My band mate got an old musicman 115 combo and blew the speaker. After further investigation I found it had a speaker rated at a lower wattage than the amp (probably not original, just from last person to tinker with it). I said "Of course it blew, you played it loud and it was more than the speaker could handle". The dudes that installed a new speaker for him at the shop said probably not the reason (??!!). Here's where the plot thickens:
My buddy had been using an ABY switch, because the amp has two inputs he had one set louder and grittier than the other (higher input volume, all through the same master volume). The guy at the shop told him switching inputs like that would blow the speaker because it is a sudden change in electrical current. This seems counterintuitive to me, but people dont pay me to work on amps. What do you think?
Musicman combo, speaker blown!!
2losthighway wrote:My band mate got an old musicman 115 combo and blew the speaker. After further investigation I found it had a speaker rated at a lower wattage than the amp (probably not original, just from last person to tinker with it). I said "Of course it blew, you played it loud and it was more than the speaker could handle". The dudes that installed a new speaker for him at the shop said probably not the reason (??!!). Here's where the plot thickens:
My buddy had been using an ABY switch, because the amp has two inputs he had one set louder and grittier than the other (higher input volume, all through the same master volume). The guy at the shop told him switching inputs like that would blow the speaker because it is a sudden change in electrical current. This seems counterintuitive to me, but people dont pay me to work on amps. What do you think?
That's pretty much crap. The amp can't tell the difference from a pop from the AB box and, say, a sharp agressive strum while muting the strings. Let's not even talk about having a loud distortion pedal in front of the amp.
However, if he had the A/B box switching cabinets, well, then that would be a problem.
Ben Adrian
Musicman combo, speaker blown!!
3benadrian wrote:However, if he had the A/B box switching cabinets, well, then that would be a problem.
Ben Adrian
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Musicman combo, speaker blown!!
4okay I was too cryptic. He used the ABY as a way to route his signal through either the left input which contains volume, bass, mid, treble. Or the right which contains all of the above and tremolo, I think they both have some kind of bass or treble boost. All is mediated by a master volume. He only used the combo, no extra cabs. Sometimes the left input with a lower volume setting on it for a semi clean, or he would use the ABY to hit up the right channel with the volume set higher to break it up and make it louder for leads etc. So essentially he would jump between inputs rapidly and fairly often during a band practice or concert.
Musicman combo, speaker blown!!
5It's simple. The amp had a speaker with insufficient power handling capacity and blew up after being played at a high volumes and with lots of transient information.
The "new" replacement speaker may fail too, even if it's rated at a higher wattage power handling level. An amp, when "pushed" to distortion, may put out more power than it's rated when run at high volume, as the manufacturer's power rating is usually measured when played clean. Your buddy would be well served with getting a 2nd cab with a 15 to produce more volume with less stress on the speakers.... or be prepared to replace the "replacement" speaker soon.
The "new" replacement speaker may fail too, even if it's rated at a higher wattage power handling level. An amp, when "pushed" to distortion, may put out more power than it's rated when run at high volume, as the manufacturer's power rating is usually measured when played clean. Your buddy would be well served with getting a 2nd cab with a 15 to produce more volume with less stress on the speakers.... or be prepared to replace the "replacement" speaker soon.
Musicman combo, speaker blown!!
6Or just use speakers that can take it, like the 200W 12" speakers that EV makes. Good luck blowing those with a Musicman.
"The bastards have landed"
www.myspace.com/thechromerobes - now has a couple songs from the new album
www.myspace.com/thechromerobes - now has a couple songs from the new album
Musicman combo, speaker blown!!
7actually, being the person that sold the guitarist the amp, the speaker that was in there was rated at 200w. it was a 200 watt celestion PA speaker, but broke up really nicely. or at least I was told it was 200 Watt when I bought it from avatar. Could it be that bryce is sort clumsy? That would be my bet.
Musicman combo, speaker blown!!
