[dukefx]

If it's dead you won't hear a thing. If the sound is off it might be a soldering issue. I once had the left channel crackling and hissing. Turned out I didn't solder one of the pins properly.

 

[palermo]

Anyone, is there benefit to swap LPF from opa1642 to ada4610-2. The dac is ak4490eq.

 

[Rroff]

Can't see there being much in it - the ADA is designed with that kind of use in mind but the 1642 I believe has slightly better specs so any differences in terms of suitability to application probably balance out. Try it see if you notice any difference.

 

[Smugsie]

Hey everyone, any suggestions for the HD600 pairing? Objective 02 amp with an Objective DAC here. I'm not interested in getting into tube rolling because from my experience I get introduced to bad tubes... opamps are more reliable.

Right now I'm using NJM4556AD x2 with a Muses02. The HD600 with Muses02 sounds sparkly, has some good bass extension/texture/tightness, relaxed upper mids, sparkly treble, good soundstage and thick vocals, maybe a little too thick.

The LME49720HA is detailed, sparkly, airy, upfront involving sweet mids, introduced mids too upfront and the HD600's 3-5khz started to shine out which became too much for me.
 
Is there an opamp that meets those two halfway? I can only assume the Muses01 would be a less thick Muses02.

Edit: Also no, I'm not switching over to the HD650! That airy extension past 10khz is a must for me on the HD600.

 

[raoultrifan]

When used in voltage amplification stage they should all from above sound the same, also the original NJM2608, NE5532 etc. MUSES opamps are a bit more musical and soundstage seems wider a bit, but no matter what opamp you're rolling in VAS sound will be quite neutral (unless you're choosing a fast opamp that start oscillating, then you'll start to like the sound a lot).
 
Feel free to try 2xMUSES02 in output buffer stage, but take care, because by doing this you'll limit output current capabilities from 150mA to 100mA and headphones like Hifiman or low sensitivity planars that requires lot of current to drive might destroy both of your opamps. Also, like Alex (adydula) said in Objective2 thread and on diyaudio forum, 2x1688 opamps might sound a bit better to your ears, just read those threads and see for yourself if worth the trouble or not.

 

[Rroff]

Feel free to try 2xMUSES02 in output buffer stage, but take care, because by doing this you'll limit output current capabilities from 150mA to 100mA and headphones like Hifiman or low sensitivity planars that requires lot of current to drive might destroy both of your opamps. Also, like Alex (adydula) said in Objective2 thread and on diyaudio forum, 2x1688 opamps might sound a bit better to your ears, just read those threads and see for yourself if worth the trouble or not.

 
While not relevant to Nec3 something else to keep in mind is that in situations like that is that not all op amps will play nice with the 1ohm output resistors and might require bumping that upto 4ohm or so. If I read the datasheet right MUSES02s would exceed their absolute max thermal dissipation when supplying current the ~75ma required for 150ma output at the voltages used in the O2 never mind their max voltage heh.
 
This is all my subjective impressions from building around a half dozen variants of the O2 but:
 
HD600s are very low current demanding which opens up a lot of options for the O2 buffers - I'm not a fan of the NJM4556AD with the HD600s (though they work very well with high current demanding headphones) - I might be completely wrong as to what the problem is but their slew rate is marginal for audio and crucially stated as their typical not the more normal minimum rate - IMO the HD600s show them up for their inadequacy there - I'm a fan of the OPA1602 for buffers here as you get a very natural sound but they might not be as resolving for detail as some might like also a fan of the AD8066 here if you can get past the veiled upper mid-range as they seem great for bass, vocals and airy high frequencies. (EDIT: Looking through the thread seems more experienced people prefer the 1662 over the 1602 for better instrument separation/detail or the 1688 as above).
 
As an aside and I'm not sure what the logic is to it - I've had good results with omitting C10 (0.22uf) and putting 10uf audio grade (KZ or FC) aluminium electrolytics rail to rail directly on the op amps otherwise there seems to be some narrowing of the sound stage compared to when using my HD600s with high end commercial amps.

