[steve468]

The Elrog 300B-Mo are the best I've encountered so far. They're bold, rich, weighty, bright, clean, and sweet. They're really the perfect tube. If you want something more "legacy 300B", I mentioned the KR-Audio 300B Riccardo Kron Anniversary Editions. Those are very bold and warm, very impactful. They lost a little bit on the top end, though. The Emission Labs 300B (family) are very nice, leaning the opposite way - they have done too end and sparkle, and the mids are very sweet.

I don't dislike the Western Electric, I just don't find anything special about them other than the historical name. There are other tube that I dislike more. For example, as nice as the Sophia Princess 274B is, the Royal Princess 300B are so incredibly noisy and microphonic that they're not worth listening to. They ping like wind chimes for sat least a half hour after start up, and if you so much as twitch in their general direction they pick it up.

I actually meant 6sn7s, but I appreciate the comparison. I’ll probably end up with Elrogs at some point - either regular, MO, or some of the rumoured beyond-MO that are supposedly in development.

I’m very curious about the KR-Audio, but I’ve had such bad luck with tubes (also had a bad pair of Psvane 300b) that I’m too scared to order anything not local.

 

[ColSaulTigh]

I actually meant 6sn7s, but I appreciate the comparison. I’ll probably end up with Elrogs at some point - either regular, MO, or some of the rumoured beyond-MO that are supposedly in development.

I’m very curious about the KR-Audio, but I’ve had such bad luck with tubes (also had a bad pair of Psvane 300b) that I’m too scared to order anything not local.

Ah, sorry I misunderstood.

IMO, the best 6SN7'S are not 6SN7 at all (with one exception). The Melz 1578 are incredibly crisp and clean with plenty of extension on both directions. Essentially colorless, they're perfect if you want clean and dynamic. Very pricy and very hard to find unless you know someone who knows someone who's willing to give up their source.

If you want some warmth and sweetness (wetness?), look for some Tung Sol Round Plate Black Glass (RPBG) 6F8G's. Currently absurdly priced, but worth it for "that sound that just blows you away". You will need adapters for these.

I'm currently playing with using 2x6J5G's (via an adapter) and have been pleasantly surprised. Probably a touch warmer than a Melz but with a touch less impact. Still brilliant on both ends of the spectrum though. This can probably be tweaked with a different choice of tubes though. I've just started experimenting, there are others with far better opinions on these than me.

Finally, the best for warmth and a traditional "tube" sound are the classic RCA Grey Glass. There also creeping up in price but can still be found at a decent price if you look hard enough. These are dark and smokey, like a classic jazz club. Lots of bass and depth, and rolled off on top. These are perfect for jazz, blues, and classic rock.

Others probably have their own favorites (7N7, Sylvania "Bad Boy", etc.), and YMMV.

 

[jamato8]

Ah, sorry I misunderstood.

IMO, the best 6SN7'S are not 6SN7 at all (with one exception). The Melz 1578 are incredibly crisp and clean with plenty of extension on both directions. Essentially colorless, they're perfect if you want clean and dynamic. Very pricy and very hard to find unless you know someone who knows someone who's willing to give up their source.

If you want some warmth and sweetness (wetness?), look for some Tung Sol Round Plate Black Glass (RPBG) 6F8G's. Currently absurdly priced, but worth it for "that sound that just blows you away". You will need adapters for these.

I'm currently playing with using 2x6J5G's (via an adapter) and have been pleasantly surprised. Probably a touch warmer than a Melz but with a touch less impact. Still brilliant on both ends of the spectrum though. This can probably be tweaked with a different choice of tubes though. I've just started experimenting, there are others with far better opinions on these than me.

Finally, the best for warmth and a traditional "tube" sound are the classic RCA Grey Glass. There also creeping up in price but can still be found at a decent price if you look hard enough. These are dark and smokey, like a classic jazz club. Lots of bass and depth, and rolled off on top. These are perfect for jazz, blues, and classic rock.

Others probably have their own favorites (7N7, Sylvania "Bad Boy", etc.), and YMMV.

I have some 6F8G but the ones I tried were very microphonic. I do have some black glass. I’ll have to try them. I also have a lot of 6J5 and the adapters so I’ll have to try them just for fun.

