[Uncle Erik]

Quote:

Originally Posted by Junliang /img/forum/go_quote.gif To each his own =/

Try spending some time with vintage equipment. You might find good reason to change your mind.

 

[leeperry]

at least, there's something both RS and I agree upon...no wonder his amps kill if they all run either of these two chips

Emmeline HR-2 Headphone Amp - Ray Samuels Audio
Quote:

The HR-2 is a high resolution headphone amplifier. It incorporates two state of the art AD797 audio IC’s—the best ever made.

REVIEW: Ray Samuels Emmeline HR-2 - SGHeadphones
Quote:

As Mr. Samuels once remarked, the LT1028 is like putting sugar all over your sound. It has a very liquid, sweet, and warm midrange that exhibits sharp bass and treble roll off. Unlike the Analog Devices op-amps, it is not dark. In fact, low level details flow through with greater clarity and definition.

 

[leeperry]

Quote:

Originally Posted by Junliang /img/forum/go_quote.gif At SGD$170, less than $85 USD, its a very good versatile head amp It powers the k701 very well imo

sound good! too bad it's $140 on ebay, and that all those cheapo amps use crappy opamps such as OPA2134/OPA2604 and all that junk

JRC4580 is a good guy coz it can drive any phone you can throw at it...I like him, I think.

but if you want something based on killer chips like AD797B/LT1028A(even RS says that they are the bests on the market), you have to shell out big bucks...major bummer here

and HLLY that almost did a perfect device here w/ 4xAD797 on the preamp...completely failed by adding an OPA2134 in the HP amp: HLLY HIGH END DMK-IV DAC USB Headphone

I've tried to hook up w/ a few DIY'ers, see if they could make me a mini3 based on AD797..but no go, they don't have an oscilloscope to make sure that it's stable(Scott Wurcer told me that it can be made stable very easily w/ a bunch of resistors on 2 pins).

but well, I see that all the Auzen soundcards are said to be compatible w/ AD797: Auzentech OPAMPS

I'll try my luck, plus all their newest cards have discrete HP amp...Burson phear

I'll also try two LT1028A because...well, this chip is amazing..as RS says it puts sugar all around your music.

OTOH, LT1028 clearly cannot be used in a CMoy apparently: Cmoy headphone amp? - diyAudio

 

[moonboy403]

You gotta realize that the HR2 has been out for many many years. In addition, Ray hasn't updated the description of the HR2 either. So I'm not sure what he said many years ago still applies today.

 

[leeperry]

good point! but if there were a mini3 based on 797, it'd be beyond words....I've listened to this chip for several months, it's just mind blowing.

majkel explained it very accurately: http://www.head-fi.org/forums/f6/aud...-v-2-a-397691/
Quote:

this is the op-amp truly deserving the name of the Analog Device.

 

[igotyofire]

using the OP logic, can i take a cmoy amp design and replace the IC with a tube of similiar power characteristics and expect it to work? would i then have a Tube CMOY ?

 

[Junliang]

Quote:

Originally Posted by Uncle Erik /img/forum/go_quote.gif Try spending some time with vintage equipment. You might find good reason to change your mind.

Pass me an Akg K1000, Thank you

Quote:

Originally Posted by leeperry /img/forum/go_quote.gif sound good! too bad it's $140 on ebay, and that all those cheapo amps use crappy opamps such as OPA2134/OPA2604 and all that junk

Well, my local distributor for AudioTrak gave it a big discount for the first week of 2010, whose original price is around SGD$350, which is around $150USD i think.

Oh well, I was aimming for that amp in the past, when my local distributor gave me the heads up on the discount in 2010, I just had to whack it no matter what

Very very pleased with it

 

[Uncle Erik]

Quote:

Originally Posted by igotyofire /img/forum/go_quote.gif using the OP logic, can i take a cmoy amp design and replace the IC with a tube of similiar power characteristics and expect it to work? would i then have a Tube CMOY ?

It's not that simple. Most tubes will want at least 200V on B+, so the battery power supply is out. You'd also need a separate supply to power the tube filament. There are other differences, too, but you get the idea.

 

[amb]

Quote:

Originally Posted by leeperry /img/forum/go_quote.gif I've tried to hook up w/ a few DIY'ers, see if they could make me a mini3 based on AD797..but no go, they don't have an oscilloscope to make sure that it's stable(Scott Wurcer told me that it can be made stable very easily w/ a bunch of resistors on 2 pins).

Sorry, but you can't use AD797 on a Mini³. The main L/R channel opamp is a dual-unit, but AD797 is a single. There is no dual version of AD797, and using adapters is out of the question in the small Mini³ casing, not to mention that inductance in the adapters tend to harm stability.

