Ea cab causing amp cut out

NickfromSOS · #1 11-16-2011, 02:43 PM

Picked up an Euphonic Audio vl210 today and it is causing my Carvin BX500 to go into protect mode. Its rated at 8ohms and 500 watts and im playing at bedroom level using my music man stingray bass. Didnt happen with mu bag ends or with the EA cab and my jazz bass.

NickfromSOS · #2 11-16-2011, 02:57 PM

I should add that it plays well for a while then shuts down.

billfitzmaurice · #3 11-16-2011, 03:14 PM

It's either the amp, the speaker or the speaker cable. Swap out each to find the culprit.

will33 · #4 11-16-2011, 03:16 PM

If the amp works fine with other cabs, check the cab for intermittent shorts, loose speaker cable jack, being rewired for 2 ohms or other wierd stuff. Check the ends of your speaker cable too, sometimes one little strand of wire can fray off and cause a partial short.

Turnaround · #5 11-17-2011, 08:43 AM

A number of years ago I had an issue with some EA cabs. The symptoms were the same - after using my amp for a little while, it would shut down in protect mode.

I tested the amp with other speakers and it was fine. So I measured the impedence of the cabs and found that they were measuring lower impedence than standard for a speaker rated at 8 ohms. The well-recognized international standard for speaker impedence ratings specifies that the impedence should not fall more than a certain percentage below the nominal impedence under any condition including application of direct current. My measurements of the EA cabinet showed values significantly below the standard's definition.

I took up the issue with EA and they said that their cabs were at spec when the voice coil was up to operating temperature (250 degrees). It seems to me that this "condition" is outside the boundaries of the standard definition.

I concluded that EA cabs did not meet this spec. I suspect yours don't either. My solution was to replace the EA cabs with another brand and I have not had a single shutdown incident since.

NickfromSOS · #6 11-17-2011, 09:40 AM

Thanks for the info. My carvin head can handle loads down to 2ohms so it shouldnt be an issue if the cab is not running fully at 8 ohms. I am running it by itself without another cab

Ric Vice · #7 11-17-2011, 09:50 AM

Quote:

Originally Posted by NickfromSOS

Picked up an Euphonic Audio vl210 today and it is causing my Carvin BX500 to go into protect mode. Its rated at 8ohms and 500 watts and im playing at bedroom level using my music man stingray bass. Didnt happen with mu bag ends or with the EA cab and my jazz bass.

Well,
Turnaround certainly has the scoop and the knowledge thats, way beyond my expertise. I do know that the crossover network connecting to 5 speakers, and two attenuators inside that cabinet, is a maze of wires and connectors. EA sometimes used crimped on connectors rather than soldered ones and they can work loose. The whole 250 degree thing sounds really wonky to me, but I've personally dealt with John Dong at EA and he helped me solve a driver distortion problem with my VL 208 which is a similar cabinet, but smaller. EA does or did have replacement drivers on hand for the VL 208 perhaps contacting them is the best way to go.

Ric

anonymous02282011 · #8 11-17-2011, 09:52 AM

the VL series have a pretty complicated x-over. There's probably a loose solder or something like that. If you feel comfortable, you can access most of the components through the side handle. If not,you're going to have to take it to a tech or send it to EA.

will33 · #9 11-17-2011, 11:32 AM

I can somewhat see the temperature thing just because as temp. rises, so does impedance and that affects how the crossover behaves but, that shouldn't be so far off as to cause a shutdown. If anything the cabs impedance would rise the longer you play it, a non-issue for a SS amp.

So, assuming cabling etc. is good and the problem is isolated to the cab itself, there must be some loose connection, short, bad capacitor, bad l-pad, something causing the amp to see a problem and protect itself.

Just out of curiosity, does it shut down when it's switched to the 2 ohm setting, even though it's not supposed to be a 2 ohm cab? Or is there something in the Carvin manual that says don't try that?

NickfromSOS · #10 11-17-2011, 11:34 AM

I spoke to John Dong at EA yesterday and he was very helpful. This cab has crimp speaker connectors and the crossover was well beyond my expertise. I returned the cab to the store, explained the problem to them, and told them that when they got it repaired , I'd certainly be interested in buying it again. They said they would call me when it comes back in.

NickfromSOS · #11 11-17-2011, 12:35 PM

It shuts down with the 2 ohm switch engaged and when it is not engaged.

will33 · #12 11-17-2011, 01:06 PM

Quote:

Originally Posted by NickfromSOS

It shuts down with the 2 ohm switch engaged and when it is not engaged.

It's likely not an impedance thing then, at least not directly. There's gotta be a bad component or broken connection in there, which could cause a dangerously low impedance dip or short (0 impedance).

From the other end of the internet, I'm going to wildass guess your amp is protecting itself from something it sees as a short.

Turnaround · #13 11-17-2011, 04:02 PM

Quote:

Originally Posted by will33

It's likely not an impedance thing then, at least not directly. There's gotta be a bad component or broken connection in there, which could cause a dangerously low impedance dip or short (0 impedance).

From the other end of the internet, I'm going to wildass guess your amp is protecting itself from something it sees as a short.

If the powering amp is rated down to 2 ohms you should not be having a problem with the cab. All of the readings I got from testing would be safe for an amp that can handle a 2 ohm load. There must be a fault in the cab. I have to agree that your amp is seeing a short.