A 91E is on its way here. This should be interesting.
One of the complications for recording comparisons is level-matching. Single tone won't do because of the frequency response variations under load. Maybe pink noise?
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Question re: tube amp grounding/safety
- Thread starter GXAlan
- Start date
One of the complications for recording comparisons is level-matching. Single tone won't do because of the frequency response variations under load. Maybe pink noise?
- Thread Starter
- #62
I renamed the thread title since I posted the review
www.audiosciencereview.com
Record breaker: Raphaelite CS30-MKII tube amplifier review and measurements
Raphaelite CS30-MKII 300B integrated tube amplifier review: A New Performance Record This is a review and detailed measurements of Raphaelite CS30-MKK 300B single ended tube amplifier. It is available on eBay for $1449 + $310 shipping to California + tax. There are some better deals from...
www.audiosciencereview.com
computer-audiophile
Major Contributor
Level dependent treble boost shall not occur in a good 300B amp.
- Thread Starter
- #65
I’d love to see some measurements of whatever you have.
“Good” is hard to define when it comes to the 300B in the same way we can say the same thing about solid state amps. So much variability depending on the tubes and circuit layout.
“Sweetness” of the treble is a term that has been used to describe 300B’s. It would be interesting to see what effects can be measured on the treble and if sweeter amps have greater level dependent changes.
This would explain why people say 300B doesn’t sound bright (because the treble gain is not consistent) but the treble stands out (during transients).
computer-audiophile
Major Contributor
Sorry, I have to deny that, I take a different approach.
By the way, I have written more than enough about such amplifiers on my former Audio-Website, demonstrated them at international scene meetings or given concerts for speakers.
I came to ASR for another reason - looking for new and affordable DACs. But that's also already done with.
I hope you continue to have fun with the Raphaelite Amp.
300B is hard to define. No-one is making anything consistent with the tube spec or with other tubes labeled 300B. These days, it's a branding designator, not a technical part number. Ditto several other fashion labels (like 2A3, 572B...).
computer-audiophile
Major Contributor
In fact, there is a wide range of variation in tubes. That has always been the case. Nevertheless, even among today's replicas, there are certain types that have found wider acceptance.
There's variation and there's "this isn't even vaguely the same tube type except for the shape of the letters on the printing."
computer-audiophile
Major Contributor
I don't see the situation so critically. I don't have a characteristic curve tracer here today, but in the past I had already measured one or the other tube to compare.
As far as 300B tubes are concerned, I used to be quite satisfied with the JJ brand, which are also used by Nagra in their expensive amplifiers, or today I use 300B tubes from Linlai.
As far as 300B tubes are concerned, I used to be quite satisfied with the JJ brand, which are also used by Nagra in their expensive amplifiers, or today I use 300B tubes from Linlai.
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- Thread Starter
- #71
I agree. It’s very much like phono cartridges in my opinion. You have some pin compatibility and shared function. The branding issue is also true. Western Electric has some correlation to history, but even then the modern ALD carbonized nickel makes it a different product from before.
The other problem is tube lot to lot variability (my WE300B don’t seem all that well matched despite paying the extra money for matched pairs so it must mean that unmatched tubes are even more different!). I have been lucky with NOS US production tubes when using my tube tester, but even then, measurements on NOS tubes are only going to be accurate for the specimens in hand and cannot be generalized.
I definitely am looking forward to your write up of the 91E. It would be great to get your insights on the lack of standardization. At least back in the day, you had KT88 and 6550 as different descriptions. Today, you can imagine a companies changing glass shape and having a different label printed on the glass!
Out of curiosity, the Canary Audio monoblocks boast extremely low distortion. It makes me wonder if those amps show any similar dynamic frequency response changes or if they show more solid state like behavior. I don’t see any deep dives of those amps.
My contribution to the W-E article will purely be measurements. Apologies in advance, but I think there's a good reason why someone else will be writing the main article.
There was a survey article some years back, and I think it was in Glass Audio (one of the predecessors to AudioXpress). of several different tubes labeled and marketed as 300B. Of course there was absolutely nothing even vaguely similar about them nor any similarity to the original 300B datasheet specs. I have not been tempted to lay out my own money to buy contemporary samples, and it would in particular pain me to put any money into the pockets of PSvane, a company which demonstrated its lack of ethics to me time and again.
computer-audiophile
Major Contributor
A good example of "reinterpretations" of classic end triodes are the tubes from the German company Elrog. I find it interesting what they do, they are very professional when it comes to tubes, because they used to make tubes for industry, aviation and military former times. Visually, I don't like the straight lines of the Elrog 300B, for example, so I don't use them. I particularly like the classic 'iconic' shape of the 300B tube. For Thomas Mayer, who owns this company today, it is a real USP. His amplifiers are highly recognised in the scene.
BTW: When I built my last 300B amp, I had a lively exchange with the head developer at Elrog. He helped me to optimise my favourite circuit by numerous PSpice simulations, which I can't do because I don't have my own private lab anymore.
BTW: When I built my last 300B amp, I had a lively exchange with the head developer at Elrog. He helped me to optimise my favourite circuit by numerous PSpice simulations, which I can't do because I don't have my own private lab anymore.
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computer-audiophile
Major Contributor
- Thread Starter
- #75
I respect these points of view of course, but sometimes I am surprised at the way some people think.
computer-audiophile
Major Contributor
Thanks, I knew the article.
computer-audiophile
Major Contributor
What do we deduce from the previous postings? Which tubes are considered recommendable? Maybe someone needs this advice.
Fantastic stuff - I think I want one of his clocks...
For what circuit? For which purpose?
computer-audiophile
Major Contributor
Good question! I came up with it because I had the impression that people here generally complain about the poor quality of 300B tubes, for example, if they are not from the WE brand.
But never mind - I will stay out of this discussion now. I always make the same mistake of 'joining in', so to speak, out of old habit because I have been dealing with these amplifiers for decades. I should know where this leads.
Sorry, I'd better concentrate on the real music again and leave the subject of DHT amps alone. (Tomorrow I'm going to two live concerts of contemporary classic at the Festspielhaus Hellerau in Dresden at the same day. This is my real love.)
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