 

[JeffMann]

I love the sound quality of my Cayin HA300 amp with its stock tubes. It is the best headphone amplifier that I have ever owned during the 22 years that my audio system has been headphone-based. I empirically purchased the Elrog ER300B tubes based on the many positive comments expressed by forum members, but I much prefer the sound of the stock Genalex Gold Lion tubes. I will probably sell my Elrog ER300B tubes (which have been used for ~100 hours) in the near future.

Jeff.

 

[Andykong]

I love the sound quality of my Cayin HA300 amp with its stock tubes. It is the best headphone amplifier that I have ever owned during the 22 years that my audio system has been headphone-based. I empirically purchased the Elrog ER300B tubes based on the many positive comments expressed by forum members, but I much prefer the sound of the stock Genalex Gold Lion tubes. I will probably sell my Elrog ER300B tubes (which have been used for ~100 hours) in the near future.

Jeff.

That's a good testimony. Sorry to know that Elrog didn't work for you. I hope the fun will cover your lost.

As I mentioned previously, tube rolling is very personal preference biased, so its not a good idea to invest in expensive or NOS tubes before you know how it sounds in your system, with your headphones. Maybe its better to give some time to the stock tubes, especially when the transformers are breaking in. When you form your opinion with the tube amplifier and know what improvements you are looking for, tube rol6 will be more efficient and meaningful.

 

[Erwinatm]

I love the sound quality of my Cayin HA300 amp with its stock tubes. It is the best headphone amplifier that I have ever owned during the 22 years that my audio system has been headphone-based. I empirically purchased the Elrog ER300B tubes based on the many positive comments expressed by forum members, but I much prefer the sound of the stock Genalex Gold Lion tubes. I will probably sell my Elrog ER300B tubes (which have been used for ~100 hours) in the near future.

Jeff.

So do I. Done a little tweak, use TS black plate for the driver, and 2x GE 22DE4 for rectifier. The stock Tungsol 6SN7 are good as well. It is a good combination for Susvara.

I am going to have Audio Note 4300e soon. I will not go down with Elrogs I think. Had bad experience with Elrogs 300B before (old production, don't know if they have improved the new ones).

 

[Erwinatm]

I have a tale of woe that I'd like to share with my fellow 300b-ers in here. I had gotten a pair of Western Electrics a few months ago, which very much angered the tube gods. The ominous thunder clap when I picked them up should have told me. A few weeks ago, one of the tubes developed a subtle but unmistakable static - not too bad, but could be heard over music. I thought I'd take advantage of that excellent warranty, and I eventually got a second pair. This pair was straight from the distributor, supposedly fresh from the manufacturer. I put them in and almost blew my left ear off! The left tube was clearly and immediately defective - the VU metre on that side was going crazy, and not long after the fuse blew. Just to be sure it wasn't the amp, I put the stock tubes back in and everything was fine again.

So did I just have the worst luck, or what? Anyway, I contacted Parts Connexion (who are EXCELLENT to deal with), telling them I was feeling a bit gun-shy about yet another pair of WE300b. It wasn't said directly, but it was heavily implied that Western Electric might be going through some of the growing pains that many other 300b manufacturers do. Western Electric isn't new of course, but their plant is new. Perhaps they don't quite have their new 300b formula down yet.

If I remember correctly, there was another person in this thread that had similar issues with WE300b. Let this be a lesson, don't anger the gods! That said, I love angering gods, so I exchanged the WEs for Takatsukis

(Elrogs are 3-4 months out from Part Connexion, one of the reasons I didn't join the cult...yet)

Sorry to hear that. Old WE used to be known for its reliability, long lasting tubes.

Congrats for your Takatsuki, IMO it is one of the finest 300B.

 

[jamato8]

6F8G. Something that has gotten very expensive. These are found plate but RCA not Tungsol. My Tungsol is somewhere. The next up are some 1940s round plate NOS. Takes about 10 minutes to burn off the gas that has infiltrated into the tube and so far, then they get very quite always as microphonic as hell. But lively and energetic. I also have some Sylvania with the same type of plates as the W series and early 1950s and some others.

