Peavey IPR class D amps - Page 21

For sure!

I never got a chance to try the one at my buddy's shop, as it sold right after they got it, but now...

I know that Mortyboy is in here trying to convince us all not to buy it... but, at least in my case, his plan has backfired!

This guy is such a bag of douche that I want to buy one and run the piss out of it; JUST TO PROVE HIM WRONG!

This is one of the worst threads ever. Which is a shame really because I would like to know how one of the higher level amps performs when they become available.

Lot of you guys should be ashamed for feeding the trolls so much.

Me too

Penngray, S.Filpansick, thank you.

Sheesh...

If memory serves this thread started out as some major discussion about the 'claimed' power ratings of this amplifier and how there is no way it can do what it says on the tin because actually what it says on the tin is 400W but SNH steps in to 'save the day' and 'educate' you lot about amplifier ratings before getting tripped as a Peavey Employee.

I am sure I am not the nicest person on planet Earth but the guy pokes a few, of the right, buttons so I look harder and question him about the 'supply pumping' issue which he still seems to be claiming is a non-issue...., lots of throbbing bass and whatever, apart from...


#597

So, it turns out that Low Frequency performance due to 'supply pumping' is an issue under certain circumstances. In this case one channel being used with a low frequency signal.

That is similar to the proposed use suggested by people over on TalkBass. One channel for the Bass, the other channel for 'something else'.

I am not a HT/AV anything but as I have suggested..... if your program materiel is such that you will have a significant difference in the Low Frequency content between the two channels then you might experience the same problems.

Of course I have also suggested that one of the ways of getting around such a problem, if it were to exist, would be to operate the amplifier, bridged or dual mono with the same input signal.

Maybe I have missed something here.... If you only have one great bit stonking sub in your system for the LF content then the above would apply as well. You would only use one amp, dual mono or bridged to drive them/it.

Regarding 'Put Up Or Shut Up' and indeed the issue of Trolling.

For the latter maybe some of you would care to take a bit of time to consider the 'Tools of the Troll'. I don't doubt that I might 'look' like one but someone else seems to be hammering on with them.

For the former someone could have 'Put Up' with some meaningful information quite a long time ago and then I would have been shut up. They have not and are still failing to do so.

Before we start shouting about 'proprietary stuff' again back to my favourite subject of the capacitors. May I just render it non-proprietary....?

It would seem for that case size [cost, since this is a cost sensitive application] within the SMH range at an 80V rating, 100V surge, what has been done is that a 4700uF device has been taken and 'overformed', and that is not an issue you just get a lower valued capacitor with a higher surge voltage rating, to achieve a 4000uF 80V device with a 110V surge rating specifically to cope with 'supply pumping'.... as a result its ESR will have been increased, but that's another 'unanswered' question.

Edit

Oh, regarding identity.... SNH should already be aware of 'who I am' as a result of my contact with the UK representative for Peavey.. The Bloke who says LOL.

so you won't leave if asked nicely?

No one cares any more, 21 pages is enough for you to prove your point. Your opinion and possible data is still in the pages. Others can choose to believe your or not.

Its really time to move on. Just a suggestion before someone requests the moderators which I think is always a shame.

Besides is not like this amp costs much. Its low, low cost so its not a problem to buy and test.

I did not notice you asking nicely.

Please

So I was riding around Behringer City in my golf cart and received a visit from my long time friend Al Gore. We have a great deal in common as you might expect.

Getting to the point, Big Al, as I like to call him, asked if I knew anyone with a special talent for data manipulation. Going further, Al asked specifically if this talent could stoke the weather data to show that the U.S had just undergone a massive heat wave. He did the ole "wink wink". He also expressed interest in massaging the recent Midwest flooding by explaining it as the drought previously warned of by climate scientists.

Does anyone have a candidate that can provide the following:
1. come across as being factual
2. provide lots and lots (and lots) of models, simulations and documents
3. appear confident in data built on a house of cards
4. not have enough experience to know the difference between reality and academia.
5. **very important** - must be able to post entries practically 24 hours per day. need a real go getter.
6. MUST love Star Trek.

Please present your nominees. Thanks to all of my fans!

