[Joshatdot]

I am going to order atleast 12 op-amps for my CMoy PCB boards, and looking for best general sounding op-amp for the CMoy. I know the 8066 will need a BrownDog adapter..I wish it was offered in 8-DIP =\

 

[balou]

AD823 has a bit more limited soundstage, and the highs are not as prominent as in the ad8066. it also consumes less power. for a portable cmoy, I'm tending to recommend the AD823. if cars are driving past you in 2m distance, you won't hear that piano player in 3m distance. I seem also to be more distracted by pronounced highs while on the go. for a home cmoy, ad8066 will likely be the better choice

but I haven't yet heard opa2227/2228. 2228 will likely not be an option for me, because it needs a gain of least 5 to be stable (I want gain 3 for my grados), and it's availability is limited. but an opa2227 should be on the way to me.

the bb/ad decision seems to depend on taste and on headphones used - I'd recommend you to buy from both companys, to get to know to their 'house sound'

 

[Joshatdot]

Quote:

Originally Posted by balou /img/forum/go_quote.gif ~snip~ the bb/ad decision seems to depend on taste and on headphones used - I'd recommend you to buy from both companys, to get to know to their 'house sound'

Yeah I would go half OPA2227 & half AD8066, but I would need the adapters which doubles the price =\

 

[fortney]

Before you order all the different op/amps you might want to do a search here and on Headwize re A/B comparisons of the sound of amps that are the same in all respects except for the op/amp chosen.

Someone offered a circuit for a push button A/B changeover and CMoy's library has one using a toggle switch.

F

 

[majkel]

OPA2227... cough, cough, puke...
TLE2142 is MUCH better if you like this kind of sound presentation. AD8066 is very nice, too. OPA2228 is worth making it stable. The gain might be a bit below 5 and will work well.

 

[balou]

joshatdot, you could diy adapters, see here: http://www.headphoneamp.co.kr/ftp/si.../Tip/SMD-4.jpg

yup, browndogs are expensive as hell... first you think 'only 3$ per piece'.. but you have to order alot of them.

I recently got on a opamp buying spree... I already have or will receive:
NE5532
LM6172
LM4562
OPA2107
OPA2604
OPA2227
OPA2132
NJM4556
AD8066
AD823
AD843
AD744
AD8620
RC4558

now I just have to order parts for my pimeta (board has already arrived) and compare them & write a review here

fortney: considering opamps, I think a long time listening test is more suitable. I must say, short-time a/b-ing seems inferior to me. well, except if it's a very clear difference between two opamps

majkel: you seem to have a non-standard opamp liking. would you care to explain which opamps you like and why?
Filburt also seems to have a quite different oppinion about popular opamps, would be nice if he'd posted in here too

 

[Zigis]

few days ago I build 4 CMoys. I solder all parts on my boards, put OPA2134s from one order in sockets, measure DC ofsets as allways. In different amps different channels 3-8 mV as allweys. Only in one amp right channel are 0.2 mv, left -0 mV. Then I start to listen to all amps. All amps sound normal, but this with low ofsets - 2x more bass and clarity. I change opamp in socket and amp start to sound as allways. Then I marc opamp SUPER and put in my treasure box.
All 5 opamps are from same order, same wrapping.
Zigis.

 

[majkel]

My favourite is AD825, it is single, stable starting from G=1, and 50mA capable. Great soundstage, no veil, very musical, impactful, no harshness, colorful but not colored sound. There is nothing better IMHO. I suggested one guy to use them, and he discarded from his amplifier 2x OPA627 for those AD825s. Another happy guy!

I heard all chips from balou's list except JRC4558 and LM4562. So...
NE5532 - the only good is from Signetics, all others suck
LM6172 - very nice, impactful, clean, dark, some people find it cold
OPA2107 - dark and laid back sound, very deep soundstage, not so broad
OPA2604 - a bit like a tube, rolled off on both ends, a bit boring and too rounded for me
OPA2227 - terribly laid back, bass heavy, veiled and slow. Completely not my type
OPA2132 - almost like OPA2134, maybe a bit smoother sound. Generally - tubby bass, mediocre soundstage, recessed subbands of the midrange and not very detailed treble. Nothing special.
NJM4556 - sounds... funny

