[spritzer]

Quote:

Originally Posted by markl /img/forum/go_quote.gif LOL, now that youse guys have been nailed, you're back-pedaling and trying to pretend you were arguing something else. OK, I'm outta here, case closed.

What ever helps you sleep at night.

You accuse me of backpedaling as I'm not continually hammering on the build quality issue? That was sorted as the chassis cost 19.3€ each at retail and all those that have seen inside a Rudistor amp knows what a mess it is with cheap parts that make an cmoy look luxurious and well built in its Hammond enclosure. There is no sense in beating the same dead horse and since you wanted proof we moved onto the specs.

We could also just call you what you are and be lowered to name calling but then Mike would close the thread and I'm going to let the fanboys ruin this discussion on the amps merits. I don't care about the sound of the amp but I do care about its technical performance. What those that aren't familiar with high end ESP amps don't know is that we are playing by a whole new set of rules. The amps power will have a large impact on its sound as it will be driving a beast like the SR-007. Slew rate, gain and output impedance are also issues much more then distortion or frequency range. The fact that those two are either false or point to a SS amp stage are worth a second look and an explanation from the manufacturer.

 

[philodox]

Quote:

Originally Posted by Wmcmanus /img/forum/go_quote.gif I'd put this kind of amp on my nightstand and let my best girl pick her own music and choose between my HE90 and Omega II. I'd be happy to listen to whatever pair she regards as second best. My Johnson noise wouldn't bother either one of us too much in such a listening session.

Fun thread. From a completely non technical standpoint, and given what I can see with my eyes... it is very overpriced. Now, if the circuit is as revolutionary as Rudi says, perhaps that is justified. Didn't someone say they had inside info or something? What ever happened with that?

 

[Roam]

24 hours have passed. Tourmaline, despite posting in the thread during this time has FAILED to provide a single shred of evidence backing his claims that my analysis of the Rudistor's specifications are incorrect, and that I have no idea what I'm talking about. Instead, it's just the usual diet of rhetoric and ad hominens.

This is what happens when there are no facts supporting one's arguments, and the person is too full of himself to concede.

BTW, tourmaline, concession accepted.
A helpful tip for the future: don't get into arguments you can't win, and when you're mistaken, learn to concede before you make an utter fool of yourself.

 

[yotacowboy]

Quote:

Originally Posted by Roam /img/forum/go_quote.gif A helpful tip for the future: don't get into arguments you can't win, and when you're mistaken, learn to concede before you make an utter fool of yourself.

“It is better to keep your mouth shut and appear stupid than to open it and remove all doubt.”

 

[morphsci]

Quote:

Originally Posted by Roam /img/forum/go_quote.gif A quick example. The Coriolan claims to give 65dB of gain using nothing but triodes in the signal path, the triode tubes in question being 12AX7s and EL34s. The best case voltage gain from a 12AX7 is 100 (see any tube database), and a triode-wired EL34 is 10.5 (from Mullard datasheet), giving a gain of 1050 for the system. Voltage gain in dB is defined as 20log(Vout/Vin), where Vout/Vin is the voltage gain. In an ideal case, this works out to 60.4dB, which is 4.6dB lower than the claimed figure. These are ideal parts in an ideal circuit, and they still don't meet specs. A real world circuit will have even lower gain due to internal degeneration on the tubes, negative feedback to achieve the claimed frequency response & distortion specs, and other losses due to non-ideal parts. Real world gain will be in the 50-57dB range, far short of claimed specs. Thus a transistor gain stage is required to meet the specs for gain, which is a direct contradiction of the use of triode topologies assure the right, coherent, and natural harmonic distortion pattern, that assisted by some solid state components (in order to control some auxiliary functions) as stated by the manufacturer, unless as I mentioned earlier, "auxiliary functions" includes being in the direct signal path and amplifying the signal.

Thank you for responding to my request (although the background noise between this and your response has been rather high

). Would some other experts on either side care to expand on this, refute it or bring up some other information. The more real evidence, the better for all of us. Pissing contests really aren't very helpful.

 

[spritzer]

Quote:

Originally Posted by morphsci /img/forum/go_quote.gif Thank you for responding to my request (although the background noise between this and your response has been rather high ). Would some other experts on either side care to expand on this, refute it or bring up some other information. The more real evidence, the better for all of us. Pissing contests really aren't very helpful.

The only counter argument would be internal pictures of the amp and PSU or even the schematic that shows another gain stage and those huge output caps needed for the 2Hz output.

 

[leonid05]

Quote:

Originally Posted by spritzer /img/forum/go_quote.gif ... and all those that have seen inside a Rudistor amp knows what a mess it is with cheap parts that make an cmoy look luxurious and well built in its Hammond enclosure.

Well, the innerts of my RPX-33 look quite satisfying to me.
Plus, they`re open for everybody interested to see in markl`s review and on Rudistor`s site, so what?

One could argue back and forth wether it`s still overpriced, but see, it`s not me complaining nor is any other Rudistor owner.
Seems like we knew what we did when ordering it, and I feel quite comfortable with what I got for my money and the role that the amp plays in my rig.

How about you simply ask for a sticky thread about how much you dislike Rudistor?
That way everybody knew, and we`re finally done with it.

