[powerman]

If you want the knobs on the front and the fancy 1" thick front panel: no.

Other configurations: yes, it could be done. Would entail making special PCBs for the switch/volume control, and moving the coupling transformers to this new PCB.

Pat

The input stage of ICEPower ASP uses the standard one op-amp balanced input most pro
products have. This works quite well except in the very worst environments.

A transformer input is needed very rarely. Generally only if the rest of the
system is really noisy and no one cares to bother fixing anything that goes
wrong with it. And if a transformer is used, an extra buffer is not
necessary anyway. The module's input impedance is quite high enough already.
And if you used a JFET input and had the impedance very high, much higher
than the transformer's characteristic impedance, it will ring when
transients are applied. In almost every case, you are better off without
this.

[art]

And you have what function at my company?????

Go start your own.

Pat

[powerman]

Hi Pat,

I apologized if you’ve feel offended!  This is not my intention.

There’re many amps deployed ICE technology and most of them don’t use input transformer and JFET as input.

We’d like to you how your amp is different from others?

[CornellAlum]

Pat, you made my morning around 5:30 am

[Hantra]

Hi Pat,

I apologized if you’ve feel offended!  This is not my intention.

There’re many amps deployed ICE technology and most of them don’t use input transformer and JFET as input.

We’d like to you how your amp is different from others?

It sounds quite a bit better than any other ICE amp I have heard.  I've had the Rowland 201 in my system, and was unimpressed.  Do a search for my thoughts on that.  I have one of Pat's amps right now and it's a much better sounding amp than the Rowland.  I've not heard one without a transformer, but without the input stage Pat uses, the Rowlands sounded rough.

[art]

Well, I do feel offended. You show up........make one post........telling everyone that I may not know what the hell I am doing.........

This is my livelihood. How am I supposed to feel? If you had been a contributing member for some time, and had made remarks like that, then I may have felt other wise. However, if you had the type of background that you seem to imply, then you would know how much Pro Audio gear is made with coupling transformers. Sure, we don't have the same concerns in our living room, but there is no reason why I should throw all that I have learned building for that market just because no one else does it.

Besides.............someone asked if I could make an integrated amp. How does your response help in a commercial posting????

If you want to discuss design criteria, start another thread in a non-commercial area. I may join in. I may not.

End of rant.

Pat

[art]

Thanks to all the feedback, comments, questions, etc.........

The input impedance will now be 50K on all amps.

Marketing rant:

Anyone can stick an ASP module in a bog standard case, and sell it for 21.37% over their cost. Fine by me. Most of them will out of business in 2-3 years, if that long. My company has been around for many years before now, and will continue to be for many more. ASP modules are reliable, but I would think that being able to buy from a company located stateside, with a history of supporting their products, is something that you might want to consider in any purchase decision.

Technical/marketing rant:

OK.........why the switch to 50K, right?

The standard IHF load is 10K, with some specified capacitance, blah, blah. I have always made amps that way. I had my reasons. It could have been higher. It is one of those things that designers do just because of..........well...........that is one of those arbitrary things we tend to do.

Frankly, I never ran into a issue of it being too low in the past. However, there are lot more people on this forum who do have an issue with that. Since it can be higher, and to accommodate a larger segment of the market, it will be changed.

Now the technical mumbo-jumbo part.........(you knew that there was going to be a technical mumbo-jumbo part, didn't you??)

Contrary to what some will say.............

With a transformer coupled input..............

The input will always be terminated with a very low impedance. In this case: the DC resistance of the transformer. This keeps to idle noise to a low level. Terminating the transformer with a 50K load will not raise the noise any.

Mainly because it also has a JFET input.

Which is there for a reason. Actually, more than one. But the exact reasons I am not about to divulge so that someone else will copy my approach.

But...........

The standard ASP input impedance is around 8.2K on the (+) input, and 4.3K on the (-) input. So, those of you with tube preamps that aren't happy with that load may want to think twice about buying a standard implementation. If you want to run balanced, the legs have unequal current draw, which kind of negates the whole idea of running balanced. Plus, you have to futz around with jumpers and shorting plugs to switch between unbalanced to balanced.

That transformer that some say is unnecessary gets around both of those issues.

Yes, I know that a lot of amps use the same input stage, but it takes very few extra parts to do it the right way. I have talked to the ICEpower guys about it, and while I can not speak for them, they may wish that they did it some other way. Rather than make an attempt to fix the problems on the module itself (not really practical), one then has to make some fixes outside of the module. There are many approaches, and I decided on a fix that uses transformers, as have others. Those of us who do take these extra measures realise that the modules sound better when driving differentially. (Actually, I feel that all amps sound better driven differentially, which is why we have built balanced input amps for over 15 years.)

