[NightWoundsTime]

They're two amps in the same product line... just seperated by a couple (few?) hundred dollars. This is like the 595/555 discussions. Expect to get what you pay for.

 

[kevin gilmore]

quote
Here you can find the 3D and even the opinion of Dr. Gilmore about this RP5 cav!!!


I said it was built better than the previous version and this is certainly
true. I said nothing about the sound as i have not heard the new unit.
The price of the new unit certainly puts it in competition with many
other amplifiers out there.

I did just spend a few days with a relatively current RP5. I did not
like the way it sounded.

 

[davebot]

Quote:

Originally Posted by kevin gilmore I did just spend a few days with a relatively current RP5. I did not like the way it sounded.

Fair enough. What was it that you didn't like?

I know that your amp designs are Krell-like; is that part of the reason you disliked the Rudistor? Since I really like my Audio Research amps, I was thinking that I might like the Rudistor RP4, and I have the hunch that the author of this thread may be aiming at the same sort of thing. Can you recommend a better amp for the price for an Audio Research fan?

 

[kevin gilmore]

quote
Fair enough. What was it that you didn't like?

(comments based on rp5 not the cav version!)

Where to start. Plenty of bass. But very sloppy bass. Not even
the slightest bit of tight with any snap. Listening to all the latest Venus
SACD's the bass (Bill Charlap... Eddie Higgins...) all seems to be one
note. All the low notes on the keyboard certainly not right either.
I play piano, i know what steinways and yamaha's are supposed to
sound like.

Probable cause the 4700 uf electrolytic output cap. More than 10
times the size of any other amp out there and without a doubt the
wrong part for this job. Caps like this are so inductive, so polarity
sensitive they are completely inapropriate. Single ended transistor
output similar to SHA melos gold, but without the servo and with
the output cap. I don't know whats up with the .01 hz thing because
first of all its silly as there is no music there, and no headphone can
reproduce it. No headphone i know of has significant output at 10hz
either. A 220 uf or 470 uf cap would sound better.

The sound of the amp is different with varying volume levels. Very
different. Approaching the design output spec the amp gets harsh.
Very harsh. Complex music like symphonies seem to turn into mush.
Just a wall of very flat sound. Look at the THD specs. When was
the last time you saw an amplifier rated at .5% thd (actually more
like .8%).

Probable cause for this the completely wrong for the job input
tube 6gm8. A 6gm8 is a low voltage tube designed for tube radios
in cars as rf amplifier and detector applications. At anything approaching
output swings of 1 volt or more the distortion is positively grim.
Now i see that newer units are using e88cc tubes which are
much more appropriate, but then you have to boost the B+ a bunch
to get the distortion down.

And the hum problem is definitely a problem. Where does it come from,
the power transformer being way to close to just about everything
coupled with an inherent ground loop. Putting the transformer in a
pretty copper box won't fix the problem either. Modern cd and
sacd players have s/n exceeding 90 db. Then you couple that to
an amplifier with a s/n that barely exceeds 50db. Does not make
sense.

I just don't understand any of the rudistor stuff. Rudi claims he is
a scientist. Reminds me of stories about Nicola Tesla. Possibly
brilliant but completely whacked at the same time. I just don't
understand his design goals. I don't think he listens to much live
music otherwise his stuff would sound better. Now maybe it
sounds better with a crappy source, but i don't see how that can
work either. His circuits are all anchient, his implementation is
questionable. Certainly nothing new here.

If you are an audio research TUBE amplifier person there are a whole
bunch of amplifiers available that are going to sound much more like
what you are looking for. And most of them are far cheaper.
Singlepower, 6moon, ray samuels... Many of the amplifiers coming out
of china... None of them have the extremely high levels of thd that
the rudistor amps have. Tubes are high voltage low current devices
and are not suitable for some applications including low impedance
headphones unless you use 6080's 6as7's or 6c33's.

If you are an audio research SOLID STATE amplifer person then there
is not much i can do to help you.

 

[KtoEto]

Something inside tells me I shouldn't have started this thread.

 

[davebot]

Quote:

Originally Posted by KtoEto Something inside tells me I shouldn't have started this thread.

