StradiTube.. review incoming (any requests?)

[Golum]

Did John give you a timeline on the Stradi 274b?

He said its kind of in the late stage of development and he'll let me know once ready. I hope soon...

 

[Golum]

Golum its good to hear your impressions were similar to mine with the rectifier. These tubes are doing some special stuff!

Exactly. I'm wrapping my head around why is that so. From technical standpoint (and I'm zero expert) somehow in my head following sentence from their website "rings" - "filament end loss structure" and for rectifier this is one of the things mentioned. For DHTs there are several things in the structure which are obviously changed vs WE300b hence I would assume this changes bring the difference we hear - and possibly the materials and process used. I've also never (at lest that I can recall) seen filament wire glowing below the bottom part of the plates...
Anyhow exceptional job done...

 

[godofwealth]

As far as rectifiers are concerned, I’m old school. Once I got the WE 274B and the WE 422a, I stopped searching. To me these are the gold (platinum?) standard. A lot of modern tubes just don’t stand the longevity tests. My WE 274B has been used by me for thousands of hours. There’s no change in its audible or measured performance. These old WE designs just last forever. I’ve been very disappointed by the newer WE 300Bs. No match to the original. I recently saw the classic WE 101d triodes are built to last 40,000 hours. Who designs tubes like that anymore? When it comes to tubes, olden is golden.

 

[TKK]

Thanks Rich for sending over the Stradi tubes—I had an amazing holiday weekend diving into some serious tube comparisons. It was a lot of fun pitting the Stradi 300B (both the S and non-S versions) against the TAK300B and WE300B.

My overall impressions align closely with Rich’s observations. For context, my setup is quite similar to his—both my 300B amp and speakers come from Rich! My DAC is Lampizator Pacific (using TAK300B and Bendix 6900), paired with a Thomas Mayer 10Y preamp. That said, one limitation in my experiment is that the TAK300Bs are the only tubes I have two pairs of, so I fixed TAK300B on Pacific for comparing tubes on the 300B amp.

Stradi 300B (Non-S Version): This tube truly stands out in terms of soundstage, dynamics, and bass detail. It reveals layers of bass texture I haven’t heard with either the TAK or WE. The bass is impactful, with impressive slam and extension—exceptional within the 300B category. However, its vocal presentation isn’t quite in my sweet spot. To my ears, vocals feel slightly recessed, dimmed, and distant, which isn’t ideal for my preferences if paired with Pacific.

Interestingly, when paired with my "little" DIY solid-state DAC (using 1541A chip), the vocal improves though still a touch distant for my taste, but enjoyable. This may actually work well for other solid-state DACs. In comparison, the WE300B delivers great vocals with the Pacific but falls short with my solid-state DAC, whereas the TAK300B shines with either setup when vocal clarity is the focus.

Stradi S300B (S Version): The Stradi S works well with Pacific in my system. Vocal has a good balance of texture and energy, without feeling dry. While it’s less rich in harmonic compared to others, it’s still engaging. Bass is tight and fast, and imaging feels more precise and pinpoint. However, it lacks some of the magic that makes the non-S version special—like the extraordinary soundstage, dynamic, and bass detail. With my DIY solid-state DAC, the S300B leans more toward what Rich described: it feels less emotional and less compelling overall.

I haven’t yet done a full comparison with all these tubes on Pacific. So far, though, each tube has carved out its own space in terms of strengths, It’s been a fun time to dive into these nuances! Thanks Rich again for being so kind and hopefully I will have sometime next week to try them on Pacific and update my thoughts here.

 

[Treehaus Audiolab]

Thanks Rich for sending over the Stradi tubes—I had an amazing holiday weekend diving into some serious tube comparisons. It was a lot of fun pitting the Stradi 300B (both the S and non-S versions) against the TAK300B and WE300B.

My overall impressions align closely with Rich’s observations. For context, my setup is quite similar to his—both my 300B amp and speakers come from Rich! My DAC is Lampizator Pacific (using TAK300B and Bendix 6900), paired with a Thomas Mayer 10Y preamp. That said, one limitation in my experiment is that the TAK300Bs are the only tubes I have two pairs of, so I fixed TAK300B on Pacific for comparing tubes on the 300B amp.