I have an IPR 1600 powering my magneplanars and I'm impressed. I've heard no better sounding solid state amplifier. Krell, Belles, Bryston, and Hafler have nothing on this baby. Mids and highs are very detailed and musical. Transients are sometimes startling. The only better sounding amps for mids and highs I know of are a 16000.00 pair of Atma-Sphere MA1 tube OTL monoblocks. For subwoofer use (4x15" IB, using my attic as the enclosure), the IPR has all the sub-20Hz performance and "slam" of any large, dual power supply, dual mono, 60+lb behemoth I compared it to. After my listening tests, I thought to myself "Out With The Stone Age" and decided to switch completely over to Class D as I get the money. My only compalint is that I have to close the door on my rack to keep fan noise out of the room at low levels. I'm going to miss the warm glow of vacuum tubes, but time and technology march on, and wait for no man.

Very good. He also must be able to explain how this last very cold winter is due to global warming.

You really just don't have a clue about capacitors. Why do spout about what you know so little about. Don't you realize this make all that you say suspect.

That gave me a good chuckle.


Interesting. But you know now that you've admitted the above, you will be permanently banned from audiophile society meetings?

Ditto on the Panasonic. I bought one years ago just out of curiosity. It sounded noticably different than my analog, but I liked what I was suddenly hearing and what I suddenly wasn't. I promptly bought a second one for the bedroom. The hardest part was getting over replacing all this analog stuff I designed with a $250 consumer receiver that didn't even have any feedback. TI makes a great chip set.

My, this thread certainly has been a busy one.

I looked at Mortyboy's LTspice analysis of the ripple current and voltage pumping in the 1600's output supply capacitors and was impressed with his effective and knowledgeable use of some of LTspice's more arcane proprietary elements as well as the general elegance of the simulation in capturing the most critical behavior without adding undue complexity. Did Mortyboy actually claim somewhere in this thread that the Peavey amp would fail prematurely or was he just raising a red flag over possible issues?

By Mortyboy's linked analysis (if memory serves), with compressed club music driving the amp to rated power into 4 ohms, the caps would run very close to the rated current and they would run a little over double that current into two ohms. This was the reason for raising the red flag, something I find very reasonable rather than taunt-worthy (don't know which behavior is more objectionable - the bully-gang taunting or the ensuing crybaby tantrums).

Anyway, again if memory serves, these capacitors are rated for 2000 hours life when operated at the rated voltage (87V), ripple current (about 4A?) and rated still air temperature (85 deg C). Two thousand hours is about 50 weeks of 8 hours per day, or roughly 1 year of professional use. Assuming the amplifier has a claimed product life of 5 years (is that correct?), can the capacitors be expected to last that long under worst case conditions?

If used sanely with respect to their ratings, aluminum electrolytic capacitors wear out due to a slow loss of electrolyte via partial pressure driven diffusion through their end seal. It is my understanding that this is strictly a function of capacitor core temperature. Ripple current does not directly reduce life - its effect is to raise core temperature, which then reduces life. If the extra heat can be removed, ripple current may safely exceed the listed rating by a factor of double or more.

The typical assumption is that capacitor life roughly doubles for every 10 deg C reduction in core temperature and that rated normal core temperature rise for 85 deg C types is typically 10 deg C (i.e., 95 deg C core). A one year life must be doubled about two and a half times to get to the 5+ years of life listed for the product, thus operating capacitor core temperature must be reduced by about 25 degrees from the data sheet assumption, that is, to about 70 deg C.

The biggest unknown with this product is the heat removal factor due to the fan and air baffle system. Life will be limited by the capacitor with the least cooling. However, even moderate airflow can double effective heat removal so let's take that as a rough guess for the 1600 (instrumenting the capacitor with a thermocouple in its core would be the best way to avoid guessing).

According to Mortyboy's analysis ripple current will be slightly over double the listed rating with a two ohm load at full power. That means ESR losses will go up by a factor of four or five (yes, ESR goes down in the short term when core temperature goes up, but it also rises over life, so let's assume it's a wash on average). However, heat removal is twice the data sheet assumption as well, so core temperature rise may be roughly double+, that is, about 20 to 25 degrees C. Subtract this from the 70 deg C limit required to meet product life and ambient air temperature must be limited to 45+ deg C worst case. This is 110 to 120 degrees Fahrenheit, which is quite hot, even for an enclosed equipment rack without air conditioning.

