Tube Amps with D7000 - No go?
Oct 1, 2011 at 12:42 PM Post #16 of 42
Uncle Erick, how would you say the Smack compares to my X-CANV8P (that is if you have heard the X-CANV8P)? I've been eyeing them up for a while and was unsure if they are worth it. If it easily beats out my X-CANV8P then I'll have to give it a try. I'll have no trouble in building it at all so there's no issue there.
 
But OP if you go OTL with such low impedance headphones then you're going to get a mushy sound. The bass becomes too pronounced and also gets very flabby. Midrange is overly colored and highs roll considerably.
 
Quote:
I would not use a 25 Ohm headphone on an OTL. All of them (save for the Zana Deux) have output impedances higher than the headphpne impedance. Look up "damping factor" for a better explanation.

You will want an amp with output transformers to get a nice, low output impedance.

I'd consider the Bottlehead Smack. About $500 and Bottlehead is terrific. Some assembly required, but get an iron and tellmyourself that you can do this. It comes with all the parts, instructions, and Bottlehead has a forum where you can get help. You can do it.

Bonus: you'll learn how to build and will be able to make anything you want on the cheap.

 
 
Oct 1, 2011 at 1:32 PM Post #17 of 42
I'm thinking I'll have a go with the Schiit LYR, since its made to take headphones with 8-600 Ohm, so it should be good for my purpose - It'll have an excess of power though...Even more so than my current iBasso PB2 rig. I'm also thinking about getting all of their Schiit (See what i did there? :) and getting the Bifrost DAC to go with it, and selling my current Cambridge Audio DacMagic, and use the LYR as a preamp for my speaker rig...
 
 
Oct 1, 2011 at 2:10 PM Post #18 of 42
I'd research a bit more about pairing the lyr with the headphones you listed in your original post. Many here, including myself, are finding the lyr to have a noise issue (hum)  with phones like the hf2 and denons. I pair my orthos and high impedence phones with the lyr and am very happy, but I would not use my hf2, denons, or dx1000 on my lyr.
Too much ground floor noise.
 
Oct 1, 2011 at 2:59 PM Post #19 of 42
The Lyr has a high gain factor of 10 which I almost sure that some of the sensitive IEM's is going to pick up a fair amount of the noise floor. I am using a gain factor of 4 in one of my Little Dots amps and it is quite plenty.
 
Oct 1, 2011 at 3:24 PM Post #20 of 42
My brief experience with the D5000 was that I didn't care for it out of my WA22's SE port and I traded it away. Shortly before I sent it off I plugged it into the modest x-head SS amp, and then I tried to get out of the trade it sounded so much better.
 
Oct 1, 2011 at 9:10 PM Post #21 of 42
Earmax pro will work well with low impedance for an OTL design.  It modifies the Morgan Jones circuit by using feedback and this helps power into low impedance.
 
You can pick one up cheap from ebay, not the Earmax ones, but clones.  I subscribe to the theory that damping factor is not as crucial in headphone applications as they are in speakers, and the removal of the output transformer can give positives that outweigh the negatives of a lower damping factor.
 
Nevertheless, I use such a clone to drive my HD650, HF2 and D7000 and I love this little amplifier...almost makes me wonder about why the heck we pay such high prices when frankly, there is no need to.  The only headphone tube amps left in my collection are OTLs and hybrids - anything with output transformers were moved on.
 
Oct 1, 2011 at 9:46 PM Post #22 of 42
I liked those when i saw them but got turned off by the steep pricing for the low impedance version...It costs close to 900... Cant find any copies either.
 
 
Oct 1, 2011 at 11:29 PM Post #23 of 42
You can try something like this which is really cheap to see how you like a pure tube amp for the D7000s.  The problem I had with mating the D7000s with pure tubes was that all my other tube amps also hummed.  Getting a quiet tube amp that did not hum seemed like a risky affair considering the price of other more established tube amps.
 
Happy listening!
wink.gif

 
Oct 2, 2011 at 9:54 AM Post #25 of 42


Quote:
You can try something like this which is really cheap to see how you like a pure tube amp for the D7000s.  The problem I had with mating the D7000s with pure tubes was that all my other tube amps also hummed.  Getting a quiet tube amp that did not hum seemed like a risky affair considering the price of other more established tube amps.
 
