[PhilS]

Quote:

Originally Posted by tom hankins Also if you think the way they are done can be improved on with lowering the cost of the amps and improving the sonic signature maybe you should either call Mikhail and clue him in on it, or try building one yourself and compare it to one of his amps and see. Until then you really are just speculating.

Hold on. If he can "improve" the build, lower the cost, AND improve the sonic signature, I'd say he should (1) build it himself and sell it cheaper, and (2) sign me up as an investor!

 

[PinkFloyd]

Quote:

Originally Posted by tom hankins you really are just speculating.

It will obviously take someone being electrocuted before anyone here takes any notice and , when that day comes, it'll be too late............ I've given my opinions, as have others, take them or leave them I (for one) am out of here.

 

[rickcr42]

Quote:

"pure" is just an adj. right? I think you can define it what you like IMHO.

nope,and IMHO is just that as obviously you do not know.A pure class A stage has a non varying stae of operation and even at idle,with no signal present, is running at full power.
only the amplitude of the voltage output will vary with a signal but the bias operating point is locked in and can not change.Full power all the time or another way to put it

all or nothing

look it up,do a google search,do some research.the truth is out there if you really want to know

 

[kevin gilmore]

Back to the class A thing again. I just looked this up to be sure.

Krell master reference amplifier. 1000 watts of pure class A into 8 ohms
2000 watts per channel into 4 ohms. 4000 watts per channel into 2
ohms. But regardless of load the amplifier drops out of class A at about
1300 watts.

The same with mikhail's amplifier. (i will calculate the exact numbers
tomorrow) Into 300 ohm headphones i believe that your ears will bleed
before the amp drops out of class A. It is getting pretty close at
70 ohms. At 32 ohms it is merely VERY loud before the amp drops out
of class A.

My dynahi is the same way. At any level up to 18 watts into any load
(which includes speakers) it is pure class A. After that it goes A/B up
to about 60 watts into 8 ohms (with a big enough power supply)

 

[comabereni]

Quote:

Originally Posted by mikeg For me, the cost factor is of extreme importance. For me spending several thousand dollars for an amplifier is really a big deal. And, I would vehemently resent having to pay thousands more just because Mikhail is either forced, or browbeaten into producing military spec. compliant amps; i.e., amps that can be bounced and jarred around. Mine just sits quietly on a desk, and produces marvelous sound. So, I appreciate getting a top notch sounding amp., at the lowest possible price.

Completely understandable that many should feel this way. Only let it be understood that when you buy said amp, the design and layout choices were made as much for pricing reasons as anything else. I have a *very* hard time imagining sonic minus points strapping components down so they aren't physically dangling on soldered joints.

If forgoing that process saves two hours under the hood and lowers the price of the amp $100 or $200, then that's great. But call it what it is. As I mentioned up-thread, I am passing on my Singlepower amp purchase for now, but I may eventually decide the risks (product durability, possible safety, resale value) are worth it. Singlepower amps seem to be spec'd out nicely at their respective price points.

In summary, I feel no one has truly lost from the inquiry that has taken place here--if anything, everyone is more informed about what they are getting when they buy from Singlepower. And Singlepower retains within its power the ability to alter our perceptions: either through clarification, by altering the execution of its products, or by other methods at its disposal.

 

[PinkFloyd]

.

 

[comabereni]

Quote:

Originally Posted by PinkFloyd Go stick your tongue inside a TV.... you may be shocked.

I hope my statement was understood to mean that strapping down the floating components and achieving great sound are not necessarily mutually exclusive.

 

[Edwood]

Quote:

Originally Posted by braillediver “All generally accepted principles of safety are followed.” Which ones? The amp in no way comes close to UL safety requirements. While it might not be feasible to test to UL requirements it is desirable to build to UL requirements at least where possible. Sure the exposed tubes will never pass UL but the internal build should be as close to standards as possible. Things like minimum spacing of high voltage components, spacing of line current leads etc. Mitch

I'm going to post this one again:

For those that don't know, UL (Underwriters Laboratory, Inc.) Listing is a voluntary process of certification. Much like USDA rating of meat grades like "Select", "Choice", and "Prime." It is a voluntary rating that is paid for by the manufacturer.