In the very worst case, perhaps one out of several thousand users might manage to wear out the capacitors within the 5 year product life, but, IMO, even if this really were to occur, it would be completely buried in the noise from all other weird causes of failure (typically customer misuse).

It looks to me like Sickneedhelp walked right down the center of the tightrope between cost and reliability (at least with regard to the output electrolytic capacitors).

Regards -- analogspiceman

Disclaimer: bear in mind that this was a very rough "back-of-the-envelope" engineering check done strictly for my own amusement. YMMV

Believe it or not but this company has been producing state of the art
mobile amplifiers since the late 1970's, SMPS, good class AB design,
combination of stuff not popular in home or pro audio.

Their full range class D has been around for a long time now. The home
and pro industries typical slack behind and when new stuff enters this field,
people act as if it's new technology.

http://www.zapco.com/prod/comp_prods/c2k90Frame.htm

http://www.zapco.com/prod/comp_prods/c2k4kwFrame.htm

Remember these guys from old school days?
http://www.jeffrowland.com/

They made massive amplifiers then, but switched over to SMPS a long time
ago, a move frowned on by the audiophile groups.

I'm not surprised to see full range class D enter the home or pro industries,
I want to know why it took so long for it to become mainstream, but more important, no matter what guts you encounter in amplifier design, a 3rd
party proper test is what you need to get an idea of what it can do.
People need to relax until that day comes. Nobody here really cares about the capacitor spam posts.

I seem to recall Infinity experimenting with full range class D car amps in the early to mid 90's as well. I was sad to see those vanish from the market... I don't think they were that popular, and may have had reliability issues as well. Personally, I'm all for full range D.

What did you suddenly hear/not hear?

Was it measurable?

Makes sense that users would mostly care about the performance of the product as a whole, preferably evaluated by competent neutral third parties, but designers tend to be interested in the "capacitor spam" type posts because they need to care about each and every component in order to produce a proper design.

These types of capacitors are especially interesting because they have a finite life and a slow wear out mechanism that isn't simple to measure or predict. Walking the line between bang and buck is not as straightforward as with many of the other components in a design. It is a good thing for the users that the designer obsess about such things.

If it's not simple to measure or predict, then why all the b!tching about
the capacitor issue in this thread? hahah...

I have a rule of thumb when it comes to certain products I purchase,
I prefer not to buy the new model year of a product, give it a year or
two to soak in the marketplace and get feedback. Let the impatient people
buy new products and be the guinea pigs.

Designers obsess about these things because their name is on the line,
they really don't care about consumers

Hi AS

MMDVC.

I credit you for recgonizing that temperature of the caps is the most significant factor. How much deterioration the design will tolerate also plays a major role. 2000 hours at max temperature, voltage, and ripple current specifies how long before performance falls outside a specified window, and not how long before failure.

A wise person recently reminded me that we were taught to not calculate when we can measure instead. Please review my temperature measurements in # 514 and note the caps run considerably cooler than the simulations predicted. The data input to Morty's simulation apparently was not correct. Two ohm duty cycle limations were not factored in and neither was the actual cooling effectiveness (among other things). These are difficult to measure from a picture. Given the actual temperature of the caps and the other components, I'm sticking with my prediction that the amp will have a very long life span. It is a low cost amplifier, but that does not mean we skimped on the quality or quantity of the components hoping to just skirt past the five year warranty. The cost reduction happened because of byproducts of the technology, such as low parts count and simplicity of construction.

I find that while name and reputation on the line is important, seeing your product successful and actually being used is the ultimate gratification. Both are rooted in engineer's ego, but the desire to have a successful product requires that the consumers are happy, hence most engineers care.



