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

[MacCali]

@GXAlan I think I have repeated this about 40 times throughout multiple threads.

Every time I say it these people think I am crazy.

My main point is if you're a real audiophile and you love audio, the experience of enjoying music. You want to have a true understanding between perfect and not perfect to see and conceptualize the difference. Merely making it fundamental knowledge that any objective person should experience.

I have literally written essays on this to everyone on here who would take the time to read and understand my point. I am very much objective and strongly believe in it, everything in my main system is greater than -115db. I really hope this will hit home especially on the main reviews page.

 

[MattHooper]

@GXAlan I think I have repeated this about 40 times throughout multiple threads.

Every time I say it these people think I am crazy.

My main point is if you're a real audiophile and you love audio, the experience of enjoying music. You want to have a true understanding between perfect and not perfect to see and conceptualize the difference. Merely making it fundamental knowledge that any objective person should experience.

I have literally written essays on this to everyone on here who would take the time to read and understand my point. I am very much objective and strongly believe in it, everything in my main system is greater than -115db. I really hope this will hit home especially on the main reviews page.

I'm not saying you're crazy; I couldn't even render such a judgement because I don't think I understood a thing you wrote there. (Does anyone else?)

 

[egellings]

WOW! "Warmth & musicality" through the roof!

Crystal triodes!

 

[Axo1989]

I'm not saying you're crazy; I couldn't even render such a judgement because I don't think I understood a thing you wrote there. (Does anyone else?)

I'd probably need to read the essay.

 

[senuc]

when I bought topping pre90 + Diy purifi 400(with very good measurement) , I guess maybe I should sell the 805 tube integrated amplifier ，but after months A/B listening ， I deside to keep them all , the tube amp in many albums sound better for my ear

 

[peng]

Resistors vs. Speakers
Ignore the SPL numbers in the legend for all of these. You just want to look at the "shape of the curve". I took these REW sweeps at different dbFS.

In a resistor, you don't see any surprises with different volume content. Lower volumes reveal the 60 Hz AC mains noise.

Now look at the JBL XPL90 which has been measured here and look at the different results depending on the dBFS sweep.

This 300B SET with my speakers offers the opposite of a loudness curve.

You get extra treble boost with higher energy, but at low volume, the treble increase is lower. This is all from extra distortion that's happening. There is even a slight bass boost at lower volumes. Again, distortion.

But at least amongst 300B fans, this may be the right "pattern/character/flavor" of distortion.

Now we're starting to see the effect of the SET and its role as a "fixed effects box". You cannot turn it on or off, but a simple Parametric EQ isn't going to let you replicate the "300B tube sound". You can pick one treble boost for the entire song, not a dynamic one that depends on the content.

We know the "showroom sound" can be fun for short periods of time, but the boost can be fatiguing. But you have to think about this in musical content. The showroom sound comes only on demand during transients! So, imagine having an effects box where the effect is subdued in the normal parts and during transients, it jumps up even more.

This is why recording the SET seems to lose the effect compared to actually listening to music on a SET tube amp. You not only have to think about the actual speaker but all the volume it's running at.

Take a look at the slope of those REW sweeps with the XPL90. The rise in treble begins at 3 kHz, right? Let's see what @amirm measured on the XPL90.

Do you see something at 3 kHz also?

What's really neat is that if I take a few different 2-way speakers that I own, and eyeball-match the volume at 1 kHz, we can see that the relative to the resistor, you get a pretty consistent bass boost while the treble gain differs between the different speakers/crossovers. This really does counteract the "rolled-off" highs that measurements into resistors generate.

When people talk about "sweet" treble, where things don't sound bright but the treble has some sort of clarity, we're seeing the signal-dependent treble boost where loud transients will see more enhancement than the softer high frequencies. This isn't sighted bias, but a measureable phenomena that isn't easily reproduced in software.

Thank you for another nice detailed review with measurements, please do more... Now that you have measured it, I wonder if you can use some sort of tone control on a transparent SS amp and see if it can replicate the "sweet" treble. If I remember right, Carver might have done something like that to the point people couldn't distinguished between the tube vs SS duts. I think there is a market for a highly flexible tone control as an add on, or it may actually be available for purchase that I don't know about?