 

[jonathan c]

6F8G. Something that has gotten very expensive. These are found plate but RCA not Tungsol. My Tungsol is somewhere. The next up are some 1940s round plate NOS. Takes about 10 minutes to burn off the gas that has infiltrated into the tube and so far, then they get very quite always as microphonic as hell. But lively and energetic. I also have some Sylvania with the same type of plates as the W series and early 1950s and some others.

When a tube is as “microphonic as hell”, is its liveliness and energy partly (largely?) due to microphony ?

 

[jamato8]

When a tube is as “microphonic as hell”, is its liveliness and energy partly (largely?) due to microphony ?

From years of use, that is what I have found. I prefer a tube with some microphonics. To me, it does not distort the music but enhances it and gives it a live presentation. If the tube is good to begin with, some microphonics, unless in a delicate stage like a phono section.

I forgot I had gotten so many 6J5s in the past. All NOS and some, from 1944 are absolutely crisp in clean boxes. Nice tubes. At least the price on 6J5s hasn't gone up much. I think I paid around 5 dollars each or so but they are good tubes with an adpapter if you have the room but it gets out of hand with them up on the adapter and using 2 for each 6SN7 tube. Kind of a mess.

 

[YungOmbat]

Cayin HA-300MK2
Transformer Coupled Direct Heated SET Class A Balanced Driven Vacuum Tube Headphone Amplifier

The Cayin HA-300MK2 is finally here. The new Cayin flagship vacuum tube headphone amplifier is scheduled to debut at CanJam Singapore 2022. Like its predecessor, the HA-300MK2 is a Class A Transformer-coupled headphone and speaker Single-ended Triode Amplifier (SETA). It uses a matched pair 300B Direct Heated Triode as output tube and a matched pair of 6SN7 as driver tube. The tube amplification circuit is operated in Single-ended, that’s why it is referred to as SETA, and then feed to a pair of output transformers for single-ended headphones, XLR-4 and 4.4mm balanced headphone output, and one set of speaker terminals.

The suggested retail price of HA-300MK2 is US$4,399, and it will be widely available by April 2022.




1. The irresistible 300B Direct Heated Triode

A lot of tube enthusiasts consider the Directed Heated Triode (DHT) as the holy grail of vacuum tubes for audio applications. DHT refers to Triode tubes that use the cathode as the filament and will heat up the cathode directly during operation. These can be considered as the minimal approach to amplification and have a huge following, especially among Japanese and Chinese audiophile communities. There is a long list of vacuum tubes belonging to this family, but for modern audio applications, the more commonly used DHT is 45, 2A3, 300B, 845, and 211, and 300B is probably the most well-known and sought-after DHT in the audiophile community.

The 300B offers an attractive tonal characteristic that is very close to the dream of audiophiles. It has a prominent full-body midrange, harmonically rich with unforced details that bring out the best of an acoustic instrument, and the holographic presence that how the singer (or the band) appeared to be directly there in front of you. Technically, 300B offers very high linearity during amplification. This probably accounts for the natural presentation and excellent low-level details that re-created the presence that brings us closer to our music.

Cayin adopts a matched pair of Gold Lion Genelex PX300B as output tube for HA-300MK2. This is a low-noise audio triode that offers a very decent frequency extension with a natural, sensible and realistic sound signature. This tube is considered to be an excellent upgrade tube by many 300B users and has been called the best “Common Man” 300B tube.

For more detail about 300B Direct Heated Triode in HA-300MK2, please check HERE.




2. SETA, a Purist’s One-way Ticket

Single-ended Triode Amplifier (SETA) is a vacuum tube-based design that uses a single-triode tube per channel to produce output without splitting the musical signal's plus/minus parts in each channel. In contrast, a push/pull amplifier, which uses a pair (or more) of tubes, splits the plus/minus of the music signal, then it has to put them back together to form the complete musical wave in each channel. ......The perceived high sonic quality is mainly attributed to the simplicity and minimalist approach of the circuits involved, as well as the triode vacuum tubes that are typically used. One SET aficionado describes it as "a Zen simplicity to reproduce the complexity of music. Less is more."

