[Shane D]

Hello Shane...

Been a awhile since I have posted....

But wanted to say that I am listening to my beloved Jazz this evening with the MK9 and a 12SL7GT RCA driver that I obtained from Brent Jesse for $5 (he sold me 4x for $20 plus a modest postage fee).

KaZow!

Sounding incredibly great in the ZMF Aeolus cans

Cheers and long live, our LD MK9's!!

~~JV~~

I was wondering what happened to you after my last post.

I have rearranged my audio rack and now the MK9 is a bit noisy. I suspect that the amp is too near the power bar and needs to be moved around.

I need to do more tube listening in the next few weeks.

 

[JazzVinyl]

I was wondering what happened to you after my last post.

I have rearranged my audio rack and now the MK9 is a bit noisy. I suspect that the amp is too near the power bar and needs to be moved around.

I need to do more tube listening in the next few weeks.

I thought your rack had changed in seeing a few recent photos. AC hum / buzzing is what your getting?

 

[Shane D]

I thought your rack had changed in seeing a few recent photos. AC hum / buzzing is what your getting?

When you pause the music and raise the volume, there is a hum.

 

[JazzVinyl]

When you turn the music off and raise the volume, there is a hum.

Try running a wire attached to a screw on the top deck to the ground in your AC strip.

 

[JazzVinyl]

Mine is still doing fine, with the external DC power supply for driver heat (and to power the fan).
I did have to run a ground wire from the ps chassis, down to power strip ground to ensure total silence.

 

[Shane D]

I have been using this amp for a few days and wanted to mention an issue that I have come across. I posted this in the iBasso SR2 thread. These headphones are only 16 ohm, which is, I think, the problem.

First I should backtrack and state that my Little Dot MK9, right from the start, has had some hum. But only when you pause the music and max the volume.

I decided to ensure that I had taken all possible steps and so I changed all the tubes, checked that the amp was on low gain, moved the gear around to try to isolate the amp, plugged the amp into a different outlet and even tried it in my office system.

With these headphones, I can even hear the hum between the songs using this amp at a low volume. I will have to quit using this amp with the SR2's.

 

[jonathan c]

I have been using this amp for a few days and wanted to mention an issue that I have come across. I posted this in the iBasso SR2 thread. These headphones are only 16 ohm, which is, I think, the problem.

First I should backtrack and state that my Little Dot MK9, right from the start, has had some hum. But only when you pause the music and max the volume.

I decided to ensure that I had taken all possible steps and so I changed all the tubes, checked that the amp was on low gain, moved the gear around to try to isolate the amp, plugged the amp into a different outlet and even tried it in my office system.

With these headphones, I can even hear the hum between the songs using this amp at a low volume. I will have to quit using this amp with the SR2's.

The SR2 16-ohm impedance seems to be the issue. From the LD Mk 9 specifications sheet:

The “output impedance” of 32 ohms - 600 ohms relates to the headphones to be used with LD Mk 9.

 

[Shane D]

The SR2 16-ohm impedance seems to be the issue. From the LD Mk 9 specifications sheet: The “output impedance” of 32 ohms - 600 ohms relates to the headphones to be used with LD Mk 9.

I figured that I when I tried them, they were a little low, but sounded OK at first. But after a few days, it was like "Roh Roh". Live and learn.

 

[Shane D]

The SR2 16-ohm impedance seems to be the issue. From the LD Mk 9 specifications sheet: The “output impedance” of 32 ohms - 600 ohms relates to the headphones to be used with LD Mk 9.

That was actually a big relief for me. I thought the amp was going to crap!

On a more serious note, do any of your amps hum if you jack the volume with no music playing?

 

[JazzVinyl]

@Shane D

My MK9 is silent w/music paused and volume at max.
But...I only use the ZMF Aeolus (300 ohm) with it. I am also heating the driver with clean DC current. I have run the driver with the internal 6.3v of AC and it was also okay (no hum).

When I first added the DC power supply for Driver heat...I did have some hum. Added a ground wire from the DC power supply chassis to power strip ground and that cleared it up.

Would recommend you try it. Just attach a wire (speaker wire...anything) to the ground of your power strip and try touching the other end to a screw on the top plate that the board (underneath) is screwed into.

