Re: Krell - discussion thread

[kowtim]

Ooh.. if sharp edges of Class A amps are hazardous, might as well say tube amps would be life threatening to kids and toddlers too, even to unsuspecting adults too. Anyway, I think most audiophiles with these equipment or well set up rigs ain't going to risk having kids lurking around their hifi gear. I've actually yet to witness any hifi session with kids there. No pun intended, just my opinion.

Hmm...a tinge of sarcasm me sees? Most welcome to go for it...

Yes, you are quite correct. Tube amps are potentially threatening to children too. And others. That's why quite a few tube amps used to come with cages over the valves. Those manufacturers today who care about such things as safety do indeed put cages over them. Or at least offer them as an option.

Your logic that the owners of such hifi gear will be able to readily prevent children from lurking around their hifi gear, is in my opinion rather unrealistic. Unless you believe that all Krell owners are either bachelors and spinsters.

If you think highlighting the safety of innocent children is out of place here, well, I will leave it at that...

Hopefully thou, some Krell owners might benefit from knowing that a lil kid and a coin wiped one out and thus take a few simple precautions.

To get things back on track.... the first Krell product I ever saw was a PAM 1.

Regards

[bimmerman]

TO THE FINE PEOPLE AT KRELL NDUSTRIES

Are you reading this? Do you realise how dangerous your products are to pets and small children? Are you planning to do anything about it at all? How about making a child friendly KRELL Mini-Compo?

Hahahaa ah ha! Sorry folks, could not resist. More than a tinge of sarcasm there...

Anyways, Krell did do something about it and did it quite a few years back already. The answer is in the rounded edges of the KAV-300iL, the KAV-400Xi and the latest mini compo of a Krell S-300i. Yup, to the Krell class A diehards, Krell does make mini-compos too. They call it the S-300i. Ha ha ha!

[kowtim]

Hmmm

Maturity seems to be ...

On the subject of pets, damage from pets urinating on equipment is something to be taken very seriously. Cat's urine in particular is so corrosive that it will etch and strip away at the copper tracks on a circuit board in hardly anytime at all.

Unlike a handphone that can usually be quite readily rescued should it come in contact or get immersed in some water, urine will effectively destroy a board within 24 hours should it go undected.

A similar warning applies to laptop keyboards...

Once again, sorry lah Mugen. That PAM 1 was the first preamp I have seen with dual mono power supplies. Never got to listen to that and an aquaintances KSA 50. That would be a lovely classic to have that 50...

I had a hard disk failure which was unfortunate as it contained lots of interesting photos. In it I photographed in great detail the Reference 64 DAC internals. Wonderful build quality that one. Also the insides of one of Krell's outboard power supplies. Interestingly Krell used a PC serial port connector on that umbilical power lead!

Regards

[azri]

why the theme sounds so masuk bakul angkat sendiri?

[kowtim]

Hi Azri

Based on a lil old radio experience, if you repeat "tag lines" often enough, they actually do register in many peoples subconscious minds.

There are sound reasons to do so, pardon the pun

Regards

[car o scope]

Not actually a Krell owner but I have heard of the Krell KAV-300i.
Definitely, the power and control are no slouch for the American.

Well, if any of you had visited last year's KLIAV, Norman Audio did a showcase of the Evolution driving a pair of Avalon Isis.

[chua55]

Oh evolution series. using current feedback and tranmission for ultra purity transmission. well. I will soon own the technology and get to hear the most neutral sounding driver. And it doesn't have to be expensive.

[bimmerman]

You will soon own the technology and get to hear the most neutral sounding driver??? How do you mean??? Do tell, do tell...

[mugenfoo]

chua55, you forgot the: "Muahahahahahahahaha...."

[tycham]

Hi Azri

Based on a lil old radio experience, if you repeat "tag lines" often enough, they actually do register in many peoples subconscious minds.

There are sound reasons to do so, pardon the pun

Regards

You mean the tag lines in a radio broadcast?

[car o scope]

chua55, you forgot the: "Muahahahahahahahaha...."

Hmmm.. Sounds like something powerful...

[chua55]

Using current feedback is not new in audio design but the way Krell advertise it seems like revolutionary.

