Ampeg PF500/350, part 4

[Truktek2]

http://en.m.wikipedia.org/wiki/Class-D_amplifier

I'm starting to think it might be characteristic of all class D amplifiers. Maybe the technology isn't quite there yet? Sad indeed.

 

[Frankjohnson]

I know everyone's definition of volume is different but you guys must be running these things hard if the PF-500 isn't cutting it. With my loudest band - two guitarists with Marshall half stacks and a fender twin between them and a heavy handed drummer - I'm running my gain at about 2:30 and master just below noon though a 4 ohm 2x15 and it's plenty for the room. Yes, We all wear ear plugs. Mine hasn't complained yet. It is odd, as said above, that for some of us we have had zero trouble while those with problems seem to have them repeatedly.

I don't know about ear plugs and all - but for the first 9.9 months.....I said the same thing. Then - one day.....nothing.

Its not that your doing it right and the people with units that failed are doing it wrong......at least not in my mind. Like I said - I commented early on how good the PF500 was. I still think it is good, but not sure about the reliability overall.

My $ 0.02 YMMV, objects in the mirror, etc....

 

[coreyfyfe]

Its not that your doing it right and the people with units that failed are doing it wrong......at least not in my mind.

I wasn't trying to imply this either, but I wonder if it's an issue of expectations vs reality and I'm trying to get a sense of where my experience fall in that spectrum.

 

[ryanfenderbass]

I will state this again for the record. Many of the folks with problems have gone several months without a problem first, then the cutting out issues seem to manifest spontaneously. If I was in fact pushing this amp too hard (I'm not), I would have seen cutting out from day one. For example, last month I played a gig with a 9-piece rock band complete with 2 guitars and pedal steel. I even busted into a solo where I was playing pretty heavy. No cutting out issues! Now when I had a low-key rehearsal with my regular band just this week, I got my first *pffffffft* cut-out since I had the unit replaced in January. It continued the entire rehearsal, even when I backed the gain off. Someone explain that!

That's why I'm starting to suspect that either something breaks in the limiter circuit when this happens and/or it's only a matter of time for those users who haven't had problems to begin seeing them.

Maybe it only takes one bad transient spike to cripple this thing for good, but does that make any sense?

 

[Frankjohnson]

My replacement is due in today - lets see what happens. I *want* it to be right - nothing more - nothing less.

In my Brad Pitt as First Lieutenant Aldo Raine voice from Inglourious Basterds -
SOUND GOOD !?!

 

[tombowlus]

Don't give up on Ampeg - they offer plenty of great products - but if you play loud and fast and slap - I don't know about the lower powered class D amps.

If for some reason a PF-500 isn't cutting it for a given player, the 7Pro is the way to go, for sure. That amp is brutal, and sounds huge.

 

[tombowlus]

Class-D amplifier - Wikipedia, the free encyclopedia

I'm starting to think it might be characteristic of all class D amplifiers. Maybe the technology isn't quite there yet? Sad indeed.

IME/IMHO, no, it is not a characteristic of all class-D amplifiers. We have tested a number of class-D heads which performed exceptionally well and sounded big, full, and dynamic. But the class-D topology does have its own unique design challenges and looking at how different manufacturers address those challenges, there can be substantial variation between products which on the surface seem like they should perform the same. AC filtering, thermal issues and limiting are three of the areas of concern which seem to strongly affect the performance of class-D amps.

 

[ddbassGA]

Me again.

I forgot to mention I also own an Ampeg BA300/115 (I know - I spoil myself) which is a class D combo rated at 300 watts with a tube preamp. This amp has also been flawless. ... but the problem with the BA300? - you cannot use an extension speaker.

Solution: Change the speaker in the BA300 combo to an 8 ohm (Delta 15a would work well in that enclosure) and install a parallel jack on the cab so you can chain another 8 ohm cab.

 

[GregT]

Here's what makes sense to me: If several hundred PF500s have been replaced by Ampeg, that would mean their techs have enough faulty ones in their hands to see a pattern by now. They wouldn't just toss them in the garbage without checking things. If there is an inherent problem, they should be offering to fix them all to avoid a mandated recall. But the bottom line is, by now they know what the problem is. If it were your company, wouldn't you!? Both of my little timebombs are still working perfectly! Hope they will continue to do so for years! If not, I will remove the horn and mount a different head. I love the cabinets!

 

[Frankjohnson]

If not, I will remove the horn and mount a different head. I love the cabinets!

Heh heh heh - actually thought about that.......

 

[Truktek2]

IME/IMHO, no, it is not a characteristic of all class-D amplifiers. We have tested a number of class-D heads which performed exceptionally well and sounded big, full, and dynamic. But the class-D topology does have its own unique design challenges and looking at how different manufacturers address those challenges, there can be substantial variation between products which on the surface seem like they should perform the same. AC filtering, thermal issues and limiting are three of the areas of concern which seem to strongly affect the performance of class-D amps.

