Peavey IPR class D amps - Page 14

For you Arthur:

http://srforums.prosoundweb.com/inde...06/#msg_528905

The delays with the Peavey and new Crown XLS amplifiers demonstrate (at least to me) the real-world implementation of Lean 6 Sigma (i.e. just-in-time-delivery) is another business school textbook solution that fails in the real world.

I always thought this concept was BS, and now it is being ingrained into the military - no wonder cost overruns and delays are now the norm.

What's the F3 of the IPR amps on the low frequency side? ie: how low can they go (at rated power) before they roll off due to the built in high pass filter?

Finally a pertinent (if the amps are to be considered for HT subwoofer power) question.

Can a frequency response graph of the amp be posted here?

Bosso

Here we go... Since I've got my grade down to F I may as well get kicked out of school.

Your secondary side capacitors are SMH 85C devices from Nippon Chemi-Con.

http://www.chemi-con.co.jp/e/catalog...n-e-100401.pdf

Those particular ones are not in the data sheets. Those who do will know that 87V 4000uF capacitors are kind of like hens teeth. 80V 3900uF/4700uF seem to be the closest standard values. What's the story behind them?

Ho-Hum...



This is my model playing a bit of 'club' music into 2 Ohms. This one here,

http://free-loops.com/download-free-loop-7951.html

Yes I know you think there is something wrong with my model but, for the purposes, it can't be that wrong... can it? Maybe variations in loudspeaker impedance save the day.

Anyway. Trust me on the figures....

I get 28 Volts RMS for VOUT so that's 392 Watts. I think that slots in with your power figures.

Peak excursion on VDD due to supply pumping is 88 Volts. That's a bit Dude

Ripple current in C3, one of the secondary side reservoirs, is 7.6 Amps RMS. Whoops, or maybe not.

The Headline Data Sheet, and they are notorious for not giving meaningful or full information, says that 'similar' devices, page 53, have a ripple current rating of 3.5A RMS so you have exceeded that by a factor of two. Well done.

This will be FUD because you, as the engineer, will have otherwise verified things. I am sure you will have some answers.

However the 'lifetime' of these capacitors operated at their limits is 2000 Hours. [Yes as qualified by what is given as being 'out of spec']. That's about 83 days of full on techno-dub or whatever the yoof are into these days.

Try not to get upset. It's called peer review. I'm sure your customers will be reassured when you blow my comments into the weeds with an appropriate response.

I've got a few more too.

Rated Power (2 x 2 ohms) - ___ watts per channel @ 1 kHz at <0.1% T.H.D. both channels driven.
Rated Power (2 x 4 ohms) - ___ watts per channel @ 1 kHz at <0.1% T.H.D. both channels driven.
Rated Power (2 x 8 ohms) - ___ watts per channel @ 1 kHz at <0.1% T.H.D. both channels driven.
Rated Power (1 x 2 ohms) - ___ watts @ 1 kHz at <0.1% T.H.D.
Rated Power (1 x 4 ohms) - ___ watts @ 1 kHz at <0.1% T.H.D.
Rated Power (1 x 8 ohms) - ___ watts @ 1 kHz at <0.1% T.H.D.
Minimum Load Impedance - 2 ohms
Maximum RMS Voltage Swing - ___ volts
Frequency Response - __ Hz - 50 kHz; +0, -3 dB at 1 watt
T.H.D. (2 x 2 ohms) - <0.1% @ ___ watts per channel from 20 Hz to 1.5 kHz, decreasing to ___ watts at 20 kHz at <0.25%
T.H.D. (2 x 4 ohms) - <0.1% @ ___ watts per channel from 20 Hz to 20 kHz
T.H.D. (2 x 8 ohms) - <0.1% @ ___ watts per channel from 20 Hz to 20 kHz

Can you fill in the blanks for the models other than the IPR 1600?

Which models can be bridged? What is their power output (as listed above) when bridged?

MortyBoy, if you want to impress me, show me some stuff. What products do you have in the real world? I have hundreds of products out there, many with awards and many with very favorable magazine reviews. I didn't get my track record and reputation designing crap as you constantly imply on the various forums. Stop your chest pounding and jumping up and down begging for attention. Show us what you have accomplished. So far, I haven't seen anything from you other than blabber based on bad assumptions.

That will be a lack of an appropriate response then.

Calm down Dear.

It might look, to you, like I am saying that you have designed 'crap'. Maybe I am.. Otherwise I'm just questioning the rational behind your design decisions.

As the designer you should have been able to toss my last post off with appropriate data or rebuttal of its basis rather than waving your willy about the place and asking me to show you mine.

I believe [?] you should have the answer in your design documentation.

Maybe I should grade you for attitude?



'Constantly'?

I've only been in the pipe for two days. Oh, and thanks for the lawyer, lack of, threat.

I look forward to your next Straw Man. I believe that is the right term?

Stereodude, sorry but I should defer to marketing as to when they want to release complete specs.

[quote=Mortyboy;18322039]It might look, to you, like I am saying that you have designed 'crap'. Maybe I am.. Otherwise I'm just questioning the rational behind your design decisions.