CAST Basics
Here is how a CAST audio system works: Internally, each CAST source transfers, or amplifies, current using Krell Current Mode circuitry. This current signal is then output using CAST circuitry. When the signal is received by a CAST input, Krell Current Mode circuitry again takes over until the signal reaches the loudspeaker. By maintaining the musical signal in the current domain from beginning to end, an entire CAST system behaves as if it is one component. With CAST, circuit board properties and signal transmission aberrations between components are eliminated. Cable impedances and their effects on the transmitted signal are non-existent.
How CAST and Krell Current Mode Interact: While CAST is a new method of transferring the musical signal between components, its origin stems from Krell Current Mode, the technology developed to transfer the musical signal within a component. CAST combined with Krell Current Mode takes circuitry signal transmission to the next evolutionary level.
In essence, Krell Current Mode maintains the integrity of the signal within the component and CAST preserves the transmitted signal between components. Together, CAST and Krell Current Mode technologies unify separate Krell components into a single global circuit. Krell Current Mode technology enjoys bandwidth increases up to an order of magnitude greater than their voltage based counterparts.
This dramatic increase in circuit bandwidth delivers near perfection in the audible band that typically suffers from phase distortions in voltage circuits.

[mugenfoo]

Actually no ... Dan D'agostino in a Stereophile interview acknowledged that alot of people are using current domain to handle signals already.
Krell only focused & specialised & refined it for audio applications.

http://www.stereophile.com/interviews/1203dagostino/


In fact, the industry pioneer is SONY back in the 80s. Think i saw it somewhere on the web sometime ago.

[bimmerman]

In fact, the industry pioneer is SONY back in the 80s. Think i saw it somewhere on the web sometime ago.

I'm not sure but i've heard Pioneer also applied current domain technology to their A400 which helped it achieve giant killer status.

[azri]

a400 rocks yeah!!

[bimmerman]

yes Azri, the A400 is an all time favourite among modders and can be modded to no end. I've seen one with a pair of 12au7 inside and an outboard power supply. If someone went through all that effort to mod it like that, i can only speculate that it must have sounded quite extraordinary.

[azri]

its a must keep amp

[kakibook]

The essence (as in the interview) is in the pure Class A design and zero feedback. a lot of design efforts is required for current signal transmission and amplification. Why zero feedback is used when the Total harmonic distortion figure given in most amplifier (including thepstreet amp) is already so low. The problem is the figure is given for commercial test purpose on pure resistor load. The real world speaker load impedance fluctuates from 2ohm to 16ohm and when feedback is applied, the total distortion is no longer what is claimed. Further the resolution (of most amp, especially the street amp) is low, meaning at low volume, you lost all the soundstage, detail. That's what Krell address (and most others) this in their amp series. So the capacitors and tranny bank and a host of electronics army are their to serve a purpose.

[car o scope]

So to say, a great amplifier will be able to maintain the quality of the sound reproduction throughout all range of volumes.

[BrAvO]

If you want more, we have to pay more. The theory is very simple. Why don't I have plenty of monies????

[car o scope]

It is because of not enough money for a nice amplifier.
So, I tell myself to work hard everyday to earn money for it..

If I cannot afford a new unit, then I shall settle with a used unit...
.... as long as I like it.

Enjoy the music!!

[wabun]

Krell and Mark Levinson is sucks when use in non aircon room.
Even high humidity can short their life too! so remember to get
the service center name card if buy one. I doubt their repliability.

[car o scope]

So, must set the budget a bit higher to get the air cond together when buying a Krell or Mark Levinson.

[bimmerman]

I've driven my supposedly hard to drive Minima Amator with a little 18 Watter valve amp before and it sounded better than my Krell at low volumes. At higher volumes is where my Krell excels.

In layman's terms, it seemed to me that the little valve amp gives higher quality small watts and my Krell gives higher quality big watts. I don't think my Krell does very well at lower output. Not sure about those hulking class A Krells though. Anyone care to enlighten?

[mugenfoo]

Krell and Mark Levinson is sucks when use in non aircon room.
Even high humidity can short their life too! so remember to get
the service center name card if buy one. I doubt their repliability.

Dear wabun, from the comments above, it is glaringly obvious that you have neither the ownership experience of a Krell or a Mark Levin, nor the long term user experience of the aforesaid fine audio products.

The phrase "sour grapes" comes to mind.

[wabun]

Haha Mugenfoo.. I am repairing Hifi gears for years, the quote is based on experience rather than comment. Reliability wise, you can ask Krell / ML user on the repair record.. gud luck man..

