[humpty1]

Hi from a new member who has been lurking here for a little while and has read about every post I can find on low impedance cans. So to my request for help and I hope someone with expert knowledge here can help and apologies for the long post.

I have a very recently purchased Little Dot Mk2 that was chosen before I had researched properly, anyway it arrived and transformed the sound of my vintage Sennheiser HD424X (expected as I now know due to high impedance) however I had already ordered Quad ERA1s which are 20 ohms/94db and everything I have since read says they are not recommended or compatible and the sound will be much less than they are capable of. So I wasnt expecting much when I connected them up but surprise surprise they actually sound really nice to me with the LD, which now has about 50 hours total on the tubes. No hiss, plenty of volume....too loud at 50-55% on the knob. Only small niggle is bass is a bit loose. Is this the only shortcoming or am I missing something else? Some posts by David on the Little Dot forum say the Mk2 has suffuicient power for 20 -25 ohm cans. Should I stick with it or return and go solid state and if so will I get a worthwhile improvement.

One last question. The amp gest too hot to touch is that normal. I was expecting warm to hot but not quite so extreme

Help and recommendations will be gratefully received

 

[tomb]

Tube amps get hot.

An amplifier with high output impedance driving low impedance headphones will lose control over bass frequencies. That is the primary effect of an impedance mis-match (low damping factor).

 

[humpty1]

Tube amps get hot.

An amplifier with high output impedance driving low impedance headphones will lose control over bass frequencies. That is the primary effect of an impedance mis-match (low damping factor).

Thanks Tomb, appeciate the response. Will get a solid state amp and give that a try for comparison. still a little surprised at quite how hot the amp body gets and yes I did expect the that but not as hot as it does get

 

[ProtegeManiac]

Hi from a new member who has been lurking here for a little while and has read about every post I can find on low impedance cans. So to my request for help and I hope someone with expert knowledge here can help and apologies for the long post.

I have a very recently purchased Little Dot Mk2 that was chosen before I had researched properly, anyway it arrived and transformed the sound of my vintage Sennheiser HD424X (expected as I now know due to high impedance) however I had already ordered Quad ERA1s which are 20 ohms/94db and everything I have since read says they are not recommended or compatible and the sound will be much less than they are capable of. So I wasnt expecting much when I connected them up but surprise surprise they actually sound really nice to me with the LD, which now has about 50 hours total on the tubes. No hiss, plenty of volume....too loud at 50-55% on the knob. Only small niggle is bass is a bit loose. Is this the only shortcoming or am I missing something else? Some posts by David on the Little Dot forum say the Mk2 has suffuicient power for 20 -25 ohm cans. Should I stick with it or return and go solid state and if so will I get a worthwhile improvement.

One last question. The amp gest too hot to touch is that normal. I was expecting warm to hot but not quite so extreme

Help and recommendations will be gratefully received

At 94dB/1mW sensitivity that isn't high enough to immediately bring up the tube noise floor. They could still be getting an EQ effect from the high output impedance depending on the drivers, but some people deliberately do that because EQ's are sacrilege but problematic measurements are not.

Tube amps do get hot but that could be due to the very low impedance. Like how speaker amps tell you not to use an effective 2ohms load (ie either 2ohms or two 4ohm voice coils in parallel) if you have bridged channels on a car amp or not to use 4ohm speakers on some home receivers. Hard to tell either way unless you get each component temp and compare it to what those temps are safe to operate at, like putting thermal couplers on the VRMs on a motherboard or graphics card to check if that stable overclock isn't just slow cooking your board.

 

[PurpleAngel]

A ($60) FiiO A3 solid state headphone amplifier has a low output impedance.
JDS Atom or Schiit Magni if you want to spend more.

 

[humpty1]

At 94dB/1mW sensitivity that isn't high enough to immediately bring up the tube noise floor. They could still be getting an EQ effect from the high output impedance depending on the drivers, but some people deliberately do that because EQ's are sacrilege but problematic measurements are not.

Tube amps do get hot but that could be due to the very low impedance. Like how speaker amps tell you not to use an effective 2ohms load (ie either 2ohms or two 4ohm voice coils in parallel) if you have bridged channels on a car amp or not to use 4ohm speakers on some home receivers. Hard to tell either way unless you get each component temp and compare it to what those temps are safe to operate at, like putting thermal couplers on the VRMs on a motherboard or graphics card to check if that stable overclock isn't just slow cooking your board.

Thanks, I have decided to return the LD to Amazon and am considering a big step up in price and getting a Quad PA One as I like the tube sound. In the meantime I have ordered a Musical Fidelity MX-HPA at ~ half retail price to try as I can feed it with the XLRs from my Azur 851N and my power amp from the RCA`s. This might be an interim solution if I can get a PA One to demo

 

[humpty1]

A ($60) FiiO A3 solid state headphone amplifier has a low output impedance.
JDS Atom or Schiit Magni if you want to spend more.

Appreciate the suggestions. To try and keep the tube sound I am attracted to the Schiit Lyr 3 or Mjolnir but UK price is a bit high vs $ prices. I have colleagues in the US so may get them to order and bring to me in the UK when they are next over.....unless I have persuaded myself to get a Quad by then

 

[buke9]

Appreciate the suggestions. To try and keep the tube sound I am attracted to the Schiit Lyr 3 or Mjolnir but UK price is a bit high vs $ prices. I have colleagues in the US so may get them to order and bring to me in the UK when they are next over.....unless I have persuaded myself to get a Quad by then

I like my tubes as well and I would recommend you not the Lyr3 and if you can swing it the Mjolnir is a much better amp in my opinion and one of the few Schiit amps that I like a lot other than the new Ragnarok which is another story.

 

[humpty1]

MF MX-HPA arrived and sound from the Quads is way better than the Little Dot. Very happy! just want to try balanced interconnects anf balanced headphone cable next but cant seem to find one for the Quads by googling...help please on this last point