlet, internal universal supply, 115/230VAC
- Frequency response
- ~50 Hz–10 kHz ruler-flat into 600Ω load per third-party bench test; rises at extremes and with high-impedance loads
- Sensitivity
- Max gain 72.5 dB, min gain -4 dB; max mic input +12 dBu (pad engaged); max output +18 dBu
- Impedance (Ω)
- 37/150/600Ω selectable (measured ~42/150/580Ω)
- Country of manufacture
- USA
Details
Controls: Stepped gain control (0–23), input impedance switch (37/150/600Ω), power toggle, rotary output attenuator, 6-way VU meter selector, phantom power toggle, polarity invert, 25 dB input pad
I/O: XLR mic input, 1/4-inch TS instrument input (auto-switching), XLR output
Notable use: Barry Rudolph; Glenn Rosenstein (compared it favorably to an original RCA OP-6 in a blind listening test)
Notes: DISCONTINUED. Manufacturer's products.php explicitly lists this as 'OP-6 Portable Amplifier (DISCONTINUED)' and the direct product URL no longer renders a spec page — it now redirects to a generic testimonial/reviews template with no product content. All technical specs above are sourced from Sound on Sound's independent bench review, not the manufacturer catalog, and should be re-verified before publishing. Recreates the vintage RCA MI-11202-A 'OP-6' broadcast remote-pickup preamp (original used 3x 1620/6J7 pentodes + 6X5 rectifier; Retro's version adds paralleled secondary valves for lower noise, removable for authentic RCA-mode operation). SoS review listed price as US $3,500 / UK £3,324 inc. VAT at time of review (not current, not manufacturer-published) — left price_usd blank since the product is discontinued and no current MSRP exists.