This review should help subjectivists see how science can help translate poorly defined descriptions like "sweet treble" into numbers. Measurements are still good for those of us who trust our ears. Likewise, the blind testing and recordings should help objectivists see how owners of 300B aren't in need of a hearing aid -- bad SINAD can still sound pretty good, and the introduction of speaker/amplifier interactions can generate a unique "sound signature" that might be preferred by some.

To reference the current season of The Mandalorian, I consider myself a walker of both paths in the audiophile hobby: objective and subjective.

This is the way.

Great point! On the other hand, I do not believe there are too many (may be a few die hard one) real objectivists who would doubt any subjectivists if they claimed their tube amps sounded warm and smooth on the treble. On the extreme end though, I have little doubt that those who heard the difference between something like a Marantz AV10 vs Denon A1H, that one will has the warmth and sweetness whereas the other has the crispness and punchiness sound, even if and when both are in direct mode using analog inputs, will fail to hear such differences in blind tests, with or without using hearing aids. On ASR, I hope we don't have extremists on both sides.

 

[pma]

@GXAlan , I have a small competitor to your tube amplifier.

It is a combo of a tube preamp and a Solid State amplifier. It has a bit higher power, near 2 x 300W/4ohm and a bit lower distortion

And quite acceptable CCIF HF twin-tone distortion

Not bad and in a blind test hardly distinguishable from a normal amplifier.

 

[dav0043]

Great example of the science vs art challenge. Equipment gets measured. We've established parameters of what audio output should conform to in order to "sound good". For the most part it works. Reviews like these with measurement outliers show that there's still work to be done to find that sweet spot of calculating what actually "sounds good" rather than what should. What's that measurement for romance & nostalgia again? ;-)

 

[frabor]

Thanks for a great review. I still find intriguing and amazing that a sinaf in the low 20 can produce an enjoyable listening experience.

 

[prerich]

A walker of both paths....objective and subjective!!!!!! This is the way!!!! BRAVO ZULU....let us bring all tribes together!!!!

 

[Ninjastar]

...And as much as Jay from Jay’s Iyagi gets a lot of flak for his recent blind testing attempt, and the level of subjectivity, I think his comments on the AHB2 sound quality are spot on.

As a long time audio enthusiast, before I even knew what SINAD was (or the Klippel or APx555 were), I had to rely on subjective reviews. YouTube reviewers are a relatively newer type of subjective review, but I personally find that consuming YouTube content is much more digestible than reading random forum posts, so I do watch them for fun.

Anyway, Jay is cringey as hell, but I must admit, subjectively he tends to hear things similarly the way I do. I like trying lots of products just for the fun/experience and I've found that he and Sean/Zero Fidelity (also cringey, but not as much as Jay) usually have the same takes on products as I do.

I know people here place absolutely no value on subjective reviews and I totally understand why. But I don't really find anything offensive about hearing people share subjectively what they think about products they've tried.

 

[RF Air]

Wonderful Review! I enjoyed the historical information which reminded me of days gone past when I was a defender of the DEW Line in the USAF. I recall the time when we upgraded Transceiver and Telephony MUX Equipment from analog-tubes to SS. The rooms were barren and the Air Conditioning Loads were reduced to a fraction of a percent for equipment cooling.

And I remember these manufacturer names as equipment builders for the long forgotten Mission of Terrestrial Command and Control for Ground, Sea and Air Assets in the defense of a Cold War Hostility. Thank you for the informative and well written lesson of historical reflection of the genesis of electronic development, it was meaningful to me.

 

[GXAlan]

Anyway, Jay is cringey as hell, but I must admit, subjectively he tends to hear things similarly the way I do.

Right, and I have to assume his peers in his generation likes the young/casual approach. Ultimately that is what keeps the lights on for him and his family.

I was a defender of the DEW Line in the USAF…Thank you for the informative and well written lesson of historical reflection of the genesis of electronic development, it was meaningful to me.

