[Asr]

Quote:

Originally Posted by Ferbose I would like to know if your unit produces any background hiss with a more sensitive headphone like Grado. Mine used to produce pretty loud hiss with SR225, but now I use some low-noise tubes (GE JAN 5751, Japanese 12AU7, Japanese EL84) and the hiss is very low level, like tape hiss heard on remastered CDs. Triode mode driving K1000 gives me a pure tone that is pure magic, as of today. Tomorow I will A/B it against HE90/ES-1 and tell you if I still think so highly of HA-1A/K1000.

Sorry for a delayed response to this, I forgot my ATH-ES5 at work again yesterday.

Anyway I do hear some background hiss with the ES5, regardless of which lower-impedance setting I use (6-32, 32-64). It was noticeable right away too, didn't even need to listen closely for it.

How much did your replacement tubes cost? I might go for those too.

 

[Ferbose]

Quote:

Originally Posted by Asr Sorry for a delayed response to this, I forgot my ATH-ES5 at work again yesterday. Anyway I do hear some background hiss with the ES5, regardless of which lower-impedance setting I use (6-32, 32-64). It was noticeable right away too, didn't even need to listen closely for it. How much did your replacement tubes cost? I might go for those too.

Like a guitar amp, the first tube (12AX7) affects noise level the most.
I would recommend oder 12AX7 and 12AU7 from Tube depot, and choose the low noise and microphonics option for only $4 more. They will hand select the quietest tube for you. Among all the 12AX7 tubes I have tried (Ei, Grove Tube Mullard reissue, Chinese C8, Chinese C9, JJ, Sovtek LPS, used Raytheon, EH), I like Sovtek LPS the most. But I found used JAN GE 5751, an 12AX7 alternative (70% gain, softer tone), to be better with Cayin HA-1A (but not in my other amp).

Tube depot still sells quite a few 12AU7 NOS tubes with alternative names. They are inexpensive and worth trying. I have Sylvania 5963, Philips 6189, JJ 12AU7, Ei Gold Elite 12AU7 and Japanese 12AU7 branded Channel Master. I like the Japanese tube because of its low noise, and it was only $11 used from Coherent Audio.

EL84 cost more and I have only tried EH, JJ, Sovtek and NOS Japanese labeled Marconi Radiotron. I like Janpanese the most.

Japan made a lot of OEM tubes in the 70's for US and Europe. Some people think Japanese tubes can't compete with American and Western tubes of 50's and 60's. Some say Japanese tubes have low noise but sound sterile. In my limited experience I find Japanese tubes really good and reasonably priced. After all, Japan has been making tubes since 1930's, and by 40's has the technological capability to attack Pearl Harbor.

Anyway, once you install some selected low-noise preamp tubes noise should go down a lot. No company I know sell low-noise EL84, but Ei Gold Elite should be pre-selected for low noise already.

 

[Piotr Ryka]

"install some selected low-noise preamp tubes noise should go down a lot"

Another way is to get some CD with high voltage outputs, like Wadia (4.25V) or Audio Aero Capitol (6V). Also most of standard 2V CD's could be change to higher voltage, but only very good electronic specialist can do that, although ussually it is only to change of few rsistors question.

 

[Gradofan2]

What am I missing here?

Isn't the real question simply... should any $750+ tube amp have any noise whatsoever? Not... which tube combinations can you select that will have the lowest noise and best sound qualities!

I've had the WooAudio 3 (all tube), and the XCAN v3 (tube/ss hybrid), which are both outstanding amps at almost 50% of the price of the HA-1A, and I've read the reports of many others in this price range - and, guess what - they have absolutely no noise with any tube!

What's the point in "futzing" around with tube selection, if the amp has inherent noise in it's circuit design / components? Why not just send it back to the distributor for a refund, and get a better amp - that has no noise???

And... to all those other Cayin HA-1A owners - do your amps also have noise with low impedence phones? If so... that should tell us a story shouldn't it?

Can it really be this complicated?

GF2

 

[Piotr Ryka]

Gradofan

Believe me, there is a long qality distance between MF V3 and Cayin HA-1A, so MF V3 is no so outstanding as You think.
Self noise is in all amplifiers and even very expensive and famous devices, particulary tubes ones, have this problem.

 

[Gradofan2]

Then why can't you hear it in them with any headphone?

You may want to get a WooAudio 3, or an XCAN v3 (with the PinkFloyd mods), or a Singlepower and see what I mean.

There have been multiple reports of noise in the HA-1A - and it shouldn't be there.

But... to each his own...

GF2

 

[Piotr Ryka]

Quote:

Originally Posted by Gradofan2 Then why can't you hear it in them with any headphone? You may want to get a WooAudio 3, or an XCAN v3 (with the PinkFloyd mods), or a Singlepower and see what I mean. There have been multiple reports of noise in the HA-1A - and it shouldn't be there. But... to each his own... GF2

So get headphones and switch attenautor to 80 percent without signal and You see if is there any noise or not.

 

[Gradofan2]

There's absolutely no noise, hiss, or hum at 0% attenuation (or max output) through the HD6XX's, or RS-1's, in the WooAudio 3, and XCAN v3... or I suspect the Singlepowers, or Raptor, or, Mapletree, or...

I'm referring to the background noise with no music playing (i.e. no signal, or between tracks), not the tape hiss in the soundtrack - which is there, more or less, with all, recordings on all amps - tube or SS.

