[Trickness]

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.

The documentation says side-by-side the power supply and the amp are 17.4 inches wide… Is this correct?

 

[project86]

Sounds about right - together they basically add up to a typical full-size unit.

But when many of my headphone amps use a more narrow form factor (Violectric, Pass Labs, Cavalli CTH, Arcam, Cayin iHA-6 and HA-1A mk2, etc), the HA-300 feels huge.

Totally worth it though.

 

[Andykong]

I actually sold mine last year simply because I wanted to dabble into electostats, but alas it was short lived. After trying a number of different amps (SS and non-300b amps), nothing really satisfied me except the HA-300 and its 300b tube magic. I had no choice but to buy another one!

I plan to utilize the speaker outputs because its such a waste to just use the 300b on headphones even though I already have KH310. I see omega speakers in my future...

I believe mine was @Level5 first HA-300.

Now this is fate.

@Level5 Now this is new to me, bought HA-300 twice and still love it? This is the best endorsement from customer, something that drive us to work harder for next breakthrough. Thank you.

 

[Andykong]

Yeah but on the other hand I’d imagine that the eddy current staff is a much simpler circuit that will be around and repairable for many years beyond the Cayin. I wonder if the E.C. even has any pcbs in the chassis? And I wonder if the Cayin is driving the tubes harder to get that greater output?

Well, I can't speak for EC but we sure didn't over-drive the tube to deliver the output we specified. Please be reminded that the power of a transformer coupled tube amplifier actually comes from the output transformer, not the tube directly. The size and quality of output transformer makes a lot of different and Cayin is one of the very few (if not the only) headphone amplifier manufacturer that design and wind all our transformers in-house.

 

[Andykong]

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.

Actually that is a common issue with DHT (Direct Heated Triode), so 45, 2A3, 300B, 845 all suffer from the same microphonic issue. Event the Nutube we used in N8 shared the same characteristics.

And the sauce of interference can literally drive you crazy. Someone shared recently that after he replaced the keyboard of his computer, the hum disappeared completely. and that's because the keyboard has LED lights built in. Isn't that crazy?

 

[Andykong]

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.

@Benny-x is correct, both 6.35mm and XLR4 output employes same output transformer for final stage amplification, so you can consider them identical in that aspect. The only different is input transformer, RCA input go straight to the 6SN7 circuit but the XLR input will do through a pair of input transformer before feeding to the 6SN7. The input transformer is working with low level signal only, so it is a small transformer by design, there is no point for us to cut corner on this inexpensive component.

Theoretically using RCA input will skip the input transformer stage, purist audiophile definitely will prefer this. However we have allow users to AB compare the XLR and RCA inputs in multiple shows and exhibition already. When we connect the XLR and RCA input of HA-300 to the same DAC, and using similar cable (well, we use Cayin XLR and RCA cable, so the shielding and conductors are the same), the different is inaudible according to visitors even when they AB compare it repeatedly.

 

[Level5]

Now this is fate.

@Level5 Now this is new to me, bought HA-300 twice and still love it? This is the best endorsement from customer, something that drive us to work harder for next breakthrough. Thank you.

Yes and what makes it worse is after getting it back and using the HD800, I've fallen out of love for PRO speakers (KH310) and actually preferred listening to HD800 instead which is just crazy! So I remedied the issue and got a different speaker to be able to use it on the HA-300 and now its the other way around, the way it should be. Speakers > Headphones

Once you get a taste of 300b, its kinda hard to go back!

 

[Level5]

The only MAJOR downside is this thing puts out serious heat which is a serious issue this summer where I live. My AC is already working overtime ever since it arrived and managing the AC noise is my real noise issue with this amp!

First world Class A + tubes problems!!!

 

[iceanddice]

Look Andy, he got the Impact monitors too!

Now this is fate.

@Level5 Now this is new to me, bought HA-300 twice and still love it? This is the best endorsement from customer, something that drive us to work harder for next breakthrough. Thank you.

 

[Andykong]

Look Andy, he got the Impact monitors too!

Speechless, so are brothers in audio, do you guys drive the same car? or use the same mobile phone?

 

[Andykong]

Yes and what makes it worse is after getting it back and using the HD800, I've fallen out of love for PRO speakers (KH310) and actually preferred listening to HD800 instead which is just crazy! So I remedied the issue and got a different speaker to be able to use it on the HA-300 and now its the other way around, the way it should be. Speakers > Headphones

Once you get a taste of 300b, its kinda hard to go back!

Speaker is definitely a better channel to experience your music, ... if you have the room to setup the speakers properly, no doubt about that.

But headphone has its up side too. You can easily own and enjoy multiple headphones in your system, a lot of friends in this thread will keep 3, 4, or even 10 pairs of headphones besides their system, I bet you can't do that with your speaker setup. Changing headphone for different mood and music genre is fun, especially when you have a headphone amplifier like HA-300, it is so versatile and literally make every headphone sing at their best.

 

[Andykong]

Cayin will host a booth at Hall 4 S04/T07, and we have HA-300 setup for audition, with our flagship source CS-100DAC. Our i-Series 3-pieces stack (iDAP-6, iDAC-6MK2, iHA-6) and HA-1AMK2 will also be displayed. If anyone plans to visit Munich High-end (9-12 May), please drop by and say Hi, I am sure you'll be excited by our new products.

One last note, I have left my full-time role from Cayin but I'll continue to serve the brand under a new capacitor. I'll participate in all the Cayin product threads as usual, so the change probably is minimal for HeadFi forum friends and customers.

 

[Benny-x]

Cayin will host a booth at Hall 4 S04/T07, and we have HA-300 setup for audition, with our flagship source CS-100DAC. Our i-Series 3-pieces stack (iDAP-6, iDAC-6MK2, iHA-6) and HA-1AMK2 will also be displayed. If anyone plans to visit Munich High-end (9-12 May), please drop by and say Hi, I am sure you'll be excited by our new products.

One last note, I have left my full-time role from Cayin but I'll continue to serve the brand under a new capacitor. I'll participate in all the Cayin product threads as usual, so the change probably is minimal for HeadFi forum friends and customers.

That's too bad, Andy. I've always really appreciated your work and support at Cayin. I hope the move is a positive one and you enjoy whatever new work you'll be focusing on.

 

[ken6217]

Doses anyone know the width of the power supply and also of the amplifier?

 

[Trickness]

Doses anyone know the width of the power supply and also of the amplifier?

It’s on the website, although the dimension of the power supply is incorrect:

https://en.cayin.cn/products_info?itemid=112

It’s under 19 inches total.

Nice Streetfighter btw.