AGI Model 511
¥ 260,000 (around 1978)
¥ 185,000 (around 1979)
¥ 230,000 (around 1980)
Commentary
A control amplifier announced by David Spiegel of AGI who tackled the problem of high-speed amplifier with problem consciousness as a concrete result of the research.
High-speed circuits with a slew rate of more than 250 v / μ sec, rise / fall time of less than 0.01 μ sec and time delay of less than 0.0035 μ sec, and ultra-wide bandwidth of more than 50 MHz make the phono amplifier completely free of TIM (transient intermodulation distortion) and other slewing induced distortion.
A circuit design has been added to prevent distortion due to intermodulation even when connected to a power amplifier whose transient response is not very fast.
In addition, the low-output impedance and spare output provide great adaptability to various load side conditions.
On the input side, there is a capacitor plug-in socket which enables to set the optimum load condition for the phono cartridge.
Equipped with TONE SEND function and DUBBING switch.
All components are assembled using only MIL-compliant parts and all amplifier elements are plug-in mounted in gold-plated sockets.
Stainless steel is also used for the chassis and cover setscrews.
Also comes with a wooden case.
Model Rating
| Type | Preamplifier |
| Phono Amplifier Section | |
| Gain | 33.0 dB ± 0.25 dB at 1 kHz |
| Input impedance | 47k Ω (90 pf) |
| Maximum allowable input | 160mV(1kHz) |
| Output impedance | Rec out : 220 Ω |
| Maximum output level | 7V/10k Ω |
| Frequency characteristic | RIAA deviation within ± 0.25 dB |
| Phase characteristic | + 12 °, -4 ° (20 Hz ~ 20 kHz) |
| Signal-to-noise ratio | 88 dB or More (10 mV, 1 kHz, IFF-A) |
| Distortion Factor (at 5V/10k Ω) | THD : 0.005% or less (usually 0.001% or less, 20 Hz to 20 kHz) IMD : ≤ 0.005% (usually ≤ 0.001% by SMPTE) |
| Transient characteristic | Slew rate : 250 V / μ sec or more Rise / fall time : 0.01 μ sec or less (2Vp-p) Time delay : 0.0035 μ sec or less |
| High-Level Amplifier Section | |
| Gain | 18.7 dB ± 0.25 dB |
| Input impedance | 38k Ω |
| Output impedance | 47 Ω |
| Maximum output level | 9.5V/10k Ω 6V/600 Ω |
| Frequency characteristic | 20 Hz to 20 kHz ± 0.1 dB |
| Phase characteristic | + 1 °, -3 ° (20 Hz ~ 20 kHz) |
| Distortion Factor (at 5V/10k Ω) | THD : 0.005% or less (usually 0.001% or less, 20 Hz to 20 kHz) IMD : ≤ 0.005% (usually ≤ 0.001% by SMPTE) |
| Transient characteristic | Slew rate : 50 V / μ sec or more Rise / fall time : 0.25 μ sec or less (10Vp-p) Square wave delay : 2% or less (20 Hz, 1000 Ω load) |
| <Others> | |
| Pwer | 100 VAC (90 V ~ 111 V), 50Hz/60Hz |
| Power consumption | 5W |
| External dimensions | Width 354x Height 132x Depth 243 mm |
| Weight | Approx. 6 kg |
| Attachment | Wooden case |