Or... are you referring to the S/N ratio with a signal - obviously, all amps will reproduce the noise inherent in the recording - some amps and headphones just repress the noise relative to the signal better than others. I understood you to be referring to the inherent noise in the amp, not the recording.

Anyway... all of the amps I refer to above sound exceptional in all respects.

But... whatever... "to each his own."

Good luck in resolving / coping with the noise in the HA-1A.

GF2

 

[Piotr Ryka]

Noise in Cayin HA-1A is not my problem.

 

[Piotr Ryka]

Another, but not cheap, solution to avoid tubes self noises is to buy PS Audio conditioner and adjust voltage on a bit low level than 110 or 220V.

 

[bluemeteor]

I agree.

Should a $750 amp have tube noise?

Unless.....

Its not a $750 amp, its a $300 amp sold in China with a $500 mark up here in the USA. So, I wonder - How does this stack up to Little Dot, Ming Da (which I love with My Grados) and BADA?

Its $399 on NY Sound

 

[Piotr Ryka]

"Should a $750 amp have tube noise?"

Probably as result of employment low-cost tubes and plastic tube sockets.

 

[Ferbose]

It is entertaining to see all this criticism on Cayin's noise when the basic principle of loudness and noise has been overlooked.
Recognize this first, Cayin HA-1A is able to pump 1.5 W into 120 ohm load and therefore drive AKG K1000 to 105 dB SPL.
When the headphone amp delivers 1 V (RMS) signal into different headphones, let's see how loud they will sound:
Senn PX-100, quite efficient (32 ohms impedance, 114 dB/mW sensitivity): 129 dB
ATH-ES5, quite efficient (32 ohms, 109 dB/mW): 124 dB
Grado SR225, medium efficiency (32 ohm, sensitivity published incorrectly): my guess is about 115 dB
AKG K501, very inefficient (120 ohms, 94 dB/mW): 103 dB
AKG K1000, speaker-like inefficient (120 ohms, 74 dB/mW): 83 dB
Therefore PX-100 is 46 dB more efficient than K1000. Have you ever seen any speaker 46 dB more efficient than another speaker (like 64 dB vs 110 dB at 1W/1m)?

Now we see HA-1A can drive K1000 to 105 dB SPL. A good tube amp will have about 95 dB S/N ratio. This means self-noise with K1000 will be 10 dB SPL, which is totally inaudible (house ambient noise is around 40 dB SPL). With K501 (20 db more sensitive), noise would be 30 dB SPL, basically inaudible. With PX-100 (46 dB more sensitive than K1000), self-noise will be 56 dB SPL, or very audible. Listening to K1000 vs PX100 on the same amp is like listening to a speaker from 10 feet away vs 0.6 inch away, is it so suprising that in the latter case you will hear noise?

A juicy headphone amp generally delivers 100 mW into a 60 ohm load, while HA-1A delivers 1.9 W, which is 13 dB higher and would fry any Grado on the fly. As such, a normal tube heapdhone amp with 95 dB S/N would likely produce 38 dB SPL of idle noise on ATH-ES5, which is likely inaudible. At my home, idle noise of HA-1A/K501 is basically inaudible, which is ocnsistent with HA-1A's specification. Comparing the level of self-noise on an ordinary tube headphone amp to HA-1A is like comparing the noise of a 20W tube amplifier to 380W monstrous tube amp for speakers. Does anyone criticize a 380W tube amp just because it is noisier than a 20W tube amp? When you amplify the signal more, you also amplify the noise of the tube more--simple as that. If you want quiet amplification for all kinds of headphones, you need to go for solid state output device. Then again, only very few SS amp can make K1000 and Shure E4 both sound good, because the efficiency is too different.

Cayin HA-1A is not for ultra-protable headphones like PX-100 or earbuds. Cayin HA-1A is good for full-size cans that really shine when the amp has tons of power in reserve. For a Grado (they don't publish sensitivity correctly), with low-noise tubes I could get the hiss to be benignly low, almost like tape hiss heard on remastered CDs. For rock and pop music, the dynamic range is pretty low so there is no need for concern. It is possible that some HA-1A units will be a few dB lower in noise than my unit (recall that 3 dB lower is half as loud), or people's hearing threshold may be different. Regardless, you just can't expect to hear blackness when you connect a sensitive headphone to an amp that can drive speakers, when the output device is the vacuum tube.

 

[adhoc]

Quote:

Originally Posted by Ferbose ...

Great post Ferbose.

Took the words right outta my mouth.

 

[Gradofan2]

OK... that does make sense. Although I believe the XCAN v3 and Woo Audio 3 both have about 1 watt output into 100 - 300 ohm phones. That's still a lot less than the Cayin - which may explain why they have no audible noise.

So what can be done about it to allow use with Grados - and... avoid the noise with Grados - if anything? Perhaps, it's just an amp for phones with higher impedence?

Can an impedence adapter be used to increase the impedence of the Grados from 32 ohms to about 100 ohms? That is... just buying a Grado 1/4 to 1/8 inch adapter, cutting off the 1/8 inch plug, and inserting two 50 to 100 ohm resistors in line and teminating with a 1/4 inch Cardas plug.

Would that help to eliminate the audible noise with Grados?

Would that cause any deterioration in their sound, or harm them?

Otherwise... I assume you just have to accept the audible noise, or limit yourself to high impedence phones.

But, in any case I guess I shouldn't buy one, expecting no noise, or expecting to be able to eliminate it with tweaks - right?