I was watching a DVD movie last night at moderate levels when I noticed a strange clipping noise coming from the right side of the room.
At first I thought it was part of the movie, but then I quickly realized that it was actually the EP500 creating these strange clipping noises!

I immediately stopped the movie and I could clearly hear a loud buzzing sound coming from the EP500.
I turned the sub switch to "off" and I removed the line-in cable from the back of EP500.
I waited a few seconds and then I turned the sub switch back to "on".
The EP500 made a loud pop,the green light turned off, and I could smell something burning.
I turned the sub switch "off" and I unplugged the unit for 15 minutes but it will no longer power on.

Do you think this could be a fuse issue?
Is the amp fried?

This is an EP500 v2 unit that I purchased new in February of 2008.
The unit has had no problems up until now.

I'm going to call Axiom now but I was just reading a post about these new "digital" replacement amps for these units.
Can someone shed some light on these new amps?

Thanks,
Zak

As you mentioned, call Axiom's 800 number, one of the techs;Alan, JC, or Brent will help and be able to answer your other questions. It should be under warranty.

Buzzing followed by popping, electrical burning smell and no power to power to unit all points to the amp frying because of some defect. Its done. You might have blew the fuse on the unit as well for its own protection so make sure to check that too. But first you will need a new amp so call Axiom and talk to their support staff and also inquire about the correct fuse if you need one. Leave the sub unplugged from the electrical outlet in the meantime.

That you could smell something burning is the clincher, I am quite certain yu will be requiring a new amp, hopefully you will get the new updated amp under warranty.

Definitely sounds like a blown amp. I wouldn't count on getting a newer model amp, at least not from my personal experience. After 3 years they will possibly send you a refurbished unit or repair yours if possible as opposed to sending you a newer updated model.

That being said, they will make sure that you are taken care of and back up and running as quickly as possible.

I received my new v3 replacement amp on Friday afternoon and I swapped it out on the weekend.
The new amp came in it's own crate which was pretty cool.
I felt like I was opening the Ark from Indiana Jones.

The new amp seems to be working fine but it doesn't have the same 'RAW' power as the original.

My old amp had the following settings and it would shake the entire room:
- Volume at 9 O'Clock
- Crossover at 150/Bypass
- Trim at Flat
- Sub speaker level -7db (Yamaha)
- Crossover at 80hz (Yamaha)
- Front speakers small (Yamaha)
- LFE out: sub only (Yamaha)

The new amp has the following settings and I can hardly feel it:
- Volume at 10 O'Clock
- Crossover at 150/Bypass
- Subsonic Filter (Off?)
- Sub speaker level at +3db (Yamaha)
- Crossover at 80hz (Yamaha)
- Front speakers small (Yamaha)
- LFE out: sub only (Yamaha)

Does anyone have any tips on configuring this new amp?
I can't find an updated manual for this amp on the Axiom page.

Are my settings ok?
Any suggestions?

Thanks!

The new amp in it's custom crate (The Ark of Axiom)




Comparing the new v3 amp (left) to the old v2 amp

This is a common complaint between these two set of amps that have the subsonic filter and the older one that incorporates a trim feature.

You have done a good job at turning the subwoofer pre-out up on the receiver end. Now, turn up the control on the back of the sub past 10.

Yeah, axiom really packs their amps well! Enjoy your new amp

Zak, I also am one EP500 owner who finds that the trim control is useful in other than the largest rooms. The subsonic filter on the newer version has no similar function and generally should be left off unless some subsonic problem(e.g., warped LPs)is present.

The calibration of the volume control was changed so that it didn't "open up" so quickly. Therefore a higher setting is necessary to allow the same voltage in to be amplified. This doesn't mean that the newer amplifier has less maximum power than the older one, just that a higher setting is needed to reach a given loudness level.

If your reference to "Yamaha" in your list of settings means that you used its auto-calibration, then the sub level should be the same as it was before if you had used the Yamaha before to set levels.

Hi John!
I calibrated my system using an analog Radio Shack SPL meter and a tripod.
I used the test tone from my Yamaha receiver and then adjusted the individual speaker levels +/- decibels via the Yamaha menu so that all speakers had matching levels on SPL meter (75db).

I ran the calibration with the new sub amp and I had to bump the sub speaker level via Yamaha menu from -7db to +3db to get the same output as old amp.