Almost always...hum is from a "non clear path to ground". Ground meaning the Earth...literally the ground beneath your feet when outside...terra firma.

Higher impedance headphone and the ground wire....worth a go.

Let us know what happens.


.

 

[Shane D]

@Shane D

My MK9 is silent w/music paused and volume at max.
But...I only use the ZMF Aeolus (300 ohm) with it. I am also heating the driver with clean DC current. I have run the driver with the internal 6.3v of AC and it was also okay (no hum).

When I first added the DC power supply for Driver heat...I did have some hum. Added a ground wire from the DC power supply chassis to power strip ground and that cleared it up.

Would recommend you try it. Just attach a wire (speaker wire...anything) to the ground of your power strip and try touching the other end to a screw on the top plate that the board (underneath) is screwed into.

Almost always...hum is from a "non clear path to ground". Ground meaning the Earth...literally the ground beneath your feet when outside...terra firma.

Higher impedance headphone and the ground wire....worth a go.

Let us know what happens.


.

Most of my headphones are very efficient. The HiFiman's are dead quiet.
I am a quiet listener so the volume, in low gain, never goes much past 9:00.

The SR2's really exaggerated the problem, but I will think it fine now.

If I had to run a wire I would just sell it.

 

[jonathan c]

That was actually a big relief for me. I thought the amp was going to crap!

On a more serious note, do any of your amps hum if you jack the volume with no music playing?

Not really. I have everything plugged into a filter / surge suppressor / wall unit separate from computer / wireless router / etc. On the Woo Audio WA6 (Gen-1, OTC), with the volume at maximum (5 o’clock) there is a faint hum. At normal levels (10-11 o’clock) with WA6, no hum.

 

[Shane D]

Not really. I have everything plugged into a filter / surge suppressor / wall unit separate from computer / wireless router / etc. On the Woo Audio WA6 (Gen-1, OTC), with the volume at maximum (5 o’clock) there is a faint hum. At normal levels (10-11 o’clock) with WA6, no hum.

Mine is about the same.

 

[JazzVinyl]

@Shane D

Most tube amps do suffer from a bit of hum.

I do realize it is irritating for someone to say they have silence when you do not. The ground wire is simple/easy and will instantly tell you if it can be completely eliminated, or not. It does not indicate a design flaw. It is just the nature of the very analog method of amplification, employed in a tube amp.


Cheers

 

[Shane D]

Well, another surprise with my LD MK9. I have a new set of planar's that I am playing with across the amp collection. These guys do like power, but are not power hogs like the HE6se V2's. Results have been up and down:

1) iFi Pro iCAN was good.

2) Violectric V220 was really good, until it became pretty horrible. Pretty warm amp with very dark headphones did not work out.

3) Went back to iFi and adjusted gain, bass boost and especially 3D effects to hit a new high in performance!

4) RebelAmp just does not have the juice for these. It cannot do them justice, IMO.

5) My last pairing was the Little Dot MK9 and I really wasn't expecting much. I switched the amp to high gain and it was still pretty underwhelming. But then I looked next to it and realized that I had forgotten that I had the Schiit Loki in this chain. So I flicked it on. Right away the higher gain is helping. And all four bands were already set at higher levels. Wow, the sound was now rocking. Volume stays between 5 and 6 on the dial. The bass is even stronger (which was already their strong point), the mids are pretty great and you can actually feel a bit of air up high. Very nice!

(Background)
The headphones are planar's called Bee's from a small one man company called Nectar Sound, down in Georgia. The owner makes each set by hand. They are Very dark. His specialty is electrostatic headphones. They were WAY too dark for me in the first couple of days, but have opened up since. Or my brain has made Major adjustments. Find out this weekend with I go back to A-B'ing the headphones against their competition.
(/Background)

Anyway, what I wanted to say is that this amp is competing with my iFi Pro iCAN, with some EQ help, to make these cans sing. I Never saw this coming. Very nice surprise!

I am actually going back forth between the iFi and MK9 and they both sound great in different ways. iFi is cleaner, but the MK9 feels bassier/fuller, because of the EQ.

You can check out the headphones here: https://nectarsound.net/about-the-headphones/

They are 11 Ohm headphones and he recommends a minimum of 1.3W per channel, but says they will do better at 3-7W per channel.