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post #46 of 211
ya wanna single end amp with POWER, pilgrim????

http://audio.eng.bton.ac.uk/833_power_amp.htm
post #47 of 211
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post #48 of 211
This is what I see looking at the pictures.



Since the components get hot when in use- it being a tube amplifier. The components will expand and contract due to thermal cycling. Don't the tightly bent leads add to component stress’s, which over time will lead to failures? So why no strain relief on the components- this is a standard assembly practice.

Do you use no clean fluxes? Since the solder connections aren't cleaned and flux is visible in the photographs.

Soldering a wire to a crimp connector isn't an acceptable manufacturing
practice. Why not use a real terminal strip?

Wire ties are made for holding wires not component bundles used in high voltage circuits. In a warm to hot environment the wire ties can fail.



Point to point relies on proper spacing and stable placement of wires in relation to other wires, the case and components.

With all the different floating components and wires isn't microphonics a concern? Transformers can induce vibrations.

What is the acceptable minimum spacing between the exposed leads, other exposed wires and the case since high voltages are present inside the amplifier? How can you ensure proper spacing of a repeatable nature in the assembly of the amplifier?

Why aren't the high voltage leads insulated to prevent shorts?

Those double-sided sticky pads are known to have adhesion problems
especially when exposed to heat. What happens if the slip?



Where are the wire nuts used and why? How will this effect the performance if someone has an expensive power cord and it eventually goes through a twisted connection contained by a 10-cent wire nut?

Even if all of the components are standards based implementing them in a non-standards based assembly defeats any individual components standard.

Since the parts are haphazardly installed how can the assembly be considered repeatable?

If someone lives in an old house with a floating ground or uses a cheater plug to remove line noise due to a ground loop they are at risk. Sure it's the exception to the rule but taking into consideration the exception is what’s required to be safe. The fuse is the last line of defense since something has already happened if the fuse blows.


Mitch
post #49 of 211
BTW-i did not make an issue out of the class of operation to be a pain in the butt but because there are many who like certain catch phrases,they know it means something good but why they have no clue.they are not up to speed and can be had.

also,some have said "so what if it is not PURE c;ass-A"

"means nothing"

well this is why :



if something claims to be a thing right there on the front panel well,it should be.

and again,i have never heard the amp and i am not picking on it but questions need answers and since not many want to step forward and be counted I have no choise but to weigh in or these things go unanswered

and that is not right
post #50 of 211
Quote:
Originally Posted by rickcr42
BTW-i did not make an issue out of the class of operation to be a pain in the butt but because there are many who like certain catch phrases,they know it means something good but why they have no clue.they are not up to speed and can be had.

...

if something claims to be a thing right there on the front panel well,it should be.

and again,i have never heard the amp and i am not picking on it but questions need answers and since not many want to step forward and be counted I have no choise but to weigh in or these things go unanswered
I agree with this -- "Pure Class A" is not just a meaningless catch phrase to be thrown around, nor is "single ended."
post #51 of 211
I personally think that it's not a trivial issue that Mikhail made statements to each of the major reviewers that this amp was single-ended when in fact it is not.

This speaks directly to the honesty of the manufacturer.

The single-ended triode sound is not a trivial thing in the tube world; it is seen by many as the "holy grail". Many people may have bought this amp thinking they were getting the single-ended triode sound, when in fact they were not.

I would urge people looking for the single-ended triode sound to patronize manufacturers whose statements about their amps are true. This includes:
- Mapletree Audio Design Ear+
- Antique Sound Lab MG Head OTL (I do not know about the OTL32)
- the Woo Audio amp GSferrari reviewed
and probably others.

Each of the three amps I listed above is also a pure Class A design, regardless of the impedance of headphones used, unlike Mikhail's amps.
post #52 of 211
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.

Nothing to do with sound preference,just clarifying through all the smoke being blown around.

Head-Fi is rapidly becoming an arena for dis-information and too much is let go
Rick now i really would like to know how you would consider any single ended output stage to be other than Class A up to the clipping point. Since one device handles the entire waveform how can it be none other than class a up to the clipping point. This is true of the seekers amp as well as all the single ended OTL Amps when you run out of current or voltage swing you are clipping and otherwise any single ended output stage is Class A up to the clipping point Am i incorrect in this statement?

The Single power amps I think are also single ended and thus class A up to the clipping point and this will be at ether its voltage or current limit, as to weather or not this is Pure Class A is debatable (Please Define Pure Class A) and I await for someone to explain how a single ended design is not ether operating in class A or clipping. Dose the waveform shift from one device to another Of course not because there is only one device all that will happen is the load line will shift and at some point clipping of the output waveform will happen.

Moving along thanks Mike for clearing up a lot of unsubstantiated Rumors and yes it’s a sad day for head-fi that for what ever reason or personal vendetta this had to happen to you I am truly sorry that members of this forum act so childish so as to go behind the scenes and rumor monger to the point that this kind of nonsense had to take place on our once civil and honest forum. This is starting to turn into a diyaddio.com drama argumentative place that is getting less and less fun to visit and as such will lose the trust and respect of both manufactures and consumers alike that will avoid this place like the Plague so as to also not be a victim of this kind of nonsense.

Civil dialog and different points of view are bound to happen however it can be conducted in an intellectual manner. So all the folks that like to send emails and PMs to other members bad rapping another member or a manufacture are mealy trying to glorify themselves at someone else expense and you know how you are.
post #53 of 211
Mikhail's statement is, in my mind, potentially misleading.