Wow. Thank you for your service.

I have three questions for you that I hope you are able to comment on.

1) It always surprises me that there is an “infinite” supply of NOS tubes. Obviously, it’s a simple supply and demand phenomenon but where you worked, was there a tube “supply closet “ or tube sections of a warehouse? Or were there buildings the size of a modern Home Depot or Wal-Mart with nothing but tubes?

2) the 300B is known as an audio tube turned industrial tube that was rediscovered as an audio tube. What about stuff like the 6550 or 12AX7? Were they just used for radios and other audio stuff? Or just about everything?

3) Last, did you have favorite tube brands for reliability? In other words, are there NOS vintage JAN tubes that in your mind failed all the time and we should avoid for use in hobbyist audio gear?

 

[RF Air]

Right, and I have to assume his peers in his generation likes the young/casual approach. Ultimately that is what keeps the lights on for him and his family.


Wow. Thank you for your service.

I have three questions for you that I hope you are able to comment on.

1) It always surprises me that there is an “infinite” supply of NOS tubes. Obviously, it’s a simple supply and demand phenomenon but where you worked, was there a tube “supply closet “ or tube sections of a warehouse? Or were there buildings the size of a modern Home Depot or Wal-Mart with nothing but tubes?

2) the 300B is known as an audio tube turned industrial tube that was rediscovered as an audio tube. What about stuff like the 6550 or 12AX7? Were they just used for radios and other audio stuff? Or just about everything?

3) Last, did you have favorite tube brands for reliability? In other words, are their NOS vintage JAN tubes that in your mind failed all the time and we should avoid for use in hobbyist audio gear?

Thanks for the response and comments. To answer your questions, I think there is some context that I need to explain.

Service requirements were on Foreign Soil for most of our missions. We had the contingency of deployable equipment that was used as direct Mission as well as Mission Critical Response to any Fixed Asset that was rendered "inoperable". In effect, with VTVM tube technology, we were fortunate to have highly reliable tube sets and equipment that only required routine testing and calibration, given the nature of their design capabilities and the limitations of tolerances available with the technology.

Equipment and Replacement Parts were all procured through Forward Area Supply Points which facilitated logistical support to many different users and assets through a distribution system that could be prioritized as needed. Honestly, the tubes were the least of our problems and I was surprised by their reliability.

Our equipment was used for all aspects of Radio Transmission, Teletype, Voice Channel Multiplexer and Data Signals. Satellite Technology was employed as well, but mostly as a secure mission critical Back-Up in the event Comm was lost among the network when "Command and Control" needed to be established as a link for maintainability of Commander Order Service.

All of of our Tubes were listed with AN and rarely JAN numbers. Sometimes the regular Retail designations (like 12AX7) would be present as well. Some of the benefits and delay for Solid State replacement with Digital equipment was the survivability of Analog Devices in the event of EMP First Strike, which was the expected scenario to disable ALL Command and Control functionality.

A weapon or defense system can be rendered ineffective if the Commander cannot communicate the necessary order requirement for activation or deployment. The warm, mechanical equipment which relied on technology developed before 1950 was a testament to the paradoxical fear that this was the system of defense that secured the Cold War as a historical footnote. No wonder there is still some romantic notions of the "Venerable Valve". The Vacuum Tube served us well!

 

[MacCali]

I'm not saying you're crazy; I couldn't even render such a judgement because I don't think I understood a thing you wrote there. (Does anyone else?)

Yea definitely I don’t blame anyone for not understanding, but if I understood his subjective take on this amp it wasn’t horrible when playing music even with such a horrible sinad.

It’s clearly not perfect, but as I’ve stated previously(on other threads) it’s not as bad as you might imagine.

 

[GXAlan]

If I understood his subjective take on this amp it wasn’t horrible when playing music even with such a horrible sinad.

It’s clearly not perfect, but as I’ve stated previously(on other threads) it’s not as bad as you might imagine.

That’s exactly right. Better than imagining, everyone can listen to some blind recordings from this amp. Those have more high frequency roll of that in real life so those are probably even worse.