Okay, so you calibrated manually with the aid of an SPL meter. If you did it correctly you should now be getting the same sub level which you had before. It's a little surprising that the changed volume control on the new amp would require that much increase in the Yamaha sub output, but as long as it's now properly calibrated to match the speakers there's no cause for concern.

It surprised me also.
I had to bump the decibel level and increase the volume knob level.
I could have bumped the decibels even higher on Yamaha and left the volume knob at 9 O'clock but I remember reading somewhere that you should never go higher than +3db on sub speaker level.

was your repair under warrantee? i have a EP-600 that is just out of warrantee who's amp is now blowing fuses.... kind of wondering how much cash to prepare for...

Yes, my amp was under warranty.
I have no idea what they would charge for a new amp.

It wouldn't hurt to give Axiom a call, they might have refurbished amps at a lower cost.
They might even split the difference if it's just out of warranty.

Not too long ago there was guy that had to buy a replacement amp for the Ep600 out of warranty. IIRC he said it was around $600.

we will see, my "amp box" is on it's way.. the B stock amp is a good idea, if my amp is not worth repairing.... this sucks though, the EP-600 is only 6 years old... my power amps were built in 1997, and still going strong...

Oh No! My EP500 is down again!
I though my replacement amp was fine but something is wrong.

I was watching a movie last night and I noticed that the deep bass seemed to be missing.
I thought it might be the movie so I put in U-571 and played the depth charge scene.
I could hear some bass but it was coming from the M60's so I muted all the speakers except for the sub and played the scene again.

I could hear a faint crackling and the woofer would spasm/reflex every time a depth charge went off.

I triple checked my connections and everything is good.
I called JC and he's perplexed so he's going to check with the engineer on Monday.
He's not sure if it's the woofer or the replacement amp.
He had me push on the woofer and it moves freely.

I must admit that I'm kind of doubting these new amps now.
Any ideas?

Well, obviously there now is cause for concern. As I mentioned before, I was a little surprised at the high voltage input that was required. I don't really have any new ideas, and also wonder about the new amps.

Have all the EP500s died?

It sounds there is something seriously wrong with the amp as the dsp should prevent the driver from moving erratically like that.

If you push in the driver, it should move freely. On the other hand if the driver is blown there often will be resistance and you will also hearing a "scraping" sound.

Mine is several years old and still going strong. One of my favorite investments.

I received an email from JC with a request from the engineer.

The boot has two pairs of binding posts and a wire to go to each side of the woofer. The positive polarity of the wire is indicated by the Axiom writing on the jacket of the cable. Connect one side of the woofer to the amp boot and check for sound, then repeat for the other side of the woofer connected to the other set of connections on the amp boot.

I performed these tests and the woofer is barely moving.
I have the woofer out of the enclosure facing the ceiling and when running 15hz to 80hz tests the woofer shakes very weakly.
The strange thing is, when the woofer is bolted into the enclosure it doesn't shake at all during these same tests.
Is it easier for the woofer to move when facing upward versus facing forward?
I also tested another sub cable just in case but the result is the same.

I'm no longer getting any audible response from the sub no matter how deep the bass is. No cracks, no flutter, no nothing...
I'm getting so frustrated with this sub and I almost wish it wasn't under warranty so that I could just replace it.

JC is going to get back to me after discussing my results with the Engineer.

That is to bad Zak, but hang in there Axiom should make it right, like you said it is under warranty.

Yeah, I understand your frustration! But if it's still under warranty, keep your cool, wait and see and eventually things will resolve themselves. It's better than having to ditch $1500 for another sub IMO.

I received an email from Axiom today:

After discussion with Axiom's engineer it was recommended to replace the woofer. I already put an order for a new woofer to be sent to you. Please, keep me posted once you will have replaced it.

I'm crossing my fingers and hoping that the woofer is the problem.
Has the woofer changed from v2 to v3?

Thanks,
Zak

I just hope that is the issue, and not the amp, can be frustrating all this troubleshooting. Ya just want the dang thing to work. I had issues with my V2 amp in my EP600 some time ago and they had to send me a new amp.

You will definitely get a same sound as previously you was getting. The sound level 75db is sufficient for Yamaha speakers.