[wabun]

Not simply talk lah, you can see my review in The Star as well..
http://sites.thestar.com.my/audio/story.asp?file=/2008/11/17/afreviews/2535134&sec=afreviews

No hard feeling to Krell / ML user. They are good stuff. Just one
need be prepare for maintainence cost only..same like driving a BMW
dun ever complain on the service cost if you can afford one.Cheers!

[car o scope]

Things about reliability are sometimes very difficult to say.
It is just unpredictable and should I say, depend on our luck as well.

When we see one or two unreliable units of a brand, it just doesn't mean that everything from the same brand is unreliable. Right?

Like cars.. There are also complains for Toyota, Honda, BMW, Porsche and etc etc.. but not all their products are struck with reliability issues.

For some reasons, maintenance should not be a problem for people who actually can afford a BMW, Mercedes or Ferrari.
Same goes to the likes of Jeff Rowland, Krell, Kondo etc etc..

No hard feelings but I just feel that sometimes we should not consider things that are totally unpredictable.
Go on and enjoy what we like. Life is Short!!

[mugenfoo]

Haha Mugenfoo.. I am repairing Hifi gears for years, the quote is based on experience rather than comment. Reliability wise, you can ask Krell / ML user on the repair record.. gud luck man..

Oh really ?

so which model Krell or MLs have you done repair work on, that forms the basis of your judgement that they are not suitable for our climate / weather / political situations ?

[wabun]

ML and Krell is running at Class A ( pure class A when < 80W) .You can estimate with 85% efficiency, how much watts converted to heat ? Engineer design the amp to operate at room temp whereby room temp in their country is 24-25 C... Or layman way, just use your hand to touch the inner heatsink to get what I mean here. Remember this, transistor get attached to heatsink with mica sheet and oil based heat transfer compound can dry up over time & humidity.What you feel on heat sink is only part of what the transistor released..and caused premature failure to power trans pair...Just sharing.

[ryder]

During winter the Americans use these amps especially the higher-powered ones to do double-duty as heaters as they produce a lot of heat to keep the room warm which is useful. During summer however, some folks have installed room conditioning system as they find the heat to be too much. Running in Class A is certainly a killer not only environmentally but financially as well especially when paying bills at the end of the month. My whole room which is dedicated would be like an oven if my Plinius is running in Class A without the air-conditioner on. It wouldn't be too severe if the system is in the living area with a large space and open windows.

[tycham]

During winter the Americans use these amps especially the higher-powered ones to do double-duty as heaters as they produce a lot of heat to keep the room warm which is useful.

...would be hot and noisy-very unbearable.

[bimmerman]

Hey Wabun, I bought the KAV-300i to escape the crazy maintenance of my Cary SLM-70 valve monoblocks. Once I blew a EL34 and had to change all 8 of them. Ouch!!! Please tell me the non class A Krells like the KAV-300i require less maintenance. I mean, not all BMW cars are crazy expensive to maintain right? My BMW E34 only requires RM2,000 per annum to maintain.

Have you had any experience with the KAV-300i? If so, do you think it's reliable???

[WongKN]

It would be good if one can back up posts with some real life information. I recommend that if you are concerned with maintenance of high-powered amps like Krells, Mark Levinson, Cello, etc, that you try to talk to an actual owner. And if you are concerned with reliability, talk to one who has owned one for many years. Do bear in mind such amps usually offers a much much longer warantty period (typically 5 years or more) compared to other amps. And they are transferable if purchased from the authorised dealer. So, if they are not reliable, then manufacturers usually won't offer such long periods of warantty. Occurrence of such amps actually failing due to a failing component is also quite rare. Actually there are only 2 places which is able to repair a Krell. Their parts are not easy to get. Same for Mark Levinson, Cello, etc. Furthermore, a number of the internal parts are proprietry and the manufacturer do not sell to non-authorized agents. Just remember what you experience with your amp might or might not translate proportionally to something like a Krell, Mark Levinson, Cello, Pass Lab, etc.

[mugenfoo]

Hey Wabun, I bought the KAV-300i to escape the crazy maintenance of my Cary SLM-70 valve monoblocks. Once I blew a EL34 and had to change all 8 of them. Ouch!!! Please tell me the non class A Krells like the KAV-300i require less maintenance. I mean, not all BMW cars are crazy expensive to maintain right? My BMW E34 only requires RM2,000 per annum to maintain.

Have you had any experience with the KAV-300i? If so, do you think it's reliable???

dude .... don't worry about the KAV-300i under local usage conditions .... (or mr/ms wabun's baseless claims for that matter)

I've used my KAV-300i for more than 10 years already. No need any bullshit aircond climate control environment or anything. On a hot day in local KL weather also i can blast the amp nice nice driving low impedance speakers until the whole unit gets damn hot but its still sounds fantastic. That's Krell quality.