Cayin recognized the beauty of SETA and has devoted a lot of resource to develop dozens of SETAs in our history. HA-300 and HA-300MK2 employs the same 2-stage single-ended amplification with 6SN7 as driver tube. It will boost the input signal to the appropriate level so that the 300B output tube will perform its second stage amplification at a very linear condition. In simple terms, driver tube amplifies signal voltage while output tubes amplify current.

Cayin always use 6SN7 as driver tube when we use 300B as output tube. Chris Marten called this combination “legendary in audiophile circles” in his HA-300 review (HiFi+ July 2018, issue 161, page 69-72). For the HA-300MK2 implementation, Cayin uses a matched pair of Tung-Sol 6SN7GTB as driver tube for almost the same reason as Genalex Gold Lion PX300B. This is a super linear, low noise high performance, highly reliable and natural sounding driver tube for SET amplification.

For more detail about SETA implementation in HA-300MK2, please check HERE.




3. Transformer Coupled Balanced Driven

HA-300MK2 is a transformer coupled SETA. The output from the 300B output tube will drive a pair of proprietary output transformers which support both headphone and speaker outputs. If the 300B triode tubes are the spirit of the HA-300MK2, the output transformers are the flesh and blood of the amplifier. Cayin believes in this design. While there are different types of vacuum tube amplifiers in the market, we stick with transformer couple whenever possible, and that means literally all our desktop tube amplifiers are transformer coupled.

We understand the preference towards balanced headphones in Personal Audio hobby. For transformer coupled design, it is fairly straight forward to support both single-ended and balanced driven in the same circuit because our amplifiers are transformer coupled. Since balanced headphone amplification is feeding opposing polarity signals to the left and right ear-cup of your headphone (in regardless of whether there is a dynamic driver or a planar inside). We can achieve this through a specific method to wind the transformer so that the positive polarity (aka "hot") and negative polarity (aka "cold") are driven in opposite directions, hence deliver a fully balanced output from a single-ended tube amplification circuit. In other word, both single-ended and balanced headphone output are "original" output from the transformers, we don't take the single-end output and then convert it into balanced through wiring. .

HA-300MK2 offers two balanced headphone outputs: 4.4mm and XLR4 and we have optimize these two headphone outputs separately. The XLR4 output is a full-fetched output from output transformer while the 4.4mm winding is a level-matched, lower noise, lower power output with the same audio performance, making it more suitable for portable headphones.

For more detail about transformer coupled implementation in HA-300MK2, please check HERE.



4. Impedance Matched Headphone Outputs

One of the very useful feature of Cayin vacuum tube amplifier is the impedance matched headphone output. HA-300 provides three headphone impedance settings, and the amplifier will optimized its output to handle the headphone loading according to the specified headphone impedance. Each impedance matched output is an independent secondary winding from the output transformers. The impedance settings are:

	Recommended for​	Target Impedance (XLR4 and 4.4mm)​
Low (L):	8Ω~64Ω​	32Ω​
Medium (M):	65Ω-250Ω​	64Ω​
High (H) :	251Ω~600Ω​	300Ω​

Matching headphone impedance should produce a natural sound with well-defined bass reproduction. This is our recommended starting point but not necessarily your preferred sound signature, so you can start with the nearest setting to your headphone and then experiment with other settings.

For more detail about Impedance Matched Headphone Output in HA-300MK2, please check HERE.

Back to Transformer

To summarize, the output transformers of HA-300B are extremely complicated because we need a pair of Multiple Winding Output Transformers that takes cares of three headphone outputs (6.35mm, 4.4mm, XLR4) at primary winding, and supports three impedance matched headphone outputs, plus one set of speaker output, at secondary winding.

Transformer plays a vital role in transformer coupled vacuum tube amplifier. The design and implementation of transformers become an important part of our product tuning. The choice of transformer core, specification of copper wire in different parts of winding, and the winding instruction will affect the performance and sound signature of our product. This is a critical core competence that will maximize our product development capability, extend our product life cycle and enhance our operate efficiency.

Given Cayin’s scale of operation and devotion to build high quality tube amplifiers for our customers, Cayin bite the bullet and incorporated a small transformer plant in our facilities. We design and wind all the power supply and output transformers of our tube amplifiers in-house. This will allow the R&D department to have total freedom in specifying the winding instructions for our products, and we have total control on the material and craftsmanship on the transformer of our tube amplifiers.

