MA230 front OK
Solid state preamp + tube power amp. Made in USA from 1963 to 1966 by McIntosh Audio Company

FRONT PANEL: Glass panel at top. Anodized gold at bottom. Input selector: aux, tape, tuner, phono 1, phono 2 and tape hd. Bass and treble each dual concentric. Volume. Mode selector: L to L+R, R to L+R, stereo rev, stereo, mono (L+R), L+R to L and L+R to R. Balance. Rocker switches: comp: RIAA or LP, tape monitor, phase: 0 or 180, speaker: on or off, power: on or off, LF: flat or filter, HF: flat or filter, loudness: flat or compensate. Headphone jacks. Red power indicator.

PANNELLO FRONTALE: Parte superiore in cristallo, parte inferiore in anodizzato dorato. Input selector (in alto a sinistra) : aux, tape, tuner, phono 1, phono 2 and tape hd. Controlli bass e treble (in alto al centro) separati per ciascun canale. Volume (in alto a destra). Mode selector (in basso a sinistra) : L to L+R, R to L+R, stereo rev, stereo, mono (L+R), L+R to L and L+R to R.. Balance (in basso a destra).8 interruttori (in basso al centro): COMP(ensazione): RIAA or LP, TAPE monitor, PHASE: 0 or 180, SPEAKER: on or off, POWER: on or off, LF (filtro bassi): flat or filter, HF (filtro alti): flat or filter, LOUDNESS: flat or compensate. 2 ingressi cuffia. Indicatore di accensione in rosso.

BACK PANEL:  (from left to right) Fuse. AC outlets: 2 switched, 1 unswitched.  Strips for 4, 8, and 16 ohms, Left speaker, Right speaker.  Outputs: Ground, L+R. and Tape.   High level inputs: tape mon, aux, tape and tuner. Low level inputs: ph 1, ph 2 and tape hd. Ground binding post. 

PANNELLO POSTERIORE: (da sinistra a destra) fusibile,  3 prese elettriche (una indipendente dall’accessione dell’apparecchio, due dipendenti). Uscita speakers con ponticello per 4, 8, 16 ohm. Uscite: Terra,Tape e L+R. Ingressi ad alto livello: tape monitor, aux, tape, tuner. Ingressi a basso livello: phono 1,phono 2,tape hd. 

Top view
Bottom View
TUBES: 4-7591, 2-12AU7, 12AX7.

Size 5-7/16″H, 16″W and 14-1/2″D. Weight 43 lbs.

ELECTRICAL

Stereo. Hybrid (solid state preamp and tube power amplifier).

30w/ch stereo, 60w mono.

Response 20-20kHz (+0 -0.5dB).

Distortion 0.5%.

Noise and hum -75dB high level, -60dB low level .

Output impedance 4, 8 and 16 ohms.

Damping factor 10.

Input sensitivity and impedance: high level 0.25V at 250k, phono 1.5mV at 47k, tape head 1.5mV at 1 meg. Tape output 0.25V into 25k. L+R output 10V into 5k.

Dual concentric tone controls +18dB to -18dB.

LF filter 50Hz at 12dB/oct.

HF filter 5k at 12dB/oct.

Year of construction: 1963 – 1966

Are available on request:

Owner’s manual
Service Manual
 
Links
Roger Russel’s Infos 

www.roger-russell.com

Audioclassics

www.audioclassics.com

 
VALVOLE: 4-7591, 2-12AU7, 12AX7.

Dimensioni in cm:  40.8 Larghezza x 13.5 altezza x 36.5 profondità.          

Peso 19.5 kg

CARATTERISTICHE

Amplificatore Stereo Integrato allo stato Ibrido (solid state preamp and tube power amplifier).

30w/canale stereo, 60w mono.

Risposta in frequenza 20-20kHz (+0 -0.5dB).

Distorsione 0.5%.

Noise and hum -75dB high level, -60dB low level .

Impedenza in uscita 4, 8 and 16 ohms.

Damping factor 10.

Sensibilità ingressi  and impedenza: alto livello 0.25V a 250k, phono 1.5mV a 47k, tape head 1.5mV a 1 meg. Tape output 0.25V entro 25k. L+R output 10V entro 5k.

Controlli di tono a due manopole concentriche +18dB to -18dB.

LF filter 50Hz a 12dB/oct.

HF filter 5k a 12dB/oct.

Anni di costruzione: 1963 – 1966

Sono disponibili a richiesta:

Il Manuale di utilizzo
Il Manuale di servizio
Links
Roger Russel’s Infos 

www.roger-russell.com

Audioclassics 

www.audioclassics.com