And there are plenty of pre/power class-A (or non class-A, irrelevant) Krell owners out there enjoying their Krell amps without a hint of any problems since day one. I could quote many names here but out of respect for their privacy, i won't. As long as you dont spill any Nescafe C, Milo panas or Teh O' ais limau over the amp , you're good to go.


I seriously doubt if dear mr/ms wabun really has any experience repairing Krells or MLs, let alone owning any of them.

One could go on and on about speaking from REAL experience about Krell and ML's (or Jeff Rowlands or Gryphon or Classe, etc etc etc) build-quality are not affected by any tropical climate and so on and so forth yadiyadiyadda but as one old chinese saying goes... "Its like playing the piano (maybe even Beethoven's Moonlight Sonata ) in front of a cow".

[auronthas]

Refer to KAV-400xi operation manual, as long as one follow manufacturer's recommendation : -

The KAV–400xi requires at least two inches (5 cm) of clearance on each side and at least two inches (5 cm) of clearance above and below the component to provide adequate ventilation. Installations inside cabinetry may need extra ventilation.

During weekend, Krell KAV-400xi nicely served me more than 6 hours music continuously via my Network Music Player without problem. No air-cond in my listening room, just make sure adequate ventilation is provided, i.e. ceiling fan.

[mugenfoo]

Oh, and one more thing, when you buy a Krell brand new from any authorised dealer, it comes with a full 5 (five) year warranty. Applies all over the world.

Compare that with a >half-a-million Ringgit Mercedes Benz S-class, you only get 3 years warranty max, and subject to conditions (mileage) !



...Somehow i didn't manage to find anything that said if the Krell is used
in a tropical country, the warranty is reduced to 1 year....

@wabun, mebbe u can check your Krell ( or ML ) manual and kindly refer us to that particular page? thanks in advance !

[WongKN]

Not to target anyone specifically but it would be nice if we are all friends here. So hope this discussion can be on a friendly basis.

[chua55]

Class A theretical efficiency is 50% while class B is 78.5% (look at how small is Naim. In actual circuit, class A eff is between 25% to 40% wwhile class B is 50% to 65%. Class AB would be in btween.

Tube amp is very different when compared to solid state. A 2A3 single ended has only 4W output power but why would people craze for such low power to drive even loudspeakers.

The resolution of amplifier at low volume has a lot to do with volume control and amplifier design. Some volume control will offer you as good a preamp in itself with good resolution. Therefore it depends on what is inside and determine the difference.

[chua55]

Well the CAST amplifier is built on 2x650W of output transformer with 16 output MOSFET (Toshibas or the MJE) of 20A per rail. it uses no global negative feedback by ensuring extreme linearity in the signal path with all active components in class A mode. All signal amplification is done in current mode (of course where voltage gain is required for output). weight however will be troublesome 33kg and this does not have to cost you an arm or a leg.

[bimmerman]

Thanks for all the input guys.

Well my 300i did run rather hot during last weekend's 8 hour marathon of vintage jazz through acid jazz but the sound never did degrade. In fact it sounded better after the first 20 minutes when the casing was warm to the touch. Room temperature was stable at 27 degrees celcius with a relative himidity of 60% with the ceiling fan on low.

[wsyam]

mugenfoo..i have to agree with u on the reliability of the krell kav 300i.....i have owned 1 for a few years now....the only problem was once the fuse blew..that was becoz of a lightning surge....i replaced the fuse (both) for less than rm10..and that was it.....another thing is that..i use my kav 300i hooked up to my astro/tv..and basically i have them running on average of say more than 10 hours daily actually its more than that.......
basically...when it comes to reliability......krell has no issues...just like our friendly toyota or honda cars.....

[bimmerman]

Fuse blow!! Oh God forbid. Mine is a very expensive silver/gold fuse. Can't afford to blow that! My audio system is always unplugged off the wall socket when not in use.

[car o scope]

Fuse blow!! Oh God forbid. Mine is a very expensive silver/gold fuse. Can't afford to blow that! My audio system is always unplugged off the wall socket when not in use.

What sort of silver/gold fuse is that??

[wabun]

it just a comment. ignore it if it stings.

[mugenfoo]

Fuse blow!! Oh God forbid. Mine is a very expensive silver/gold fuse. Can't afford to blow that! My audio system is always unplugged off the wall socket when not in use.