5. Tube Regulated Outboard Power Supply

The power supply for HA-300MK2 uses a custom-build toroidal power transformer. This is a special circuit to supply different gain stages, and we have used 4 pieces of NOS RCA 22DE4 rectifier tubes to convert incoming power source to DC current for cleanest power with minimum interference for the amplification circuit. These are one of the best version of 22DE4 tube and when used as rectifier tube in HA-300MK2, they can easily last heavy usage of 5 to 10 years. The four 22DE4 are supposed to work independently from each other. When we replace a 22DE4 rectifier tube, we can do that per piece without any matching process. Please check back later for more detail about the outboard power supply of HA-300MK2.

Design and Features

• Single-ended Direct-Heated Triode design, brings out the charm of the tubes with natural and realistic music playback.
• Driver Tube: matched pair of Tung-Sol 6SN7GTB
• Output Tube: matched pair of Genalex PX300B
• Rectifier Tube: 4 pieces of NOS RCA 22DE4
• Support Balanced (XLR) and single-ended (RCA) input, balanced input will transform to single-ended through a pair of input transformer.
• The output from 300B will feed into a pair of custom design in-house manufactured high quality EI output transformer for speaker, single-ended (6.35mm) or balanced (4-pins XLR and 4.4mm) headphone output.
• Choice of three impedance matched headphone outputs (L, M and H) to make sure HA-300MK2 can handle vast variety of headphones satisfactory.
• Powerful headphone output, handle demanding headphones with ample headroom.
• Custom make silica gel shock absorber as anti-shock buffer between critical tube components, chassis mainframe and tube socket, remove microphonic of 300B DHT effectively and provide quiet and realistic playback from sensitive headphones.
• Minimize interference by reinforcing shielding of transformers, effective circuit layout and optimized circuit design
• 60sec startup delay circuit to enhance circuit protection and minimize pop noise when startup.
• One set of speaker terminal as alternative output, can be used as an integrated speaker amplifier with 8 watt per channel Class A output.
• Outboard power supply provides pure and steady power for the amplification circuit with minimum interference.
• Custom design in-house manufactured high quality toroidal power transformer and EI output transformers.
• High voltage power rectification with set of four NOS RCA 22DE4 tubes.
• Two-boxes design with multi-stage tube regulated power supply reduce interference to signal amplification effectively through independently regulated power supply for voltage amplification circuit. Optimize power provision to all circuit and enhance audio performance significantly.
• Point-to-point Wielding to ensure shortest signal path and enhance the transparency and refinement of audio performance
• High-Precision JRC MUSES72320V electronic volume controller with 41-steps ALPS balanced potentiometer to provide low noise and accurate volume control.
• Premium grade MultiCap coupling capacitor improves resolving capability and soundstage.
• High quality shielded silver-plated cable for internal wiring, minimize interference during internal transmission.
• Beautifully design and crafted VU meter
• Lock On quick-release aviation grade copper connectors with silver plated Teflon umbilical cable for outboard power supply connection.
• Detachable vacuum tube shielding cage, easy to detach and install.

Comparison between the original HA-300 and the newly announced HA-300MK2

	HA-300MK2	HA-300
Output Tube	Gold Lion Genelax PX300B	Full Music 300B/n
Driver Tube	Tung-Sol 6SN7GTB	Shuguang WE6SN7
BAL Phone Output	4.4mm, 4-pin XLR	4-pin XLR
Output Transformer	Wide bandwidth EI transformer with reinforcing shielding	Wide bandwidth EI Transformer
Power Supply Transformer	Wide bandwidth toroidal transformer with reinforcing shielding and lower ripple	Wide bandwidth toroidal transformer
Volume Control	JRC MUSES72320V volume controller with 41-steps ALPS balanced potentiometer	Custom-built 24 Stepa balanced potentiometer
Coupling capacitor	Custom AudioCapX MultiCap	Mundorf MCap SilverGold
Fuse for Output Tube	User-replaceable on amplifier chassis	Non-user-replaceable on circuit board
Power Connectors	Locking quick-release aviation-copper connectors	Military-grade screw-on connector
Umbilical cable	Low internal resistance low loss silver plated Teflon	Braided multi-strand heavy-duty copper cable

kind of reminds me of the bhse with that dual chassis design thingy

 

[tinariwen]

I love the sound quality of my Cayin HA300 amp with its stock tubes. It is the best headphone amplifier that I have ever owned during the 22 years that my audio system has been headphone-based. I empirically purchased the Elrog ER300B tubes based on the many positive comments expressed by forum members, but I much prefer the sound of the stock Genalex Gold Lion tubes. I will probably sell my Elrog ER300B tubes (which have been used for ~100 hours) in the near future.

