[ken6217]

I felt the same about this comment, my volume is plenty low at one or two clicks, progressivly louder untill 12 which is high, but thats where I like it. Impedance at M.

Same impedance for me as well.

 

[project86]

It's all down to headphone choice. I can crank up to 50% with Audeze or HiFiMAN, no problem. Using a K812 though, not so much. Westyjeff, try your Elex (which I like with this amp) then imagine it being even more sensitive.

EDIT I also like it at the Low impedance setting which feels the loudest of the three settings. I find the other two mess with the bass definition on many headphones (dynamic drivers specifically) so I prefer low despite the potential volume issues.

 

[Andykong]

My review of the HA-300 is (finally) complete - take a look if you are interested. I know a growing number of folks in this thread already own the amp but at least there are pretty pictures to view.....

I agree with the past few pages where folks called out the imaging, layering, etc as particularly noteworthy. But it's hard to keep up with all the things this amp does well.

When John said "for 90% of the headphones I tried, the result was up there among the very best performance that particular headphone has ever displayed - which means the HA-300 is doing something right", I take that as the biggest compliment to our HA-300 ever. I am sure the very positive impression with Sennheiser, HiFiman, Fostex and Audeze has drawn the attention of a lot headphone collectors already, let's hope the HA-300 will now be included in their audition list after this reviews get published.

Regarding the Volume setting, I would to point out that we had gone through a lot of different combinations before we arrive at this final volume setting. John's comment is 100% valid, but on the other hand, the same volume setting were applicable concurrently to speaker setup. We can indeed solve the problem by expanding the first volume position to 2 or 3 slots, leaving more room for the most sensitivity headphones, but then we won't have enough volume control on the top to explore speaker setups.

We used AKG K812 as the reference for sensitive headphones during HA-300 development stage, it works fine for most but not all users/music genre in our initial test. The K812 is my personal unit and it is also a mod set. I used Neotech Rectangular OCC to mod the K812 into a double entry XLR4 balanced headphone. I picked this cable because it is flat/slim instead of circular shape, so I can open the headphone cup, install the cable, and put the cup back without drilling any hole.


From circuit design topology of HA-300, I don't know the correct description so shall we call it "Balanced Driven" tentatively? It is different from the fully balanced designed which operated in fully differentiate amplification from input to output. It is not a Single End Amplifier with XLR output connectors attached because the rated output of 6.35mm phone jack and XLR-4 should be largely the same, if not identical. However, the output of 6.35mm phone jack and XLR4 are completely different and non-correlated (don't ask me why, I can't understand that even I consulted our Engineer specifically ). The tube amplification stages (6SN7 and 300B) of HA-300 remain Single-ended, but the final output stage of HA-300 is the dual output transformers and they are running in balanced configuration - it is fairly straightforward to create the inverted phase in a transformer.

If someone can provide an accurate description of this circuit topology, please give me a hand. While we design HA-300 based on our own know-how and experience with tube amplifier, I suppose we are not the first amp. using this topology in headphone application.

 

[ken6217]

I have the Meze Empyrean headphones which weren’t part of the review. I can say that these sound absolutely stunning with the HA-300.

 

[project86]

Andy - thanks for the background info on volume stuff, totally makes sense. Balancing between headphone out and speaker out is surely a difficult task. Btw your K812 solution is clever, I love that it doesn't require drilling holes.... mine required a lot more work and the end result probably isn't any better than what you did. Clever!

As far as the output topology, that sounds vaguely similar to some of the newer Luxman amps like the P-750u. They use a bridge tied load (BTL) for the XLR4 output, while the 6.35mm output uses a dual paralleled design. This results in different power delivery and slightly different sound from each jack, though nothing drastic. I believe the Auralic Taurus mkII was configured similarly as well, if I recall correctly. But HA-300 is better than either of those amps by a large margin (Luxman is expensive but I'm not really sold on their house sound, too syrupy).

Ken - you are like the 5th person I know who says HA-300 and Empyrean is an amazing combo. That's my one disappointment, that I didn't get to hear them together.

 

[ken6217]

- Ken - you are like the 5th person I know who says HA-300 and Empyrean is an amazing combo. That's my one disappointment, that I didn't get to hear them together.

I have to thank Peter for that recommendation. He had heard the combo at a show and told me how great they were together.

 

[ken6217]

Last night I was listening to my amplifier and we had a storm and I lost my power and so obviously the amp turned off. I then immediately push the off button and pull the plug out of the outlet in case the power came right back on. I was curious if having the amp turned off by the power plug is the same has turning off using the switch. I’m just curious if any any damage can be done to the amp or tubes by the power going off losing power to the house

 

[Andykong]

Last night I was listening to my amplifier and we had a storm and I lost my power and so obviously the amp turned off. I then immediately push the off button and pull the plug out of the outlet in case the power came right back on. I was curious if having the amp turned off by the power plug is the same has turning off using the switch. I’m just curious if any any damage can be done to the amp or tubes by the power going off losing power to the house

It doesn't matter. You can power off the amplifier using the ON/Off switch in the front panel. That will work better then unplug the power connection or turn off the power connection on your powerbar directly.

