Description
Solid state stereo preamplifier.
Introduced
1976
Discontinued
?
Revisions
SP-4A (1978)
Options
Wood cabinet (WC-2) $75
MSRP (US new retail)
SP-4: $895
SP-4A: $1,195. Later increased to $1,395
Specifications
| Frequency response | High level: 1 Hz to 100 kHz (-3 dB) |
|---|---|
| Magnetic phono: +/- 0.5 dB of RIAA, 20 Hz to 20 kHz | |
| Head amp (optional): 5 Hz to 100 kHz (-3 dB) | |
| Distortion (THD) | Harmonic distortion: Less than 0.005% @ 2 V RMS output (IHF load, with optional head amp or phono input) |
| Intermodulation distortion: Less than 0.005% @ 2 V RMS output (IHF load, SMPTE method, with optional head amp or phono input) | |
| *THD and IMD decreases with decreasing output | |
| Noise & hum | High level: less than 2 µV equivalent input noise with shorted input and max. gain (20 Hz to 20 kHz). Typically 95 dB below rated output |
| Magnetic phono: less than 0.5 µV equivalent input noise with 1k ohms input (RIAA weighted). Typically 84 dB below 10 mV @ 1 kHz | |
| Head amp (optional): less than 50 nV equivalent input noise with 10 ohms input (RIAA weighted) | |
| Gain | High level: 24 dB (IHF load) |
| Magnetic phono: 36 dB | |
| Head amp (optional): 26 dB | |
| Input impedance | High level: 50k ohms (nominal) |
| Magnetic phono: 47k ohms (50 pF min.) | |
| Head amp (optional): 10 ohms | |
| Other values may be substituted. Head amp (optional) adjustable up to 100 ohms. Magnetic phono adjustable up to 100k ohms. | |
| Output impedance | Less than 50 ohms |
| Output polarity | |
| Maximum inputs | Magnetic phono: 150 mV RMS @ 1 kHz |
| Head amp (optional): 5 mV RMS @ 1 kHz | |
| Rated outputs | Maximum 10 V RMS (all outputs, IHF load) |
| Power supplies | |
| Power requirements | 120/240 VAC, 50/60 Hz, 25 watts |
| Other | |
| Dimensions | 19" (48 cm.) W x 8 1/2" (21 cm.) D x 3 1/2" (8.9 cm.) H (rack mount front panel) |
| Weight | 12 lbs. (5.5 kg) Net, 15 lbs. (7 kg) Shipping |
Reviews
Number 9 (SP-4: Full Review)
Vol. 4 No. 1 (SP-4)Pictures
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SP-4:
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SP-4A:
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