Crest repair center needed
- Thread starter Alan Sledzieski
- Start date
It could be that your nominal impedance includes some frequencies you use a lot with a much lower impedance ?
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Re: Crest repair center needed
Apparently not....
Josh works in a different part of Peavey across town from where the service guys work. He is just trying to help you out.
Did you PM him the name of the service tech that you were working with, like he asked?
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I am not sure what exactly you are looking for? Peavey/Crest service is generally above industry average in most aspects, and Josh is going way out of his way as a Peavey employee to help you. You should actually be talking to Crest service directly if you have unresolved issues.
JR
Apparently not....
Josh works in a different part of Peavey across town from where the service guys work. He is just trying to help you out.
Did you PM him the name of the service tech that you were working with, like he asked?
=======
I am not sure what exactly you are looking for? Peavey/Crest service is generally above industry average in most aspects, and Josh is going way out of his way as a Peavey employee to help you. You should actually be talking to Crest service directly if you have unresolved issues.
JR
Re: Crest repair center needed
Yes I sent him my tech's name and location.
What I'm looking for is, why are they failing in this area?, he said he would look into it, so just wondering.
Yes I sent him my tech's name and location.
What I'm looking for is, why are they failing in this area?, he said he would look into it, so just wondering.
Re: Crest repair center needed
The strongest chain will always have a weakest link. The science of reliability engineering for power amps gets a little circular. After you beef-up, fuse, or parallel, every component that ever failed, you end up with a 20W power amp that weights 20#, and all the extra parts are just more things that could break. After decades of experience, reliable for a price that the market will support emerges.
You have already second-quessed the packaging. I can only say that even with perfect hindsight is it not quite that easy.
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Good luck with your pursuit. I trust you are also working to get the amps repaired and either back in service, or sell them if you no longer trust them.
JR
PS: Back a few decades ago I killed a bunch of brain cells, looking into what it would take to make a power amp that can't be blown up. I found back then you quickly get into diminishing returns for the extra money spent. Modern amps are generally more reliable for the simple reason that more efficient amp topologies generate less heat, and heat kills. MTBF drops in half for every 10'C temp rise, so cooler amps run longer (all else equal).
The strongest chain will always have a weakest link. The science of reliability engineering for power amps gets a little circular. After you beef-up, fuse, or parallel, every component that ever failed, you end up with a 20W power amp that weights 20#, and all the extra parts are just more things that could break. After decades of experience, reliable for a price that the market will support emerges.
You have already second-quessed the packaging. I can only say that even with perfect hindsight is it not quite that easy.
======
Good luck with your pursuit. I trust you are also working to get the amps repaired and either back in service, or sell them if you no longer trust them.
JR
PS: Back a few decades ago I killed a bunch of brain cells, looking into what it would take to make a power amp that can't be blown up. I found back then you quickly get into diminishing returns for the extra money spent. Modern amps are generally more reliable for the simple reason that more efficient amp topologies generate less heat, and heat kills. MTBF drops in half for every 10'C temp rise, so cooler amps run longer (all else equal).
Re: Crest repair center needed
JR,
I had both amps repaired, would be hard to sell them and go a different route, I have 8 8200's and 2 9200's, I'll just put a 9200 and a 8200 in a rack and bring them in for every show as spares. I don't know what I would get anyways, nothing that I could afford.
As far as beefing up,, if the same trace is going on the 8200's when running 4 ohm bridged, I would say there would be a issue, but then like you say, beef that up, the next weekest thing in the chain will blow.
JR,
I had both amps repaired, would be hard to sell them and go a different route, I have 8 8200's and 2 9200's, I'll just put a 9200 and a 8200 in a rack and bring them in for every show as spares. I don't know what I would get anyways, nothing that I could afford.
As far as beefing up,, if the same trace is going on the 8200's when running 4 ohm bridged, I would say there would be a issue, but then like you say, beef that up, the next weekest thing in the chain will blow.
Re: Crest repair center needed
FWIW a repaired PCB with wire and solder could actually have more cross sectional area and more current carrying capability than the original copper that was only a couple mils thick.
The PCB trace opening up was probably not the primary failure mode, but a side effect of some other parts failing and then drawing excessive current after that failure that caused the additional incidental damage.
Amp designers routinely use over-wattage parts in places like emitter current sharing resistors on power devices since they have a tendency to vaporize when transistors fail (which is pretty common). PCB traces are typically sized adequately, but it is hard to anticipate every possible failure scenario.
AFAIK the 8200 and 9200 are good soldiers and should treat you well, if you treat them OK.
JR
FWIW a repaired PCB with wire and solder could actually have more cross sectional area and more current carrying capability than the original copper that was only a couple mils thick.