Nice sound but I don't know why it sounds funny to me. Smooth sounds with long decay, no harshness. I haven't listened to this one for prolonged time.
AD8066 - good soundstage, a bit narrow, big bass, veiled midrange, nice treble and overall caramel sound signature. I like it
AD823 - a bit harsh making it perceived as detailed, but it is not very detailed. Weak impact in sound, rather analytical. One of the noisiest I know. I don't remember all details well because I found better chips later soon.
AD843 - impactful and harsh, sometimes it's getting unpleasant. IMHO tangensoft overrated it saying it's around OPA637's class. It is not. Too unnatural.
AD744 - very natural in color and soundstage which might give impression as present everywhere. What I dislike is its relaxed and therefore "dead" sound. However some people may like it.
AD8620 - good impact with quick and punchy bass, very good soundstage, not spectacular though, slightly harsh and slightly veiled - kind of a nonsense tradeoff. Some people find its highs too aggressive, I don't.
Other tested...
OP275 - like V-shaped equalization curve, bass up, treble up, recessed mids, overally good and just nothing special, simply good, maybe very good.
OPA2228 - uncompensated alter ego of OPA2227 but totally different. deeper but not muddy like 2227's bass, actually very nice, lots of air in midrange and silky highs. Warm and natural. Just slightly laid back with delicate veil which pairs well with 2228's airy presentation. Electric guitars and female vocals sound nice and intimate. Very likable chip, but not for low gains. You can compensate its feedback loop with capacitors, but I don't like this method and find it degrading the sound a bit.
TLE2082 - many times my favourite but no longer. It's like unveiled, more metallic in treble and less harsh AD8620, better and clearer soundstage, punchy and filled up bass. This chip is more on the bright side.
TLE2142 - sounds dark, with well detailed highs, strong and precisely articulated bass but not as filled with mass as AD8066. You may find the midrange a bit loosing color, but soundstage and its deepness is ver good.
AD797 - is like more analytical version of AD825, less impactful and with some glaze over highs.
OPA637 - very natural and detailed in the whole spectrum, preserving all music singature besides life. For me this chip is uninvolving. It's good for analysing music, not listening for pleasure.
AD8397 it is power hungry and truly powerful. 310mA peak makes sense as a true amplifier. However you need efficient ground channel to keep AD8397's pace. It is a bit bright, very close soundstage, almost like being between performers. Short decay, overally gives impression of being transparent but it's a bit on the bright and smooth side. Comparing it to be more efficient than 2x BUF634 gives it overall high rating. You can use AD8397 as a dual buffer because it is unity gain stable.
I think, that's all... Is my liking non-standard?

 

[NelsonVandal]

Majkel, nice list of opamps. It would be nice to know what your impressions are based on. Like, were they used bufferd or not, at what voltage, did you try AD744 comp pin out etc.

 

[balou]

thanks majkel, an interesting list.
dunno exactly if your overall liking is non-standard - but your recommendation for the ad825 sure is. the only time I've seen it mentioned was in the jung superregulated power supply. as a better alternative to the ad797, which you interestingly seem to place in the same performance category.

about the rc4558: I heard it in a phono preamp. terribly noisy with high gain. [I btw fixed that preamp by replacing the opamp, grounding it properly and removing that dual micro/phono preamp option (yeah, a strange amp...)]. but only costs like 30 cent. I'm gonna use them to practice mounting so8 chips to dip8 sockets with sijosaes bending method. and I'm interested how such an ancient chip will perform. maybe its even better than the opa2132

 

[Joshatdot]

Quote:

Originally Posted by balou /img/forum/go_quote.gif joshatdot, you could diy adapters, see here: http://www.headphoneamp.co.kr/ftp/si.../Tip/SMD-4.jpg ~snip~

Ahh yeah, but I would like the op-amps changeable.

 

[colonelkernel8]

Josh, just scrap the cmoy, lol. Its time to move on! Hasn't upgraditis set in yet?

 

[jcw122]

majkel, what is used to let two single channel op amps work in a dual channel setup? Like what adapter would I buy for that?

http://cimarrontechnology.com/index....WPROD&ProdID=9 Is it this?

Thanks.

 

[Joshatdot]

Quote:

Originally Posted by colonelkernel8 /img/forum/go_quote.gif Josh, just scrap the cmoy, lol. Its time to move on! Hasn't upgraditis set in yet?

They are not for me, they are for gifts & Kits for others here in Head-Fi.

 

[jcx]

I wouldn't reccomend AD8397 for unity buf use when you want to swing close to the rail V, the input common mode range is much less than the output swing

either use inverting or gain of +2 or more to prevent input stage limits from causing distortion when the output stage would be quite happy swinging close to the rail