How to biamp ADS L1290 or L1590 speakers with a PA1

Discussion in 'Speakers' started by ADS-Lover, Apr 5, 2009.

  1. ADS-Lover

    ADS-Lover New Member

    DC Metro Area
    There have been several requests recently for instructions on how to properly configure the PA1's with either 1290's or 1590's so I thought I would share this information so that the precious few amps that exist are not marginalized. One of my PA1's which failed 2 weeks ago is currently in the shop and I'm hoping it gets resuscitated! If not, I'll need to find someone with a bad amp I can use for spare parts! :D

    Its not too difficult to set these up, here goes.

    **Read IMPORTANT note at the very end FIRST!!**

    1) Make sure that the PA1 amp wiring to the banana plugs is correct. The wires coming out of the amp (2 pair) to the banana plugs have a rib on one wire. This ribbed wire connects to the side of the plug that has a little tab labeled ground. Hopefully it's already like this.

    2) You must set the biamp switch on the crossover to the left position to be in biamp mode. Note, the biamp switch is directly below the tweeter attenuation switch and behind the left set of speaker input connectors. There is a cover plate that is removed to expose these switches. (Mine are 1590 Series 1 which also have fuses under this cover plate, between the tweeter attenuation and biamp switch)

    3) The Red banana plug connects to the mid/hi while the black connects into the low. You simply press the banana plug down one each set of terminals like a plug into an outlet. Make sure that the GND tab on the banana plug goes into the black input terminal.

    4) On the PA1 have your source set to Pre not Spkr. Use a coin edge to turn the switch if not already in Pre.

    5) To connect your preamp or low level signal to each speaker simply run the left channel (single RCA) to your left speaker and plug it into the Main Input (2nd from the left, bottom row). Same for the right side. Make sure you use a high quality shielded cable as this run will probably be longer than your usual low-level interconnect run. You don't want to have any interference on the low-level signal you now are running to your speaker amps.

    6) Connect power to each speaker.

    Other notes:
    I am an audio purist so the idea of "chaining" is not attractive. Basically what you do with chaining, either for your low level signal or power is to run the lines to one speaker then "chain" from that speaker to the other. Its OK to do it with the power cord if you have the special chaining power cord that the PA1's came with, but don't do it with the preamp signal. Just run one direct to each speaker from the preamp/HTR.

    Power toggle switch can be set to On or Auto. If you set to On, use your home theater receiver's switched outlet to turn it on for you, or leave it on.

    ** Very important detail ** not mentioned in text above is that depending on what speaker the PA1 is used with (1290 vs. 1590), certain resistor connections change. This affects 2 resistors. Please see attached document. Also, if you unscrew the plastic cover of a PA1 (only 2 screws) you will see a notice regarding the same on the inside of the plastic cover. This is VERY important for those switching amps between one model and the other. However, I would expect that what came from the factory for a given speaker should be correct, though its always best to check.

    Good luck!

    Attached Files:

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