Quote:

Originally Posted by Ripped from UL Website FAQ Manufacturers submit products to UL for testing and safety certification on a voluntary basis. There are no laws specifying that a UL Mark must be used. However, in the U.S. there are many municipalities that have laws, codes or regulations which require a product to be tested by a nationally recognized testing laboratory before it can be sold in their area. UL is the largest and oldest nationally recognized testing laboratory in the United States. UL does not, however, maintain a list of the jurisdictions having such regulations.

Mikhail has stated that his amps are safe, and that SinglePower is covered by liability insurance. If someone really has a doubt, then have your amp inspected if you wish.

-Ed

 

[drewd]

Quote:

Originally Posted by kevin gilmore Any class A amplifier is only class A up to a specific power level. That power level may vary due to the load. It could be 10mw it could be 100mw. This is not specified. No one has bothered to ask either. Even the largest krell amplifier ever made will fall into A/B operation at some point.

Quote:

Originally Posted by rickcr42 then it is not "pure" class A.you can have degrees of class A operation but if you are claiming pure class A the operating points are consitant,non varying until you hit clipping.then it matters not what class you are running as you are out of steam anyway and it will sound like crap. I defy anyone to prove to me and back it up with measured results where a Szekeres Amp EVER goes out of classs A up to full clipping.That my freinds is what PURE CLASS A IS ! You can bias for class a up to a pre specified level and have an amp switch over to class A/B by design but that does not make the amp a Class A amp.

You're both right, if you're describing a single-ended amplifier, which, I believe, is what the amplifier in question is supposed to be. Crank up the volume on a single-ended amplifier and at some point, the plate current will hit zero and it won't be in Class A anymore. It'll be clipping, certainly, and that's what Mikhail pointed out in the original post in this thread. That's no different than any other single-ended Class A amplifier.

Kevin's post is a perfect example of a push-pull amplifier. Run it up so far and the plates will stop conducting and it will go from Class A into Class AB mode.

An amplifier is operating in Class A mode if the plate current is flowing in all output devices for a full 360 degrees of a signal cycle. So the Krell can operate in Class A up to a point, where half of the devices are in cutoff and the other half are in saturation, then it's in Class AB. In the single ended example, once the amp hits cutoff, it's technically in Class AB, but, since it's clipping, that's sort of a useless point.

-Drew

 

[sft]

Quote:

Originally Posted by rickcr42 nope,and IMHO is just that as obviously you do not know.A pure class A stage has a non varying stae of operation and even at idle,with no signal present, is running at full power. only the amplitude of the voltage output will vary with a signal but the bias operating point is locked in and can not change.Full power all the time or another way to put it all or nothing look it up,do a google search,do some research.the truth is out there if you really want to know

Ok, Ok... I really want to say is that "pure" is not so importat.
the key point is ?W/? ohm Class A

Maybe Single Power is not so "pure". Just kiddig...

 

[PinkFloyd]

edit: silly comment

 

[kevin gilmore]

I was going to make a comment about single ended but got hauled
away for dinner. In any case mikhail's amplifier is push pull, not
single ended. There is no other way to get an output impedance
that low with tubes of that size.

To be single ended and put out that much power would require a 6c33.
You think his amps are big now, just wait till he puts a couple of those
in...

 

[strohmie]

So basically what I'm getting out of this part of the discussion is that the "Pure Class A" and "single-ended" parts of the amps are innaccurate.

Meanwhile, I'm glad I don't have to search for the patents anymore, but am still curious as to what the patents are in relation to. But since Mikhail mentioned that he's not going to go any further into this, I suppose that ends that discussion.

 

[rickcr42]

From the master


http://www.passlabs.com/downloads/articles/seclassa.pdf

applies to any amp whether tube or solid state.

you can have Pure class-A,class-A,quasi class-A,class A until Class A/B,full A/B,class H,class whatever.All it means is

when,at what time the actual amplifying device turns on.Pure Class A means it never "turns on" because it is
always on

why do you see a boatload of Class-A/b 200WPC amps but no PURE Class A 200 watters ?

Because you would need to upgrade your house wiring,put it in another room and run a big *ss fan on it just so your house didn't burn down !

obviously an exaggeration but not the first one here

 

[Zanth]

Quote:

Originally Posted by Nik If I'll like (a lot) the sound I'll probably buy one. Best! Nicola

Nik you kick some serious behind.