Hopefully, that will answer some of the questions that some of you guys have, without giving away the farm. Anyway, time to get back to work............working on some new products.

"Typical engineer..............making new products to manufacture while ignoring the ones already in manufacture. You engineers are all alike."

Uh, yeah............maybe.........sort of............we do enjoy coming up with new stuff more than getting bogged down into production. One reason that custom products are more fun than standard ones.

Thanks for all the feedback. More is always welcome.

Pat

[guest1632]

Thanks to all the feedback, comments, questions, etc.........

The input impedance will now be 50K on all amps.

Marketing rant:

Anyone can stick an ASP module in a bog standard case, and sell it for 21.37% over their cost. Fine by me. Most of them will out of business in 2-3 years, if that long. My company has been around for many years before now, and will continue to be for many more. ASP modules are reliable, but I would think that being able to buy from a company located stateside, with a histor ...

Hi Pat,

I read somewhere that across the speaker outs there is some current there to give you a nice shock. Is that true?

Ray

[art]

The output of all of the ICEpower modules is one half of the supply voltage. So, yes, if you decide for some obtuse reason to grab the output lead(s) in one hand, and grab hold of ground in the other, you will be in for a shock. (Yeah, bad pun, but you should have seen it coming.)

As long as there is no return path to ground, with you in between connected to the outputs, everything is fine.

I would hope that anyone who makes amps like this would use insulated binding posts. A lot of speakers use non-insulated posts, so some degree of caution should be observed in that case. The chances of finding a return path to ground on a wooden speaker enclosure is obvioulsy much lower. But still........caution is advised.

BTW, I have not heard from any of my associates, who build and sell many more units than I do, of any incidents. I hope that is reassuring.

Pat

[art]

Some of y'all may have heard a small set of monoblocks at the NY Rave this last weekend. So what is the deal with those, you ask.

We have made several custom 5-channel amps for our private customers. We had the idea one day to take the guts of one channel, put it into a small, inexpensive chassis, and see if it had legs. The idea was primarily for Home Theater systems. Not everyone has the room, or desire, to mount a large box for 5 channels. We felt that perhaps some people would rather have a small monoblock that they could mount next to their speakers, with short speaker leads, and concealed from view. They might want to run 5 interconnects around their HT room, as opposed to 5, big, fat, thick speaker cables that can be a pain when it comes to WAF. Since the amp would be out of view, aesthetics would not be a major issue. This would allow us to sell a 5-channel system for around $2500, as opposed to $3500 for an "all-in-one" 5-channel version. So, that is how it came about.

The next logical progression was to see if had legs for a "budget" stereo system. So, we enlisted the help of TV Yankee, or "Krusty the Clown" if you prefer. (I haven't asked Dave which he prefers, but we all watch every episode of The Simpsons whenever one comes on......................)

So there you have it: a small monoblock for $500. Or $2500 for all 5 channels. Let me anticipate some of your questions:

"How does it sound? Compare it to your expensive model."

It sounds very similar. It uses a different module. Not because of sound, or performance, or stuff like that. It is because it is the only technology we found that will work in a very small enclosure.

"How can it sound close if it is a different technology?"

We feel that a lot of the new generation Class D modules share a family resemblance. The guys who design the modules don't like me saying that, but let us assume that after I work on them that they do.

Yes, there are subtle differences. While you may hear them, you would be challenged to say which is which. Or which you prefer. The differences are not as great as you might expect. The biggest difference, as it stands today, is that the small monoblocks will sound a bit brighter (or less laid back) when compared to the Velluto series. That is something that I designed in, as our experience leads us to believe that the HT crowd wants a more forward presentation than the stereo crowd does. So, if you get the chance to audition them, you should keep that in the back of your mind. (Whether it will stay that way, or if there will be toned down version.........we are getting ahead of ourselves.)

"So, are you going to put this into production? And speaking of which, when are you ever going to finish all the various 5-channel versions that you have been promising?"

This should be in production soon. The 5-channel ones............well.........

I have made my share of chassis with screw holes in the wrong place for one year. So, let me use circumlocution to sidestep that issue by stating that first and foremost that we are a stereo equipment company. That will eventually migrate to the Home Theater market. We have built stereo equipment for around 20 years now, and sometimes change takes longer than one would hope. Did I dodge that question sufficiently?

