[jamato8]

Damn! These black plate rectifiers are freaking fantastic. They have made my amp dead silent, and notes just pop out of pitch blackness. These are very well made rectifiers and you can hear it. Wow!

Not an uncommon phenomenon with tubes. They will burn in and often once settled, change characteristics. I have noted this for many, many, many years. Thinking I had found the holy grail of settings for the tube, the right tubes etc., and then small changes set in. Still great sound but the magic declines. I am not trying to be negative but I am realistic on expectations from many years of experience using tubes in all types of setups. One rectifier, that could maintain the quality is the metal based GZ34. I have one with 1000s of hours of use and it still tests as new and superb in what it does with rectification. I wish the MKII used GZ34 tubes, two of them but not to be and the 22DE4 is a good tube. One, even better than the GZ34 is the 6X4 but it is a small rectifier and not used very much.

 

[krude]

Not an uncommon phenomenon with tubes. They will burn in and often once settled, change characteristics. I have noted this for many, many, many years. Thinking I had found the holy grail of settings for the tube, the right tubes etc., and then small changes set in. Still great sound but the magic declines. I am not trying to be negative but I am realistic on expectations from many years of experience using tubes in all types of setups. One rectifier, that could maintain the quality is the metal based GZ34. I have one with 1000s of hours of use and it still tests as new and superb in what it does with rectification. I wish the MKII used GZ34 tubes, two of them but not to be and the 22DE4 is a good tube. One, even better than the GZ34 is the 6X4 but it is a small rectifier and not used very much.

100% I have only a few years with tubes undery belt but I was surprised many times already.

 

[Wes S]

Not an uncommon phenomenon with tubes. They will burn in and often once settled, change characteristics. I have noted this for many, many, many years. Thinking I had found the holy grail of settings for the tube, the right tubes etc., and then small changes set in. Still great sound but the magic declines. I am not trying to be negative but I am realistic on expectations from many years of experience using tubes in all types of setups. One rectifier, that could maintain the quality is the metal based GZ34. I have one with 1000s of hours of use and it still tests as new and superb in what it does with rectification. I wish the MKII used GZ34 tubes, two of them but not to be and the 22DE4 is a good tube. One, even better than the GZ34 is the 6X4 but it is a small rectifier and not used very much.

These Black Plate Rectifiers are well burned in, and I have been using them on and off for the past year or so. Also, I have 3 quads of backups, so I am good to go for a long long time.

This is the first time however, listening with a full quad of them, and fully burned in WE300B's and the 6S5S, and that's where my newly formed enthusiasm for them is coming from. The synergy is incredible.

 

[jamato8]

These Black Plate Rectifiers are well burned in, and I have been using them on and off for the past year or so. Also, I have 3 quads of backups, so I am good to go for a long long time.

This is the first time however, listening with a full quad of them, and fully burned in WE300B's and the 6S5S, and that's where my newly formed enthusiasm for them is coming from. The synergy is incredible.

Yes, the signal rides on the DC and is all important, which wasn't the case in the past as the power supply was an afterthought or one used that was a do all power supply.

Also the AC in general. Today, here it is very good. Yesterday, not. I have a large balanced toroid used to clean up the AC but even with that, if other things are going on the line, it helps but good AC, like a good/great power supply, is the basis.

 

[krude]

Utopia and Elrog ER have a very special synergy going in my system. It's not pushing Utopia detail wise in any way, it can get a lot more technical, reference and all that, but it just sounds awesome to my ears ... "pleasant and powerful".

I want to turn this combo up every time and I need to keep stoping myself not to damage my hearing

 

[jonchard]

Utopia and Elrog ER have a very special synergy going in my system. It's not pushing Utopia detail wise in any way, it can get a lot more technical, reference and all that, but it just sounds awesome to my ears ... "pleasant and powerful".