Quote:
Originally Posted by Mikhail
We meet all the standards that we’re required to meet.
Translation: In the USA, we are not "required" to meet any standards. So yes, this statement is trivially true. Be specific. Which standards, if any, do you meet?

Quote:
All ground points are run back to star ground.
I have my doubts as to whether this is entirely true. In one of the pictures Braillediver posted, the earth ground appears to be tied to the chassis separately from other ground points. It is difficult to be certain about this from the pictures, however. Perhaps Mikhail's statement is only true for signal ground points.

Quote:
Third, the circuit itself is our design and may look like another type, but the fact is that many tube electronics circuits look similar.
Translation: the claims that the amp circuit (except for the power supply) is identical to Chu Moy's optimized Morgan Jones save for a few resistor values are probably true.

Quote:
The circuit itself runs in class A during normal operation. It can cross over into other classes when overdriven.
Translation: for low impedance headphones, this amp runs in Class AB unless you listen only at low and moderate volumes.

Despite all the claims made to reviewers, this amp is not single ended.

Quote:
Fifth, we will make available pictures of our products to those customers who are interesting in seeing them. There is nothing for us to hide...
Translation: once we clean up our layout and improve our assembly practices, we'll make pictures available. We tried to prevent pictures from getting out for the first two years of our operation, but now we'll just have to fix up our work.

Quote:
Finally, as to patent issues, our patent attorneys are in the process of handling our patent claims. This is all we can report at this time.
Translation: Now that someone has told us that claiming something is "patent pending" when in fact it is not is a violation of the law, we're no longer using that wording.
post #54 of 211
Quote:
Originally Posted by Wodgy
I would urge people looking for the single-ended triode sound to patronize manufacturers whose statements about their amps are true. This includes:
- Mapletree Audio Design Ear+
- Antique Sound Lab MG Head OTL (I do not know about the OTL32)
- the Woo Audio amp GSferrari reviewed
and probably others.
Well, at least you're straightforward about your bias/prejudices. I mean, let's not make people make up their own minds, right? Let's tell people what they should do and sprinkle in some more specualtion and questionable accusations to help them along.

Man, I hope this all gets ended soon. What a poor reflection on this forum, the internet, and humanity in general.
post #55 of 211
He wrote it in English, so I don't see the need to provide a translation. You don't get to reinterpret the meaning of his statement.
post #56 of 211
Thanks for the reply Mikhail. I can't imagine you guys not buying a car before ripping off the dashboard to see if it is well built. Or in another venue: If you all chose politicians with such concern and ferver maybe the world woulden't be as screwed up as it is. I am still waiting for a manufacturer to build a better TUBE amp than the SinglePower MPX3 at it's given price point and sound as good. It would sure be a thrill to listen to.
post #57 of 211
Quote:
Originally Posted by braillediver





Mitch
Thanks for the photo reminder of why this whole thing started as well as your thoughtful commentary on why this represents questionable manufacturing practice. It seems rather obvious (to me), this is either about cost-cutting or simple inability/unwillingness to implement a better (more durable, duplicatable, and probably safer) layout solution. Oh well--some people have messy desks and never mate their socks together, but they dress nice and can carry a tune.

Whether true or not, I can't help but imagine the final checkout as the lid is closed and exposed wires gets crunched closer together: "nothing touching here... check... nothing touching there... check..." all the while keeping an eye on the connections with a flashlight. If this represents state-of-the-art, then I am hopelessly misguided. This reminds me of Chevy Chase's "Christmas Vacation" house lighting project.

Note that my remarks are not directed toward the honesty or integrity of the manufacturer or his claims--I'm not qualified to comment. The workmanship simply appears to be quick, sloppy, potentially unreliable and possibly unsafe for the reasons Braillediver described. But I'm sure it sounds great and am willing to bet it would go up in price if executed differently.

I'm finished now.
post #58 of 211
Quote:
Originally Posted by PhilS
Well, at least you're straightforward about your bias/prejudices.
I am not biased. I do not own any of the mentioned amps.

I dislike people who do not tell the truth. The manufacturer claimed this amp was single ended when in fact it wasn't. Case closed.
post #59 of 211
Quote:
Originally Posted by bln
He wrote it in English, so I don't see the need to provide a translation. You don't get to reinterpret the meaning of his statement.
His statement was carefully couched in such a way as to be, in my mind, potentially misleading. This statement was not quite as brazen as his earlier claims that his amps were single-ended, however.
post #60 of 211
Quote:
Originally Posted by PhilS
Well, at least you're straightforward about your bias/prejudices. I mean, let's not make people make up their own minds, right? Let's tell people what they should do and sprinkle in some more specualtion and questionable accusations to help them along.
Have you been reading and do you understand the nature of "pure class A" and "single-ended" circuits? The entire second page is loaded with very useful, straightforward information about what those terms mean and why the Singlepower amps don't seem to adhere to those claims, as are printed right on the front of the chassis. It is entirely anyone's choice to ignore this and simply enjoy the sound of the amp, there is nothing at all wrong with that. But it simply should be known and acknowledged that the amps are not quite what they claim to be. The amps themselves don't say anywhere "I sound wonderful" -- that's a judgement many happy owners have made for themselves.

This isn't a matter of viciously attacking Mikhail for his sweet sounding amps -- it's simply about addressing what those amps are claimed to be.
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