Sorry for hijacking!

Let's see. Maybe I can help. I think you were interested in the RP5 but wondered if the less expensive RP4 would get you most of the way there. I recall comments that the RP4 was close to the performance of the RP5; maybe someone can corroborate. There's also the completely solid-state RP3, but Rudi told me that my interest in classical / jazz music would make the RP4 more appropriate for me.

So. . . RP4 versus RP5 : how do they stack up?

 

[Nik]

Just for you to know... I have no more any interest in defend something I like so mutch, sorry!

I cannot find actually any headphone amps that sound like the RP5 cav! IMHO !!!

Best!
Nicola

 

[rudi]

dear kevin,
I don't remember to have sold RP5 to you, but you are enough clever an expert, and I belive you have made something very similar. I'm happy if you don't like it, we are different persons with differnts minds. My assistant who love to vaste his time, have made a KGSS ( or something very similar ) and he and me don't like it.!!!!
************************************************** ***
If you can use elevators, air conditionign system, subway, and many other machines moved by multiphase ac engines, this is due to the Nikola Tesla studies.

I'm so little man that to be compared to Tesla is a great honour.

On Tesla there are many stories and legends, I'm not interested on it but he certanly was a scientist in pure terms. A man who dream, study and works for a better world.

On the audiophile point of view ( many years before hi-fi ) he discovered the best way to reproduce sounds. The Plasma Transducers are based on Tesla Coils principles.
On this link you can see simple audio application and notes based on Tesla Coil. ( it is a good base for experiments not a final product )
www.rudistor.com/sound-lab/plasmic.htm

Who have not heard an hi-end systems based on hi-energy plasma transducers can't have an Idea of what is "Pure Hi-End Sound " The best traditional systems is a toy, if compared!!!!!!!

Since nothing in the human life is free of charge the plasma systems are dangerous and expensive.

rudi

 

[oneeyedhobbit]

Quote:

Originally Posted by kevin gilmore quote Here you can find the 3D and even the opinion of Dr. Gilmore about this RP5 cav!!! I said it was built better than the previous version and this is certainly true. I said nothing about the sound as i have not heard the new unit. The price of the new unit certainly puts it in competition with many other amplifiers out there. I did just spend a few days with a relatively current RP5. I did not like the way it sounded.

Solely as a question of clarification, was the relatively current RP5 you heard actually one of Rudi's, or one you built based on pictures posted on Head-Fi?

 

[kevin gilmore]

A real honest to goodness rp5 that was sent to me for a few days
for evaluation. I did spend a couple of days listening to it vs other
things in my listening room.

I would not waste my time building one. I did build one of the
rudistor public domain electrostatic amps. Don't really like that either.
But it is certainly better than an rp5.

quote
I cannot find actually any headphone amps that sound like the RP5 cav! IMHO !!!

Of this i have absolutely no doubt.
So Nik, which is better, egmont signature with omega2's or
rp5 cav with ???

Rudi is very much like tesla. This is a compliment. Well sorta

Tesla was a genius, there is no doubt. All my magnets are rated
in tesla's, the biggest of which is 21 tesla. He was also insane.

Plasma transducers are very interesting, but the ones based on the
tesla coil have way to much noise and are way to dangerous for
an average person to own.

I am building one of the "plasma" headphones from pictures posted
here recently. However it is not really a plasma at all, much more
like a corona generator. How many people are willing to wear
6000 volts on their head??

 

[Nik]

Quote:

Originally Posted by kevin gilmore A real honest to goodness rp5 that was sent to me for a few days for evaluation. I did spend a couple of days listening to it vs other things in my listening room. I would not waste my time building one. I did build one of the rudistor public domain electrostatic amps. Don't really like that either. But it is certainly better than an rp5. quote I cannot find actually any headphone amps that sound like the RP5 cav! IMHO !!! Of this i have absolutely no doubt. So Nik, which is better, egmont signature with omega2's or rp5 cav with ??? Rudi is very much like tesla. This is a compliment. Well sorta Tesla was a genius, there is no doubt. All my magnets are rated in tesla's, the biggest of which is 21 tesla. He was also insane. Plasma transducers are very interesting, but the ones based on the tesla coil have way to much noise and are way to dangerous for an average person to own. I am building one of the "plasma" headphones from pictures posted here recently. However it is not really a plasma at all, much more like a corona generator. How many people are willing to wear 6000 volts on their head??

