Denon - DCD-620 / TU-710 / PMA-757 / SC-M70 Stereo set - Multiple models

A fixer-upper.
For the hobbyist/enthusiast.
It still needs a little love and then it's worth your money twofold.
The descriptions below are as far as I could tell, within the limits of my technical ability.
Private seller.

A set consisting of three components, plus two speakers:

Denon PMA-757 amplifier: fully operational, but with minor defects.
- of the selection buttons "Speaker A" and "DAD" (the term for "CD" at the time the amplifier was released) the lights do not come on when you press them. The buttons otherwise work, functionally.
This amplifier has a huge number of options (and, of course, also a working phono output).

Denon DCD-620 CD player: basically working, but the player has faults.
- drawer/turning mechanism has a worn plastic gear; opening and closing itself currently works well, but when turning it occasionally skips. The player mechanism is easily accessible to remove/replace the gear;
- The RCA output (the little plugs) needs to be checked and tightened more securely. The contact occasionally drops to mono as a result.

Denon TU-710 tuner: fully functional.
- I no longer have a cable connection, so the operation was tested by connecting an antenna wire to the coax.
- perhaps the tuning itself could be improved and adjusted further.

Denon SC-M70 speakers: function perfectly and excellently
80-watt, 6-ohm loudspeakers:
- light signs of use, especially on the fabric coverings
- damage to the wood on the top of one of the speakers, but not distracting.

Preferably pick it up, so you can really see how it works and what small issues there are.
If you wish, I will print the manuals in black and white for you and include them with the shipment as an extra service.

Shipping is at your own risk or, for an additional charge, insured shipping is available (and it is heavy, 20kg+).

Technical data:

CD player

Model: DCD-620
Type: CD Player
Years of construction: 1988 - 1990
Produced in: Japan
Colors: Champagne, Black
Remote control: Yes (not included)
Power consumption: 12 W
Dimensions: 434 x 103 x 315 mm (WxHxD)
Weight: 3.8 kg
New price approx.: 595 DM

Converter: Burr-Brown
Frequency range: 2 - 20,000 Hz
Dynamic range: 96 dB
Signal-to-noise ratio: 100 dB
Distortion factor:
Canal boundary
CD-Text: no
MP3 support: no
Pitch control: no
Intro scan: no
Shuffle: yes
Title programming: yes
Repeat: yes
Plays Audio/CD-R
Special features: Display can be switched off, 10+ number keys


Amplifier

Manufacturer: Denon
Model: PMA‑757
Type: Class A/B power amplifier
Year of manufacture: 1984–1986
Made in: Japan
Color: Premium silver or black
Wooden side panels: optional
Remote control: no
Power consumption: maximum 650 W (IEC standard 240 W)
Dimensions (W×H×D): 434 × 136 × 413 mm;
Weight: 12 kg

Connections
Number of entrances: 6

Input Level Impedance Connector
Phono MM/MC 2.5 mV, 47 kΩ / 200 µV, 100 Ω – –
Tuner, DAD (CD), Aux 150 mV, 47 kΩ – Cinch
Tape 1 150 mV, 47 kΩ – Cinch
Tape 2 150 mV, 47 kΩ – Cinch / DIN
Number of outlets: 4

Output Connector
Tape 1 Cinch
Tape 2 Cinch / DIN
Speakers 2 pairs (screw terminals / banana plugs)
Headphones 310 mV, 8 Ω (6.3 mm plug)
Technical data
Parameter Value
Nominal output power (20 Hz – 20 kHz) 8 Ω: 2 × 80 W ( THD) 4 Ω: 2 × 100 W
Music power 8 Ω: 2 × 115 W 4 Ω: 2 × 200 W 4 Ω (alternative): 2 × 230 W
Total Harmonic Distortion (THD) (8 Ω)
Damping factor –
Frequency response 5 Hz – 80 kHz (IHF, 0.03% THD)
Total frequency response 1 Hz – 250 kHz (± 0 dB, −3 dB)
Phono MM/MC 20 Hz–100 kHz (RIAA ±0.3 dB)
Signal-to-noise ratio Phono MM: 87 dB Phono MC: 70 dB Tuner, DAD, AUX, Tape 1 & 2: 110 dB
Stereo channel separation –
Sound adjustment Bass: ± 8 dB (100 Hz) Treble: ± 8 dB (10 kHz)
Loudness – 7 dB (100 Hz) – 6 dB (10 kHz)
High-filter no
Low-pass filter (subsonic) 20 Hz, 6 dB/oct
Mute, no
Direct/Line-Straight: yes
Special equipment
Fast slew rate (200 V/µs) and dynamic power reserves (non-NFB)
2 × 15,000 µF capacitors and rugged power transistors, suitable for demanding loudspeakers
All switching paths DC-coupled (DC) for distortion- and coloration-free sound
6 inputs with illuminated input/monitor indicators
Phono preamplifier for MM/MC, switchable and with an excellent linear frequency response.
Adjustable sound control; mode selector (stereo, rev., mono)

TUNER

Product: Denon TU‑710 LW / MW / FM‑tuner (1987).
Electrical power requirements: Input voltage: 220 V
Input frequency: 50 Hz
Semiconductors present
Superheterodyne (common)
Radio frequency bands: FM (87.5-108 MHz), MW (522-1611 kHz) and LW (153-560 kHz)

A stereophonic hi-fi AM-FM tuner in a black or champagne-gold metal housing that covers FM (87.5–108 MHz), MW (522–1611 kHz) and LW (153–560 kHz). Six LED signal-strength indicators, FM stereo indicator. Line-out cable with RCA plugs, connections for the included clip-on AM loop antenna, 75-ohm coax connector for the FM antenna. FM frequency response 20–15,000 Hz, channel separation 40 dB, THD mono 0.1%, stereo 0.3%.
Enclosure finish gold-champagne.
Dimensions (W × H × D): 434 × 75 × 238 mm
Weight: 2.6 kg

Loudspeakers

Type: Passive
Placement: Standing (standmount)
Enclosure: Bass-reflex
Port position: Front
Number of speakers: 2
Nominal impedance: 6 Ω
Frequency response: 45–30 Hz
Maximum power: 80 W
Sensitivity: 90 dB
Dimensions (W × H × D): 16 × 29 × 25.5 cm