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

[computer-audiophile]

@Waxx

I also like Line Magnetic, once owned two of their amplifiers. I don't like Cayin either. Agreed so far.

The Sophia Electric may be quite good soundwise, I don't know it and I don't doubt it. But I don't find the impression of quality from the inside particularly inspiring when I look at the picture.

 

[Ken Tajalli]

I have the 1/2 watt data. Clearly better, but not much better.

Post in thread 'Record breaker: Raphaelite CS30-MKII tube amplifier review and measurements'
https://audiosciencereview.com/foru...er-review-and-measurements.44020/post-1565746

The power supply noise is the biggest issue for sure.

I published the 5W data just to set the record but also because in the blind test, it really shows that horrible SINAD is not horrible in sound.

If you look at Figure 6, that’s probably what I am seeing with this unit too but at lower powers since it doesn’t have the MOSFET SCS tech.

Western Electric Type No.91E integrated amplifier Measurements

Sidebar 3: Measurements I performed the measurements of the Western Electric 91E with my Audio Precision SYS2722 system. I carefully installed the tubes following the instructions in the excellent manual, and after turning on the amplifier, waited for the 91E to optimize the bias for the 300B...

www.stereophile.com

How big (power wise) is the PSU transformer?
Are there any series chokes on the PSU?
The more I look at these charts, the more I suspect the PSU.
A SET amp needs pristine power and filtering.
I bet this amp would measure much better with an SS regulated supply.

 

[Waxx]

@Waxx

I also like Line Magnetic, once owned two of their amplifiers. I don't like Cayin either. Agreed so far.

The Sophia Electric may be quite good soundwise, I don't know it and I don't doubt it. But I don't find the impression of quality from the inside particularly inspiring when I look at the picture.

It's old fashioned point to point wireing, that is true. But when done right that can be good. And they (and most SET amps) are way overpriced, that is also true. But subjectivly they did sound very clean and musical for a SET amp. That's why i would like that they got tested on the objective ASR way.

A Shindo Labs WE 300B looks a lot cleaner on the inside, but sounded a lot more distorted when put side by side (what we did). Speaker that we used was a Altec 620 with the 604E driver (owned by the owner of the Shindo). We had a speaker level switchbox with a dummy load for the not used amp to compare and both amps were in a semi blind test (aka the son of the owner did switch, behind a curtain so we did not know what was amping the speaker because the owner could not believe that a 5K amp outclassed his 30K amps...

 

[computer-audiophile]

It's old fashioned point to point wireing, that is true. But when done right that can be good.

That's true, of course. I'm not a Shindo fan either. I have already seen some Shindo amps from the inside. Some are tidier than others. I also attach a lot of importance to a mechanically clean construction including the wiring. Fortunately, I can do it all myself, according to my imagination.

 

[Waxx]

That's true, of course. I'm not a Shindo fan either. I have already seen some Shindo amps from the inside. Some are tidier than others. I also attach a lot of importance to a mechanically clean construction including the wiring. Fortunately, I can do it all myself, according to my imagination.

Wel, this is the amp (Prima Luna Prologue 4, and older model) i did not mind to pay money for, and this layout is also a reason why i did buy it. Clean layout, and use the right tech on the right space. The board with the ic's is the voltage regulator and autobias system, something most audiophools would think is blasphemy for a tube amp... But it makes the amp more clean sounding and controlled. PSU also is with a solid state (diode) bridge rectificer, not a tube based one. And no expensive snake oil parts in it, just good engineering for this type of amp. And it costed half the price of the Sophia Electric (as list price, i paid way less) for a stereo PP amp.

 

[GXAlan]

This tread is as subjective as it gets. Soon there will be talk of Holly water…

That's my hope. If you're going to talk about subjective opinions at ASR, you should be able to back them up with measurements.

How big (power wise) is the PSU transformer?
Are there any series chokes on the PSU?
The more I look at these charts, the more I suspect the PSU.
A SET amp needs pristine power and filtering.
I bet this amp would measure much better with an SS regulated supply.

It is rated for 300 watts.

I have a photo in the original post of the internals. I personally don’t see any filtration. I feel as if adding random ferrite improved residual noise (to my ear; I have to measure and I have line of sight to a large regional broadcast tower).

I will try to see if connecting it to an AC conditioner does anything.