The PCB trace opening up was probably not the primary failure mode, but a side effect of some other parts failing and then drawing excessive current after that failure that caused the additional incidental damage.
Amp designers routinely use over-wattage parts in places like emitter current sharing resistors on power devices since they have a tendency to vaporize when transistors fail (which is pretty common). PCB traces are typically sized adequately, but it is hard to anticipate every possible failure scenario.
AFAIK the 8200 and 9200 are good soldiers and should treat you well, if you treat them OK.
JR
Re: Crest repair center needed
I know he removed and tested a few items, all checked out good.
I know he removed and tested a few items, all checked out good.
Re: Crest repair center needed
JR,
As far as me treating amps ok, I am treating the 82's and 92's better then I ever treated amps, I used to run ca9's, ca '18's v and vs 1500's, pushing them to the limits, taking them out of frezing trucks into hot humid bars with condensation forming on them, pushing them all to the limits, never a failure. Now I have more subs, more power, and do 1/10 the shows I used to, and things are blowing up.
I even had mackies and ashley amps, beat the daylights out of them, no problems,, well ribbin cable on a mackie
JR,
As far as me treating amps ok, I am treating the 82's and 92's better then I ever treated amps, I used to run ca9's, ca '18's v and vs 1500's, pushing them to the limits, taking them out of frezing trucks into hot humid bars with condensation forming on them, pushing them all to the limits, never a failure. Now I have more subs, more power, and do 1/10 the shows I used to, and things are blowing up.
I even had mackies and ashley amps, beat the daylights out of them, no problems,, well ribbin cable on a mackie
Re: Crest repair center needed
Hi Alan,
I'm poking around on this issue, but it has been a regular zoo around here.
I'll let you know when I find something out. I've got my regular day job to keep up with, too!
Hi Alan,
I'm poking around on this issue, but it has been a regular zoo around here.
I'll let you know when I find something out. I've got my regular day job to keep up with, too!
Re: Crest repair center needed
Hi Alan,
So, I was able to get a few minutes of time from the guys in engineering and showed them the photo you shared on this forum. They looked at it, figured out what part of the board it was on and then informed me of the following:
That particular trace is part of the startup circuit for the amplifier. It is only supposed to be on for a very short period of time with very low current. Having it on long enough to burn up off the board like that is indicative that there is something else wrong. For some reason the startup circuit is possibly staying on all the time... an undesirable condition and not what it is supposed to be doing. There are likely some resistors in some related circuitry that are burnt, but they would have to look at it to figure out what is up with this.
After learning about this I passed this photo and problem description around the actual repair techs who fix the amplifiers that people send in for repair. No one could recall seeing anything like this in the past. However, they seemed confident that if the amplifier were sent here for repair, they would be able to repair it and return it to you in fully operational condition.
So, I would encourage you, if you have problems with your amplifiers blowing up again, send them in to the factory for repair. When these amplifiers are purchased, they have a FIVE year warranty.
See, I didn't forget about you, even though I'm sure you thought I was going to allow this to slide into oblivion...
I don't know why you are having such a problem with these amplifiers, it seems like this is a particular failure that is extremely uncommon. It is especially uncommon when you consider that the particular issue you have outlined for us in this thread has absolutely nothing to do with operating the amplifiers bridged into a 4 ohm load.
Hi Alan,
So, I was able to get a few minutes of time from the guys in engineering and showed them the photo you shared on this forum. They looked at it, figured out what part of the board it was on and then informed me of the following:
That particular trace is part of the startup circuit for the amplifier. It is only supposed to be on for a very short period of time with very low current. Having it on long enough to burn up off the board like that is indicative that there is something else wrong. For some reason the startup circuit is possibly staying on all the time... an undesirable condition and not what it is supposed to be doing. There are likely some resistors in some related circuitry that are burnt, but they would have to look at it to figure out what is up with this.
After learning about this I passed this photo and problem description around the actual repair techs who fix the amplifiers that people send in for repair. No one could recall seeing anything like this in the past. However, they seemed confident that if the amplifier were sent here for repair, they would be able to repair it and return it to you in fully operational condition.
So, I would encourage you, if you have problems with your amplifiers blowing up again, send them in to the factory for repair. When these amplifiers are purchased, they have a FIVE year warranty.
See, I didn't forget about you, even though I'm sure you thought I was going to allow this to slide into oblivion...
I don't know why you are having such a problem with these amplifiers, it seems like this is a particular failure that is extremely uncommon. It is especially uncommon when you consider that the particular issue you have outlined for us in this thread has absolutely nothing to do with operating the amplifiers bridged into a 4 ohm load.