Take the blind challenge! 300B SET vs. Straight Wire with Gain

The challenge: How does a budget 300B SET compare to a "straight wire with gain"? You tell me. It's time to put your ears to the challenge. Poll is open for 14 days. No peeking at the results. Test Setup: I connected a Topping D90, set it at 0 dB volume, to a budget 300B single-ended...

www.audiosciencereview.com

 

[GXAlan]

“we were fortunate to have highly reliable tube sets and equipment that only required routine testing and calibration, given the nature of their design capabilities and the limitations of tolerances available with the technology.”

“Honestly, the tubes were the least of our problems and I was surprised by their reliability.”

“Our equipment was used for all aspects of Radio Transmission, Teletype, Voice Channel Multiplexer and Data Signals. Satellite Technology was employed as well, but mostly as a secure mission critical Back-Up in the event Comm was lost among the network when "Command and Control" needed to be established as a link for maintainability of Commander Order Service.”

That is super helpful. Tubes were mission critical elements that were essential for the survival of the nation. So clearly, you had to build a lot and have them in forward deployed warehouses that could rapidly deploy to the various military bases of the U.S. and Allies. Would help if you had the tubes on the East Coast, but there was West Coast strike. Then, you probably added redundancy in case a first strike hit the tube factory and then warehouse.

To hear that they were the least of your problems sort of answers the question for me. The tech from this era truly was reliable!

In a properly designed circuit, tubes are reliable…

 

[MacCali]

That’s exactly right. Better than imagining, everyone can listen to some blind recordings from this amp. Those have more high frequency roll of that in real life so those are probably even worse.

Take the blind challenge! 300B SET vs. Straight Wire with Gain

The challenge: How does a budget 300B SET compare to a "straight wire with gain"? You tell me. It's time to put your ears to the challenge. Poll is open for 14 days. No peeking at the results. Test Setup: I connected a Topping D90, set it at 0 dB volume, to a budget 300B single-ended...

www.audiosciencereview.com

My light bulb moment came after I purchased an amp that was on clearance for 20 dollars, msrp was 150. I took it home and hooked it up to my system in the living room which is cheap and janky. Oddly I was fond of the amp even due to its imperfect presentation but I was really cool with it and still to this day I use the amp.

I later was interested in what its measurements were, and after finding out it was at -38 db sinad. Distortion in the teens even very low watts and all this purely horrible objective performance. The top worst basically

Made me wonder how is it possible that I get any pleasure out of listening to this amp. I imagined that something with sinad less than 40 would be garbage and not even listenable.

I was also frequently on audioholics prior to this form and recall Gene saying an amp with 95 db is totally acceptable. After coming to ASR and getting the idea that it needs to be -115 to be fully transparent I wrote audioholics off. Since I definitely have more consideration of what Amir says vs others.

But now I definitely understand where Gene is coming from.

On another note, everything else in my system which included this amp was crap too. I used an apple airport express 2 as a streamer and dac into this amp and the speakers I was using only cost 150. The system in total was $210. Msrp of 400

 

[pma]

It's a good amp for SINAD haters, I guess But it really should be measured at lower output to see if it's simply clipping at 5W.

It was not clipping at 5W. If it was clipping, you would see high order harmonics rising considerably. The key to distortion shown in post#1 being acceptable is the distortion profile, with low order harmonics dominating and higher order harmonics decaying. Human ear then tolerates 10% distortion and more with some music samples. I would like to see a THD+N plot vs. output power, as I have shown in post #87.

 

[pma]

The DC is an artifact from the recording device (E1DA Cosmos) and NOT the amplifier.

Would it be possible for you to use some meaningful scale units on Y-axis when showing noise, like dBV or uV? There is no DC from E1DA, the DC is there only seemingly because of the Y-scale units used, dBr for noise makes no sense. It is also very difficult to read Y axis values from your measurements (small characters).

Is there an audible hum and buzz from the speakers? Seems it must be, with respect to mains frequency multiples amplitude in every plot.