If that's the case Ampeg should get on the ball and fix the problem. Hopefully they will within the next 2 years before my warranty runs out.

 

[coreyfyfe]

their techs have enough faulty ones in their hands to see a pattern by now. They wouldn't just toss them in the garbage without checking things. If there is an inherent problem, they should be offering to fix them all to avoid a mandated recall. But the bottom line is, by now they know what the problem is.

Assuming they can identify a problem. Their early responses - and for some people, the response they're getting now - is that it's a user issue between the input gain, limiter, and compressor. That seems to be a load of bs, but them sticking with that explanation could be explained by them not being able to find a single source of issue in the returned amps.

A few people have said they're swapping boards, which may or may not indicate they've found an issue either. With these amps it's probably cheapest to just swap out the board than to try and repair anything. Which begs the question, are they trying to pinpoint a component or set of components and modify their specs, have they found a component/set of components that is the likely culprit, or have they found the definitive culprit; and whatever the answer, are they swapping out boards/amps as appeasement, or because they've identified an issue?

 

[fivestringgecko]

In their defense, though, I've seen what people do to floor models at GC, and there's every chance a parade of nincompoops mishandled it.

Jes' sayin', as the kids say.

+1. I don't EVER buy a floor model of ANYTHING at GC. It's like a screen door on a submarine... just doesn't make sense.

5sg.

 

[fenderhutz]

+1. I don't EVER buy a floor model of ANYTHING at GC. It's like a screen door on a submarine... just doesn't make sense.

5sg.

More like buying used toilet paper.

 

[JimmyM]

Well look, I'm going to take off the endorser hat and speak honestly here...obviously we know that micro technology in bass amps is a relatively new technology that still has some kinks to be worked out. We also know that price is always relative to performance, and while sometimes a lower priced item can outperform a higher priced item, generally you get what you pay for in all walks of life, and I believe that's especially true for amps.

We got spoiled by the fact that these little inexpensive amps are quite the little tone monsters, and when an SVT is rated 300w and a PF350 has 50 more watts, I think some folks tend to forget that their sweet little $300 PF350 is not an SVT and shouldn't be expected to perform like one or sound as good as one. And micro technology just plain doesn't behave like lead sled and tube technology, especially in $300 and $400 bass heads no matter who makes them.

But our pro sound bretheren, who are way ahead of the curve when it comes to light amp technologies and who have pretty much gone completely class D except for a few holdouts, seem to make it work just fine. Did a gig on a great class D powered gig Saturday, and the PA didn't cut out once, it always had balls and crystal clear sharp sound that really you hear the nuances of the music. He also said it had much higher powered amps than he used when he was powering his cabs with lead sleds to make sure it had headroom and didn't let you down when you needed it the most. And I hear that in the bass micros, too. Once you start pushing higher levels, you run out of headroom a lot quicker and the amp limits you severely, starts clipping in a horrible way, and in extreme cases shuts down.

But nobody's lying about power levels. Those amps will push what they say they do. The only difference is where lead sled solid state and tube technologies will clip more gracefully and give you a little elbow room to push them hard, these do not. They let you know immediately when you're done because most of them just plain don't have anything else to give you, especially at lower price points. But when you have way more headroom than your older technology amps, they do a surprisingly good job of holding up at higher volumes and not giving out on you. I don't notice a drastic difference in volume between the Micro VR and the PF350, but I do notice which one stays cleaner at a slightly higher volume. Probably why I got on so well with the Micro VR on gigs and many can't...I just don't need that kind of volume.

But I'm now firmly convinced that if you want to make micro technology work for you AND play super loud, you're going to have to overbuy on wattage compared to tube and SS amps. If a 100w heavy amp used to do it for you, buy a 300w micro. If a 500w heavy amp used to do it for you, buy a 1000w micro amp or more. Just don't push it. I really think that's the only way you can do stupid loud with these small amps and not run into trouble on a gig.

Or just go back to the heavy technologies...I'm going back to all tube for good, quite honestly, and keep the small amps for backup and the smallest of small gigs. The little 210av cabs are keepers for me, though But I was under no illusions that my Micro VR was truly competing head to head with my B-15, though I do still really like the sound of it and won't ever sell it short as a nice little tone monster for the money. I think some folks are under the illusion that one is just as good as the other in every way.

Listen, if there's one thing I know, it's about making the best with what you have. I love cheap gear and I love that you can get a $300 amp with some balls that weighs 1/10th of what an SVT does. But saving money always comes at a price, and you have to find out what it does best, what it does worst, and accentuate the positive and eliminate the negative. And while all the different technologies can be quite good, no matter whether you're into micros, lead sled solid state, or all-tube, there's a reason why the best stuff costs so much...it's worth it.

So everyone just ratchet it down a notch or two...you're all too damn loud anyway!!!

 

[carl h.]

Or just go back to the heavy technologies...I'm going back to all tube for good, quite honestly, and keep the small amps for backup and the smallest of small gigs.

 

[Bassoballs]

Well spoken Jimmy!