Stradi 300B (Non-S Version): This tube truly stands out in terms of soundstage, dynamics, and bass detail. It reveals layers of bass texture I haven’t heard with either the TAK or WE. The bass is impactful, with impressive slam and extension—exceptional within the 300B category. However, its vocal presentation isn’t quite in my sweet spot. To my ears, vocals feel slightly recessed, dimmed, and distant, which isn’t ideal for my preferences if paired with Pacific.

Interestingly, when paired with my "little" DIY solid-state DAC (using 1541A chip), the vocal improves though still a touch distant for my taste, but enjoyable. This may actually work well for other solid-state DACs. In comparison, the WE300B delivers great vocals with the Pacific but falls short with my solid-state DAC, whereas the TAK300B shines with either setup when vocal clarity is the focus.

Stradi S300B (S Version): The Stradi S works well with Pacific in my system. Vocal has a good balance of texture and energy, without feeling dry. While it’s less rich in harmonic compared to others, it’s still engaging. Bass is tight and fast, and imaging feels more precise and pinpoint. However, it lacks some of the magic that makes the non-S version special—like the extraordinary soundstage, dynamic, and bass detail. With my DIY solid-state DAC, the S300B leans more toward what Rich described: it feels less emotional and less compelling overall.

I haven’t yet done a full comparison with all these tubes on Pacific. So far, though, each tube has carved out its own space in terms of strengths, It’s been a fun time to dive into these nuances! Thanks Rich again for being so kind and hopefully I will have sometime next week to try them on Pacific and update my thoughts here.

No worries at all. The more ears we have on these tubes, the better for the community at large.

 

[DetroitVinylRob]

Looking forward to more intel on the horizon of the upcoming 274B, and possible ETA.

Also the Stradi Eb based 2A3s sound extremely enticing to my mind, leaving me quite curious. Always exploring new munitions for my beloved Triode Lab 2A3 GT-C FFX squadron. Think I’d be Interested to take the jump, have a listen, and compare and contrast their talents to some of the fine WWII era RCA and Sylvania specimens, the J.J.s?, or EMLs? stockpiled currently in the HiFi bunker. Most certain that these very thoughtful reviews above of the Eb based 300b variants will likely be quite translatable to our own weapons of choice (2A3).

*Bonus points! Sooo happy to see Stradi choosing to forego the precious need for ridiculously pretentious and inevitably wasteful (imho) “presentation boxing”.

Thank you all for sharing your kind research and impressions guys.

What a great time to be an audiophile and music lover!

 

[TKK]

After spending a few more weeks with the tubes and experimenting with various combinations—including swapping tubes in Pacific and trying different driver tubes (801A/VT-25A) in my 300B amp—the main conclusions remain the same. However, I’ve noticed that optimizing the Stradi 300B (Non-S Version) involves using them in the amp rather than the DAC. Placing them on the DAC diminishes some of the dynamics and bass extension, which are standout qualities of the non-S version.

On the other hand, the Stradi S300B (S Version) performs very well in the DAC. It delivers great clarity and texture without sounding overly thin, remaining engaging and enjoyable.

A particularly satisfying combination I’ve discovered is using Stradi non-S 300Bs in the amp with VT-25A driver tubes, paired with Stradi S300Bs in Pacific. This setup is very impressive and holds its own against my current favorite: TAK300B in the DAC, 801A drivers + WE300B in the amp. The latter has the edge when it comes to treble and vocal engagement, which are the most important characteristics for me. However, the Stradi combo excels in dynamics, bass, soundstage, separation, and detail. While I personally value treble (being vivid) and more engaging vocal of the TAK+WE setup, I can see why some would prefer the Stradi in this setup.

And thanks again to Rich for letting me hold onto these tubes over the holidays!

 

[ketcham]

I was going to write a topic on Stradi and their applications with Allnic equipment. While I am uncertain if the 300B reviewed above is their latest version recently released, I know the 300B was refined and I would agree this tube competes well with Takatsuki. Modern Western Electric 300B had issues with Allnic equipment UNTIL Q3 2024 WE tube production. This issue has since been resolved and feedback is universally favorable with Allnic owners. Stradi’s innovation in the last few years has been rapid succession and these are some of the best modern production tubes I have heard. They have been willing to manufacture necessary tubes for Allnic’s legacy equipment: HL2, rs242, 3A/109E, 5U4G and 300B.