 

[Ken Tajalli]

That's my hope. If you're going to talk about subjective opinions at ASR, you should be able to back them up with measurements.

It is rated for 300 watts.
View attachment 283320

I have a photo in the original post of the internals. I personally don’t see any filtration. I feel as if adding random ferrite improved residual noise (to my ear; I have to measure and I have line of sight to a large regional broadcast tower).

I will try to see if connecting it to an AC conditioner does anything.

OK it is big enough.
I was thinking about a large series inductor/choke in the HT line, not ferrite chokes.
If you look at the Prima Luna picture that @Waxx post, you see one in centre left with a sticker saying 180mA on it.
Ferrites may help with RF, nothing else.
Did you try lifting the ground to see if noise figures improve or not?

 

[GXAlan]

Did you try lifting the ground to see if noise figures improve or not?

I have not tried yet.

 

[Ken Tajalli]

I have not tried yet.

Thanx for replying.
Come to think of it, if it has input transformers, then lifting the ground shouldn't do anything.
I am no expert, but the one I know is, is @SIY ! Perhaps he could chip in.
SET amps I don't like! they have noise issues, power output issues, output impedance issues, output transformer issues (I believe they need an air-gap in the core), many more.
The fact that it sounds good, is a miracle, I guess mostly related to the output tube.
If it was me, I would have given it as clean a supply as I could, and make sure there is "that air-gap" in the core.
My OTL's sounded good and measured better than this, but I was scared of them! they were heavy, and the price of electricity being what it is now in UK and EU, I couldn't justify burning so much electricity just to get 50W max out.
They are in storage.

 

[SIY]

Thanx for replying.
Come to think of it, if it has input transformers, then lifting the ground shouldn't do anything.
I am no expert, but the one I know is, is @SIY ! Perhaps he could chip in.
SET amps I don't like! they have noise issues, power output issues, output impedance issues, output transformer issues (I believe they need an air-gap in the core), many more.
The fact that it sounds good, is a miracle, I guess mostly related to the output tube.
If it was me, I would have given it as clean a supply as I could, and make sure there is "that air-gap" in the core.
My OTL's sounded good and measured better than this, but I was scared of them! they were heavy, and the price of electricity being what it is now in UK and EU, I couldn't justify burning so much electricity just to get 50W max out.
They are in storage.

Input transformers will help with input common mode hum, but if the grounding past them is incompetent, there's no hope for it.

 

[GXAlan]

The fact that it sounds good, is a miracle, I guess mostly related to the output tube.

Input transformers will help with input common mode hum, but if the grounding past them is incompetent, there's no hope for it.

Agree -- hopefully my discussion in the original post helps capture my perspective. We may buy artwork from the flea market with no hope that it will appreciate in value or the antique shop to pick up a decorative item. There is an appreciation of the aesthetic look or an appreciate of the history of the tubes.

If I had the option of finding a low-cost 300B SET that was cheap enough and attractive enough to treat as artwork/antique that was made in the USA, it probably would have been my preference. The Raphaelite had the nicest appearance for the price and in a way, it seemed like something worth trying/gambling on. I lost the bet that it would measure better than expected, but won the bet that it was a valuable learning *experience*, hopefully for the community in hearing a blind measurement of a 22 dB SINAD product (that's only 40 dB SINAD at lower powers), and myself to identify the treble variability with load.

On paper, it seemed like a promising bet
[X] Based off the Western Electric 91B circuit.
Utilizing off-patent technologies seems like a reasonable strategy.

[X] Utilizes tubes that I could readily supply.
The expensive WE 300B are "forever tubes" any time I want to play with a 300B. If you look at the rated life in hours, it explains their 5 year warranty but it likely will last longer. Knowing that plenty of truly vintage 300B tubes are available, I'd bet these tubes will last forever in their usual audio use.

[X] Company "known" for their transformers
Before they made their own amplifiers, Raphaelite apparently was a hobbyist brand selling transformers to DIY'ers. That has a similar story to Sonic Frontiers/Anthem. Big difference in measured performance though! Hard to know if the issue is the cost savings of the 91B circuit or something else.

[X] Company that hired a visual design expert to make the tube amplifier look nice
I love that this isn't a copycat of any established visual look (audio electronics wise). If this had measured well under the hood and was assembled in the US, EU, or Japan, you could easily imagine the MSRP being 10x.