Noah, the first thing that jumped out at me was what appeared to be a difference in EQ. It was as if there was a broad band mid range boost. I immediately attributed that to imperfection in the amplifier. After all, there was no overall feedback, and it sounded different so it must have been wrong. To my surprise, I didn't care. For me it's about listener fatigue. When doing A/B tests, I start with the typical check list: Which amp brings the sound stage closer? Bass is overdamped for my speakers on amp A. Drum sticks sound like they are nylon tipped when the drummer hits the Zildjians on amp B. Can't tell about the sticks on A, blah blah blah. If the amp differences are subtle during an A/B, I just close my eyes and keep flipping the A/B switch until I finally settle in on the one I prefer to listen to. With the Panasonic, I just didn't sense anything that would lead to fatigue. I didn't need to A/B it. I just knew. I didn't care about the perceived difference in EQ. I liked listenting to it more, and if it was wrong or imperfect, it didn't matter at the time. What I didn't hear was a film over the entire band. There was some unfairness due to it being a digital amp (as opposed to analog class D). The input is digital and remains that way throughout the signal processing and finally to the digital to pulse conversion. There was no analog until the speaker connectors. The hum and noise I learned to live with as various pieces were patched together prior, was now gone. Maybe the lack of hum and noise contributed more than one would think. No, I never tried to measure it because, frankly, I didn't care. Zoom back up to the part about I just liked the way it sounded. The experience was short lived. The receiver was 5.1 and I moved on to 7.1 with automatic room correction. Now I'm back to a mix of analog and digital along with hum, noise, film, and some lister fatigue. Maybe it's old age, but I spend much more time listening in the bedroom where Panasonic receiver #2 is still in use.

Sorry for the excessive use of words.

Spcieman thank you for the good and logical post. The reason for the difference in your delta T and actual results as posted by Sick is as follows:

Mortyboy's analysis that the ripple current will be slightly over double the listed rating with a two ohm load at full power is not correct.
The actual ripple current rating of this capacitor is 4.4 Amps and ESR drops significantly at higher frequency. Thus the still air ripple current rating at frequency above 10 kHz is 5.3 Amps. Then when you account for the air flow the ripple current rating is over the 6.5 Amps indicated by Mortyboy.
Therefore using your 45C (113F) would actually give 16 year life (2^4). Perhaps 35C for average temperature is a bit more realistic. If so then the life is now at 32 years. Either way it is not close to 5 years. Also as indicated the end of life does not mean that the capacitor is no longer fit for use. It just means that the parameter drift will be less the specified.

"Very good. He also must be able to explain how this last very cold winter is due to global warming."



I always thought it was because of the effect of 'el nino'

WOW! This can't hurt the cause. When you get right down to it; The big ?? will be, how does it sound, how long will it last and how much does it cost?

Sigh...

As Sick [sic] posted his measurements of temperature by waving his thermocouple on the top of the capacitor and, as a result, did not measure it's core temperature.


But, obviously, after the event, 'we' can make a thing and make measurements on it which suit 'our' purposes.

Uhm we also am have thing [not] wot measures wipple current in the offensive device because I did not use Spice to have a look and I like to measure stuff or if it works on my bench it is good to go.... I'll just change this wesistor and not tell no-wun.

Winky Winky.

HUGE THROBBING AMOUNTS OF CAPACITORS ON THE PRIMARY SIDE, 210,000 CHARGES PER SECOND, SECONDARY SIDE CAPACITORS DON'T MATTER.

Anyway.....

I've got a slow circuit breaker
I drive about a bit and a bit

And I, I had a feeling.....

Bwah Hah Hah Hah

Can I Haz CheeseBurger?

Bum... that's alright, I'll cook my own.

JD, thanks for elaborating on the Panasonic, most interesting.

"No, I never tried to measure it because, frankly, I didn't care."

I guess I find that a little surprising from an amplifier designer.

I wish the 3000 series had come out sooner because I had to get an amp yesterday and went with the EP4000 instead.

In the end the "lowrider" look of the blue lights and no bridge feature just did me in on the 1600.

I'm not trying to be critical, I just wish the lighting was able to be shut off without butchering the wiring.

I also wish it could have been bridged, cause I would have bought one for each sub.

If they had the 3000 series on the shelf today I would have bought one and moved it behind my curtain just because of all the great info SNH has given on here.

In the end it came down to supply and demand, family demanded supply and I got it done.

Jeff

p/s the fan complaints on the EP4000 are waaaay overblown no pun intended

Is it just me or does anyone else find it strange to have so many new (mar 2010) members here?

SNH pointed out how to bridge the 1600 in post 142 of this thread.