Trace Elliot Combo problem

[Oscar South]

Hello, I use a Trace Elliot Boxer 65 as my standard amp for most of the gigging I do and its always done me proud. However at this Fridays gig on switching it on it powered up as normal but made no audible 'pop' from the speaker as it always has done on powering up, and produced no volume on playing through it.

The amp worked perfectly on Thursday so the fault must have occurred in transit. It has also been modified to be able to disconnect the head from the speaker so that a DI can be placed after it in order to take an affected signal to the desk, because of this I was able to test the amp by sending a signal to a different cab; this also produced no sound so I assume the problem is with the head.

Would anyone be able to inform me of what the problem may be? I love the tone I get from this thing and have some important gigs coming up, I wouldn't want to use anything else!

Cheers for any help or advice you can give me,
Oscar.

[KiOgon]

[quote name='Oscar South' post='1282637' date='Jun 26 2011, 12:09 AM']Hello, I use a Trace Elliot Boxer 65 as my standard amp for most of the gigging I do and its always done me proud. However at this Fridays gig on switching it on it powered up as normal but made no audible 'pop' from the speaker as it always has done on powering up, and produced no volume on playing through it.

The amp worked perfectly on Thursday so the fault must have occurred in transit. It has also been modified to be able to disconnect the head from the speaker so that a DI can be placed after it in order to take an affected signal to the desk, because of this I was able to test the amp by sending a signal to a different cab; this also produced no sound so I assume the problem is with the head.

Would anyone be able to inform me of what the problem may be? I love the tone I get from this thing and have some important gigs coming up, I wouldn't want to use anything else!

Cheers for any help or advice you can give me,
Oscar.[/quote]
Hi Oscar,
That'll be my old combo won't it? Sorry to hear it's developed a problem, it's been a while.
Depending on your working knowledge of amps, I'd suggest a look at the circuit board for loose joints.

Cheerz, John

[icastle]

I'd check the area around the modification.
It'd only take one wire off around there to create the fault you describe.

[neilb]

Output fuse??

Or is the DI not kicking out a signal either?

[Ghost_Bass]

Hi Oscar, how was it moddified? From your description i got the feeling that you're interrupting the signal going from the power amp to the speaker and sending it to a DI... this isn't healthy to your amp! Another way to take the signal safely from the amp and retaining the amps EQ is to take it out of the headphones socket (some mod is needed to work out the problem of muting the speaker when conncting the jack to the socket) and probably add a boost pedal to this exit if needed...
Good luck with the amp, i have a Boxer15 in my room (my first amp) and i won't sell it, it sounds great for such a little thing!

[Oscar South]

[quote name='KiOgon' post='1282655' date='Jun 26 2011, 12:25 AM']Hi Oscar,
That'll be my old combo won't it? Sorry to hear it's developed a problem, it's been a while.
Depending on your working knowledge of amps, I'd suggest a look at the circuit board for loose joints.

Cheerz, John[/quote]

Hey, yeah its been amazing up until now and then just anomalously stopped, I've opened it up and had a look and everything looks in order but I'm not enough of an expert to delve deeper though.

Here's a little excerpt taken from the desk at a gig in Stratford Upon Avon recently so you can hear how great its been sounding until now though
[url="http://dl.dropbox.com/u/134504/bearbeats/Just%20For%20You.mp3"]-->> Just For You - The Bear Beats Band Live 2011 <<--[/url]


[quote name='icastle' post='1282949' date='Jun 26 2011, 12:46 PM']I'd check the area around the modification.
It'd only take one wire off around there to create the fault you describe.[/quote]

Had a look and it looks fine as far as joints, solder etc., I don't know what to look for further than that though.



[quote name='Ghost_Bass' post='1285174' date='Jun 28 2011, 12:29 PM']Hi Oscar, how was it moddified? From your description i got the feeling that you're interrupting the signal going from the power amp to the speaker and sending it to a DI... this isn't healthy to your amp! Another way to take the signal safely from the amp and retaining the amps EQ is to take it out of the headphones socket (some mod is needed to work out the problem of muting the speaker when conncting the jack to the socket) and probably add a boost pedal to this exit if needed...
Good luck with the amp, i have a Boxer15 in my room (my first amp) and i won't sell it, it sounds great for such a little thing![/quote]

To be honest, I'm not sure as it was modified when I got it, KiOgon might be able to shed some light on the situation though? I think it was modified while he owned it and I just assumed it was for that purpose, perhaps that's the cause of the fault? I'd be grateful if you could elaborate on how/why so that I can avoid potential similar problems in the future.

I'll definitely look into the headphone out as a DI source.

Thanks for the help so far everyone.



Edit: Just tested the headphones out and there's also no volume coming from that

Edited July 1, 2011 by Oscar South

[steve]

you've done the obvious of checking the output of the bass and swapping leads?

Edited July 1, 2011 by steve

[Oscar South]

[quote name='steve' post='1289009' date='Jul 1 2011, 01:43 PM']you've done the obvious of checking the output of the bass and swapping leads?[/quote]

Yeah, in every combination imaginable

[steve]

[quote name='Oscar South' post='1289030' date='Jul 1 2011, 02:00 PM']Yeah, in every combination imaginable [/quote]

I guessed as much.

if you're ok with electronics, you could knock up an audio test probe and check along the pcb tracks to find where the signal was lost?

[Oscar South]

I'm probably not knowledgeable enough about amp circuitry to to pull that off, I think that this is over my head so I've put out a feeler looking for people who can have a look at it around Chester. Hopefully it can be fixed, just a really bad time for it to break when I've got a really big couple of gigs coming up, no money and have to move house in a month too! Typical luck, ha

Edited July 1, 2011 by Oscar South

[escholl]

[quote name='Ghost_Bass' post='1285174' date='Jun 28 2011, 12:29 PM']Hi Oscar, how was it moddified? From your description i got the feeling that you're interrupting the signal going from the power amp to the speaker and sending it to a DI... this isn't healthy to your amp! Another way to take the signal safely from the amp and retaining the amps EQ is to take it out of the headphones socket (some mod is needed to work out the problem of muting the speaker when conncting the jack to the socket) and probably add a boost pedal to this exit if needed...[/quote]
Actually it's fine for the amp if done correctly, although generally this signal is taken before the power amp stage. Incidentally, in this particular amp, the headphone output is also taken off of the power stage so taking the DI off of the headphone out wouldn't change anything.

[quote name='Oscar South' post='1289192' date='Jul 1 2011, 03:52 PM']I'm probably not knowledgeable enough about amp circuitry to to pull that off, I think that this is over my head so I've put out a feeler looking for people who can have a look at it around Chester. Hopefully it can be fixed, just a really bad time for it to break when I've got a really big couple of gigs coming up, no money and have to move house in a month too! Typical luck, ha [/quote]
You can do a quick test of a few basic things here if you like. First, measure the voltage across Z1 and Z2, there should be 15 volts across each. If there are, then you can try making an audio probe (very easy to do) and testing for signal across R20 -- that will tell you if it's the pre-amp or something after.