Jeff.

What made you prefer the gold lions to the Elrogs?

 

[ARCXENOS]

From years of use, that is what I have found. I prefer a tube with some microphonics. To me, it does not distort the music but enhances it and gives it a live presentation. If the tube is good to begin with, some microphonics, unless in a delicate stage like a phono section.

I forgot I had gotten so many 6J5s in the past. All NOS and some, from 1944 are absolutely crisp in clean boxes. Nice tubes. At least the price on 6J5s hasn't gone up much. I think I paid around 5 dollars each or so but they are good tubes with an adpapter if you have the room but it gets out of hand with them up on the adapter and using 2 for each 6SN7 tube. Kind of a mess.

That looks like a whole box of fun

 

[Wes S]

Ah, sorry I misunderstood.

IMO, the best 6SN7'S are not 6SN7 at all (with one exception). The Melz 1578 are incredibly crisp and clean with plenty of extension on both directions. Essentially colorless, they're perfect if you want clean and dynamic. Very pricy and very hard to find unless you know someone who knows someone who's willing to give up their source.

If you want some warmth and sweetness (wetness?), look for some Tung Sol Round Plate Black Glass (RPBG) 6F8G's. Currently absurdly priced, but worth it for "that sound that just blows you away". You will need adapters for these.

I'm currently playing with using 2x6J5G's (via an adapter) and have been pleasantly surprised. Probably a touch warmer than a Melz but with a touch less impact. Still brilliant on both ends of the spectrum though. This can probably be tweaked with a different choice of tubes though. I've just started experimenting, there are others with far better opinions on these than me.

Finally, the best for warmth and a traditional "tube" sound are the classic RCA Grey Glass. There also creeping up in price but can still be found at a decent price if you look hard enough. These are dark and smokey, like a classic jazz club. Lots of bass and depth, and rolled off on top. These are perfect for jazz, blues, and classic rock.

Others probably have their own favorites (7N7, Sylvania "Bad Boy", etc.), and YMMV.

Interesting, no one ever mentions the RFT 6SN7 Welded Plates with Ceramic Spacers, and I personally think it's one of the best 6SN7 ever made hands down. The dynamics and detail are incredible, and in the HA300MK2 it doesn't get any better for my preferences. I listen to a lot of Folk and Bluegrass with some Electronica sprinkled in, and the RFT makes all three genres sound as if it's being performed live right in front of me. RFT has this amazing ability to throw the stage further/deeper out in front of me, with vocals that are clean clear and present, and bass that slams with PRAT for days. I think perhaps due to it's limited availability, many have not heard or heard of this tube, but I assure you it's worth the hunt and price of admission if you value speed, detail, dynamics and immediacy with a hint of warmth (life) and don't like the look of adapters.

 

[ARCXENOS]

Interesting, no one ever mentions the RFT 6SN7 Welded Plates with Ceramic Spacers, and I personally think it's one of the best 6SN7 ever made hands down. The dynamics and detail are incredible, and in the HA300MK2 it doesn't get any better for my preferences. I listen to a lot of Folk and Bluegrass with some Electronica sprinkled in, and the RFT makes all three genres sound as if it's being performed live right in front of me. I think perhaps due to it's limited availability, many have not heard or heard of this tube, but I assure you it's worth the hunt and price of admission if you value speed, detail and dynamics and don't like the look of adapters.

And price + there being a couple variants that I am not sure of are my reasons

I think I have also come to accept that I don't really seek the "best" sound, I just love experiencing the changes each tube brings. It only just so happens I love UK valves abit more.

Maybe I just have an addiction.