Casting all the abovementioned issues aside, AD797 neither swings rail-to-rail like the specified Mini³ opamps, nor does it have nearly the same output current capability (particularly the high performance edition with AD8397). Extracting maximum voltage swing out of the opamp is important with Mini³'s limited supply voltage, so we don't encounter clipping with high-Z loads. High output current capability is needed to handle low-Z loads while minimizing distortion. These are what make the Mini³ perform so well with such a wide range of headphones, from 300Ω Sennheisers to 16Ω IEMs.

To use AD797s in a headphone amp would require an additional output buffer and higher supply voltage. Things that are clearly not feasible in the existing Mini³, given the size and single 9V battery power.

 

[leeperry]

Quote:

Originally Posted by amb /img/forum/go_quote.gif Sorry, but you can't use AD797 on a Mini³. The main L/R channel opamp is a dual-unit, but AD797 is a single. There is no dual version of AD797, and using adapters is out of the question in the small Mini³ casing, not to mention that inductance in the adapters tend to harm stability. Casting all the abovementioned issues aside, AD797 neither swings rail-to-rail like the specified Mini³ opamps, nor does it have nearly the same output current capability (particularly the high performance edition with AD8397). Extracting maximum voltage swing out of the opamp is important with Mini³'s limited supply voltage, so we don't encounter clipping with high-Z loads. High output current capability is needed to handle low-Z loads while minimizing distortion. These are what make the Mini³ perform so well with such a wide range of headphones, from 300Ω Sennheisers to 16Ω IEMs. To use AD797s in a headphone amp would require an additional output buffer and higher supply voltage. Things that are clearly not feasible in the existing Mini³, given the size and single 9V battery power.

Hi Ti Kan, thanks for passing by!

well how about getting the audio colored by AD797/LT1028, then drive it through a JRC5480 for headphones?

yes, ok I guess browndogs can indeed make them oscillate even further...but LT1028 is one of the sweetest opamps, and AD797 has one of the most amazing 3D SS

I'm quite sure that the reason why RSA amps are so famous is because they use these two chips to great extend, fed w/ high quality power...this is a major winner here!

I have to admit that I'm curious about how AD8397 sounds...I'll grab a miniv3 anytime soon.
Quote:

Originally Posted by Slash47 /img/forum/go_quote.gif No, it's a Pimeta (PIMETA v2 Headphone Amplifier)

and they've just told me that the opamps you're seeing are 5532 of course! but they're on swappable sockets so you can roll them I was told

and of course the specs are much better than a Burson headamp....because we all know that what matters is the specs! nothing's better than a very low THD, this is the true warrant of superior SQ

 

[Born2bwire]

Quote:

Originally Posted by TheAudioDude /img/forum/go_quote.gif Not only can we make the choice, but we usually have 30 days to decide if we're satisfied with it.

This to me is a big thing. Many retailers and manufacturers, like Headroom, Todd the Vinyl Junkie, Meier Audio, and Ray Samuels Audio, offer 30 day trial periods. In addition, there are a bevy of people here who have taken the time to write indepth reviews and comparisons and organize meets all over the world where you can sit down and sample a myriad of equipment. Honestly, it is up to you on whether or not you are getting your money's worth but there are many many opportunities where you can verify this with little to no monetary risk. Is the Hornet worth $3XX? Just go to a meet, read reviews, order one for a trial period and find out yourself. Why people need to treat this stuff like a conspiracy theory is beyond me.

As for portable amps being glorified CMOYs, well, yeah, duh. The CMOY circuit is just the basic amplifying circuit for an opamp. If you are designing with regards to small footprint and low power then there isn't really much for you to work with. You have a minor power supply circuit, the amplifier stage, a buffer stage and if you are being extravagant even a charging circuit. All of these are pretty basic and it is difficult to get more complicated topologies in a very small package. Even if you look at say the MINT or PINT they are exactly what I stated above. They aren't any more sophisticated than a CMOY or buffered CMOY when you get down to it.

 

[vrln]

Interesting thread... Many good interesting posts. Asia is rising, the internet is everywhere (people can find out more, and order from anywhere) and the traditional high end hifi cash cow is facing some very heavy challenges these days. Before the internet was this widespread the lack of information was a great aid to the audiophile industry. There´s a new kind of consumer awareness that rightfully questions many old "traditions". While a part of me understands the ideal to build inside the EU for example, but it will be extremely hard for those products to compete these days. A nice middle road is what Meier Audio has been doing: design here, build in Asia.

 

[Avro_Arrow]

It's funny, you know. After reading through everything so far, no one has questioned or 
explain just what qualifies as a CMoy.
As for me, a CMoy is a non-inverting amp based on a dual op amp, powered by a 
battery and using some sort of virtual ground.
Add much more complexity and is it still really a CMoy?
Chu Moy didn't invent this either, he just popularized it.

 

[audiofil]

If every headphone amplifier is an overpriced CMoy, then every car is ... what ?
An overpriced Ford Model-T ?!

 

[Skylab]

I can promise you that this amp of mine is nothing like a CMoy: