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Record breaker: Raphaelite CS30-MKII tube amplifier review and measurements

computer-audiophile

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As an output tube, there's nothing special about a 300B other than legend and price.
I am fascinated by this almost 100 year old triode, with which (or its replicas) you can still listen to music quite wonderfully today, if you don't play dumb. In my opinion, it rightly has the status of a legend, since it represents a kind of milestone in the development of audio technology. I appreciate that.
 
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GXAlan

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If you're concerned with the wiggles below 100Hz, try changing the sweep FFT size: you may have it set too large.
In a sign of bias, I admittedly mentally ignored those wiggles! :)
 

egellings

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So the magic is in the middle volumes to get those dithyrambic experiences? :)

Is this the 91E that you are commenting on? If you can, it would be great to run a sweep at different volumes through a speaker even if you are measuring acoustically instead of electrically.
Love that word dithyrambic; it could be a cool brand name for a cable or a least a descriptor of one.
 
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GXAlan

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I am fascinated by this almost 100 year old triode, with which (or its replicas) you can still listen to music quite wonderfully today, if you don't play dumb. In my opinion, it rightly has the status of a legend, since it represents a kind of milestone in the development of audio technology. I appreciate that.

The main challenge is that I cannot find any other test of an FR Sweep of different input levels for a 300B integrated amp.

At least with this amp, there is something special and measurable. You get an inverted loudness curve to juice-up-the-treble without making everything sound bright.

You've mentioned that your designs don't do this.
@SIY has said that his 300B amp on review doesn't have anything special either.

I'd love to see the same measurements with different 300B amps.

Scenario:
1) I used a standard 2V output DAC into the integrated and adjusted volume to taste. It'll probably be a watt of power.
2) I ran an electrical measurement with the speaker in place, with the signal generator running at different dBFS's.

Since my music isn't at 0 dBFS, this is showing me that the peaks/loud transients get a bit of treble boost while the normal volume/quiet portions have less of a treble boost.

Completely fits with the subjective experience of "Treble sweetness".

The problem is that we have n=1 for measurement.
 
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I have often wondered about these large triodes and whopping transfomers - (Jadis was one - 845SET ).
A pair of those powering Tannoy Westminsters sounded singularly revolting for all the reasons described above.
 
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Port

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Paul Klipsch thought that harmonic distortion was a minor issue while intermodulation distortion was a major problem because most music contains harmonics but intermodulation introduces nonmusical frequencies.
I have an Elekit 8600S 300B amp with Western Electric tubes that has good reviews in Stereophile. It would be interesting if the reviewer compared one of these to the Raphaelite.
Thanks to the reviewer and commenters for an interesting read.
 
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Paul Klipsch thought that harmonic distortion was a minor issue while intermodulation distortion was a major problem because most music contains harmonics but intermodulation introduces nonmusical frequencies.
Paul Klipsch was right, it's one of the main reasons why Jack E - spends so much time eliminating IMD from his designs often using transfomers instead of active components.

An auto former for phase inversion is an absolutely briliant idea.
All the stuff on his site had now gone, so luckily I archived it while it was still there.

We had many interesting conversations one of course was related to doing IMD tests with a DAW, then real time FFT to show the IMD waveforms, fed back via a voltage divider directly from dummy load or speakers..... which for various reasons he couldn't accept was valid, who knows why!

ie. these methods...
(The smart thing about it, being setting bias and anode/screen load/NFB to null out IMD - and as he suggested avoiding Beam tetrodes at all costs).
The other great thing about DAW (pro sound card digital audio workstations) is the low noise/distortion - with resistive voltage dividing. eg. I routinely use a digigram card in a notebook (AKM DAC+ADC) with a program called "scope".

U can compare input waveform into the output valves with the output from the transformer.
I used this method on an ancient cathode follower/choke driven AB2 amp by substituting a Bogen 6V6 output transformer for the choke then reading the input waveform off the secondary.... against the output waveform from the OPT. (superposing the 2 traces, recording them on the DAW and doing FFT on each channel to determine which bit of the chain was responsible for which bit of the IMD....)

This enabled aboslute optimisation of NFB, valve matching and balance.
It was nothing close to recommended values, or the manufacturers figures...
 

EVDavis

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Hi, I'm new here. I just wanted to say that I used to live in China and have owned several Raphaelite amps. Now, I only own two. I actually took a long day trip from Beijing to visit their 'factory' many, many years ago. Anyway, I own a single ended el84 and single ended 6v6 amp made by this company. Both have been great amps over the past 15 years or so. In fact the 6v6 amp was under their old name Sinovt. I believe the gov't made them change the name because it used the word Sino (China). I had a single ended 300B amp made by them but I traded it with a "friend' that hasn't returned my calls to complete the trade.
 
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GXAlan

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Hi, I'm new here. I just wanted to say that I used to live in China and have owned several Raphaelite amps. Now, I only own two. I actually took a long day trip from Beijing to visit their 'factory' many, many years ago. Anyway, I own a single ended el84 and single ended 6v6 amp made by this company. Both have been great amps over the past 15 years or so. In fact the 6v6 amp was under their old name Sinovt. I believe the gov't made them change the name because it used the word Sino (China). I had a single ended 300B amp made by them but I traded it with a "friend' that hasn't returned my calls to complete the trade.
What does their factory look like? Glad to hear that the units are still going strong after 15 years
 

EVDavis

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What does their factory look like? Glad to hear that the units are still going strong after 15 years
Well, it was a small village and, at that time, it was just a couple of buildings. Very rural. I was surprised something looking so nice could come out of such buildings. I don't want to be rude but the buildings weren't anything special. I have no idea what their facilities are like today. Perhaps better or maybe the same. I find it a shame they can't get even some small distribution in the US but I know the Chinese ways and even though some of them make good products their after market support a such can be a real headache.
It's interesting that the early 6v6 I bought from them has a very, very good paint finish on it and even came with optional wood sides. I guess after that they started to cut back because the other amp's finish weren't as good.
I want to get their push pull 6v6 amp. They have been making it since the beginning.
 