Re: Crest repair center needed
Thanks Josh, I'll copy and paste this and send it to my tech. Unfortunatlly I'm at the mercy of others finding the problem, so far there are conflicting answers. Its hard for me to believe in a way, because all my amps at 8 ohms are fine, 4 ohm stereo fine, bridge them into 4 and they fail. Maybe some other part is going out do to heat, then going down the line. I have no idea.
Thanks for the responce!
There are issues with these amps, others just don't talk about it, thats why the bigger sound companies are selling these off around here, sorry to say.
Thanks Josh, I'll copy and paste this and send it to my tech. Unfortunatlly I'm at the mercy of others finding the problem, so far there are conflicting answers. Its hard for me to believe in a way, because all my amps at 8 ohms are fine, 4 ohm stereo fine, bridge them into 4 and they fail. Maybe some other part is going out do to heat, then going down the line. I have no idea.
Thanks for the responce!
There are issues with these amps, others just don't talk about it, thats why the bigger sound companies are selling these off around here, sorry to say.
Re: Crest repair center needed
" See, I didn't forget about you, even though I'm sure you thought I was going to allow this to slide into oblivion... "
Josh I didn't think you would do that, I'm just impatient, heck, the parts I ordered from eaw in Sept are still not here, latest excuse, stuck in customs. Thanks again for getting some answers.
" See, I didn't forget about you, even though I'm sure you thought I was going to allow this to slide into oblivion... "
Josh I didn't think you would do that, I'm just impatient, heck, the parts I ordered from eaw in Sept are still not here, latest excuse, stuck in customs. Thanks again for getting some answers.
Re: Crest repair center needed
Interesting... the only folks I know who are selling them off are only selling them to buy amplifiers with more power output. They are buying things like Lab.gruppen PLM and Powersoft K series... this is not exactly apples / apples.
Interesting... the only folks I know who are selling them off are only selling them to buy amplifiers with more power output. They are buying things like Lab.gruppen PLM and Powersoft K series... this is not exactly apples / apples.
Re: Crest repair center needed
Josh said...
" In one case I know they have displaced racks of Crown MA5000 and MA5002 amplifiers to provide lighter sub racks. Also, they have threatened to replace the Lab.gruppen FP6400's in another set of racks... "
...And we couldn't be happier with the job those 9200s are doing on that sub duty, as well as other duties to which they are assigned...
At the time, Lab Gruppen service (via TC Electronics) was rather lethargic, fortunately, that has improved considerably. And while there are more Lab Gruppens in our future, there are more 9200s as well.
THERE. IS. NO. WAY. IN. HELL. I'D. GO. THROUGH. THIS. SERVICE. NIGHTMARE.
I've been (kinda) following this thread and I've read all the explanations and responses. I don't see the reason for the OP not sending the Crests in for repair. But don't even try to rehash the topic. I will not be convinced. And it doesn't matter, since it's not my cross to bear.
Respectfully,
Geri O
Josh said...
" In one case I know they have displaced racks of Crown MA5000 and MA5002 amplifiers to provide lighter sub racks. Also, they have threatened to replace the Lab.gruppen FP6400's in another set of racks... "
...And we couldn't be happier with the job those 9200s are doing on that sub duty, as well as other duties to which they are assigned...
At the time, Lab Gruppen service (via TC Electronics) was rather lethargic, fortunately, that has improved considerably. And while there are more Lab Gruppens in our future, there are more 9200s as well.
THERE. IS. NO. WAY. IN. HELL. I'D. GO. THROUGH. THIS. SERVICE. NIGHTMARE.
I've been (kinda) following this thread and I've read all the explanations and responses. I don't see the reason for the OP not sending the Crests in for repair. But don't even try to rehash the topic. I will not be convinced. And it doesn't matter, since it's not my cross to bear.
Respectfully,
Geri O
Re: Crest repair center needed
Josh, crest techs said this failure is do to a startup circuit staying on as you stated. Well that would be a noticable current draw. I tested current draw on these 2 amps, vs 4 others. They are all the same. Start up it jumps to about 4.7 amps, then drops to about 1.08 at idle, all 6 amps do this.
Now my tech did take apart and test all components in this area, they all tested good.
I did pound the daylights out them, and all is good,,, so far.
Josh, crest techs said this failure is do to a startup circuit staying on as you stated. Well that would be a noticable current draw. I tested current draw on these 2 amps, vs 4 others. They are all the same. Start up it jumps to about 4.7 amps, then drops to about 1.08 at idle, all 6 amps do this.
Now my tech did take apart and test all components in this area, they all tested good.
I did pound the daylights out them, and all is good,,, so far.
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