There is a brief description of the new amp, which we call the Vellutino, on our site. It is not long on description, probably contains some errors, just like the rest of the site. But when you turn EEs loose, stuff like that happens. (Would you rather that I spend my time writing html, or finishing chassis designs? Or doing it myself, and taking the money a professional web designer would want to buy parts to develop new stuff?)

http://www.analogresearch-technology.com/vellut~1.html

Any other questions????

Pat

[peranders]

Also, what's the efficiency of your amps?
Are there any appreciable real estate of heatsinks, fans etc?

Pretty good effiiciency, datasheets can be found here:

www.icepower.dk

http://www.icepower.bang-olufsen.com/sw2013.asp
http://www.icepower.bang-olufsen.com/sw2014.asp
http://www.icepower.bang-olufsen.com/sw2025.asp

EDIT: Changed to the correct datasheets

[guest1632]

Some of y'all may have heard a small set of monoblocks at the NY Rave this last weekend. So what is the deal with those, you ask.

We have made several custom 5-channel amps for our private customers. We had the idea one day to take the guts of one channel, put it into a small, inexpensive chassis, and see if it had legs. The idea was primarily for Home Theater systems. Not everyone has the room, or desire, to mount a large box for 5 channels. We felt that perhaps some people would rather have a small mon ...

Hi Pat,

Well, some time has passed since your post here, and was just wondering if you have had a chance to listen to the Hypex UCD stuff yet? I've heard excellent things about the modules, and besides, they are safer at the outputs too.

Ray

[art]

Well........thanks for the links. I guess.

Too bad none of the products being discussed here use ICEpower ASP modules, so the links end up being just more noise.

It would help if you pay attention more closely next time before you attempt to lecture me.

Actually, I can do without the lecture.

BTW, the complete specs are in a password protected part of the site.

Pat

[peranders]

If you are using ASP modules I'm sure Andrikos can find the data for them since they were listed in the first link.  

[art]

The products in this thread do not use ASP modules.

I don't want to have to 'splain it again, bub.

Pat

[guest1632]

If you are using ASP modules I'm sure Andrikos can find the data for them since they were listed in the first link.  :D

Hi, Well, go back to the first page, and you will find out what modules he is using. Otherwise, you are wasting bandwidth, "if you are using ASP ..."

Ray

[peranders]

Too bad none of the products being discussed here use ICEpower ASP modules, so the links end up being just more noise.

Sorry, somehow I misunderstood... or not. My links were not ASP modules to begin with, was those right, modules without PS? So the  links were right in the first place, yes?

I can't understand either how lecture came into this, never mind.

[dazzdax]

As a non technical dude I would like to know how complex an ASP1000 module is. If one is trying to make a fully discrete module which is equivalent to a standard ASP1000, how many passive components would it comprise? At the ICEpower homesite there is a graph that shows that ICEpower can deliver superior sonics similar to class A amps. Is this primarily based on testbench results or after extensive listening? Is the -70 degrees phase shift due to low-pass filtering audible?

Chris

[guest1632]

As a non technical dude I would like to know how complex an ASP1000 module is. If one is trying to make a fully discrete module which is equivalent to a standard ASP1000, how many passive components would it comprise? At the ICEpower homesite there is a graph that shows that ICEpower can deliver superior sonics similar to class A amps. Is this primarily based on testbench results or after extensive listening? Is the -70 degrees phase shift due to low-pass filtering audible?

Chris

As an observation, Chris, for a "non technical dude", those are some rather techy questions. I admittedly don't have the answers. I'll let "Art" answer the questions.

Ray

[art]

The lecture reference came from the part where you told me that I ought to make something of my own design, instead of buying something made by someone else in Denmark. Since you seem to have little to contribute, please waste bandwidth somewhere else.

Now, Chris.................

The ASP1000 is not something that I would attempt to build. Not only do you have to come up with a Class D amp capable of delivering 1000 W into 4 ohms, you also have to build the SMPS to power it. And mount it all on one PCB.

The 70 degree phase shift is not something that I would worry about. The interaction of the load and the output LPF is something that I would worry about. Not so bad with the 250 and 500 modules; pretty bad with the 1000. I would not advise trying it for a full range amp.

Trust me...............I have tried.

(BTW...........in case my ol' buddy "Vince" is reading this:

Making the interaction of the output LPF with the load less than with competitor's amps is one of the little tricks that I have up my sleeve.)

Pat