[music_man]

which would you choose and why? rp030,p1u,apache,gs-x,something else. mostly for single ended use. to power l3000,r10,ps1000,010,hd800,etc. no homebrew stuff please.
i have the p1u but i was wondering how the others factor in. my cullen gcha still seems to be my favorite ss amp even though it was only $1,400. i don't know what that says but i wonder how the others are. you don't have to give a review, just say which you would pick.  only if you have heard them please.
 
thanks

 

[Uncle Erik]

Do you consider the Beta22 to be "homebrew"? It's about the best I've heard and you can have one professionally built, as well. I think AMB has a list of builders.

The Beta22 is a fine amp - it is thoroughly documented and well-regarded by the DIY community.

 

[music_man]

i don't know. i have seen the quality of them all over the place. some are a mess, some are top notch. thats why i said no home brew. even if it it can sound the best there is a lot to consider. like warranty, build time. i can't seem to find a pic of the inside of the rudister. they are usually not as cleanly built as ray's and headamp. on the other hand i think the apache and gs-x use op amps?
with the beta22 i suppose i could get an alps rk50. thats a plus. i still prefer a "off the shelf" product. the luxman is a fine amp but somehow i do not think it is as good as the other $3,000+ amps. i am just guessing that by looking at them. that really says nothing of course. it depends how they sound.

 

[music_man]

i read up on here a bit. should have before i posted. it appears you are correct. i probably already have the top commercially available amp. p1u. not to mention i like the cullen gcha plenty. i have other ss and tube amps including the hp4. i prefer ss. that being said, the only way to best what i have in ss appears to be a top notch b22. this comes from reading many posts here about the amps i mentioned. it always comes down to the b22. it must be very well made though. i am also weary of expensive amps with op-amps as others seem to be. it has been said the rp030 is not a good value when shipped to the states. so, i will think about a b22. if it really is even so much better than the p1u. i guess i'd have to listen to one pretty good first. i know someone has one so i intend to do so.

 

[vcoheda]

headroom balanced max.
 
now discontinued, but there is actually one for sale here. some models included the alps rk50 too.

 

[music_man]

i would agree with you on that vcoheda. i did not consider it because i wished to buy new. it is a shame to me that their current offerings are not at that level(imo).
i am afraid of the b22 builders. it could go great or be a whole mess. i suppose as far as the p1u is concerned it is "up there". i could have worse. i guess ss can only take it so far before you are looking at tubes. i just prefer solid state personally.

 

[jcx]

for line level input, driving high impedance headphones requiring < 12 Vpk to reach 120 dB SPL there is little reason to think better op amp implementations - particularly multiloop types are at all inferior
 
with A/DSL driver chips easily giving 400 mA with single digit ppm distortion even low Z cans are quite readily driven by monolithic op amps today - only when headphone drive V requirement goes beyond ~15 V do you need to consider alternatives  - like bridging which works with chips too
 
where the differences are big enough to DBT the differences are measurable and better op amp based amps are more likely to be more objectively accurate than most discrete SS amps
 
why are you willing to spend $K on discrete SS using mostly 30+ yr old parts and forgo the advantages of the last few year's op amp releases that have incredible investment in reseach due to telcom and biomedical demands that have been implemented on new fabrication processes specifically developed for high speed, precision analog
 
active parts cost can be pretty much the same in SS discrete vs monolithic op amps - audiophile respected input attenuation can cost more than the rest of the amp's circuits combined
 
the 5534 isn't the last word in precision analog op amps for a few decades now 

 

[music_man]

that is possible. the gs-x and apache seem "higher quality" than the p1u. i have heard them but have not a/b'd them. i wonder, if you do not need balanced or a preamp if the hr-2 fits the bill. apparently not. as i have heard both and the apache is much better. it must be a completely different cicruit i'd guess. are the apache or gs-x known to sound better than the p1u?
i was just a little let down that the upgraded gcha with "30 year old technology" bested the p1u here. to my ears at least. of course that was a heck of a bargain amp. one thing about those mosfet's is they can put out 15 watts! not that it matters to headphones since i value my hearing. the problem with the rp030 is as said. it is not a good value when shipped to the states. it looks great but high end to me does not mean simply overspending. if you are in the eu i am sure that is a very solid contender. i have not even looked at what meir has to offer for like two years. so i will. meanwhile maybe someone could compare the apache and gs-x to the p1u. thats what i am looking at probably. thanks
 
