[jaxwired]

Considering a bryston BIT.  Will the baby of the line work with my 4bsst2 amp?

[James Tanner]

Considering a bryston BIT.  Will the baby of the line work with my 4bsst2 amp?

HI

It will depend on the impedance of your speaker and the current draw needed for the levels you listen at.  The 4BSST2 can draw 7 amps at full power.

james

[RLL1]

HI

It will depend on the impedance of your speaker and the current draw needed for the levels you listen at.  The 4BSST2 can draw 7 amps at full power.

james

James

Is this determined using the formula "Amps = Watts / Volts"? If so, what wattage value are you using to get 7 amps?

Thanks
Rick

[James Tanner]

James

Is this determined using the formula "Amps = Watts / Volts"? If so, what wattage value are you using to get 7 amps?

Thanks
Rick

Hi Rick,

It is just from the sheet that engineering supplied me.

james

[srb]

It would seem that if the 4BBSST consumes 2100W at full power per your spec sheet, that the current draw would be far greater than 7A at full power, closer to 17A with 120V line voltage.  I doubt that anyone would drive it to that level, but 7A seems too low.

It is just from the sheet that engineering supplied me.

Were they perhaps quoting output current?

Steve

[James Tanner]

It would seem that if the 4BBSST consumes 2100W at full power per your spec sheet, that the current draw would be far greater than 7A at full power, closer to 17A with 120V line voltage.  I doubt that anyone would drive it to that level, but 7A seems too low.
Were they perhaps quoting output current?

Steve

I will check - maybe a typo (7) vs (17)????

james

[James Tanner]

James

The 4B is rated at 300 Wpc. Generally, a Class AB amplifier is about 70% efficient at maximum power, so 2 X 300 W / .7 = roughly 860W. The idling power is about 125W, so 125 + 860 = 985W. That would require just over 7A from a 120V line, 120V X 7.143A = 985W.  If a spec sheet says 2100W it is a misprint.

cwr

[srb]

The 4B is rated at 300 Wpc. Generally, a Class AB amplifier is about 70% efficient at maximum power, so 2 X 300 W / .7 = roughly 860W. The idling power is about 125W, so 125 + 860 = 985W. That would require just over 7A from a 120V line, 120V X 7.143A = 985W.  If a spec sheet says 2100W it is a misprint.

Using the same exact calculations, the current draw at 500W/ch full power with a 4 ohm load would be ~ 13A.

I don't know what the efficiency of the Bryston amplifiers are, but 70% may be a bit optimistic, as some other A/B amplifiers are rated between 55% and 65% efficiency.  If it were 60%, the 4 ohm full load current would be ~ 16A.

Steve

[werd]

Get a bit 20 in 240. No such thing as overkill with amp in the 4b range and up. Trust me on that.

[James Tanner]

Using the same exact calculations, the current draw at 500W/ch full power with a 4 ohm load would be ~ 13A.

I don't know what the efficiency of the Bryston amplifiers are, but 70% may be a bit optimistic, as some other A/B amplifiers are rated between 55% and 65% efficiency.  If it were 60%, the 4 ohm full load current would be ~ 16A.

Steve

Yes, with both channels running at 500W each the circuit breaker would eventually open.  However, no musical signal would ever produce full sustained power, and circuit-breakers do allow for temporary overloads.

cwr