Portable Amp to run a HD650

the general idea seems to be that the HD650 really needs a good desktop amp to show their full potential.

That's easy, i did it.  Triad Audio Lisa lll.  It is the only portable/home combo that will drive the HD650 IMHO.  I have used it at home with the power supply and taken it for my breaks at work with my HD650's over several years.  Only lately have i changed that due to buying a high end iem and portable phone that don't need that kind of drive.

The Lisa III isn't exactly "portable" though...maybe "transportable", but you certainly can't slip it into a pocket.  OP, I'll let you know once my Headstage Arrow gets here...seems like it might be decent enough, but I doubt it'll be anywhere near OTL tube amp levels of "decent".

i just tried my HD650's out of a PA2V2 just for the hell of it. absolute crappy combination. it clips and distorts waaaay before they get to a decent volume. i could tell right away that it didn't give them anywhere near enough.

maybe an amp with a 9 volt will be able to have enough of a voltage swing but the 2 rechargeable AA batteries in the PA2V definitely weren't cutting it at all.

glad i got a full size.

My old skool Headroom Total Airhead is actually fairly decent with them, believe it or not.  I mean, I can drive them to listenable levels without clipping or distortion.  They don't rock my socks off this way, but I can putter around the house this way.

You can put the Lisa in your coat pocket or the back pocket of jeans but otherwise no it is not the best portable due to size.  It helps with an ALO harness type set up.  The harness has L connectors out of the back and comes up and attaches to your ipod on top.

It is the one on the right, this is an old shot I had with an earlier ipod.  It is a bit big but it does drive the 650's.

How heavy is the Lisa III?  Looks solid!

Our Hellenback says the Arrow does a good job of driving the HD650's, which would be amazing if it can!  Those high impedance cans tend to do better with tube amps, due to their high voltage demands, whereas solid state amps tend to deliver more current, but if this little guy can pull it off I will be amazed.  Only problem with the Arrow though is the really long wait times on it, but Robert has changed his production on them and assures us that delivery turnaround should be much quicker now.  I ordered mid-November, and he's stating that this batch will be delivered before Christmas, but who knows?  By all accounts though it's worth the wait.

Quote:

Originally Posted by Golden Monkey 

Our Hellenback says the Arrow does a good job of driving the HD650's, which would be amazing if it can!  Those high impedance cans tend to do better with tube amps, due to their high voltage demands, whereas solid state amps tend to deliver more current, but if this little guy can pull it off I will be amazed.  Only problem with the Arrow though is the really long wait times on it, but Robert has changed his production on them and assures us that delivery turnaround should be much quicker now.  I ordered mid-November, and he's stating that this batch will be delivered before Christmas, but who knows?  By all accounts though it's worth the wait.

FiQuest does an even better job with my 600's than my lisa III, drives them better than any tube amp i've tried; and ive tried a few. the above though strictly true is really meaningless, solid state amps have infinitely more voltage than is needed by even the most demanding headphones, even if usually tube amps have more voltage/less current and SS amps more current and less voltage, a good solid state amp will drive HD600 into clipping all the same and i'm aware there are 2 sorts of clipping, clipping from not enough power and clipping from too much. in fact the FiQ will do this at about 70% on the middle gain setting, and much earlier on high. this is definitely the headphones clipping and not the amp

also its not true anymore, last couple of years a company called semisouth has been making some fantastic sounding very high voltage N-Channel power Jfets that run up to 1700v, high enough voltage to even run stats. Nelson pass of Firstwatt and PassLabs fame has been using them to great effect, along with some of his deciples, I have some on their way to me now for use in a DIY circlotron amp with gain

there are different ways of listening - for all day background music you do want to keep the average SPL way down

but it is a plausible "Audiophile" goal to want to reproduce the "live event sound" as a infrequent treat - say less than an hour long session once a week - which even for strictly acoustic music can involve dynamic peaks of >120 dB SPL to accurately reproduce symphonic peaks, big band jazz, hard hit drums, cymbals without transient clipping when the amp runs out of juice

for Senn's higher end 300 Ohm cans ordinary op amps ran at +/-15-18 V supplies just manage - for AKG, Beyer's 600 Ohm or low sensitivity "monitors" I would really like more V than most op amps can manage - and portable amps overwhelmingly use op amps

for portable use most could forgo the "live event" SPL requirement - but some users may be disappointed by single "9V" battery supplied SE amps with higher Z, insensitive cans - again few portables use V doubler circuitry to boost the "9 V" battery (which can be as low as 7.2 V for some "9 V" rechargables )

before you run out the inane, knee jerk "you'll go deaf at those levels" remarks try actually critically reading http://gilmore2.chem.northwestern.edu/articles/hearing_art.htm and look at Moulton, Katz, Cordell or other serious sound pros for estimates of real event peak Dynamic (ie short time, transient) SPL - no one is suggesting average levels of 120 dB - just the ability to cover the Peaks without clipping

but yes many listeners raised on "Loudness War" victim dynamic range compressed drek with <10 dB peak to ave "dynamics" could be happy with amp/headphone combos that never reach 100 dB SPL

to mangle another industry's tag line "If it can't get loud enough to make you deaf it can't get loud enough to sound good"

it is possible to want a headphone/amp combo that can exceed 120 dB SPL for dynamic peaks and to carry broad-band attenuating ear plugs for amplified Club "music" and Rock Concerts which can easily have too high SPL for too long and even single night's exposure can leave erars ringing and cause permenant hearing loss

Quote:

Originally Posted by jcx 

 

for Senn's higher end 300 Ohm cans ordinary op amps ran at +/-15-18 V supplies just manage - for AKG's 600 Ohm or low sensitivity "monitors" I would really like more V than most op amps can manage - and portable amps overwhelmingly use op amps

 

for portable use most could forgo the "live event" SPL requirement - but some users may be disappointed by single "9V" battery supplied SE amps with higher Z, insensitive cans - again few portables use V doubler circuitry to boost the "9 V" battery (which can be as low as 7.2 V for some "9 V" rechargables )

 

 

Lisa lll uses two 9v batteries for the record.

Quote:

Originally Posted by Camomille 

I'm not sure I get the argument going on (my english and my technical knowledge are a bit overwhelmed...), but I'm not really looking for "loudness" or anything, just more comfort and quality! Any news of the Arrow, Golden Monkey?

Nothing yet, sorry...still waiting *sigh*.