 

[computer-audiophile]

The fact that it sounds good, is a miracle, I

If you were my neighbor I could invite you to a listening session.

 

[computer-audiophile]

@GXAlan

With a few targeted tweaks, you can often boost these types of amplifiers quite a bit. With some it is also necessary, because they sometimes contain stupid design errors (Not all!). An audio friend of mine has specialized in this and often achieved quite excellent results, tweaking the circuits and/or use better components. He gives the amplifiers to audiophile friends when they are fine. He doesn't do it commercially but just for fun. For comparison, he owns amplifiers from renowned brands. E.g. Audio Note and others.

For the Raphaelite DUT I have unfortunately no circuit documents.

 

[JMAudio]

@Waxx

I also like Line Magnetic, once owned two of their amplifiers. I don't like Cayin either. Agreed so far.

The Sophia Electric may be quite good soundwise, I don't know it and I don't doubt it. But I don't find the impression of quality from the inside particularly inspiring when I look at the picture.

 

[GXAlan]

How much point to point wiring do you have in your microwave putting out 1200W?

One of the strengths of point to point wiring is the ability to space things apart and very much the benefit of repairability.

But if you look at these $125,000 WE97A amplifiers you will see judicious use of circuit boards.

 

[JMAudio]

well hold on.. I can show another image of Hiroyasu Kondo Audio Note Ongaku- as well as other Audio Note Amps similarly - amps with point to point no circuit boards which are boutique and considered the most obsessed in the world- and quite pretty in a way... kind of like the wiring inside the body of every living mammal... all point to point no circuit boards I know of in any of those I know of... speaking of microwaves and unicorns these are made of unobtainium $$$ entry fees not reasonable by any stretch for mere mortals I know of... but yet they are considered the most obsessed with P to P wiring - I like it - serviceable for ever... and unlimited transients response and current loads not capable by circuit boards in a smilar fashion- its all about current you know...or so some one said one time somewhere...

 

[SIY]

well hold on.. I can show another image of Hiroyasu Kondo Audio Note Ongaku- as well as other Audio Note Amps similarly - amps with point to point no circuit boards which are boutique and considered the most obsessed in the world- and quite pretty in a way... kind of like the wiring inside the body of every living mammal... all point to point no circuit boards I know of in any of those I know of... speaking of microwaves and unicorns these are made of unobtainium $$$ entry fees not reasonable by any stretch for mere mortals I know of... but yet they are considered the most obsessed with P to P wiring - I like it - serviceable for ever... and unlimited transients response and current loads not capable by circuit boards in a smilar fashion- its all about current you know...or so some one said one time somewhere...

Cool story, bro.

 

[JMAudio]

Cool story, bro.

Its all in the resistance, currently...

 

[IPunchCholla]

well hold on.. I can show another image of Hiroyasu Kondo Audio Note Ongaku- as well as other Audio Note Amps similarly - amps with point to point no circuit boards which are boutique and considered the most obsessed in the world- and quite pretty in a way... kind of like the wiring inside the body of every living mammal... all point to point no circuit boards I know of in any of those I know of... speaking of microwaves and unicorns these are made of unobtainium $$$ entry fees not reasonable by any stretch for mere mortals I know of... but yet they are considered the most obsessed with P to P wiring - I like it - serviceable for ever... and unlimited transients response and current loads not capable by circuit boards in a smilar fashion- its all about current you know...or so some one said one time somewhere...
View attachment 285042

View attachment 285039View attachment 285038

View attachment 285035View attachment 285036

Ummm. You might want to play with this.

A trace 1inch long 21mm thick can handle up to 20A.

Also, what is up with transients? Assuming the wave form of the transient can be recreated by the bandwidth of the amp, won’t the be? I really don’t understand why it’s brought up in discussions of topology, wiring, etc.

 

[JMAudio]

Ummm. You might want to play with this.

A trace 1inch long 21mm thick can handle up to 20A.

Also, what is up with transients? Assuming the wave form of the transient can be recreated by the bandwidth of the amp, won’t the be? I really don’t understand why it’s brought up in discussions of topology, wiring, etc.

good question I was just mentioning the guy from the video - what he said - I don't have any idea about that I never built an amp but that guy does in that video from Rogers Audio