[doobooloo]

OK. The past few days I've been enjoying my newly built META42 very much. I've been using it with the expensive OPA637BP opamp, which I loved very much for its detailed, yet very smooth sound. A nice match with my new CD3000, I thought.

Today I was just playing around and opamp rolling, and tried the OPA602BP opamp that I had lying around. Same family of Precision High-Speed Di-fet Opamps, specwise this amp is inferior (and cheaper) but...

With my CD3000, these opamps are pure magic! Better than the OPA637 opamps. What's so amazing is that this opamp has this powerful 'snap' to its sound that the 637 lacks - it's as if the 637 has lifted a layer of veil or something! The bass is a lot more controlled also; whereas the 637 had some sort of looseness to its bass, this is just fast and black black black. so dark, so nice.

Instruments just sound so much more real.

Listening to live music makes me feel like I've upgraded the seat twenty rows forward.

Anybody with a similar experience with the OPA602BP?

 

[fiddler]

Have you tried the AD8620? IMO it's far more detailed and textured in the midrange without ever losing its smoothness, and tighter in the bass.

 

[doobooloo]

I have tried both the 8610 and 8620, but it's almost too harsh for my tastes... especially with the CD3K.

I think the OPA602 really strikes the sweet spot with my cans.

I can see how a Grado lover can love the OPA637...

And how a HD-600 lover can love the AD8620...

With the CD3K, the OPA602 is it for me.

...at least for now.

 

[fiddler]

Heh yeah, for us people who can't quite afford a neutral headphone and neutral amp and neutral source and neutral cables, we have to mix and match colourations to come as close as we can to neutrality... or not? Whatever. As long as it sounds good.

 

[SENOR4Q]

"Have you tried the AD8620? IMO it's far more detailed and textured in the midrange without ever losing its smoothness, and tighter in the bass."

fiddler

Have you tried both op-amps in identical situations. I ask because I'm at odds with what you say. Chiprolling my META from AD8620 to OPA637 gave me more potent and tighter bass and a slight tip-down in the treble. With bright or bass light cans, I think it's the ideal. The only prob is they need more power to sound good. I have 30v. running through my META and it sounds great to me.

 

[inthused]

I'm reading this thread and wondering are you talking metas that are ac/dc portable? I ask this because I would like to learn about the opamps and match my meta to my phones. I sold my dt880's with the cd3000's next in line,but I've held off until I can figure this amp/phone synergy thing out.

Sorry if I'm out of line in this thread.I don't mean to be rude,but I'm dying here trying to find out how to increase the voltage in my meta as a portable amp to drive either new 880's or the 3000's.

As many rechargeables as neccasary is fine too.

 

[gavinbirss]

Hi everyone

I sure that many of you agree that changing an opamp can make a big difference, but to be fair it is not the opamp that makes the difference.

It is the circuit design (and tuning thereof) that increases the performance of an opamp in a circuit.

I am sure that you would be impressed by the OPA637 if the circuit was optimized for that particular opamp.

My reasoning is that if you put say a NE5532 (TI) part in your circuit you may find that it sounds terrible. It is not the opamps fault but only a indication that compensation is required and that the circuit needs to be tuned.

Gavin

 

[guzzler]

the META board is optimised for low offset FET input opamps, whereas the older bipolar amps such as the 5532 may need trimming to remove DC components in the signal... so really, any FET amp can be used, but if you were wanting to use a bipolar opamp in, you could probably make an adaptor board to allow the required trimpots...

g

 

[Tina]

Quote:

Originally posted by gavinbirss I am sure that you would be impressed by the OPA637 if the circuit was optimized for that particular opamp.

i'm sure doobooloo has taken extra consideration for that matter when he built his max:

 

[fewtch]

Hi Guys,

I've listened to these op-amps on my setup with doobooloo's amp (same one he mentioned here). My taste leans toward the OPA637. The 602 sounds kind of flat and dead to my ears with the already laid-back Senn HD600s and my particular source... I think this particular combination just doesn't work. I much prefer the 637.

The AD8620 sounds to me precisely like everyone describes it -- synergizes well with the HD600s because of its liveliness, yet at the same time it sounds so "ho-hum" like it could be a generic sort of sound with a headphone amp (know what I mean?).

Anyway, just thought I'd throw my opinion into the mix and revive the thread, if anyone's interested. I guess these op-amps would apply to use with the PPA as well, so it can't be too out of date.