edit: i did some more reading here. these amps have been compared. it looks like i may already be at the top of solid state. the apache looks much nicer but that is not really that important to me. the fact that the cullen gcha is as good as or better than the p1u to me is interesting. what is also interesting is it's price is not far behing the gs-x. which is balanced, added cost. the apache is a feedback loop like the gcha. the op-amps are probably better. i think i really need to spend more time with my tube amps and maybe i will change my mind about ss. i guess ss can only take it so far. thats with headphones i presume. ss monoblock's can sound great with speakers and simply put out much more power. for headphones i am seeing everyone is running tubes at the high end. i really don't know why i don't prefer that sound then. i saw that the gs-x vs apache was a toss up. the p1u fits in there too. so probably no reason to buy something just for the heck of it. don't get me wrong. i like the sound i have. i just thought there was "much" better to be had. maybe not.

 

[music_man]

 
Quote:

for line level input, driving high impedance headphones requiring < 12 Vpk to reach 120 dB SPL there is little reason to think better op amp implementations - particularly multiloop types are at all inferior
 
with A/DSL driver chips easily giving 400 mA with single digit ppm distortion even low Z cans are quite readily driven by monolithic op amps today - only when headphone drive V requirement goes beyond ~15 V do you need to consider alternatives  - like bridging which works with chips too
 
where the differences are big enough to DBT the differences are measurable and better op amp based amps are more likely to be more objectively accurate than most discrete SS amps
 
why are you willing to spend $K on discrete SS using mostly 30+ yr old parts and forgo the advantages of the last few year's op amp releases that have incredible investment in reseach due to telcom and biomedical demands that have been implemented on new fabrication processes specifically developed for high speed, precision analog
 
active parts cost can be pretty much the same in SS discrete vs monolithic op amps - audiophile respected input attenuation can cost more than the rest of the amp's circuits combined
 
the 5534 isn't the last word in precision analog op amps for a few decades now 

i just looked at burson audio linked from here. according to him ic's suck. it is only a $699 amp. is that just his opinion? i mean there are very nice amps that use ic's in a feedback loop. i guess i would have to hear his amp to be able to decide.
i thought transistors were better. however, driving headphones i can understand why they may not always be. transistors do not spec nearly as good as some of the op amp ic's. i have no idea. is the burson a totl amp? i like the price.
 

 

[jcx]

early 70's-80's monolithic op amps were compromised by not being able to use equally good npn and pnp transistors or jfets together
 
by the 90's complementary symmetry processes became available
 
in the late 90's thru to today there has been an explosion in demand for higher performance op amps and huge investment in research, design, and semiconductor manufacturing processes for high performance analog signal processing
 
early monolithic op amps were easily beaten in performance by better discrete op amp modules of the day - the JE990 is the classic discrete op amp for audio
 
now days individual designers using catalog discrete parts can't do that much better than the JE990 - but today's monolithic op amp designers have unprecidented control over transistor parameters, matching and use thin film high accuracy resistor on the chip - they have better modeling, design tools, experience and institutional knowlege than any lone wolf designer
 
and they have applied those advantages competing for market share in telecomm A/DSL drivers that are perfect for dynamic headphone amps
 
medical ultrasound demands low noise, distortion and high bandwidth too - modern monolithics far outperform any discrete op amp at audio frequencies for anything except moving coil phonograph cartridge preamps or high Voltage output
 
 
that doesn't mean you can easily buy the best of today's monolithic op amps in a great headphone amp - exactly because of the deep rooted market predjudices that cause most to dismiss "op amp" audio
 
another bad meme here is that amplifiers should be chosen to "tune" your sound - logically all "good enough" (for all errors to be inaudible) amps of any technology Should "sound" the same - series impedance can be added to SS amps to tune their response to more closely resemble tube amplifiers - but it doesn't increase the amp's technical accuracy