The 5U4G is better than the OSRAM/MARCONI U52 - more crisp sound, but retain all the qualities I appreciate in U52. Across the board, these tubes are remarkable.

HL2 and 3A/109: Stradi makes the best version I have heard. These tubes are prone to be microphonic and the Stradi versions are consistently stable, making the H-8000 DHT, A-5000 DHT and L-8000 DHT models user friendly.

Note: Stradi is factory direct purchase only. Kevalin Audio and Allnic have no financial affiliation. Kevalin Audio does not sell Stradi tubes.

 

[AudioAbe]

I have a quad set of RS242s arriving today from Straditube for my H-8000 DHT. I had issues with the tubes supplied by Allnic with the phonostage itself. One died very quickly. The replacement RS242 sent by Allnic was made by KR , whereas the other 3 were Allnic's own. So I did end up purchasing some NOS Telefunken RS242 (at quite some expense), which have been absolutely wonderful, however I have been looking for suitable RS242s to roll, to keep the hours down on the Telefunkens if nothing else. Looking forward to hearing the Staditubes.
I will consider their HL2s and possibly 5U4Gs if I like what I hear.
I have not rolled the 300Bs yet - my understanding is that rolling the rectifier makes a greater difference, but I am sure that the temptation to tinker will get the better of me eventually (I use Taki 300Bs in my Gakuohs)
Communication from John at Straditubes has been exemplary.

 

[ketcham]

In the H-8000 DHT - 300B is only a voltage regulator. Save your money here and use cheap tube set.

I love to hear your opinion on rs242. I have not heard the latest version of this. If a tube were to fail early - Stradi would be actively correcting the cause and change the design. So feedback for them is essential.

 

[Treehaus Audiolab]

I have a quad set of RS242s arriving today from Straditube for my H-8000 DHT. I had issues with the tubes supplied by Allnic with the phonostage itself. One died very quickly. The replacement RS242 sent by Allnic was made by KR , whereas the other 3 were Allnic's own. So I did end up purchasing some NOS Telefunken RS242 (at quite some expense), which have been absolutely wonderful, however I have been looking for suitable RS242s to roll, to keep the hours down on the Telefunkens if nothing else. Looking forward to hearing the Staditubes.
I will consider their HL2s and possibly 5U4Gs if I like what I hear.
I have not rolled the 300Bs yet - my understanding is that rolling the rectifier makes a greater difference, but I am sure that the temptation to tinker will get the better of me eventually (I use Taki 300Bs in my Gakuohs)
Communication from John at Straditubes has been exemplary.

Ill be very curious to hear how they compare to the Telefunkens too!

I was going to write a topic on Stradi and their applications with Allnic equipment. While I am uncertain if the 300B reviewed above is their latest version recently released, I know the 300B was refined and I would agree this tube competes well with Takatsuki. Modern Western Electric 300B had issues with Allnic equipment UNTIL Q3 2024 WE tube production. This issue has since been resolved and feedback is universally favorable with Allnic owners. Stradi’s innovation in the last few years has been rapid succession and these are some of the best modern production tubes I have heard. They have been willing to manufacture necessary tubes for Allnic’s legacy equipment: HL2, rs242, 3A/109E, 5U4G and 300B.

The 5U4G is better than the OSRAM/MARCONI U52 - more crisp sound, but retain all the qualities I appreciate in U52. Across the board, these tubes are remarkable.

HL2 and 3A/109: Stradi makes the best version I have heard. These tubes are prone to be microphonic and the Stradi versions are consistently stable, making the H-8000 DHT, A-5000 DHT and L-8000 DHT models user friendly.

Note: Stradi is factory direct purchase only. Kevalin Audio and Allnic have no financial affiliation. Kevalin Audio does not sell Stradi tubes.

Thank you for also posting up with your experience. I am under the impression the 300Bs I have are the latest variants.

What I like about Stradi is not only that they produce a superlative tube, but they are also producing rare european tubes which have a lot to offer us modern listeners.