8how many watts is this amp supposed to put out? the most I've heard of an amp putting out with four 6L6's is something like 130W, clean, which should probably still be less than 200W when reasonably clipped. is it a 4 x 6L6 amp? it really shouldn't blow a 200W speaker.
maybe something is really messed up with the amp itself... like it's somehow putting DC out to the speaker, or it's got some kinda weird oscillation that's inaudible but is there and is problematic. Ben, is it possible for DC to leak backwards through a NFB circuit if there's a failed cap? hell, I don't know if this amp even has a NFB loop, i'm just guessing here.
but if this amp is causing speaker breakup in a speaker rated to handle 200W, it sounds like something's wrong with the amp.
it doesn't seem like the ABY clicking should be a problem.
how's about checking the coupling caps between the phase invertor and the output tubes? maybe there's DC leaking onto their control grids?
yeah, lotsa ideas here. no idea if any of them will solve your problem though. take it to a tech.
and speaking of techs, what's up with the cryptic message from the repair guy that he didn't think the speaker was the problem? what did he think was?
maybe something is really messed up with the amp itself... like it's somehow putting DC out to the speaker, or it's got some kinda weird oscillation that's inaudible but is there and is problematic. Ben, is it possible for DC to leak backwards through a NFB circuit if there's a failed cap? hell, I don't know if this amp even has a NFB loop, i'm just guessing here.
but if this amp is causing speaker breakup in a speaker rated to handle 200W, it sounds like something's wrong with the amp.
it doesn't seem like the ABY clicking should be a problem.
how's about checking the coupling caps between the phase invertor and the output tubes? maybe there's DC leaking onto their control grids?
yeah, lotsa ideas here. no idea if any of them will solve your problem though. take it to a tech.
and speaking of techs, what's up with the cryptic message from the repair guy that he didn't think the speaker was the problem? what did he think was?
"The bastards have landed"
www.myspace.com/thechromerobes - now has a couple songs from the new album
www.myspace.com/thechromerobes - now has a couple songs from the new album
Musicman combo, speaker blown!!
9It wasn't the speaker breaking up so much as the classic rock master volume trick (pumping the prevolume for clipping and then controling it with the master volume being a little lower).
The tech dude thought it was a blown speaker due to a sudden change of electrical current, which would be caused by suddenly jumping from one channel with one setting (via the ABY) to another channel with a different setting. None of the electonic guts were dysfunctional, the amp could still be played through an external cabinet, we just had to replace the speaker. Sounds fine now (I should say great) but he's scared to use the ABY and has switched to an overdrive pedal, after the tech guys theory provoked him.
The tech dude thought it was a blown speaker due to a sudden change of electrical current, which would be caused by suddenly jumping from one channel with one setting (via the ABY) to another channel with a different setting. None of the electonic guts were dysfunctional, the amp could still be played through an external cabinet, we just had to replace the speaker. Sounds fine now (I should say great) but he's scared to use the ABY and has switched to an overdrive pedal, after the tech guys theory provoked him.
Musicman combo, speaker blown!!
10Unless you consistently blow speakers with this thing, theres really no proof of what blew it.
Did it tear the cone out or fry the voice coil? Many speakers that are rated for say 50W RMS really are better off with a 100W amp. If an amp is clipping its output into speaker that is made to handle higher wattage, it sends the voice coil into pole to pole square wave oscillations that can damage stuff including blowing the cone and burning the coil. According to some manufacturers anyway. This is not a situation I have experienced with guitar amps, but I don't see why the same wouldnt apply. So maybe you need a lower wattage speaker with the correct impedence. I don't know, electrons are confusing.
Did it tear the cone out or fry the voice coil? Many speakers that are rated for say 50W RMS really are better off with a 100W amp. If an amp is clipping its output into speaker that is made to handle higher wattage, it sends the voice coil into pole to pole square wave oscillations that can damage stuff including blowing the cone and burning the coil. According to some manufacturers anyway. This is not a situation I have experienced with guitar amps, but I don't see why the same wouldnt apply. So maybe you need a lower wattage speaker with the correct impedence. I don't know, electrons are confusing.