I want to turn this combo up every time and I need to keep stoping myself not to damage my hearing

THhs is me exactly what i feel but with susvara and CV6 ... the volume is ALWAYS northwards.... the realness of presentation is fabulous. Last night was Elrog MO + Mullard CV6 Red prints and 22de4 black plates. Volume was nearly always 1:00-2:00 o'clock on the dial, gain on medium, with Qobuz at close to max. Every minute was like hearing something new in everything, Familiar songs represented with a polish and shine! I still feel CV6 is pushing dynamics beyonds most others i have tried. CV6 ability to push sounds around the soundstage in a truly believable manner, sounds popping from nothing, Zero noise floor. I think if i only have Mullard CV6, and all other driver tube options were removed, i dont think id miss a thing. And yet im still chasing 6s5s, 6c5g, 6j5. Also a few other CV6 like E1148 and the chinese variant.

Does anyone have a rare brown base GEC Kb/a cv1135 (cv6) variant? Happy to buy one or two to complete a set.

 

[Wes S]

Elrog MO + Mullard CV6 Red prints and 22de4 black plates.

Heck of a tube combo right there.

 

[Ake_Y]

Hello,

I need your help.

How long is the lifetime of your new pair of 6SN7 on HA300? Mine is only 1.5 years for each pair ( < 3000 hours - PSVane CV181-TII and LinLai E-6NS7.) .

Since I'm working from home, I normally use my HA300 from 8 AM to 5 PM ( connecting to DAC via PC USB ) . Sometimes, I leave it idle after meeting via MSTeam to focus on my work. ( forget to turn on music )

I tried NOS tubes couple times ( 2 sets of Sylvania 6SN7W and 1 set of Melz 1578 ) . They lasted a couple days or a week.

The weirdest thing is the cracking noises always start at the right channel only. When I swapped left/right, the tube from left would be ok for around 2 weeks. After that, it had the same cracking noises. For the tube from the right ( crackling noise ) , it does not have any issue while it was on the left.

I sent my HA300 back to my distributor last week for checking. They could not find anything per images.

Any suggestions are welcome. Thank you very much in advance for your help.

Note : - I just bought Electro Harmonix 6SN7 gold pin from AliExpress. There is hum sound on the right side as well, but it is gone when I swapped left/right.

- These cracking / hum sounds are directly varies to gain level only.

 

[jamato8]

Hello,

I need your help.

How long is the lifetime of your new pair of 6SN7 on HA300? Mine is only 1.5 years for each pair ( < 3000 hours - PSVane CV181-TII and LinLai E-6NS7.) .

Since I'm working from home, I normally use my HA300 from 8 AM to 5 PM ( connecting to DAC via PC USB ) . Sometimes, I leave it idle after meeting via MSTeam to focus on my work. ( forget to turn on music )

I tried NOS tubes couple times ( 2 sets of Sylvania 6SN7W and 1 set of Melz 1578 ) . They lasted a couple days or a week.

The weirdest thing is the cracking noises always start at the right channel only. When I swapped left/right, the tube from left would be ok for around 2 weeks. After that, it had the same cracking noises. For the tube from the right ( crackling noise ) , it does not have any issue while it was on the left.

I sent my HA300 back to my distributor last week for checking. They could not find anything per images.

Any suggestions are welcome. Thank you very much in advance for your help.

Note : - I just bought Electro Harmonix 6SN7 gold pin from AliExpress. There were hum sounds on both sides, but very low level on the left channel.

- These cracking / hum sounds are directly varies to gain level only.

You said all the tubes have a shorter life than expected. The driver/input tubes should have a longer life than what you are getting. The crackling, always in the same channel is suspect. They need to also measure the bias (easy, you just measure across a resistor and then do the math) on the tubes and the heater voltages.

 

[DrDen]

You said all the tubes have a shorter life than expected. The driver/input tubes should have a longer life than what you are getting. The crackling, always in the same channel is suspect. They need to also measure the bias (easy, you just measure across a resistor and then do the math) on the tubes and the heater voltages.

Seems like Duelund mod became a mainstream

 

[DrDen]

Hello,

I need your help.