computer-audiophile

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Well, it was a small village and, at that time, it was just a couple of buildings. Very rural. I was surprised something looking so nice could come out of such buildings. I don't want to be rude but the buildings weren't anything special. I have no idea what their facilities are like today. Perhaps better or maybe the same. I find it a shame they can't get even some small distribution in the US but I know the Chinese ways and even though some of them make good products their after market support a such can be a real headache.
It's interesting that the early 6v6 I bought from them has a very, very good paint finish on it and even came with optional wood sides. I guess after that they started to cut back because the other amp's finish weren't as good.
I want to get their push pull 6v6 amp. They have been making it since the beginning.
Thanks for the report. I have also always enjoyed meeting manufacturers, designers and outstanding protagonists of audio in person or visiting their places. There would also be some people in China that would interest me. Raphaelite is one of them, Line Magnetics but also Lii-Audio, the speaker manufacturer. I think they also have a small flagship store. The speakers they make today and their philosophy are similar to earlier DIY work of mine, which I had published in the internet decades ago, but more elaborately made and more advanced. Well, they also do it commercially.

However, I will probably not travel to China again in this life.

%E6%B0%B4%E6%99%B68-1-1.jpg
 

EVDavis

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Thanks for the report. I have also always enjoyed meeting manufacturers, designers and outstanding protagonists of audio in person or visiting their places. There would also be some people in China that would interest me. Raphaelite is one of them, Line Magnetics but also Lii-Audio, the speaker manufacturer. I think they also have a small flagship store. The speakers they make today and their philosophy are similar to earlier DIY work of mine, which I had published in the internet decades ago, but more elaborately made and more advanced. Well, they also do it commercially.

However, I will probably not travel to China again in this life.

%E6%B0%B4%E6%99%B68-1-1.jpg

Yes, travel to and in China can be a bit tiring but they have made wonderful upgrades in their rail travel.

I am also personal friends with Eric Liu, the owner of Opera Consonance. I have a few of his turntables one 2a3 amp and his M15 speakers. I had several of his amps but I sold them, except for the 2a3. I do wish I kept the 300B in parallel amp, oh well. Oh I forgot I also have 2 Super A100II solid state amps. For some reason I really like these solid state amps but they would be a bit better if they have a tad more bass. I would like to get them tested here for review someday.
 

computer-audiophile

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Yes, travel to and in China can be a bit tiring but they have made wonderful upgrades in their rail travel.

I am also personal friends with Eric Liu, the owner of Opera Consonance. I have a few of his turntables one 2a3 amp and his M15 speakers. I had several of his amps but I sold them, except for the 2a3. I do wish I kept the 300B in parallel amp, oh well. Oh I forgot I also have 2 Super A100II solid state amps. For some reason I really like these solid state amps but they would be a bit better if they have a tad more bass. I would like to get them tested here for review someday.
This is interesting. I know some of their products amps and so on very well. Once, a long time ago, I owned e.g. a DAC from Opera-Audio with a very own sonic signature. Quite musical.


Pictures from the web:

8a38wsa.jpg

s-l1600.jpg


BTW: A member of our private audio circle in the city I lived before, was the managing principal of Opera Audio for more than 10 years in Germany. He was also a friend and mentor of Eric Lu when they started the business. (If I remember it right)
 
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EVDavis

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This is interesting. I know some of their products amps and so on very well. Once, a long time ago, I owned e.g. a DAC from Opera-Audio with a very own sonic signature. Quite musical.


Pictures from the web:

8a38wsa.jpg

s-l1600.jpg


BTW: A member of our private audio circle in the city I lived before, was the managing principal of Opera Audio for more than 10 years in Germany. He was also a friend and mentor of Eric Lu when they started the business. (If I remember it right)

Yes, Opera Consonance (from my understanding) has a decent following in Europe but it doesn't in America. I have an old and probably outdated Hegel HD2 DAC on my computer setup made by Opera. That's how I got it, lol.

I really want an Opera T99 preamp. They stopped making it a long time ago so I have to find one on the used market and that's not easy.

I remember meeting Liu and his brother in law Ma Wei sometime around 1997 or 98 when they were at an audio show in a Beijing hotel. Later, I went to their first humble office, basically a medium sized warehouse in an alley. I didn't know anything about tube amps back then except that I wanted one. They offered me a few models (at that time cheap but to me expensive) I wish I bought one. I recall saying to them "Only 10 watts? How can this power anything?" Now I know better and wish I had bought one of those old amps.
 

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egellings

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Thanks for the report. I have also always enjoyed meeting manufacturers, designers and outstanding protagonists of audio in person or visiting their places. There would also be some people in China that would interest me. Raphaelite is one of them, Line Magnetics but also Lii-Audio, the speaker manufacturer. I think they also have a small flagship store. The speakers they make today and their philosophy are similar to earlier DIY work of mine, which I had published in the internet decades ago, but more elaborately made and more advanced. Well, they also do it commercially.

However, I will probably not travel to China again in this life.

%E6%B0%B4%E6%99%B68-1-1.jpg
Show a close up of the name plate.
 
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GXAlan

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Show a close up of the name plate.
 

egellings

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Excuse me, I think I do not understand your question. Can you explain?
The connections to the speakers are mounted on a metal plate that has some wording on it. I'm curious as to what is printed on it, likely a brand-name and other info, such as impedance and power handling limit.
 
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