 

[johnk_10]

i was going to buy a PF500 this week since i really dig the sound of them, but until i hear a definitive answer as to what's causing the cutting out issues that some people are having with them, i'm going to wait.

that said, my streamliner 900 has a class D power amp and i've pushed it beyond levels that i would ever play it at and it hasn't had the slightest hiccup, so rather than say that it's a 'class D' amp problem, i believe it is more 'amp specific', and i hope they get it sorted soon.

 

[Truktek2]

Well look, I'm going to take off the endorser hat and speak honestly here...obviously we know that micro technology in bass amps is a relatively new technology that still has some kinks to be worked out. We also know that price is always relative to performance, and while sometimes a lower priced item can outperform a higher priced item, generally you get what you pay for in all walks of life, and I believe that's especially true for amps.

We got spoiled by the fact that these little inexpensive amps are quite the little tone monsters, and when an SVT is rated 300w and a PF350 has 50 more watts, I think some folks tend to forget that their sweet little $300 PF350 is not an SVT and shouldn't be expected to perform like one or sound as good as one. And micro technology just plain doesn't behave like lead sled and tube technology, especially in $300 and $400 bass heads no matter who makes them.

But our pro sound bretheren, who are way ahead of the curve when it comes to light amp technologies and who have pretty much gone completely class D except for a few holdouts, seem to make it work just fine. Did a gig on a great class D powered gig Saturday, and the PA didn't cut out once, it always had balls and crystal clear sharp sound that really you hear the nuances of the music. He also said it had much higher powered amps than he used when he was powering his cabs with lead sleds to make sure it had headroom and didn't let you down when you needed it the most. And I hear that in the bass micros, too. Once you start pushing higher levels, you run out of headroom a lot quicker and the amp limits you severely, starts clipping in a horrible way, and in extreme cases shuts down.

But nobody's lying about power levels. Those amps will push what they say they do. The only difference is where lead sled solid state and tube technologies will clip more gracefully and give you a little elbow room to push them hard, these do not. They let you know immediately when you're done because most of them just plain don't have anything else to give you, especially at lower price points. But when you have way more headroom than your older technology amps, they do a surprisingly good job of holding up at higher volumes and not giving out on you. I don't notice a drastic difference in volume between the Micro VR and the PF350, but I do notice which one stays cleaner at a slightly higher volume. Probably why I got on so well with the Micro VR on gigs and many can't...I just don't need that kind of volume.

But I'm now firmly convinced that if you want to make micro technology work for you AND play super loud, you're going to have to overbuy on wattage compared to tube and SS amps. If a 100w heavy amp used to do it for you, buy a 300w micro. If a 500w heavy amp used to do it for you, buy a 1000w micro amp or more. Just don't push it. I really think that's the only way you can do stupid loud with these small amps and not run into trouble on a gig.

Or just go back to the heavy technologies...I'm going back to all tube for good, quite honestly, and keep the small amps for backup and the smallest of small gigs. The little 210av cabs are keepers for me, though But I was under no illusions that my Micro VR was truly competing head to head with my B-15, though I do still really like the sound of it and won't ever sell it short as a nice little tone monster for the money. I think some folks are under the illusion that one is just as good as the other in every way.

Listen, if there's one thing I know, it's about making the best with what you have. I love cheap gear and I love that you can get a $300 amp with some balls that weighs 1/10th of what an SVT does. But saving money always comes at a price, and you have to find out what it does best, what it does worst, and accentuate the positive and eliminate the negative. And while all the different technologies can be quite good, no matter whether you're into micros, lead sled solid state, or all-tube, there's a reason why the best stuff costs so much...it's worth it.

So everyone just ratchet it down a notch or two...you're all too damn loud anyway!!!

OoOoOoOoOooooo.....snap! Now I don't know what to believe

 

[ryanfenderbass]

Not to undermine Jimmy's well-written prose (thank you!), but I have a reached a breaking discovery with my issue.

It just dawned on me that my PF500 only cuts out when I'm running both cabs. Single cab... no issue! My last gig and last 3 months of rehearsals were only with the single cab. Sunday night, I used both cabs for SnGs... and it cut out!

I AB tested to confirm this just now. Single cab... perfect. Both cabs... whenever I slapped a C# on the A string (bass at 1:00, no ultra lo)... *pfffffft* Unplugged the bottom cab... flawless.

Now it gets weirder. I can make the full stack not cut out by turning the bass down to 7:00-8:00. I can slap the crap out of my bass with this setting, no cut-out. When I turn the bass any higher than 9:00 it starts cutting again. Weirder still... with the bass down, I can engage the ultra bass with NO problems?

*I tested all of my cables tried running the bottom cab both using the head's 2nd output and daisy-chain. Makes no difference to the above.
*tested chain using speakon-1/4" + 1/4"-1/4" and quarter inch only. Same results.
*tested each cab separately. Each cab works flawlessly independently.
*Mix n matched in/outputs in the back of the cabs. Same results.

So what does this all mean? I think I reached a turning point with this whole thing.