[SpudHarris]

What's the difference (apart from price) between OPA627AP and BP??

 

[zilch0md]

What's the difference (apart from price) between OPA627AP and BP??

 
http://www.diyaudio.com/forums/solid-state/9155-opa627ap-bp.html

 

[FritzS]

Been loving the LME49600 as buffers in my P4 but the modules I bought would not fit my Fi-quest.



So with the advice of my guru 'HiFlight' I made up some within a DIP foot print to fit. These are by far the nicest of buffers...

Please look for this old suggestions from Walt Jung!
http://waltjung.org/PDFs/WTnT_Op_Amp_Audio_1.pdf
http://waltjung.org/PDFs/WTnT_Op_Amp_Audio_2.pdf
http://waltjung.org/PDFs/WTnT_Op_Amp_Audio_3.pdf
http://waltjung.org/PDFs/WTnT_Op_Amp_Audio_4.pdf
http://waltjung.org/PDFs/WTnT_Practical_Circuits_for_Quiet_Audio_Transmission.pdf
 
and his new blog  http://waltsblog.waltjung.org/

 

[Mad Max]

Still no word on what opamps are in the Sennheiser amplifiers?

 

[Magic77]

Just replaced the AD825 in my Nighthawk Headphone Amp for the OPA1641. The results are astounding. Completely blows away the AD825 in my opinion. I didn't know I could roll opamps in this amp until I opened the cover. For SOIC chips all you need are the Browndog adapters, such as with the OPA1641. If there are any Nighthawk owners out there, have some fun rolling the opamps. I'm going to try a couple other opamps too.

 

[Magic77]

Can anyone explain the difference between a Bipolar input opamp and a Jfet input opamp? Also, can a bipolar input opamp be used in a circuit that originally used a Jfet opamp? My Nighthawk headphone amp came with an AD825 which is a Jfet input. I first replaced the AD825 with the OPA1641 which seem to work very well. But now I am curious about trying other opamps as well that may have a Bipolar input. Thanks for any help or advice.

 

[imran27]

Can someone please compare between these:

1. OPA1612
2. OPA1642
3. LME49722
4. LME49990

I want to know their strengths and weaknesses when used for AMP section. And also which one of the above will be best for I/V and filter stage

 

[Magic77]

I use the OPA1641 in my headphone amp, which is the single version of the OPA1642, 1642 being the dual version. I love the sound of the 1641. I am familiar with the other chips you mentioned also, all being very good for audio applications. I can't give you any specifics about them off the top of my head. Best thing to do is to look at the data sheets for each one on the Texas Instruments website. You should then be able to compare them somewhat. I can only speak for the 1641/1642 as far as sound performance, haven't heard the others you mentioned, but have only seen some of the specs on them. I am probably going to try the 1611 and 49990 sometime soon.

 

[imran27]

I use the OPA1641 in my headphone amp, which is the single version of the OPA1642, 1642 being the dual version. I love the sound of the 1641. I am familiar with the other chips you mentioned also, all being very good for audio applications. I can't give you any specifics about them off the top of my head. Best thing to do is to look at the data sheets for each one on the Texas Instruments website. You should then be able to compare them somewhat. I can only speak for the 1641/1642 as far as sound performance, haven't heard the others you mentioned, but have only seen some of the specs on them. I am probably going to try the 1611 and 49990 sometime soon.

I looked at specs already and have been comparing them since last week. They confuse me a lot.

I just wanted to know their relative sonic comparison. Like which opamp is best for what stage, best for i/v or Filter or amp.

I like my sound to be detailed, very will extended in bass & treble and must must have a good soundstage. For sound-stage I guess 1641 will be best. Does it provide a good level detail and extension?

 

[Magic77]

Yes, the specs can be confusing to me too. Are you replacing just a dual chip or a single chip? I know the LME49990 is only a single channel chip. The others come in single and dual versions. What chip would you be replacing with one of these? I know the pinouts of the chip should most likely match the chip you are replacing.

 

[imran27]

I'm building a DAC/AMP. Hence everything required to properly implement these OP amps is under my control

 

[therealbene]

OpAmp gurus, I need some advice. I'm trying to improve the sound of my iBasso DX90. I'm registering the help of an experienced technician since I'm a total newbie.
The DX90 has 4 OPA1611A inside it. I'm thinking to replace it's OPA1611A chips with ADA4627-1BRZ. Will the sound be better? Or would the OPA4637 be better suited for the task?
I want a wider sound stage, sweeter "analogue" timbre and weighty (bass). Will the ADA4627 be a suitable chip? I'd really appreciate your suggestions.

 

[imran27]

You could give OPA1641 a try, has a great soundstage

 

[Mad Max]

ADA4627-1B is a greater current hog than 1611, so battery life will suffer.  It could end up sounding a pinch better and in the manner you would like, sure, but 1611 is plenty hi-fi as it is, plus iBasso know how to use that chip well.  I would suggest just leaving the 1611 there.
For the sound you seek, DX90 probably wasn't a step in the right direction.  ESS DACs like the one in the DX90 are probably not the right choice for a more analogue sound, but that's just speculation on my part based on what a few guys have told me about DACs they tried with ESS chips.

 

[Magic77]

I am currently now using the OPA627PA in my headphone amp, definitely the best opamp I have ever heard. Other good ones are the OPA1641, OPA827 and OPA134. The OPA627PA are $25 each, but worth every penny in my opinion.