Pioneer F-91 FM/AM Tuner

Here we have a vintage tuner from Japanese company Pioneer. The F-91 FM/AM Tuner was part of Pioneer’s “Elite” series and dates from the late-1980’s. Our example is in good condition for its age with some light marking – please see photographs. It will be professionally packaged and comes with reprinted manual plus our usual three month warranty.
Pioneer Say….
We’ve pushed the level of FM sound quality to record highs with the addition of two Pioneer exclusives to the F-91.
The first is the ARTS (Active Real-Time Tracing System) included in the IF section of the tuner. With some tuners, especially expensive ones, you have the choice of using a narrow or wide IF bandwidth. The first lets you avoid interference, but you have to settle for an in­ crease in distortion. The second provides lower distortion and better sound, but interference may get in the way. Pioneer ARTS – it’s simply the best of both worlds: its IF filter actively follows the desired signal while rejecting interference. Now you can enjoy both the low distortion of a wide bandpass and the high selectivity of a narrow bandpass. Sensitivity is improved, too.
The second Pioneer feature is the Digital Direct Decoder Type III. It takes the output from the ARTS IF circuitry and converts it into digital form before directly turning it into stereo analogue signals. Thanks to digital operation, our DDD Type III is less prone to signal degradation. Moreover, in the Type III, we’ve simplified the circuitry using a new PLL
detector, which has reduced noise even further.
Improvements extend to other circuits of the tuner as well. The front end, for instance, features an ID MOS FET to improve reception. Indeed, the front end is as highly sensitive and selective as an elaborate 4-ganged tuning capacitor.
The F-91, like our amps and CD players, is designed based on our anti-vibration concept to damp harmful resonance and vibration for improved sound. We’ve turned circuits into modules and filled them with epoxy resin. And we’ve added honeycomb ribs to the chassis and used large insulators to shut out external vibration.
Then, of course, there are a wealth of features designed to improve convenience. You can preset up to 24 FM and AM stations in any combination. Up to three different stations can be programmed so that, when controlled by an optional timer, they are tuned in sequence – a convenient way to make unattended recording.
More features for convenience are an auto tuning mode, selectable muting level, recording level calibrator, and a fluorescent display.
A conventional wideband filter permits low-distortion reception but suffers when undesirable signals interfere. An alternate narrowband filter may cut interference, but can add distortion because of the limited bandwidth. The response of the F-91 with ARTS. delivers a low-distortion signal even when there’s interference. The Pioneer ARTS simply combines the low-distortion performance of a wide bandwidth and the high selectivity of a narrow bandwidth.
Specifications:
FM Tuner Section –
Usable Sensitivity (mono): 9.8 dBf (0.85 µV, 75 ohms)
50dB Quieting Sensitivity: Mono: 12.8 dBf (1.2 µV, 75 ohms); Stereo: 34.8 dBf (15 µV, 75 ohms)
Signal-to-Noise Ratio Mono/Stereo (IHF): 95 dB/87 dB
Distortion (at 80 dBf):
100 Hz (mono/stereo): 0.015%/0.02%
1 kHz (mono/stereo): 0.009%/0.02%
6 kHz (mono/stereo): 0.02%/0.07%
Frequency Response: 20 – 15,000 Hz + 0.2 dB, – 0.8 dB
Capture Ratio: 0.8 dB
Alternate Channel Selectivity: 85 dB (400 kHz)
Spurious Response Ratio: 80 dB
Image Response Ratio: 70 dB
IF Response Ratio: 100 dB
AM Suppression Ratio: 70 dB
Subcarrier Product Ratio: 60 dB
Muting Threshold: 25.2 dBf (5 µV, 75 ohms)
Stereo Separation 1kHz: 65 dB; 20 – 10,000 Hz: 55 dB
Antenna Input: 75 ohms unbalanced
AM Tuner Section –
Sensitivity – IHF, Loop Antenna: 150 µV/m
Selectivity: 18 dB
Signal-to-Noise Ratio: 50 dB
Image Response Ratio: 40 dB
IF Response Ratio: 60 dB
Antenna: loop antenna
Output (Level/Impedance): FM (100% Mod, Fixed): 650 mV/900 ohms; AM (30% Mod, Fixed): 150 mV/900 ohms
Power Requirements: 120 V 60 Hz
Power Consumption: 25 W
Dimensions: 457 (W) x 316 (D) x 84 (H) mm
Weight: 5.2 kg