Happy listening!
wink.gif

Have you tried that amp? It looks decent, but i wouldn't want something with a ton of background hum etc. And it says for 32-600ohm so it may now cope well with low impedances?
 
 
 
 
Oct 2, 2011 at 11:49 AM Post #26 of 42
Yes I have heard it.  Dead silent with the D7000s.  My D7000s and HF2 never sounded better to me.  Helps out with the D7000 recessed mids.  Bass not the tightest, but very well textured and far from one note - helps tame the D7000 bass and shrill highs.  Noticeably the most transparent and detailed tube amp pairing with my D7000s by a very good margin.
 
What people don't realise about damping factor is that the DC resistance of the headphone coil is included with what the reactive load will see as the output impedance...a quick measurement of headphone resistances will illustrate why damping factor for headphones might be moot.
 
Enjoy. 
wink.gif

 
Oct 2, 2011 at 1:12 PM Post #28 of 42


Quote:
Yes I have heard it.  Dead silent with the D7000s.  My D7000s and HF2 never sounded better to me.  Helps out with the D7000 recessed mids.  Bass not the tightest, but very well textured and far from one note - helps tame the D7000 bass and shrill highs.  Noticeably the most transparent and detailed tube amp pairing with my D7000s by a very good margin.
 
What people don't realise about damping factor is that the DC resistance of the headphone coil is included with what the reactive load will see as the output impedance...a quick measurement of headphone resistances will illustrate why damping factor for headphones might be moot.
 
Enjoy. 
wink.gif


It doesn´t seem to be moot. I use the DX 1000 and ED 8 with my Trafomator Head One. Has 30/100/300 ohm selectors. Works fine no hiss at all.  However if I select 300 ohm for the ED 8 it totally dies. 100 ohm is still quite okay though. 
 
Taking the LCD-2 (orthos are supposed not going to need any damping factor) I can´t discern any difference at all between the settings on a quick listen.
 
 
Oct 2, 2011 at 10:00 PM Post #29 of 42


Quote:
It doesn´t seem to be moot. I use the DX 1000 and ED 8 with my Trafomator Head One. Has 30/100/300 ohm selectors. Works fine no hiss at all.  However if I select 300 ohm for the ED 8 it totally dies. 100 ohm is still quite okay though. 
 
Taking the LCD-2 (orthos are supposed not going to need any damping factor) I can´t discern any difference at all between the settings on a quick listen.
 


Damping factor or current limited?  Two separate issues, then again it worked OK for your 50 ohm LCD2s - not sure what the impedance and current requirements for the ED 8.  I can't say with absolute authority either way.
 
I did the same sort of experiment with my Cayin HA1A, it had a 4 position impedance switch from 25-600 ohms.  Using the K701 (60ohms) and HD650 (300ohms), it always sounded better with the switch all the way up to 600 ohms.  More clarity, better separation, staging and imaging.  Absolutely no difference in bass control as far as I could perceive, with the lower settings always sounding more like an extra component in the signal chain.  I was probably able to get away with this because the Cayin HA1A had the sheer current capability to supply 2 watts per channel into an 8 ohm load.
 
The point was for headphones - using an amplifier with an output impedance of 1 ohm for a HD650 which has a passive resistance of well over 200 ohms (can't remember, but I measured all my headphones when re-terminating for balanced operation) would effectively yield an output impedance of well over 200 ohms.  It makes sense for speakers which may have a passive resistance of just below 8 ohms but can fluctuate wildly to many multiples of 8 ohms, and high reactive EMF due to higher physical forces of inertia of which when compared to headphones, headphones have much less of - by far.
 
When it comes to OTLs perhaps the problem is more to do with current capability more so than damping factor.  Which is what the transformer is primarily for, converting voltage into current.  When it comes to the D7000, I reckon the Alex Cavilli modified Morgan Jones circuit sounded ****** amazing.
 
 
Oct 3, 2011 at 7:49 AM Post #30 of 42
Hard time believing the ED 8 is that demanding regarding current then the LCD-2 I must say.
 

Users who are viewing this thread

Back
Top