[krisno]

Dear Head-fi users

Which are the top tube amp's for AKG K 701? Is a hybrid solution preferred b/c of need of power which transistors deliver the best?

Mapletree Ear+ HD - some says its the best, other say its nothing special

Woo Audio amps - these are said to be bright and therefor not much suited with the AKG's.

X-Can V8 - tried it, and it was good but lacked details.

X-Can V2 modded - tried it, was too bright, but not bad.

Which you recommend?

K

 

[punk_guy182]

I suggest you take a look at the Little Dot MK IV SE amp. It delivers incredible detailed and warm sound for its price.

 

[Dept_of_Alchemy]

I like the LD amps with my K701 as well, tube rolling options are great with LD amps too so you can optimize the sound to your preference.

 

[dannie01]

Quote:

Originally Posted by krisno /img/forum/go_quote.gif Woo Audio amps - these are said to be bright and therefor not much suited with the AKG's.

I'm not agree with this, my WA6SE drive my K701 very well, never too bright but just with wonderful highs, detail, airy............You should try if you have a chance, hearing is believing.

Cheers

 

[tonsosnot]

Quote:

Originally Posted by Dept_of_Alchemy /img/forum/go_quote.gif I like the LD amps with my K701 as well, tube rolling options are great with LD amps too so you can optimize the sound to your preference.

I have not tried the Little Dot IV SE, but I would say that the LD Mk III does NOT do a great job driving the K701. It does a decent job, but the headphones need more. The Head-Direct EF-1 is much better than the LD Mk III for driving the K701s, but the EF-1 narrows the soundstage quite a bit.

 

[Uncle Erik]

The K-701 has a 62 Ohm impedance. Therefore, you have to use an amp with an output impedance of 62 Ohms or less. Otherwise, you'll have an impedance mismatch. If there's a mismatch, you'll lose power, it will unnecessarily heat the amp, and the amp will have poor control over the drivers.

Most OTL tube amps have an output impedance above 62 Ohms - they are not the best choice. Look for either a transformer coupled tube amp with a low output impedance or buy a solid state amp. Solid state always has a low output impedance.

 

[fdhfdy]

also want the answer to the question.

 

[flatmap]

I tried my K-702's with Big Poppa's Dark Voice 336 SE amp at a recent gathering here in Seattle. That was a very nice match. Good rich tone and bass sound. It seemed like a well built component. Not expensive.

 

[gonzalo]

My 701's + EF 1 Head direct with a sylvania tube, really niiiiice

 

[rjoseph]

A Question to Uncle Erik, I have a K501 and am using a Little Dot II++ (with Mullard M8161) to amp it. I bought it recently and I find that the sound out of it is good. But I'm not familiar with the impedance and stuff and so I wanted to check with you if I have the right stuff. Since I dont have apples to compare the oranges with, I dont know if I'm listening to the right output. To me it sounds good and way better than the K501 unamped. Thanks.

 

[saintalfonzo]

Woo6 SE is a good match from my experience, and has a high and low impedance output. There is definitely no need for more power; the volume will never even see 12 o'clock on quiet albums, and there is no lack in low end response unless you are a basshead. Of course if you were you wouldn't own the K701.

 

[MrSlim]

Quote:

Originally Posted by rjoseph /img/forum/go_quote.gif A Question to Uncle Erik, I have a K501 and am using a Little Dot II++ (with Mullard M8161) to amp it. I bought it recently and I find that the sound out of it is good. But I'm not familiar with the impedance and stuff and so I wanted to check with you if I have the right stuff. Since I dont have apples to compare the oranges with, I dont know if I'm listening to the right output. To me it sounds good and way better than the K501 unamped. Thanks.

Typically in regular audio amplifiers, the output impedance is a factor of 10 or 100 lower than the impedance of the device connecting to it (a loudspeaker). The ratio is called the "damping factor" (see: Headphone amplifier - Wikipedia, the free encyclopedia for more info) The higher the damping factor, the better the amp will be at controlling the movement of the headphone (or speaker) diaphrams, giving you more accurate and controlled sound, especially in the bass, because of how much more the diaphrams have to move to produce the low notes. In the example on wikipedia, the Gilmore amp(if the output impedance is 1 ohm) had a damping factor of 32 but only when connected to the Grados. If you connected the K701's to it, the damping factor would be 62. meaning in the Gilmore amp would actually be able to control the K701's better than the Grado's.

Commercial headphone amps don't typically give the output impedance rating, they just give a suggested range of impedances (say 30-1200 ohms) that would work well with their amp . Of course "work well" is relative
If you look at AMB's website, he gives the output impedance of his amplifier designs.. For example the M3(http://www.amb.org/audio/mmm/), has an output impedance of 0.05 ohms.. meaning that if you ran the K701s with it, the damping factor would be something on the order of 1200.. meaning that it should be very good at controlling the K701's . The Beta22 has and output impedance of .01, with an equivalent damping factor of 6000.. a very good number... Of course that one of the reasons the Beta22 is so good..

Unfortunately as I mentioned above, not all vendors give you output impedance measurements to use for comparison purposes..

Just for fun, I just stumbled onto the Granddaddy of AMB's Beta22, which he called the B18 here: AMB β18 Stereo Headphone Amplifier
Notice that he has the output impedance rated at .2 ohms. See how far he has come with the Beta22, in improving the output impedance..

The bottom line is, if you like the sound, don't worry about it. It's not a reason to replace what you already like.. If it ain't broke, don't fix it..

JD

 

[KLJTech]

I'm getting very nice results driving my 701's with the Cute Beyond and Supplier. You also have the option to change out the stock Op-Amps from the OPA2227 (which sounds much better than it should) to the OPA267BP w/adapter for only $51 and enjoy even better sound. I've only compared the Cute/Supplier to the X-Can V8 (I really wanted to love this amp), the battery powered Grado (I also have Gold 325i's) and two different Creek units. There are a lot of nice amps out there, some with a tubes some without, try as many as you can and you'll find a nice match that you enjoy.
Good luck!

 

[jpstereo]

I tried the LD MKIII but I was not happy with the results. Believe it or not - the Lunch Box Pro is superb with my K701s. Too bad it is out of production!

 

[OutdoorXplorer]

Quote:

Originally Posted by dannie01 /img/forum/go_quote.gif I'm not agree with this, my WA6SE drive my K701 very well, never too bright but just with wonderful highs, detail, airy............You should try if you have a chance, hearing is believing. Cheers

Quote:

Originally Posted by saintalfonzo /img/forum/go_quote.gif Woo6 SE is a good match from my experience, and has a high and low impedance output. There is definitely no need for more power; the volume will never even see 12 o'clock on quiet albums, and there is no lack in low end response unless you are a basshead. Of course if you were you wouldn't own the K701.

These are positive feedbacks that I need. My WA6SE is due for delivery in Mid May and I would expect to hear the same. I kinda have lesser favorable experience with my earlier WA6 Maxxed though. I guess that I have made the right choice in opting of a WA6SEM.