Crest CA6 amp question.

[jonz]

I picked this amp up from Craiglist... I notice in the back there is no switch for running bridged like my other amp.... is there something I am overlooking?

[Zero Cool]

Nope, the bridge switch is internal! This is an older model that has a jumper to set stereo or bridged.


also while you are in there. Check the capacitors in the power supply. (large Blue cans) the tops should be flat. If they are not flat and the tops are bulging out. REPLACE THEM! they are about to explode.

I have a half dozen crest amps stinking up my shop that have all caught fire! Crest had a bad issue with power supply caps in this and the VS series. the caps have no pressure vent and they explode and the amp catches fire! yeah fun!.

Also FYI, the caps in the protection circuit go bad causing the amp to stay in protect even though there is nothing wrong with the amp. The zener diodes should be removed, cleaned and resoldered in place and the caps replaced.

[jonz]

I checked the caps and they look pretty new.... also this switch to put in bridged mode .. where is it exactly?

Thanks for the heads up.... so you think I got the short end of the stick?

[m2003br]

the simple option: Run with 2 input plugs, just wire +L togheter -R inputs and vice-versa.
If you want run unbalanced input, just ground -L AND +R inputs.
Hope this helps.
Marcos

[m2003br]

Please, understand "L" and "R" as "A" and "B" channels.

[Zero Cool]

those caps look perfect. the input board is mounted vertically behind the rear panel. there should be a jumper on the top edge of the board. the labeling is backwards. when you think its bridged, its stereo and vs vs.

attached is the jumper in bridges pos

[Zero Cool]

back of the board showing the printing. some models are backwards.

The only way to know for sure is to inject a LF signal into the amp with a Y-cable to both channels. connect a dual channel scope to both outputs. if they are in phase. the amp is in stereo. if they are out of phase. then its bridged.

You can also connect up a pair of speakers watching to make sure the polarity is connected right. inject a 40-50hz signal into both channels and if you have bass. the amp is in stereo. no bass. then bridged....


Lots of people love these amps. bass players dig em. they have a built in compressor circuit and i think thats why. the amps were the last of the good crest amps before they were peavey-ised! but they were not nearly as good as the brutal but old 4001, 6001, 8001, 10001 series! they saw heavy heavy touring duty.



Zc

[jonz]

Thank you... that was very helpful ZC!