Hello,
Got a BANG amplifier over one month ago from Melbourne, Burson Audio. For some reason they like when I dismantle their stuff and try to find bugs inside.
Burson BANG's PCB
It's 2 x 29W/8Ohms or 2x40W/4Ohms speakers amplifier based on LM3886TF, so yes...another gainclone, but one that fits inside a desktop computer case and done with really good parts: ELNA caps, WIMA caps, Panasonic relays, ALPS potentiometer, Vishay metallic resistors.
The two LM3886TF chips (see the surrounding decoupling capacitors; there're also 2 decoupling caps on the backside as well)
Initially I got a pre-production PCB and there was a bit of roll-off on trebles...like almost -1.5dB @20KHz, but seems that I got a wrong PCB. Next day they sent me another one from the normal selling batch. The later has a flat response, even @20Hz, which is great.
24-bit/192KHz RMAA frequency response
It has the size of a 5.25” internal computer bay size (CD/DVD-ROM/old 5.25"floppy) and using a very well positive ventilated case this amp is colder when inside the case then on the desk. However, a good low-noise PSU is recommended for this, otherwise just stick to the power brick provided by BURSON which is really low-noise and powerful enough (well, for 4 Ohms operation the included 120W power brick is on the edge, but still OK for a regular computer user or gamer).
The main SMPS (power brick) has an output of 12V/10A and is indeed low-noise. When overcharging it, the internal chopper becomes a bit noisy, but under normal conditions you can't really overcharge it (I was able to make both LM3886TF to oscillate to overcharge the PSU and actually hear chopper's noise).
The 2 output chips are powered through 4 x SMPS power regulators, 2 x XLSEMI 6019E1 and 2 xXLSEMI 4015E1, each regulator being able to sustain a load of 5 Amps, so quite beefy. I was able to measure +/-24.5V on each dual PSU without any visible spikes or high frequency artefacts on my scope, so pretty clean rails for a switching power supply.
The 4 power regulators
Power regulators close-up
There's also an input buffer stage created by a dual op-amp. Choosing the best op-amp here will matter a lot in regard with amplifier's DC-voltage output. I find MUSES8920 having a 1-2mV of DC, way better than NE5532 (15-20mV of DC). This input op-amp gets power from 2 linear regulators ST7812/7912. From this stage we can setup the gain as well from the built-in small switches: 0.75X vs. 1.5X.
Linear regulators for the input op-amp
Manufacturer specifications:
Input impedance: 100 KOhms
Frequency response: ± 1 dB 0 – 20Khz
THD: <0.03%
Output impedance: 1.5 Ohm @ 1 kHz
Signal-to-Noise Ratio: 92.5dB
Inputs: 2 X RCA (2V RMS line level)
Outputs: 2 X Speaker Outputs
Power/Impedance, Signal To Noise Ratio, Separation between the two channels:
- 40W/4Ohm, 91db, 99%
- 29W/8Ohm, 91db, 99%
- 15.2W/16Ohm, 91db, 99%
Power Supply 100-240V AC (12V 10A)
Weight: app. 2.5Kg
Dimensions: 210mm x 145mm x 45mm
Got a BANG amplifier over one month ago from Melbourne, Burson Audio. For some reason they like when I dismantle their stuff and try to find bugs inside.
Burson BANG's PCB
It's 2 x 29W/8Ohms or 2x40W/4Ohms speakers amplifier based on LM3886TF, so yes...another gainclone, but one that fits inside a desktop computer case and done with really good parts: ELNA caps, WIMA caps, Panasonic relays, ALPS potentiometer, Vishay metallic resistors.
The two LM3886TF chips (see the surrounding decoupling capacitors; there're also 2 decoupling caps on the backside as well)
Initially I got a pre-production PCB and there was a bit of roll-off on trebles...like almost -1.5dB @20KHz, but seems that I got a wrong PCB. Next day they sent me another one from the normal selling batch. The later has a flat response, even @20Hz, which is great.
24-bit/192KHz RMAA frequency response
It has the size of a 5.25” internal computer bay size (CD/DVD-ROM/old 5.25"floppy) and using a very well positive ventilated case this amp is colder when inside the case then on the desk. However, a good low-noise PSU is recommended for this, otherwise just stick to the power brick provided by BURSON which is really low-noise and powerful enough (well, for 4 Ohms operation the included 120W power brick is on the edge, but still OK for a regular computer user or gamer).
The main SMPS (power brick) has an output of 12V/10A and is indeed low-noise. When overcharging it, the internal chopper becomes a bit noisy, but under normal conditions you can't really overcharge it (I was able to make both LM3886TF to oscillate to overcharge the PSU and actually hear chopper's noise).
The 2 output chips are powered through 4 x SMPS power regulators, 2 x XLSEMI 6019E1 and 2 xXLSEMI 4015E1, each regulator being able to sustain a load of 5 Amps, so quite beefy. I was able to measure +/-24.5V on each dual PSU without any visible spikes or high frequency artefacts on my scope, so pretty clean rails for a switching power supply.
The 4 power regulators
Power regulators close-up
There's also an input buffer stage created by a dual op-amp. Choosing the best op-amp here will matter a lot in regard with amplifier's DC-voltage output. I find MUSES8920 having a 1-2mV of DC, way better than NE5532 (15-20mV of DC). This input op-amp gets power from 2 linear regulators ST7812/7912. From this stage we can setup the gain as well from the built-in small switches: 0.75X vs. 1.5X.
Linear regulators for the input op-amp
Manufacturer specifications:
Input impedance: 100 KOhms
Frequency response: ± 1 dB 0 – 20Khz
THD: <0.03%
Output impedance: 1.5 Ohm @ 1 kHz
Signal-to-Noise Ratio: 92.5dB
Inputs: 2 X RCA (2V RMS line level)
Outputs: 2 X Speaker Outputs
Power/Impedance, Signal To Noise Ratio, Separation between the two channels:
- 40W/4Ohm, 91db, 99%
- 29W/8Ohm, 91db, 99%
- 15.2W/16Ohm, 91db, 99%
Power Supply 100-240V AC (12V 10A)
Weight: app. 2.5Kg
Dimensions: 210mm x 145mm x 45mm