 

[spritzer]

Quote:

Originally Posted by leonid05 /img/forum/go_quote.gif Well, the innerts of my RPX-33 look quite satisfying to me. Plus, they`re open for everybody interested to see in markl`s review and on Rudistor`s site, so what? One could argue back and forth wether it`s still overpriced, but see, it`s not me complaining nor is any other Rudistor owner. Seems like we knew what we did when ordering it, and I feel quite comfortable with what I got for my money and the role that the amp plays in my rig. How about you simply ask for a sticky thread about how much you dislike Rudistor? That way everybody knew, and we`re finally done with it.

I don't dislike Rudistor in particular but all manufacturers that claim to produce a high quality component when the finished product is anything but. Manufactures have a duty, moral mostly, not to rip off their customers that don't know any better. The sad part is that most retailers abuse this duty or trust by selling inferior product at a high price but that doesn't justify it. As small community of electrostatic nuts it is our duty to scrutinize all new arrivals and especially if somebody claims their product is the best there is and charges a fortune for it. This isn't about the sound but rather the value of the product and does it stand up to the manufactures claims.

I'm sure you are happy with your amp but what else have you heard and compared it to, both sound and build quality wise? I know a few that sold their amps in a fit of rage when they were told just how badly made they were. Educated would be a better word as it was explained what was wrong. We all think we have the best available until we hear something better, its human nature. You can't possibly know that something is wrong if you don't know the difference though no DBT is necessary. You also see the really good stuff and how it is built, not only the materials, but how they laid out. Wires are bundled together and damped, capacitors damped, special attention is taken to the grounding procedures and it is made sure that no evil heater current comes close to the signal path or any low current lines. Add this to any DIY or EE experience and you start to notice that most hi-fi equipment is in fact crap and it shines through in the sound.

 

[n_maher]

Quote:

Originally Posted by morphsci /img/forum/go_quote.gif Would some other experts on either side care to expand on this, refute it or bring up some other information. The more real evidence, the better for all of us.

I'm no expert but perhaps I can help the layman understand some of what the people in this thread are criticizing, particularly the claimed SNR of 120db. All audio devices have background noise, it's just a fact of life. Why? There is a phenomenon called Thermal Noise or more commonly Johnson's Noise. This type of noise is present at the input of every audio device and is proportional to the temperature of the conductor. That's why some people are saying things like "in a liquid nitrogen bath" and so on because without super-cooling everything is going to have thermal noise. Now because this noise is present at the input it is going to be subject to whatever gain the amplifier has. So even a tiny amount of noise, run through a circuit with 65db of gain is going to show up on the output and reduce the SNR. What is also interesting about this is that the amount of thermal noise is directly related to the bandwidth and Rudi is making some pretty aggressive claims with regards to that as well (stated on his site as 2-100,000Hz 0.05db). If this is true it would give new meaning to the term ruler flat frequency response. Most companies rate their FR at +/- 3db or sometimes 1db but I don't think I've ever seen it done to the hundredth of a db.

Unfortunately I don't know enough to really explain things further but that's where people seem to be coming from with regards to their criticisms. Rudi is pushing (and perhaps beyond) the theoretical limits which seems unlikely given the technical analysis by other members.

Now, an important note before I get lit up like a Christmas tree: nothing I said in any way tells you about how this amplifier might sound. It might sound great, it might not, I have NO clue. But given the information presented by the manufacturer there are certainly some aspects that look questionable.

 

[spritzer]

Great post and I really have only one more thing to add. The rated frequency range is from 2Hz all the way up to 100Khz and the 2Hz figure is something I have a problem with. This amp most likely has output caps to prevent any DC leakage to the stators and thus damaging the headphones but to reach a 2Hz figure requires a large value cap rated for a very high AC voltage. That would be physically a very large film cap and I just can't see him fitting four of them in that small case.

 

[n_maher]

Quote:

Originally Posted by spritzer /img/forum/go_quote.gif That would be physically a very large film cap and I just can't see him fitting four of them in that small case.

Technically speaking he could use an electrolytic cap on the output, right? That'd be a much smaller form factor given the need for high uF, high voltage. Granted, I wouldn't expect that on a statement audio product but it could explain things.

 

[braillediver]

This is one of the more ridiculous threads on Head-Fi. And it’s an example of the attitudes and opinions that hurt head-Fi.

What are you arguing about? An amp no one has heard, no one has seen, no one owns, no one knows the circuit or components of. So what are you arguing about?

I know competent people who know and enjoy audio that could contribute greatly to Head-Fi but are completely turned off by the childish attitude of some people here.

They compared some of the commentary here to a bunch of grade schoolers fighting in the playground. And they didn’t want any part of this foolishness.

These are competent people who run audio businesses unlike the people arguing here.


I’d like to say- If you guys know so much about audio design put up or shut up and design and market your own amp and show the other guys how to do it right.

The silence is deafening.


Back to our previously scheduled bickering.

Mitch

 

[tyrion]

Nate, excellent explanation. I actually understood.

Mitch, I couldn't agree more, which is why I am locking the thread. This horse has been beaten to death.

 

[StevieDvd]

I'm not getting into the heated debate other than to say from experience Rudi has often had quite a few typos on his web pages due to English not being his native tongue and probably as he does his own web updates.

He quickly corrected the tube error so I would not bank on all the other figures being 100% accurate (sorry Rudi no offense).

Anyway I'm happy with my NX33 and since I don't own oscilloscopes or possess enough electrical engineering experience I rely on my ears since the figures are more or less meaningless to me.

Rudi also allowed me to post pictures of the insides of the NX33 here so it's not as if he was hiding anything.