How long is the lifetime of your new pair of 6SN7 on HA300? Mine is only 1.5 years for each pair ( < 3000 hours - PSVane CV181-TII and LinLai E-6NS7.) .

Since I'm working from home, I normally use my HA300 from 8 AM to 5 PM ( connecting to DAC via PC USB ) . Sometimes, I leave it idle after meeting via MSTeam to focus on my work. ( forget to turn on music )

I tried NOS tubes couple times ( 2 sets of Sylvania 6SN7W and 1 set of Melz 1578 ) . They lasted a couple days or a week.

The weirdest thing is the cracking noises always start at the right channel only. When I swapped left/right, the tube from left would be ok for around 2 weeks. After that, it had the same cracking noises. For the tube from the right ( crackling noise ) , it does not have any issue while it was on the left.

I sent my HA300 back to my distributor last week for checking. They could not find anything per images.

Any suggestions are welcome. Thank you very much in advance for your help.

Note : - I just bought Electro Harmonix 6SN7 gold pin from AliExpress. There were hum sounds on both sides, but very low level on the left channel.

- These cracking / hum sounds are directly varies to gain level only.

Could that issue be related with the caps modification?

 

[Andykong]

Hello,

I need your help.

How long is the lifetime of your new pair of 6SN7 on HA300? Mine is only 1.5 years for each pair ( < 3000 hours - PSVane CV181-TII and LinLai E-6NS7.) .

Since I'm working from home, I normally use my HA300 from 8 AM to 5 PM ( connecting to DAC via PC USB ) . Sometimes, I leave it idle after meeting via MSTeam to focus on my work. ( forget to turn on music )

I tried NOS tubes couple times ( 2 sets of Sylvania 6SN7W and 1 set of Melz 1578 ) . They lasted a couple days or a week.

The weirdest thing is the cracking noises always start at the right channel only. When I swapped left/right, the tube from left would be ok for around 2 weeks. After that, it had the same cracking noises. For the tube from the right ( crackling noise ) , it does not have any issue while it was on the left.

I sent my HA300 back to my distributor last week for checking. They could not find anything per images.

Any suggestions are welcome. Thank you very much in advance for your help.

Note : - I just bought Electro Harmonix 6SN7 gold pin from AliExpress. There were hum sounds on both sides, but very low level on the left channel.

- These cracking / hum sounds are directly varies to gain level only.

If the dealer is helping you to cross-examine your HA-300, I couldn't offer any solid advice beyond what they have been doing. Your dealer is always your best bet for repair and warranty service because they can examine the amplifier in person. If you want to seek a second opinion from the Cayin service department, you can drop an email to service@cayin.cn

My comment therefore focuses on the non-circuitry issues.

2 sets of Sylvania 6SN7W and 1 set of Melz 1578 lasted a couple of days or a week, but PSVane CV181-TII and LinLai E-6NS7 lasted 1.5 years. This is abnormal IMHO. If all 6SN7 tubes last roughly the same time (say from 1 year to 1.5 years) and they are significantly shorter than the norm, then we probably will suspect the amplifier is the problem because the amplifier is the only common factor. However, since we are talking about 1.5 years vs 1 week, the logical deduction implies the quality of your NOS tubes is questionable.

Did you keep the stock 6SN7 vacuum tubes? they are the Shuguang WE6SN7? Maybe you can use the stock 6SN7 to verify this hypothesis. If the stock tube can last 1 month without showing any problems, then we have a stronger case to suspect your NOS tubes are part of the problem.

The other possibilities, again a matter of logical deduction, suggested that the amplifier has developed a certain problem or has been subject to certain changes (I have noticed the Duelund cap in your photo) in due course, and this led to my second comment. If you were to send your HA-300 back to the Cayin factory, the Duelund cap mod is going to be a problem, Maybe you should restore the HA-300 circuitry to the original condition before you do that. Even with that, if our service engineer has identified a trace of circuitry mod, we might refuse to offer repair service or charge you extra for testing and restoring the amplifier to its original condition before we proceed to repair. Unfortunately, under these circumstances, we cannot take the customer's word for granted. We have no choice but to examine the amplifier in detail to make sure we have documented and restored all the changes.

