[Trickness]

Forgot to mention I have a Primaluna Dialogue HP integrated which I LOVE and I believe is manufactured in the same facility as some of the Cayin stuff if I’m not mistaken

 

[Fatdoi]

I am wondering on earlier posts there is a hum issue... Is it still there or it's been fixed?

 

[Level5]

I am wondering on earlier posts there is a hum issue... Is it still there or it's been fixed?

I'm currently not hearing any transformer hum or buzz on my new one with the stock tubes paired with my HD800, only when I upped the impedance selector to HIGH that I start to hear a very faint hum, but its not audible when music is playing and I prefer to keep at LOW or else I wont have as much play on the volume steps due to higher watts on balanced. However, some 300b tubes are more/prone to microphonics than others and also do make sure you don't have any ac line noise/ground loops issues and keep away any devices like wifi router or phones from causing the tubes to pick up those stray radio frequencies.

 

[Level5]

I want to mention that my previous tube amp (Dragon Inspire IHA-1) supposedly had some hum issues, but I didn't hear it on mine so YMMV!!! (due to a wide variety of setups/hps/tubes and etc)

 

[westyjeff]

No hum on mine, hum can be from the amplifier, tubes or even the source electrical supply, bad house wiring can induce a hum.

 

[project86]

I never heard hum on the review unit but there is just a tiny bit of that "tube hiss" or "grunge" that many tube amps have, depending on what headphones are used. I was able to get perfect, silent results with LCD-3, LCD-2, Susvara, HE1000, HD650 and HD800, various Fostex-based models like TH900 and TH-X00, plus the AKG K7XX. That's a lot of choices!

On the other hand, I did get a touch of background hiss when using AKG K812, Focal Utopia and Elex, Sony Z1R, and just a tiny bit with HD660S. This was not bothersome enough to ruin the listening experience in general, but it did impact my enjoyment of quiet classical recordings.

I'll note that very few potent tube-based amps like this are truly silent with all headphones.

 

[Level5]

I'm surprised nobody tried high efficient speakers yet or maybe I missed it? Usually I'm listening to speakers during the day, but each passing day, I've slowly started sneaking in some HD800 session. Its just hauntingly GOOD!

 

[iceanddice]

I use a Tekton Design Impact monitor with them. Compared to my Cayin mt35 mk2, which is definitely a lower tier of an amplifier, the HA300 emphasizes those lovely mids. I also believe it scales well in speaker setups with great DACs as the difference between a mojo and a Qutest is apparent. Not crazy night and day for the common man but I can tell the instrument separation is more prevalent with the Qutest.

I use a Utopia and an Auteur on it as well.

 

[Thenewguy007]

I am wondering on earlier posts there is a hum issue... Is it still there or it's been fixed?

I also think most of the hums issues were with the balanced inputs.
I think, correct me if I'm wrong, the Cayin 300B uses separate smaller (cheaper) transformers inside the chassis for the XLR, while the RCA connections uses the superior larger transformers on the top of the amp?

 

[iceanddice]

I also think most of the hums issues were with the balanced inputs.
I think, correct me if I'm wrong, the Cayin 300B uses separate smaller (cheaper) transformers inside the chassis for the XLR, while the RCA connections uses the superior larger transformers on the top of the amp?

I first noticed a hum when I changed 6sn7’s... but after some burn in the hum from the tube went away. Could be a case of burn in or rebiasing in my case! Other than that, I noticed a time where it picked up radio signal while speaker cables were attached to the taps. You’d hear a certain radio station especially if listening through cans. I was thinking my speaker cables werent shielded so I attached some ferrites and it fixed the problem.

 

[Level5]

I use a Tekton Design Impact monitor with them. Compared to my Cayin mt35 mk2, which is definitely a lower tier of an amplifier, the HA300 emphasizes those lovely mids. I also believe it scales well in speaker setups with great DACs as the difference between a mojo and a Qutest is apparent. Not crazy night and day for the common man but I can tell the instrument separation is more prevalent with the Qutest.

I use a Utopia and an Auteur on it as well.

Thanks for the input! Going to try out those Tektons Impact monitors, since I heard they seem to be a good alternative to Klipsch Forte III's and actually useable for my mostly nearfield listening.

 

[Benny-x]

I also think most of the hums issues were with the balanced inputs.
I think, correct me if I'm wrong, the Cayin 300B uses separate smaller (cheaper) transformers inside the chassis for the XLR, while the RCA connections uses the superior larger transformers on the top of the amp?

Not quite. The XLR input, 4-pin XLR output, and the speaker taps all use transformers to convert from the amp's native single ended, internal design to a balanced signal.

In the case of the XLR input, the balanced signal is converted to single ended, then follows the standard signal path just like the RCA input, until you reach the output stage.

In the case of the 4-pin XLR output and speaker taps, the amp's single ended internal signal then goes through output transformers to be converted to balanced. In the case of speakers, unless your amp is balanced end to end and uses a balanced attenuator (if it has one), there will always be a transformer or an op-amp on the output to create a regular+inverted signal to send to the speakers (+/-).

And in the case of all SET (Single Ended Triode; 300B, 2A3, 845, etc.) speaker amps, they will have some kind of output transformer because the design requires that the internal signal be Single Ended.

Someone might argue that these transformer conversions make the signal "less pure" or "less direct", but if the designers are designing everything from step 1 and there isn't some constraint, then you can bet that they know what they're dealing with and the conversion stage is leveraged in achieving the final sound. That doesn't mean they won't sound different or that one might have better synergy with your up/down stream components or that you might just prefer one to the other, though.

"RCA in -> signal path -> 6.35mm TRS out" is the most 'direct' signal path this amp has.

"XLR in -> conversion -> signal path -> conversion -> (A) 4-pin XLR or (B) speaker taps" is the 'less direct' signal path that that side follows.

 

[Level5]

Finally able to try the speaker outputs on my Tekton Impact and they sound even amazing! Plenty of power since they're only 4ohms/94db which is perfect for the HA-300's 4-8ohms @ 8w per ch and even better no hiss or hum!

 

[Ricky64]

Have to say, I was quite familiar to the Final D8000 prior to hearing it though this amp at RMAF in 2018. The HA 300 sounded remarkable in its imaging and dynamics. Thinking about one of these, although I'm not sure I have the room for it and a DAC on my desktop...

 

[project86]

Have to say, I was quite familiar to the Final D8000 prior to hearing it though this amp at RMAF in 2018. The HA 300 sounded remarkable in its imaging and dynamics. Thinking about one of these, although I'm not sure I have the room for it and a DAC on my desktop...

The size aspect is one of the few downsides I can think of when it comes to this amp. Thought it's not the only amp in the world to feature a large external power supply, the HA-300 is also rather tall and extremely heavy. So you really must have the space for it on your rack or desktop.

I ran into trouble when I tried running my ModWright Instruments Oppo 205 (with external PSU) along with the HA-300 in a traditional audio rack (multi-tier, 20" wide). The umbilical cable on the Cayin could stand to be a bit longer.... or maybe give us an option of buying a longer one. Switched to my wide cabinet stand and the combo sounded amazing together, worth the effort for sure, but it's something to consider when planning out your system.