To be honest I'm also convinced that the real best amps of Rudistor are those for the electrostatic headphone. The Omega/Egmont I have is mutch better than the HD650/RP5 (as any other dynamic setup I had).

But... but... but... ??? ??? ??? I cannot say for the moment... I'm going to another dynamic system that can arrive to the quality of the Omega/Egmont or, may be even better ????

Best!
Nicola

PS:
Not so good thing that two designers that have good ideas and projects even if so different do not have any possibility to arrive to appreciate each other!

 

[braillediver]

“How many people are willing to wear 6000 volts on their head??”

The designer and builder get to try them out first. Then I’d consider it.


What I find interesting is Rudi didn’t take the opportunity to clearly state his design goals or to justify his choice of parts or designs parameters. Any engineer I’ve worked with would proudly point out benefits of his design or clever aspects of its implementation- Proud Papa syndrome.

Instead he said, “Well I built your amp and didn’t like it either”?


Mitch

 

[rudi]

Quote:

Originally Posted by kevin gilmore Rudi is very much like tesla. This is a compliment. Well sorta Tesla was a genius, there is no doubt. All my magnets are rated in tesla's, the biggest of which is 21 tesla. He was also insane. Plasma transducers are very interesting, but the ones based on the tesla coil have way to much noise and are way to dangerous for an average person to own. I am building one of the "plasma" headphones from pictures posted here recently. However it is not really a plasma at all, much more like a corona generator. How many people are willing to wear 6000 volts on their head??

The plasma transducer don't have any noise when the carrier generator work at HF or VHF frequency ( Acapella and Magneplanar use 16-20 Mhz ) I use 10 to 50.
The plasma transducers are absolutly safe if properly built ( even e TV set have voltage of 10-15 KV inside , but all the children in the world watch TV ).

I must admit, plasma techology is not appropriate for cans, becouse one of the advantages of hi-energy plasma is the spheric sound propagation, totaly missed if closed in a can. Much better it is in a near field application, I'm developing a 3 point systems ( 3 transducers ) of course it need a processor with appropriate alghorithm to split stereo in 3 point, but the solution avoid stationary waves and combined with 3 plasma transducer, can generate a sphere of sound having in the middle the audiophile head. A great experience!!

 

[eric343]

Ahh, Nikola Tesla... the original "Fools! They think I'm crazy, well, I'll show them all, muahahahaha! [cue lightning and thunder]" mad scientist. Also one of the most underappreciated engineers in history. (gotta love a guy that generates an earthquake in the middle of New York, by accident, using a device the size of a pop can

) What's really interesting is that both the Tesla coil and the "earthquake machine" oscillator are fascinating examples of constructive interference and resonance/natural frequency.

I fail to see where Rudi resembles him, though

Anyway...

Rudi, the problem you might have is creating a Tesla-coil based plasma generator that runs at megahertz frequencies without causing massive electromagnetic interference. As I'm sure you know, the first radio transmitters were spark gaps, and a Tesla coil happens to be an excellent broadband radio transmitter. (that's why large ones in museums and such are always surrounded by a Faraday cage) In the United States, products that aren't meant to be radio transmitters are generally governed under Part 15 of the Federal Communications Commission regulations, which state that said products are not allowed to cause harmful interference -- something that a Tesla coil of sufficient power almost certainly would do (especially running at radio frequencies).

 

[rudi]

Quote:

Originally Posted by eric343 Rudi, the problem you might have is creating a Tesla-coil based plasma generator that runs at megahertz frequencies without causing massive electromagnetic interference. .

This is the problem. But like for any problem there is a solution. Carrier generator create RF, not the plasma flame, plasma flame is hi temperature ionized air, not an RF generator. i know three way to separate plasma from generator, a generator closed in a grouned box is less dangerous than a computer. But the game is not easy, and only special amps can be used.
But now we are OT!!