Vintage Ampex 403 Mic Preamp w/ UTC HA-100X & HA-133 Transformers
Vintage Ampex 403 Mic Preamp w/ UTC HA-100X & HA-133 Transformers
Vintage Ampex 403 Mic Preamp w/ UTC HA-100X & HA-133 Transformers — sourced facts: Tape speeds: 7½ and 15 ips, selected via convenient motor and equalization switches.; Frequency response: At 15 ips, 30 Hz to 15 kHz within ±2 dB; at 7½ ips, 40 Hz to 10 kHz ±2 dB or 30 Hz to 15 kHz ±4 dB, depending on equalization.; Sig
Specifications
| Tape speeds | 7½ and 15 ips, selected via convenient motor and equalization switches. |
|---|---|
| Frequency response | At 15 ips, 30 Hz to 15 kHz within ±2 dB; at 7½ ips, 40 Hz to 10 kHz ±2 dB or 30 Hz to 15 kHz ±4 dB, depending on equalization. |
| Signal-to-noise ratio | Over 65 dB unweighted and exceeding 55 dB by NARTB standards, including bias and erase noise considerations. |
| Wow and flutter | Under 0.2% RMS at both speeds for stable playback quality. |
| Controls | Relay-operated pushbuttons for Start/Play, Stop, Fast Forward, Rewind, and a separate Record button enabling safe switching. |
| Transport mechanics | Three motors managing capstan, take-up, and rewind functions, delivering fast tape speed stabilization and minimal tape movement after stopping (less than two inches at 15 ips). |
| Head design | Complete lug-in plug-in head housing with erase, record, and playback heads for easy maintenance and versatility. |
| Playback timing accuracy | Approximately 0.2%, meaning around 3.6 seconds drift over a 30-minute recording. |
| Audio resolution | 10 kHz |
| Tape format | Full-track recording, half-track playback on ¼-inch tape. |
|---|---|
| | Size | 11 MB |
| Format | Eurorack |
| Physical dimensions and power | Console or rack mountable, operating on 115V AC at 2 Amps, with durable build suitable for professional studio applications. |
|---|---|
| Power | 115V AC at 2 Amps, with durable build |
Fit and constraints
Intended use
Constraints
To use it
Comparison
Questions
Can you confirm exactly what is included in the sale and show it in current photos?
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Are there any functional issues, repairs, or missing parts not shown in the listing?
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Can you provide close-up photos of wear points, serial numbers, and any modifications?
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Description
Ampex microphone preamp in excellent condition. Finish: gray metal, black, cream/beige.