Help! Ashdown issue

Rock-Bassman · #1 08-14-2011, 08:04 PM

Just recently got a new amp, an ashdown abm evo 500, made in the uk from 2001. At practice today, the amp was running and sounding great, but I did notice that it took a few seconds for the amps input to get up to speed, meaning it started at a lower volume for a few seconds but then got louder as if I increased the gain. I just chalked that up to the pre-amp tube warming up (if pre amps do that..) but when i got home tonight and plugged it in, it never got up to the full input like it did at practice and the sound was distorted even with the input low and the valve drive on clean. when i cranked the input and tube drive up and really dug in, the amp clipped out for a few second. Anybody have any thoughts? bad preamp tube?

RockBobby · #2 08-14-2011, 08:09 PM

I got the same amp. Mine ramps up, but pretty quickly (2 seconds). I would swap out the input tube first. A cheap first look.
Do you know how to get the amp apart?

Rock-Bassman · #3 08-14-2011, 08:16 PM

Yeah it was fairly quick to get up to speed. No i have no idea.. I'm assuming you undo some screws haha

scowboy · #4 08-14-2011, 08:18 PM

check the tube blend. turn it all the way down. if it does not come on pretty much instantly there is something wrong.

RockBobby · #5 08-14-2011, 08:33 PM

Quote:

Originally Posted by Rock-Bassman

Yeah it was fairly quick to get up to speed. No i have no idea.. I'm assuming you undo some screws haha

On the top of the head case there are flat plastic "plugs" that cover the screws. They just lift out and expose the screws. The bottom screws are in the feet.

Rock-Bassman · #6 08-14-2011, 08:42 PM

Quote:

Originally Posted by scowboy

check the tube blend. turn it all the way down. if it does not come on pretty much instantly there is something wrong.

Even with the tube blend all the way down, clipping out still occurs when i dig in with the input and master way up. Also, there is a significant loss of volume since this happened, i can crank this thing and still not have my 100 watt or so b-15 cab not even flinch.

Rock-Bassman · #7 08-14-2011, 09:56 PM

Just opened it up, one of the 4 black circles/ cylinder things on the top left corner near the fans has broken open and is now leaking black/brown gooey stuff.. touched it and got a nice shock up my finger.. not good i assume

RockBobby · #8 08-15-2011, 06:06 AM

That's one of the power capacitors. An easy fix.

crguti · #9 08-15-2011, 07:01 AM

mm... yeah, bad capacitors. sh*t happens sometimes. I won't blame ashdown amps for that.