Last but not least, the PSVance and LinLai are not particularly impressive on the longitude tests we performed in-house. I don't have the original HA-300 testing figures around, but from what I noticed, the Tung-Sol 6SN7GTB that we used in the current HA-300MK2 is more reliable in the longitude tests.

 

[Ake_Y]

If the dealer is helping you to cross-examine your HA-300, I couldn't offer any solid advice beyond what they have been doing. Your dealer is always your best bet for repair and warranty service because they can examine the amplifier in person. If you want to seek a second opinion from the Cayin service department, you can drop an email to service@cayin.cn

My comment therefore focuses on the non-circuitry issues.

2 sets of Sylvania 6SN7W and 1 set of Melz 1578 lasted a couple of days or a week, but PSVane CV181-TII and LinLai E-6NS7 lasted 1.5 years. This is abnormal IMHO. If all 6SN7 tubes last roughly the same time (say from 1 year to 1.5 years) and they are significantly shorter than the norm, then we probably will suspect the amplifier is the problem because the amplifier is the only common factor. However, since we are talking about 1.5 years vs 1 week, the logical deduction implies the quality of your NOS tubes is questionable.

Did you keep the stock 6SN7 vacuum tubes? they are the Shuguang WE6SN7? Maybe you can use the stock 6SN7 to verify this hypothesis. If the stock tube can last 1 month without showing any problems, then we have a stronger case to suspect your NOS tubes are part of the problem.

The other possibilities, again a matter of logical deduction, suggested that the amplifier has developed a certain problem or has been subject to certain changes (I have noticed the Duelund cap in your photo) in due course, and this led to my second comment. If you were to send your HA-300 back to the Cayin factory, the Duelund cap mod is going to be a problem, Maybe you should restore the HA-300 circuitry to the original condition before you do that. Even with that, if our service engineer has identified a trace of circuitry mod, we might refuse to offer repair service or charge you extra for testing and restoring the amplifier to its original condition before we proceed to repair. Unfortunately, under these circumstances, we cannot take the customer's word for granted. We have no choice but to examine the amplifier in detail to make sure we have documented and restored all the changes.

Last but not least, the PSVance and LinLai are not particularly impressive on the longitude tests we performed in-house. I don't have the original HA-300 testing figures around, but from what I noticed, the Tung-Sol 6SN7GTB that we used in the current HA-300MK2 is more reliable in the longitude tests.

@Andykong : Thank you very much for your reply.

I totally agreed with you regarding to NOS condition.

For Duelund cap mod, it was just applied on September 2023 per link ( https://www.head-fi.org/threads/cay...ode-tube-headamp-page-91.872093/post-17736576 ) .

Before modification, I already swapped to Linlai E-6SN7 for a while since PSVane CV181 TII on the right fails from cracking noises. So I believe cap mod has nothing to do with it.

I already contacted service@cayin.cn and got a reply. He also told me to install 6SN7 to the original pair, which I still keep them ( Shuguang WE6SN7 ) to check whether there are still cracking noise from any channels or not.

Note : I would like to correct on Electro Harmonix 6SN7 gold pin. I just sent HA300 back to distributor after I firstly tried EHX 6SN7 so I forgot the exact what actually happened. Last night I tried again. There is hum noise on the right side when I tried them. However, there is very low volume of hum ( barely hear it ) when I swapped left/right, which is quite the same symptom as other new 6SN7 and CV181, except for cracking noise and spending 1.5 years to have the issues.

 

[jonchard]

What is this joy I hear in my ears? Is it the Russians? Oh yeaaaaaahhhh! 6S5S...

 

[trollbearpig]

Ayyye new tube day. I will join you ! I just got the GEC ST L63's in ^__^