What sort of silver/gold fuse is that??

it must be "super high end audiophile grade" fuse..... hahahahahahahahahaha

[kowtim]

Not to target anyone specifically but it would be nice if we are all friends here. So hope this discussion can be on a friendly basis.

Hi Wong

Im glad you made that comment. If I could expand on it by making some observations.

We have a new member Wabun come here and offer his opinions. It seems to me he is / has been rather poorly treated here for simply voicing his opinion.

Now, I know very little about Krell. I admit this. But my experience in matters from other aspects of life and technology suggest that if you buy a new Krell, then chances are you will have a wonderful experience with it provided you are aware and happy with whatever sonic signature it may or may not have when you bought it.

It seems quite a few have purchased Krell integrateds and they are happy and have found this particular model to be very reliable.

But the question is, what is the reliability like for the other Krell models? Was and Is EVERY Krell bullet proof? Krell's operate at very high temperatures and heat is a semiconductors big enemy and will ultimately experience accelerated aging. And so, what happens when the Krell experience of ownership is viewed when made as a ten year old purchase used? One has to look into these questions, because this is a forum where old Krell's will most likely be bought and sold.

My own highly limited experience is that there have indeed been some issues with some Krell's. I personally know two Krell owners who have had troubles with their power amps. It is thus reasonable to assume that Wabun may know of similar instances where someone else had some unfortunate experiences.

And so..... the big question....how do we progress?

By not attacking people who make reports on troubles that they or others they may know have experienced. It seems to me that most Krell owners have had a fabulous experience of the brand. My personal opinion is that its a great brand.

But the time has got to come for owners of high end equipment to stop attacking others for making observations that others have had problems. Let the good and bad comments coexist peacefully and let others make their own informed decisions. The more input placed in the pool, the better a decision one can make when needed.

In my books, the only one who can give an accurate assessment of it all would be a Krell Authorized service agent who has been in the game for many years. He would, in my opinion, be the only one who has the moral right to tell Wabun off if he was wrong.

Regards

[BrAvO]

No doubt that by changing the fuse will be further improve the sound quality of any equipments use. Think of 230-240v going through a RM1-2 fuse then only to the transfromer inside and as compare to the price of your value component, that's nothing.

A good fuse like the Furutech as what i am using now for my amp, CDP & buffer, it really shape up the staging & improve on the clarity & tighter bass too.

Try to replace a better fuse as the last tweek if you have nothing else to play with. It's also the cheapest tweek to play with too.

[WongKN]

Hi Kautim,

Actually I wasn't specifically referring to any particular posts in thsi thread. To be honest I actually thought Wabun made his statements without giving information to back them up. I can understand why some Krell owners are a bit worked up. But the more important thing is I really wanted/hoped to avoid a flame war. Not to say it looked like it will happen but just thought some 'preventive maintenance' would be nice.

About the higher-end Krells, if people is willing to take my word for it, I can say I have close friends who owns Krell, Mark Levinson, Cello, etc amps. One of my closest friend, an uncle, has been using 2 pairs of Krell monoblocks to drive a pair of Apogee speakers for over 15 years now, without any problems at all. And as he is retired for many years, he switches on the system and listens for a few hours every-day. Actually he uses them as part of his home-theatre as well.

The points about needing an air-cond room is valid but that is more for our own human creature comfort than it is necessary for the amp. Actually according to my friends, if you put the amp under the air-cond, it actually won't warm up properly and will not sound at its best.

Anyway, my original intention was just to make some observations and then a suggestion. It looks like you guys have things well under control. Thanks for the keeping things friendly.

[kowtim]

Hi Wong

I think we are for the most part of things, on a very similar track and in agreement over much of it.

The point I am raising is that members of this forum should be allowed to be able to express a plausible opinion and not be harrased for doing so and furthermore members of this forum should be allowed to make reasonable comments WITHOUT the need to back it up.

Many members who are watching this thread will believe that they have absolutely no means to argue a case against a technical oponent like Mugenfoo and will in the end, continue to just be lurkers.

Forums come to life when non technical people can genuinely contribute without fear of being hammered for being unable to explain unfortunate events experienced by others, disliked equipment, purchasing mistakes etc etc.

Perhaps you can enlighten me why Krell owners should get worked up when a forumer wishes to genuinely help prevent others from falling into a trap whereby someone they knew had a bad experience with one?

Regards

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