As the designer you should have been able to toss my last post off with appropriate data or rebuttal of its basis rather than waving your willy about the place and asking me to show you mine.
QUOTE]

Mortyboy, I would be happy to toss off your last post as it was rather silly. The problem is that with you it just doesn't stop. If do that you come back with more crap. I have a day job. I don't intend to spend it defending my designs against your need for attention. I'd rather spend my day job designing very well selling successful products like the IPR1600. Besides, this is entirely the wrong venue for mudslinging by those who have no track record and no identity that they are proud of.

Come back when you have something of use to contribute.

For the heatsink pcb, it's fine, but not so good as you say because a +90% class D efficient design doesn't need a fan at the IPR1600 power with a proper heatsink. Our last model runs all day long at 2ohm with a small heatsink attached on top of the 2 mosfets (without fan)...

For the breaker, we disagree. It works yes, it's cheap yes, but it's not done in a proper "academic" way.

Finally, I will be pleased to show you some designs I've done. Unfortunately, by contract I cannot reveal it (OEM manufacturing). I can only say that my last job was technical director at a 800 employees factory producing 10,000 professional amplifiers per month for many customers around the globe, some been famous brands. I have started my own company last October and many OEM designs are already in the pipe. Again, I will not be able to tell you which design I'm doing, except one for a customer so happy by the product that he allows me to talk about it. This new series of switching amp + DSP was planned to be introduced at Frankfurt Prolight & Sound on March 24th but some parts did not come back on time to build the samples. So the launch will be one month later, in April. Not too far from now

Morty,
ArthurG had enough sense to walk away and count to ten when he was unwilling to bring forward any products for "peer review".

Frankly, grading a successful product's design with freeware makes your points look a little silly and transparent.

I have not had a chance to "evaluate" the IPR 1600 here at Behringer. Oh, you can bet that I will in due time.

Until then I was hoping that you and Arthur would also present your latest and greatest so I can extend my product line. It is mutually beneficial, you see.

Get the 'Axel Foley' out of here!!

Uhm... and where was the happy toss off my post being silly?

As to Venue and Mud. Well, given the distinct lack of information beyond the marketing message, I'll assume your 'day job' might be disassociated with 'design'.

Oh. Mind you we are talking Pro-Audio Here.

Pffffffffft

Dear Uli,

I don't walk away, I have just ethics and I respect my customer's confidentiality.

Otherwise, I know you will try to copy my amps but I promise you a big surprise when you will get one in hands

We can't even get a preview on the F3 or bridge-ability of the amps? Some sales guy you are!

The specs say the IPR 1600 has a F3 of 10Hz, are they all the same?

Are the 1600 and 3000 the only two models that can be bridged?

Oh... UhmKay.

Sorry about using 'free software'. I'm sure it doesn't give the right answer because it is 'free' and stuff. Probably designed by Rooskies to stop 'our' missiles getting through.

Hi SD

Sorry, I got distracted responding to Mortyboy the heel nipper as opposed to legimate questions. F3 is more like 8Hz on the 1600. The others are around 16.

We don't advertise bridge capability, but it is possible to bridge the 1600 and 3000 if you are willing to patch and use two twist lock speaker connectors.

By the way, I'm not a salesperson..... as should be evident.

Pro Audio? Not sure what that is. Teach me. Have you designed any Pro Audio products? Please, show us your accomplishments. Surely you have some. None?? Nothing to show us at all?? Geesh

Arthur, I went to the link in your PM to look at your amplifiers. Next to the VS series pic it said this: VS series is designed for small installation, DJ market, retail market, but NOT for professional usages. It has quantity sales. When you need an amp with nice and stable performance and high quality-price ratio, VS series is the choice

If this is how your former employer describes your design work, why are you picking on my work?

Dear JD,

I was thinking you were a bit smarter than that
I was in charge of technical department, not marketing nor website. The website was done by people knowing nearly nothing about amps and talking Chenglish (contraction of Chinese and English ). Thus I have nothing to do with that and, like you, I find the quote quite absurd In fact, these marketing guys never took my input to build their material ! One day, if you work for a Chinese company, you will understand...


edit: I've send you another link with documents done with my input. Very different style, you must admit...

So. That, perhaps for the second time of asking, will be no answer to the question about ripple current ratings of the capacitors you are using on the secondary side which, according to my armchair analysis, are being stressed out by twice as much as the manufacturers recommendations under your claimed performance specifications.

Should be easy... Shouldn't it?

Just scan some of the graphs from Nippon Chemi-Con for the devices, draw some lines on them and justify the warranty period beyond 83 days of seriously wicked Techno-Dub and post them up.

Tell you what.. Since I am in Mr Bad Mood Mode and you have Proprietary Peavey Parts on your board hows about you publish data on these 87V/4000uF parts that 'must' have been specially designed for this particular application.

Not that I might be suggesting that, for cost purposes, you are fitting re-sleeved 'failed' dross out of the skip.

So I decided to check out what the company you were in charge of (technically speaking) considers a professional product. The blurb says this: MT is middle-high class amp for professional fixed installation market. It aims at real professional market, while with very attractive price.

