Just swapping out tubes for other ones and seeing how it changes the sound (usually for the better obviously).  

Tube rolling lets you change the voicing of the amp to compliment the headphone.

OTL amps can and do sound really good with the 70x. You can't go cheap though as mentioned. I've used an otl amp with the 701s for about 5 years. Output impedance is low (20 ohms) and .5 w output drives them very nicely.

Quote:

Originally Posted by Happy Camper 

Tube rolling lets you change the voicing of the amp to compliment the headphone.

 

OTL amps can and do sound really good with the 70x. You can't go cheap though as mentioned. I've used an otl amp with the 701s for about 5 years. Output impedance is low (20 ohms) and .5 w output drives them very nicely.

Which OTL amp was this?

Quote:

Originally Posted by brasewel 
Cheap tube amps in general sound bad through any headphone since they sound "tubey". Most tube amps under $500 sound tubey to me so listening to a similarly priced tube amp will sound atrocious. I haven't heard a SS amp that beats the synergy good tube amps have with the K701 IMO.
 

Except the person I was quoting was suggesting the user purchase $300 tube amps, which from my own experience are definitely in the "poor sound quality" range of synergy with the AKG 70x. In that price range, nothing surpasses the CanAmp. While I do suspect high quality tube amps, in the $500+ may present a different story, I have not yet experienced any such setups yet and thus cannot speak about them.

the dynalo and m^3 are easily superior to the canamp.

Quote:

Originally Posted by dcpoor 

the dynalo and m^3 are easily superior to the canamp.

Yes and they're more expensive and both DIY. There are plenty of SS amps under $1k that are superior to the canamp.

they can be often purchased used in the FS/FT forum in the same price range. dynalo for <$300, M^3 for <$400

Quote:

Originally Posted by menchi 

Except the person I was quoting was suggesting the user purchase $300 tube amps, which from my own experience are definitely in the "poor sound quality" range of synergy with the AKG 70x. In that price range, nothing surpasses the CanAmp. While I do suspect high quality tube amps, in the $500+ may present a different story, I have not yet experienced any such setups yet and thus cannot speak about them.

 

I had Heed Canamp and it sounds worse then Trends Audio for example. Trends isn't OTL amp but hybrid with 2x mosfets and single 6DJ8 or 12AU7 tube. (TBH both tube types can't drive 701's very loud but PCC88 [6DJ8 equivalent with +1V] does quite well but quality wise 12AU7 rocks)

First: I used the search function (that's how I got here) and besides from a vague comment from U. Erik saying that impedance is very complex which didn't really help, I got no answers.

So: I guess we could say, at least in the world of high-end cans, that 62 Ohms are low, right? Even in this thread someone commented that.

So why is it that they are so amp-needy? Why can't an iPod drive these things properly? I'm not asking for wonders in sound, but 62 Ohms are 62 Ohms! I'm not saying that their volume is low, because I know that has to do with the sensitivity, which is low in the K701's case, but that apparently they need a 600 Ohm suitable-amp to drive these things, which would give you an impedance mismatch of 90%. Please consider I am not saying that their sound is good or bad through low-imp amps, but that they get recommended amps that are suitable for headphones with about 10x the K701's impedance.

I'm sorry, I must sound arrogant and bitchy right now, but I have searched and read extensively on impedance and only found out that a lot of people quote the same thing over and over without explaining it, that even when you thought you finally got it you didn't, aaaaand that electronics are freaking annoying. I am seriously considering in converting to that kind of people that believe this is all magic.

PS: my apologies to U. Erik, this is simply me being annoyed at understanding that everyone else finds obvious.

I use my K 701 with a matrix m stage with wonderful detail a litle light on bass but overall teriffic They sell on ebay and used here for very little 100+$ Real value

Ok, I have seen some posts about coupling the K701 with the M Stage, I'm checking it out right now. But I was asking if anyone could explain the science behind the need for a high-imp amp for a low-imp can.