 

[adydula]

The 1688's work well for me....but there is also the AGDR O2 Booster Board creation (OPA827 + LME49600 looped). You can build one or buy one from AGDR I believe.
 
The 1688 require some soldering and an adapter.
 
I think if you go over to DIYAUDIO.COM there is more data on the 1688's, I think AGDR was concerned with oscillations with the 1688's depending on cable capictance etc...I tried to make my 1688 O2 oscillate by changing caps but it seemed solid. Sounds good!
 
Alex

 

[Rroff]

For some reason I was concentrating mostly on the buffers above - probably because for me that has been one of the weaknesses with my HD600s.
 
The 1688 even with low gain in the first stage shouldn't see the buffer as a high capacitive load right? so shouldn't be a problem in that respect though the lack of close 0.1uf bypass might be an issue in some circumstances.

 

[raoultrifan]

OPA 1688 might be used as output buffers and not voltage stage in Objective2.

 

[weedophile]

Hi guys, am looking to get a cheap portable amp to bring around with my Benjie S5 and chanced upon the Bluebird U3 Mini. What attracts me is its looks (much better than the Topping NX1A) and its available at almost the same price on AE.

So my question is since i can opamp roll with the amp (stock OPA264), can i say all 8 pins audio opamp will work with it? Or is there anything i have to take note of? (Sry i am a real noob on electronics and circuits)

Thanks!

 

[vapman]

Hi all,

I have XTA 446 sound management module. It has 15 opamps (NE5532) inside. I never replace opamp before and have been reading forum like crazy to find the best opamp for me.

Some people mention Sonic Imagery 994Enh-Ticha Dual Discrete Opamp to be the best one but why no one discuss it here?

Hope someone can give some feedback.

So far im thinking to use 6 discrete opamps in the output and use Burson V5i for the rest. Replacing all with discrete will certainly kill the power supply. Here is the xta board hope someone can give me some guides as im new to this. According to XTA, the unit supplies -15v -+15v but i have no idea the current for each opamp.

Thanks.

What don't you like about it? The ne5532 sound is not everybody's cup of tea but for pure neutrality and honesty with good bass power few else come to mind. V5i in that large a quantity (15?) will be an extremely hefty investment. What do and don't you like about it? V5i sounds like ne5532 but with better soundstage imaging and treble extension but is otherwise very similar.

 

[vapman]

Hi guys, am looking to get a cheap portable amp to bring around with my Benjie S5 and chanced upon the Bluebird U3 Mini. What attracts me is its looks (much better than the Topping NX1A) and its available at almost the same price on AE.

So my question is since i can opamp roll with the amp (stock OPA264), can i say all 8 pins audio opamp will work with it? Or is there anything i have to take note of? (Sry i am a real noob on electronics and circuits)

Thanks!

There are single and dual channel opamps as well as dual to mono and mono to dual. It is probably a dual in there but as long as you get the same channel kind then you're all good

 

[NCSUZoSo]

My recent review (still in progress) on the Burson V5-OPA and V5i series. Includes DSD audio files and EL-8 open-back for playback to ensure quality. I will be posting a full video review after I receive a few replacement parts from Burson Audio.

This is a very detailed review already, but it is still missing 1/4 of it or so.
 
http://www.head-fi.org/products/burson-audio-supreme-sound-opamp-v5/reviews/17827

or read it on my new website, always looking for new readers! https://zosoncsu.com/reviews/
 
This is the video I am trying to expand on to create a video review. I would welcome any ideas on ways to use the written review + this type of analysis to make a full-length video review of an op-amp series.
 



 

 

[weedophile]

There are single and dual channel opamps as well as dual to mono and mono to dual. It is probably a dual in there but as long as you get the same channel kind then you're all good

Thanks Mr Vap! Helpful as always

 

[Emerpeje]

Hey guys, I'm kinda new to this audio and electronics stuffs and I just bought a Walnut V2 player. Are there any suggestion on what kind of opamp that I should take to "upgrade"(not uograde, just change the soundsig a little bit) my Walnut V2?

Thanks!