Now here is the funny part. I click on the picture, and I see a copies of my Crest CA series! Your flagship products start off as copies of my 16 year old work Then it says: The front panel design is patent. .... and they are copies! At least you didn't copy too much of my circuitry since the feature list says: Special LRS short circuit protection. When the output is short circuit, it can mute the input signal and switch off the relay. At the same time, it locks the amp by circuit. You need to switch off the amp and then switch on again to restart the amp.

DUDE ...... if you sell a professional an amplifier that has to be switched off to restart in the event of a short circuit, that professional is going to hunt you down and torch your house.

It also says: MT can work very stable at 2ohm with music signal. What happened to all the bluster about your designs handling continuous power??????

It also says: The semi-conductor of MT is with world recognized brand "Toshiba". Guess who introduced Toshiba flat pack transistors to the pro audio industry? Me, Crest 8001 back in 1986.

Don't feel too badly however. The Crest CA series is the most widely copied amp in China as far as the mechanicals go. Circuitry wise, most eliminate circuit blocks that they don't understand or circuitry that is not absolutely necessary for basic functionality.

Are we now finished playing your game of your designs are better than mine? Surely folks in here are really tired of the bickering ...... although at the moment I am laughing my ass off

Well, that too bad on the other amps.

How the power output down low on the IPR 1600?

I don't understand your issue about the heat sinks...I've done plenty of class D designs with just a PCB copper heatsink. I am quite certain JD knows how to deal with thermal dissipation, and in an efficient design there just isn't a lot of heat to dissipate.

The thermal impedance going through the plastic package, thermal grease, and into an aluminum heat sink is going to be way higher than the metal of the die soldered to a copper plane anyway. There's a lot of interesting research that I would recommend as further reading for those against DPAK's.

I gotta side with JD on the breaker issue too considering the price point. In a competently designed sound system, behavior at the limits is irrelevant to sonic performance anyway. And in a home setting, I would never ever consider running anything remotely close to its limits. But then I also care about sound quality...

Thanks for the help Mike!

Are you serious?

How many power designs have you done where the ripple correlates to overly simplistic models like the one you're showing? You don't even know if you have the circuit correct, let alone taking into account all of the parasitic behaviors.

When I was in college (which wasn't that long ago), I used to wonder why all the audio engineers never spent a lot of time on the forums. Now that I'm just a few years into the industry, it's very apparent why they don't. It gets incredibly boring/frustrating to rehash elementary design issues over and over....and it's only worse when stupid assumptions are being made....and yet even worse when one chooses to assume bad design decisions were made, which ultimately means you're assuming JD and company is incompetent. And then you wonder why JD feels the need to point out his credentials? Sheesh.

If this amplifier needed capacitors with a higher voltage rating in order to ensure reliability, then I have no doubt that such capacitors would have been chosen. It's really not that hard of a design decision. All you're pointing out is that JD and company made the capacitor as small as possible, which is obviously just one of the many design decisions made to hit an aggressive cost target. No competent engineer pulls cost out to the point of creating a problem...and to imply that is the case is just insane. More voltage margin on the capacitors might result in longer product life, but you don't even know how long the current design would last. You have to draw the line somewhere (and it's not like amplifiers are intended to be run at the red line all the time either...).

Pardon me for singling you out Morty, but your writing sounds like an academic lacking experienced design perspective. Anyone with any real hardware design experience knows the models don't tell the whole story....so if your model is showing stuff breaking when the real world isn't breaking, then obviously your models are wrong. I honestly thought some of your jabbing was funny at first, but I think you're more interested in the intellectual masturbation - and sorry for the crude term, if there was a PC way of saying the same thing I would definitely be using it. But then I don't think it's very PC to be dragging another design through the mud without using facts.

Btw, did anyone ever find out specifically how many filters the DSP version provides per channel? My original interest was using it for a 2-way constant directivity system. The Crown XTi-1000 is a bit noisy for a home setting when running super efficient horns and I was wondering how the IPR-1600 would compare. However, if the DSP version doesn't have a full enough feature set, then it's not gonna be worth the time.

@ 20Hz, 600 watts both channels driven into two ohms. 470 @ four ohms, 250 @ eight.

What would you like to see on the other amps. Until they go into production, I can still change stuff, although it will be test, write ECNs, make purchasing scramble, etc.

I think they want to see 10,000W down to DC...

Is the low frequency limit related to AC coupling on the signal path, or more the power supply? I bet if you got the low power handling frequency response to be flat into the single digits that a lot of these bass heads would never know the difference

We at Behringer like to call what Morty does as braggadocio. Except with braggadocio, there is sustenance to the echo. Sickneedshelp may exhibit braggadocio at moments, but he has put the Sauer with the Kraut. I haven't had the chance to "review" the IPR 1600 first hand, so I cannot claim he is a "good" engineer.

We at Behringer like to call "good" engineers in terms of time to market. That aside to us Germans, Uli, as many call me, yes call me Uli, I proclaim that you begin the sequence of forthcoming of products so we can peer review them.

"fist pump"

Well, I think a lot of the people here would like to see a lower F3 than 16Hz for the other models, and the ability to be bridged.