[Palantiri7]

Ah yes, I'm sticking my neck out with my presumptuous self to put up a thread, as I need a little help.

I've got a LD Mk II with stock tubes running an AKG K701. The tubes bring this headphone to life. The problem is that at loud levels, the deep bass stops getting louder, and the sound starts to become sort of 'compressed'. I know it's not the fault of the 'phones as they can definitely scale up with a NAD C352 pushing them. Unfortunately, the NAD makes the k701 sound dry, and the midbass dries up. So, I was wondering, will replacing the stock tubes help? Or do I need a more 'powerful' tube amp? Or, is it possible that there is a SS amp out there that can reproduce a 'tubey' sound? Long ago I read (in Stereophile) that some amps operating in class A can sound 'tubey' like the Pass Labs Aleph 3, which isn't a headphone amp, of course. Anyway, any advice, thoughts, reprimands about not doing a proper search before posting, etcetera etcetera, would be gratefully received. Thanks.

Rory

 

[HeadphoneAddict]

Take a look at the Purity Audio K.I.C.A.S. Caliente - Sklylab has a great review of it http://www.head-fi.org/forums/f5/rev...ne-amp-329643/

And another review done with K701 and the Caliente here: Review Purity Audio Caliente Headphone Amplifier - Head-Fi: Covering Headphones, Earphones and Portable Audio

If I didn't have amps coming out the Wazoo, I'd already have bought one

 

[breakfastchef]

I would sugest rolling tubes as a starting point. Much less expensive than buying new amps. Read through the MKII and MKIII review threads for tube options and opinions. When I sold my MKII, I had rolled the power tubes to 6H6N - И and the driver tubes to Mullard 6QC6/CV1312. This paired well with HD650's.

 

[Palantiri7]

Thanks very much!

 

[Uncle Erik]

Sounds like your amp is clipping. You need a more powerful amp, not necessarily solid state. A less powerful solid state amp will clip, as well.

 

[jcx]

there is some evidence that the main determinants of an amp's "sound" are the frequency response and output impedance - when not clipping

it is usually the case that ss amps are flatter in frequency response and have lower output Z than tube amps so it is relatively easy to modify ss amps in the direction of tube amps:

"the Carver Challenge"

diyAudio Forums - Blind Listening Tests & Amplifiers

which suggests nulling a higher power ss amp against your preferred tube amp at levels where the tube amp isn't clipping - although the ss amp's sound may still diverge from what you liked about the tube amp at higher volume levels simply due to Loudness-Curve changes in perceived frequency balance

 

[Dash]

Quote:

Originally Posted by jcx /img/forum/go_quote.gif there is some evidence that the main determinants of an amp's "sound" are the frequency response and output impedance - when not clipping it is usually the case that ss amps are flatter in frequency response and have lower output Z than tube amps so it is relatively easy to modify ss amp's in the direction of tube amps: "the Carver Challenge" diyAudio Forums - Blind Listening Tests & Amplifiers

Awesome read. Great stuff. Thanks.

 

[Palantiri7]

Thanks for digging up the "Carver challenge". Yes, the tube amp seems to be clipping. I have a new pair of power tube upgrades on the way, whether they will make a difference or not, I'll see. Well, I was sufficiently impressed with the reviews of the Purity Sound Caliente (thanks HeadphoneAddict) so I'll be looking into one for the K701. Thanks everybody, and I'll keep you posted.

 

[sclamb]

Don't forget the Shanling PH-100. It has a nice warmth to it that really makes the K701s shine. It drives them especially well.