Hi guys.. I'm very new to this forum and not know much about community. But it's really nice to meet all of you guys.
I have a MBL 8004 power amplifier which I have brought from a US seller. Yes I live in sri lanka. The amplifier was completely re capped and serviced by a professional before I purchased. Even when I went to change the 115v to 230v ( to suit my country) the technicain said the amplifier is very well serviced and done nice.
I dunno much about this amplifier. It seems like a class AB amplifier and when I asked mbl of course they said the information is not possible to expose. They don't even provide any service manual. So it's a close end for me. I'm currently using this power amplifier to run a pair of emerald physics kcii open baffle speakers. My pre amplifier is a Yamaha c6 and sometimes I use my schiit sys passive pre amplifier as well.
My problem is this amplifer get crazy hot. The kinda hot where if I keep the hand on that perticular hot spot for more than 10 second I could get a really painful burn. Also this happens when I keep the amplifier in idle as well. As far I know only class A amplifiers behave like this. Although this amplifier has no heat sink inside. Instead the amplifier board is upside down fitted to dissapate the heat from the top lid of the amplifier. Although I understand the heat is normal with any amplifier, I'm concerned how hot this gets as I have mentioned. Is this normal? Or do yall think this is a class A or a class AB design with a extremely high class A bias or even the first initial watts are running at class A?
I'm sorry for my unorganized thoughts about this matter.
My Kindest regards to anyone who is willing to help me out here.
Ashen.
( I have attached the spec sheet and a picture to show the topology of the amplifier)
specs of my amplifier.
mono / stereo
Peak Pulse Power / Impulsleistung 900 / 300 W (2Ω)
Rated Power / Nennleistung 310 / 135 W (2Ω) 270 / 90 W (4Ω)
180 / 60 W (8Ω)
Max. Output Voltage / Max. Ausgangsspannung 60/30 V peak
Max. Output Current / Max. Ausgangsstrom 30A peak
Input Impedance / Eingangswiderstand 5kΩ
Unweighted signal-to-noise ratio 109dB
S/N ratio 116dB
Frequency Response / Frequenzbereich DC - 100kHz
Distortion / Klirrfaktor <0.003%, 8Ω, 3V Damping Factor / Dämpfungsfaktor 300 (4Ω)
Slew Rate 30V/µs / 15V/µs Rise Time / Puls Anstiegszeit 600ns / 1200ns
Power Consumption / Leistungsaufnahme 50VA (Idle Mode) 400VA (Max.)
I have a MBL 8004 power amplifier which I have brought from a US seller. Yes I live in sri lanka. The amplifier was completely re capped and serviced by a professional before I purchased. Even when I went to change the 115v to 230v ( to suit my country) the technicain said the amplifier is very well serviced and done nice.
I dunno much about this amplifier. It seems like a class AB amplifier and when I asked mbl of course they said the information is not possible to expose. They don't even provide any service manual. So it's a close end for me. I'm currently using this power amplifier to run a pair of emerald physics kcii open baffle speakers. My pre amplifier is a Yamaha c6 and sometimes I use my schiit sys passive pre amplifier as well.
My problem is this amplifer get crazy hot. The kinda hot where if I keep the hand on that perticular hot spot for more than 10 second I could get a really painful burn. Also this happens when I keep the amplifier in idle as well. As far I know only class A amplifiers behave like this. Although this amplifier has no heat sink inside. Instead the amplifier board is upside down fitted to dissapate the heat from the top lid of the amplifier. Although I understand the heat is normal with any amplifier, I'm concerned how hot this gets as I have mentioned. Is this normal? Or do yall think this is a class A or a class AB design with a extremely high class A bias or even the first initial watts are running at class A?
I'm sorry for my unorganized thoughts about this matter.
My Kindest regards to anyone who is willing to help me out here.
Ashen.
( I have attached the spec sheet and a picture to show the topology of the amplifier)
specs of my amplifier.
mono / stereo
Peak Pulse Power / Impulsleistung 900 / 300 W (2Ω)
Rated Power / Nennleistung 310 / 135 W (2Ω) 270 / 90 W (4Ω)
180 / 60 W (8Ω)
Max. Output Voltage / Max. Ausgangsspannung 60/30 V peak
Max. Output Current / Max. Ausgangsstrom 30A peak
Input Impedance / Eingangswiderstand 5kΩ
Unweighted signal-to-noise ratio 109dB
S/N ratio 116dB
Frequency Response / Frequenzbereich DC - 100kHz
Distortion / Klirrfaktor <0.003%, 8Ω, 3V Damping Factor / Dämpfungsfaktor 300 (4Ω)
Slew Rate 30V/µs / 15V/µs Rise Time / Puls Anstiegszeit 600ns / 1200ns
Power Consumption / Leistungsaufnahme 50VA (Idle Mode) 400VA (Max.)
Attachments
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are you able to measure the bias current of the amp - the value across each Emmitter-Resistor should read about 26mV when its trimmed to class B. The use of 4pairs of power Transistors per channel refers to the 2 Ohm Load capability, i guess. The power consumption of the data you have shown gives a hint that it should be class B, otherwise the power consumption on idle would be much higher. Did you measure the power consumption on idle?