On the other hand, power surge from thunder/lighting is more risky then sudden power lost in lighting storm. If you live in area where thunderstorm is common, make sure you have a decent surge protector in the power supply of your sound system

 

[Andykong]

Andy - thanks for the background info on volume stuff, totally makes sense. Balancing between headphone out and speaker out is surely a difficult task. Btw your K812 solution is clever, I love that it doesn't require drilling holes.... mine required a lot more work and the end result probably isn't any better than what you did. Clever!

As far as the output topology, that sounds vaguely similar to some of the newer Luxman amps like the P-750u. They use a bridge tied load (BTL) for the XLR4 output, while the 6.35mm output uses a dual paralleled design. This results in different power delivery and slightly different sound from each jack, though nothing drastic. I believe the Auralic Taurus mkII was configured similarly as well, if I recall correctly. But HA-300 is better than either of those amps by a large margin (Luxman is expensive but I'm not really sold on their house sound, too syrupy).

Ken - you are like the 5th person I know who says HA-300 and Empyrean is an amazing combo. That's my one disappointment, that I didn't get to hear them together.

I did try your method because it looks better, but I gave up after I investigated the path seriously. I want to make sure the headphone cable remain the same length on both earcup, and unless I use very thin internal cable, otherwise I'll have a hard time to find space for the extra cables of the right earcup.

BTL is equivalent to dual mono, so the Luxman is not balanced driven, the signal is single-ended by nature, just better current and control due to dual mono design? Besides, HA-300 can maintain very similar sound signature between the 6.35mm and XLR4 output.

 

[silversurfer616]

Had a chance to listen to this amp at the HighEnd in Munich and I was seriously impressed. Various top headphones were available and they all sounded spectacular( although Empyrean is not my taste)but best were the people there. After mentioning that I came all the way from NZ I was treated like royalty...it really felt like a community of friends sharing the same hobby. If I wouldn‘t be focusing on my Stax rig right now, I would get this amp...and the music player.

 

[ken6217]

A question about the ECC32 tubes. I know these tubes are compatible with the HA-300. I just purchased a pair, and waiting to receive it.

I received an email from the person that I purchased them from and said the following:

“Are you going to put these ECC32 in an amp that normally uses 6SN7 tubes. They will go straight in, but have a voltage rating of 300V. 6SN7 has a rating of 450V. If the volts are fine they sound superb. Most amps run the 6SN7s under 300V so it will most likely be fine.”

Can someone explain this to me, and will my amp be able to take advantage of any potential benefits of these tubes?

Thanks.

 

[Ake_Y]

I bought HA-300 a couple weeks ago, but just have time to set up this afternoon. This amp is so heavy. Thank you all for your suggestions.

After listening for an hour, it improves textures and bass impact from internal amp of Audio-GD R-28.

My next target should be DAC and power conditioner. Any recommend for DAC would be welcomed. Still decide between R2R and Dual ES9038PRO.

 

[ken6217]

I bought HA-300 a couple weeks ago, but just have time to set up this afternoon. This amp is so heavy. Thank you all for your suggestions. My next target should be DAC and power conditioner. Any recommend for DAC would be welcomed. Still decide between R2R and Dual ES9038PRO.

It depends on what you like. I’m not a fan of Sabre chips. I do have an R2R DAC. Get something that you can listen to and return if you don’t like, if that’s possible.

Don’t get anything yet until the amp and tubes are broken in otherwise you won’t know what’s what.

If you are using a stock power cord, put the money into an aftermarket power cord instead of a power conditioner.

 

[project86]

A question about the ECC32 tubes. I know these tubes are compatible with the HA-300. I just purchased a pair, and waiting to receive it.

I received an email from the person that I purchased them from and said the following:

“Are you going to put these ECC32 in an amp that normally uses 6SN7 tubes. They will go straight in, but have a voltage rating of 300V. 6SN7 has a rating of 450V. If the volts are fine they sound superb. Most amps run the 6SN7s under 300V so it will most likely be fine.”

Can someone explain this to me, and will my amp be able to take advantage of any potential benefits of these tubes?

Thanks.

We'd need Cayin to tell us if their design exceeds that 300V limit or not. As the person told you, it's not all that common, but also not totally unheard of to go higher... and unless Cayin tells you for sure, you'd be potentially sacrificing the new tubes just to test it out.

I bought HA-300 a couple weeks ago, but just have time to set up this afternoon. This amp is so heavy. Thank you all for your suggestions. My next target should be DAC and power conditioner. Any recommend for DAC would be welcomed. Still decide between R2R and Dual ES9038PRO.

I loved the HA-300 with iFi Pro iDSD (4x PCM1793), Resonessence Mirus Pro Signature (2x ES9028Pro), Wyred4Sound Anniversary DAC (single ES9038Pro), Sonic Frontiers SFD-2 mkII (2x UltraAnalog 20400A R2R), and Airist R2R (discrete R2R). They all sounded unique in their own ways, regardless of ESS or TI or R2R etc. So I wouldn't get caught up in that one aspect alone, but rather find something that fits your needs for sonics, budget, features, looks, etc, no matter what type of chip it uses.

 

[ken6217]

We'd need Cayin to tell us if their design exceeds that 300V limit or not. As the person told you, it's not all that common, but also not totally unheard of to go higher... and unless Cayin tells you for sure, you'd be potentially sacrificing the new tubes just to test it out.

John, what did you mean about sacrificing the tubes? I do know that I can use ECC 32 tubes with this amp as Andy confirmed that, and it says so in the manual. I was just wondering if the amp can take advantage of these tubes (whatever that means)?