2B-LP
STEREO POWER AMPLIFIER
GENERAL DESCRIPTION
Bryston's 2B-LP stereo power amplifier consists of two amplifier modules, each with its own "37.5v power supply, which can be operated independently or combined (MONO mode) to form a single 200 watt amplifier (8O load) in a 1 rack height chassis. Operated independently (DUAL mode) each channel can deliver 65 watts into 8O (or 125 watts into 4O). Each of the two amplifier modules use 2 of Bryston's custom power transistors for a total of 4 output devices per 2B-LP.
POWER CONSIDERATIONS
In general, if your preamp has a three prong grounded line cord you can avoid local ground loops which could cause hum or noise in the system by plugging the preamp's line cord into the same wall outlet next to the power amp.
CLIPPING INDICATORS
The 2B-LP amplifier uses a pair of 2 colour LEDs with green indicating power on and red indicating actual overload or distortion.
SPEAKER POWER HANDLING & FUSE PROTECTION
Most speakers will safely absorb an undistorted musical signal up to the full power capability of even large amplifiers like the 2B-LP (DUAL mode). However, once the signal starts to be clipped the distortion by-products generated by the overdriven signal can result in very high power levels fed to the smallest and most fragile of the speaker's components (it should be noted that an amplifier is quite capable of distorted power levels of twice the undistorted rating and that all the excess power goes to the high frequency driver). It is also quite possible to damage the woofer by causing it to exceed its excursion limits and impact against the back of the magnet by doing such things as turning up the bass control on a preamp and playing music quite loud. This is especially true with amplifiers which can develop full undistorted power down to extremely low frequencies as all Bryston amplifiers can. Many speaker manufacturers recommend series fuses to protect the drivers in case of accidental (or even wilful) overload. If you wish to use fuses follow the manufacturers recommendations since even what seems like a small increase in current rating on a fuse will result in large increases in power allowed. Example: A 3 amp fuse will allow about 70 watts but a 4 amp fuse will nearly double this to about 130 watts and a 5 amp fuse will allow 200 continuous watts. It should be emphasized that almost any amplifier is capable of inflicting damage on almost any speaker if used in a thoughtless or abusive manner and that Bryston cannot be responsible for speaker damage caused in this way.
BRIDGED OPERATION (MONO mode)
When operated in BRIDGED (MONO) mode the two internal amplifier sections are operated out of phase and the load is connected between the two HOT (RED binding post) terminals with no connection to ground. The two amplifier sections operate together to form a single push-pull amplifier with double the normal output voltage. In this mode the amplifier can generate output voltages of greater than 42v(rms) into loads as low as 8 ohms thus producing output power levels exceeding 200 watts (rms). N.B. Only the left channel input is used in MONO mode.