When one of my EP500s malfunctioned 1-2 years ago. Axiom not only replaced the amp but also installed the original DSP programming on my request in order to keep both subs identical. Keep your faith in Axiom in bringing your sub back to full function, no matter what it takes. They take customer service and satisfaction extremely seriously.

Zak, did the new driver help? I just got my version 2 amp installed in my 600. and i have the same "underwheliming" experience. The 600 use to be a freaking raw beast, now its like a neutered beast...

I am going to call Axiom. I may end up returning my V2 amp and getting my V1 repaired.. I will wait and see...

Zak, did you take any comparison photos of the back of the amp side by side. It seems like the transformer on the V2 amp is MUCH smaller than the V1's?

Hi,
The new version of the amplifier will give you the same level performance as your previous one. It simply needs to be adjusted differently. Dial Axiom's toll free number 866-244-8796 and Brent will assist you at extracting the full potential of your new subwoofer amplifier.

Dakkon, I'm sure you calibrated it correctly right, your not a newbie?

Alex, I believe what Jean-Claude is referring to is the fact that on the old amp the volume control "opened up" very quickly and maybe a setting about 1/4th up was plenty. On the newer amps the control(which is a variable resistor)lets in voltage much more gradually and a much higher setting is needed for the same output. The maximum output is said to be essentially the same, but a higher setting is used for a given volume level. Hopefully this is the reason for the problem that you're experiencing.

talked to Brent about 15 minutes after your post J.C., he explained that the gain on the new amp is a logarithmic algorithm, where the gain on the version 1 amp was a cubed function. I have the gain at the 1 oclock position so i will adjust up a bit. I am using the XLR input, after telling Brent this i asked if the gain circuitry is the same, I am pretty sure it was not the same on the V1 amps, he is going to see if the gains are the same for the XLR and RCA inputs.

Hahaha, i had this reply typed and didn't submit it.

SirQuack, your right im not a Newby.. I was use to the old amp... The new amps logarithm for the gain threw me off, the old amp you set to the 9 oclock position and adjusted everything off of that, the new one is 1 oclock, i didn't know that.. Tomorrow i will adjust the gain on the 600 slightly more to the 2 oclock postion, as at the 1 oclock position i think your getting close to the vertical slope in the function.


John, after talking to Brent, he had the exact same initial impression that i did, he wasn't aware of the change in the gain logarithm upon initially getting his V2 amp either. I will adjust the gain on the amp tomorrow and report back... Right now the gain on the processor for the amp is +7, this is exactly where Brent's was when he first got his amp as well, when he adjusted the gain on the amp to the 2 oclock position he was able to turn the gain on his processor down to 0, i hope to do the same.

Alex, actually the "gain" isn't what's being adjusted by these settings. Audio amplifiers have a fixed gain, typically in the 25-30dB range. This gain is often set 6dB lower on a balanced XLR input to compensate for the double voltage that's coming in on that input(a doubling of voltage is a 6dB increase)so that the volume is the same on either input at a given level setting. The level controls on the receiver/processor and sub are variable resistors which adjust the amount of voltage being let out/let in to be subjected to the fixed gain of the amplifier.

Whenever I introduce a new speaker or sub into the mix, you always want to recalibrate everything to the same SPL. Even my old EP500 and EP600 were different, and they were the old design.

ca-li-braaate. Calibrate? What's that?

I've just done it totally by ear in my new place, since I don't have the Qs up yet, and it's a pain in the butt to do it manually, esp with 3 toddlers.

Start the process, except for the final step. Load the kids into the car. Run back and let it rip. Run back to the car and go out for ice cream. Come back home and it's done.

Process? HA! I don't have any auto-calibration to speak of. I do it all by hand, the old fashioned way, with a DVD.

But yeah, I did notice the same volume knob difference with my new EP350 amp.

Oh. I though you had either Audyssey or MCACC, or whatever.

The cat ate my mic.

I didn't think about the XLR being 6db lower. However, the overall output signal at a given input "should" be the same, on the V1 amp it seemed like the XLR input had no "gain" adjust.

I will tinker with it here in a few minutes.

Ok, so the sub is back to normal now... I realized this yesterday when i took the dog outside and could hear the explosions outside AFTER i shut the door.... That is the EP600 i remember!...


Just though i would share.

Good to know you have it straightened out.