Misbehaving Combo Amp!

[Hand slap]

Hello, TalkBass community. My 15-inch cone CRATE BX-100 has been malfunctioning. That's one of the reasons why I wanted to buy another amp. I might do that but, regardless, I would like to know what is wrong with my CRATE.

Being located in Italy, it is not easy (should I say impossible?) at the moment to have my amp checked by a tech, especially because I live in a remote location. So I was wondering if anybody here had seen something similar.

I created a video that shows what's going on with my amp. Please, check it out.

I was a Crate service Cntr, literally repaired hundreds, probably close to thousands, that sounds like a power supply issue, or lack of. In that amp there is a +/_ 15 volts DC, and rails are probably +/- 40-60, I don't remember, regardless, there are several 5-10 watt large resistors that develop bad solder joints, due to heat, check those connections, check the connections on ALL Big filter caps, and connections on wire harnesses. If you play an open note, HIT THE AMP ON TOP, with your fist, my guess is you can make the distortion, come and go, due to bad connections. Crates are notorious for bad connections, I did a lot Crates, back in the day.

 

[Ostie]

A lot of guys here paid good money for a pedal to give them tone like that.

 

[trevcda]

In that amp there is a +/_ 15 volts DC, and rails are probably +/- 40-60, I don't remember, regardless, there are several 5-10 watt large resistors that develop bad solder joints, due to heat, check those connections, check the connections on ALL Big filter caps, and connections on wire harnesses.

Do not go poking around in there if you're not sure what your doing and comfortable with it. Big filter caps can bite pretty hard, if they are not discharged.

FWIW- I have a Crate Keyboard amp, from that same line, that had that same problem. Replaced a bad cap and reflowed the solder points on the rest.

 

[Hand slap]

Do not go poking around in there if you're not sure what your doing and comfortable with it. Big filter caps can bite pretty hard, if they are not discharged.

FWIW- I have a Crate Keyboard amp, from that same line, that had that same problem. Replaced a bad cap and reflowed the solder points on the rest.

Their bite is nothing like the output of a Flyback transformer, in a CRT circuit, it won't kill ya.

 

[Engineer_Josh]

Oh, does it happen with headphones too? If not, the problem is not in the preamp section.

Great suggestion!

 

[Almuzura]

I saw you tried different basses, but have ya tried a new (or known good) cable?
??

I am using 2 brand new cables, one of which is a premium Fender cable.

Maybe one of these needs replacing where you plug into your amp. View attachment 3807160

It seems there is nothing wrong with the plug.

hopefully you don't have to haul it around anywhere because between the size and just a single handle on the top it's not very fun to move

I used to go around with it and now I wonder how I did it

Oh, does it happen with headphones too? If not, the problem is not in the preamp section.

In my original post I forgot to mention that the issue is there when using the headphones as well.

check those connections, check the connections on ALL Big filter caps, and connections on wire harnesses.

That's why I mentioned about taking the bass to a tech. But if you say I can manage myself... I'll give it a try!

I have a Crate Keyboard amp, from that same line, that had that same problem. Replaced a bad cap and reflowed the solder points on the rest.

This gives me hope.

Thank you everybody, it feels good to see so many people willing to help. I will post a reply when and if I manage to fix the amp.