Home Donate New Search Gallery Reviews How-To Books Links Workshops About Contact ADCOM GFA-535 II Intro Specs Performance Measurements Compared Usage Recommendations ADCOM GFA-535 II Power Amplifier (about $250 used). enlarge. This free website's biggest source of support is when you use these links, especially this link directly to the ADCOM GFA-535 II Power Amplifier at eBay (see How to Win at eBay), when you get anything, regardless of the country in which you live. Thanks! Ken.
Rear, ADCOM GFA-535 II Power Amplifier. enlarge.
December 2011 ADCOM Reviews Audio Reviews All Reviews
Right now, all I have is this lab report. Audition is still to come.
AP118: 4 x 6,800 µF 63V 6' polarized plug extruded front not a heat sink 4A 250V internal fuses 30W idle warm power consumption.
1994: 0.04% $375
GFA-535L added two level control trims above the IOC lights 535: crappy rear connectors, 2 swotchale sets of speakers Whicte versions
Gain Measured at 1 kHz, 1 Watt output into an 8 Ω load:
This calculates out to 22.74x gain. 124 mV in is 1W out into 8 Ω. 1.24 V is 100 W out into 8 Ω.
Frequency Response AP230 sample: ADCOM GFA-535 II (AP230) Frequency Response to 20 kHz, ±5 dB scale.
ADCOM GFA-535 II (AP230) Frequency Response to 20 kHz, ±1 dB scale.
ADCOM GFA-535 II (AP230) Frequency Response to 20 kHz, ±0.2 dB scale.
ADCOM GFA-535 II (AP230) Frequency Response to 110 kHz, ±5 dB scale.
ADCOM GFA-535 II (AP230) infrasonic Frequency Response. (-60 dB scale).
AP118 sample: ADCOM GFA-535 II (AP118) Frequency Response to 20 kHz, ±5 dB scale.
ADCOM GFA-535 II (AP118) Frequency Response to 20 kHz, ±1 dB scale.
ADCOM GFA-535 II (AP118) Frequency Response to 20 kHz, ±0.2 dB scale.
ADCOM GFA-535 II (AP118) Frequency Response to 110 kHz, ±5 dB scale.
ADCOM GFA-535 II (AP530) infrasonic Frequency Response. (-40dB scale.)
Noise AP230 sample: Adcom GFA-535 II (AP230) Output noise spectrum.
A-weighted noise (AP230):
Unweighted noise (AP230):
AP118 sample: Adcom GFA-535 II (AP118) Output noise spectrum. Roll mouse over to compare to AP230 sample.
A-weighted noise (AP118):
Unweighted noise (AP118):
DC offset (AP230 sample) Measured into 8 Ω:
Damping Factors and Output Impedances AP230: Output Impedances
Damping Factors at 8Ω
Method and raw data Voltage drop when applying an 8 Ω load:
R source = (R load/attenuation ratio) - R load.'
AP118: Method and raw data Voltage drop when applying an 8 Ω load:
R source = (R load/attenuation ratio) - R load.
Maximum Output at 1 kHz into 8 Ω load 89W at 121.3 V AC power input at 0.1% THD (1.1700V RMS input). 94W at 121.2 V AC power input at 1% THD (1.2150V RMS input). Overload lights start to turn on at 1% THD, 50% on at 2% THD, and 100% on at 2.8% THD.
10 ms burst of 1 kHz (10 cycles) at 1 per second: 46V Pk = 32.5V RMS = 132W Pk at 122.1V AC power input. Burst Input level: 1.400 V RMS.
THD ADCOM GFA-535 II THD at 1 Watt.
ADCOM GFA-535 II THD at 1 kHz.
SMPTE IMD (AP230 shown, AP118 similar) SMPTE (60Hz+7kHz @ 4:1) Intermodualtion Distotrion vs. input voltage.
19+20 kHz DFD ((AP230 shown, AP118 similar, per DIN IEC 268-3 or 118) ADCOM GFA-535 II DFD at 1 watt RMS.
ADCOM GFA-535 II DFD at 25 watts RMS.
ADCOM GFA-535 II DFD at 50 watts RMS.
Driving a pair of B&W Matrix 805 (AP230 shown, AP118 similar) ADCOM GFA-535 II (AP230) Frequency Response driving B&W Matrix 805, ±0.2 dB scale. ADCOM GFA-535 II (AP118) Frequency Response driving B&W Matrix 805, ±0.2 dB scale.
ADCOM GFA-535 II THD at 100 mW driving B&W Matrix 805. Note expanded scale down to 0.0002% THD.
Introduction top Intro Specs Performance Measurements Compared Usage Recommendations
The
Rated Specifications top Intro Specs Performance Measurements Compared Usage Recommendations ± Ω µ ¼ ½ ¾ Input 3 VR
Output 8 VRMS 3 VRMS or more into 2 kΩ.
Frequency Response 20 - 20,000 Hz ±1dB.
Distortion Less than 0.25%.
Internal Components 8 integrated circuits ("ICs"). 28 transistors. 91 diodes.
Power 6-foot rubberized cord. Unpolarized plug. 120 VAC. 50-60 Hz. 25 watts. 1/4 amp AGC fuse.
Size 9.5 x 5 x 11.8 inches, WHD, without wood case.
Weight 6 pounds (2.7 kg).
Warranty Three years, parts and labor.
Price $375, 1994.
Performance top Intro Specs Performance Measurements Compared Usage Recommendations
Overall This cra
Measurements top Intro Specs Performance Measurements Compared Usage Recommendations
I used a state-of-the-art Rohde &Schwarz UPL for these measurements. The traces are color coded for the Left Channel and the Right Channel.
Processors Bypassed Gain vs frequency, Phase Linear 1000, processing bypassed, 200mV sine wave input. (measurement: Rohde & Schwarz UPL.) I didn't separate the traces for clarity; there really is an 0.2 dB imbalance.
Compared top Intro Specs Performance Measurements Compared Usage Recommendations Dynamic Range versus Data Compression Dynamic range compression is when the differences between loud and soft are reduced. After dynamic rang
Usage top Intro Specs Performance Measurements Compared Usage Recommendations Rear, ADCOM GFA-535 II Power Amplifier. enlarge. See also the ADCOM GFA-535 II Owner's Manual.
Recommendations top Intro Specs Performance Measurements Compared Usage Recommendations Hey, for $150 or so, the
If you've found this report helpful, this free website's biggest source of support is when you use these links, especially this link directly to the ADCOM GFA-535 II Power Amplifier at eBay (see How to Win at eBay), when you get anything, regardless of the country in which you live. Thanks! Ken.
More Information ADCOM GFA-535 II Owner's Manual. ADCOM GFA-535 II Service Manaual. http://passdiy.com/ http://www.linearaudio.nl/interviews/np.pdf http://www.diyaudio.com/forums/solid-state/5280-adcom-555ii-nelson-pass.html
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