DENON PMA-501
¥ 59,800 (around 1977)
Commentary
This is a pre-main amplifier equipped with a newly developed PCC system to bring out the essence of records.
While maintaining almost the same configuration as the PMA-701, cost reduction has been attempted.
The PCC (Phono Crosstalk Canceler) is a device that adds reverse crosstalk to the Phono Pickup type crosstalk and cancels it out. By using the attached adjustment record to operate two knobs, it is possible to improve the frequency range most easily perceived by the ear to approximately -40dB.
The power amplifier section is composed of a direct-coupled OCL circuit for all stages of differential amplification. It is composed of a low-impedance power supply circuit, and new power transistors such as double epitaxial structure and triple diffusion structure are adopted for the output final stage respectively.
To protect the speakers from errors and accidents, it has a built-in protection circuit with extremely fast response time and high reliability.
In consideration of the effect on sound quality, we have adopted a relay with a special structure.
In order to improve crosstalk caused by interference between channels, mutual interference is reduced by a circuit configuration in which two circuits are separated, and by disconnecting the power supply of a power circuit with high current and the power supply of a preamplifier circuit with low current.
To prevent the small signal sent from the record player from being degraded by wiring or changeover switches, one phono input circuit is used and the input terminal is directly connected to the equalizer amplifier.
This reduces the shielding wire and stray capacitance and improves the input impedance.
In order to improve dynamic crosstalk, a two power transformer system is used for the power supply section, and a pre-main and main separately wound power supply trans configuration is used.
Model Rating
Type | Pre-main amplifier |
Power Amplifier Unit | |
Circuit system | DC-DC pure complimentary service OCL circuit |
Dynamic Output (IHF) | 160W (80W + 80W, 8 Ω) |
Rated output (both channel drive, sine wave continuous output 20 Hz to 20 kHz) |
65W + 65W (4 Ω) 50W + 50W (8 Ω) |
Total harmonic distortion factor (Main in → SP out) | 0.05% or Less (at Rated Output) 0.02% or Less (at 1W output) |
Cross modulation distortion factor (60 Hz : 7 kHz = 4 : 1, Main in → SP out) |
0.05% or Less (at Rated Output) 0.02% or Less (at 1W output) |
Output Bandwidth (IHF, both channel drives) | 5 Hz to 50 kHz |
Transmission frequency characteristic | 5 Hz ~ 100 kHz + 0 -1dB or less |
Input Sensitivity / Impedance | 1Vrms/50k Ω ± 10% (20 Hz to 20 kHz) |
Signal-to-noise ratio | 116 dB or more (IHF, A-network, input short) |
Output impedance | 0.16 Ω or less |
Output terminal | Speaker AORb : 4 Ω ~ 16 Ω Speaker A + B : 8 Ω ~ 16 Ω Headphone port |
Preamplifier Section | |
Input Sensitivity / Impedance | Phono : 2.5Vrms/50k Ω Tuner, Aux, Tape1, 2 : 150mVrms/85k Ω |
Phono maximum allowable input (Phono → Rec out) | 230 mVrms or More (1 kHz) |
Total harmonic distortion rate (1 kHz) | Phono → Rec out : 0.008% or less (at 3 vrms output) 0.1% or Less (Maximum Output) Aux → Pre out : 0.008% or less (at rated output) |
RIAA deviation | 20 Hz to 20 kHz ± 0.2 dB |
Output Level / Impedance | Pre-out (load 50k Ω or more) : 1 Vrms (rated), 10 Vrms (maximum) Rec out : 150mVrms/50k Ω or more |
Frequency characteristic | 5 Hz ~ 100 kHz + 0 -1dB at Tone Defeat |
Tone control | Bass : 50 Hz ± 10 dB Treble : 20 kHz ± 10 dB |
Filter characteristic | Low : 20 Hz, 6dB/oct. |
Muting | -10, -20dB |
<PCC Part> | |
Maximum allowable input | 14Vrms |
Post-cancellation phono crosstalk | About -40dB |
Transmission frequency characteristic | 5 Hz to 100 kHz + 0 -1dB |
<General> | |
Transmission Frequency Characteristics (at Tone Defeat) | Phono → SP out : 20 Hz to 20 kHz ± 0.3 dB Aux → SP out : 5 Hz ~ 100 kHz + 0 -3dB |
Signal-to-noise ratio (IHF, A-network, input short circuit) | Phono : 76 dB or more Tuner, Aux, Tape1, 2 : 100 dB or more |
Crosstalk (Phono → SP out) | -75dB or less (20 Hz to 1 kHz) -60dB or less (20 kHz) |
Power outlet | Switched : 2 systems, total 250W Unswitched-1 line, 100W |
Pwer | 100 VAC, 50Hz/60Hz |
Power consumption (Electrical Appliance and Material Control Law) | 125W |
External dimensions | Width 430x Height 147x Depth 310 mm |
Weight | Approx. 13 kg |
Attachment | Record for reconciliation |