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Audio-gd discrete op-amps reviewed: OPA-Earth, OPA-Moon, OPA-Sun v.2 - Page 3

post #31 of 393
Thread Starter 
Try Elna Silmic II at all analog supplies of the DAC chip. I had the Sanyo WG previously in those places but ATM they remain at digital supplies only. BTW my DAC is based on the CS4397 chip and if you look at the Evaluation Board datasheet, there is the LT1028 proposed as the unbalancing filter op-amp. They knew what they suggested.
post #32 of 393
Thread Starter 
What headphones are you using? The OPA211 has got somewhat corrupted "instrument drawing structure". For me the LME49710 is too blurry. It is great in my friend's headphone amp preamp section to compensate for somewhat edgy sound from the TI's NE5532 used in the first stage. I left the Sanyo WG in my CDP near the DAC together with the Panasonic PX's but I'm using it as the digital source only nowadays. Sometimes as a comparison when there is a doubt I did something wrong to the DIY DAC.
post #33 of 393
Thread Starter 
syllabus, I understand your preference but don't agree that looking for exact playback is audiophile related. I'd rather say audiophiles are looking for sepcial effect and that's why they dissect what they hear to evaluate if certain effect is sufficiently present. It might turn out that in another circuit I will prefer LME49710 or another op-amp. As I realised yesterday, the AD797BRZ and the OPA211ID, the grounded OPA Sun v.2 are still serious contenders for the ultimate op-amp.
post #34 of 393
Thread Starter 
@syllabus, it looks like TI stopped sending free samples to Poland, at least they refused to send them the last time explaining I already had ordered those parts which wasn't true. I see no source of these op-amps to buy them. The OPA827 is not yet available at European vendors, either. I went back to the OPA211ID pair in the meanwhile, due to capacitors changes mainly. As a general rule I would say that any low distortion op-amp might be your favorite dependng on the surroundings from the power supply to the electroacoustic transducers, so I defer from telling anybody the LME49720, the OPA211, the Sun v.2 or the LT1028 is the best.
post #35 of 393
Thread Starter 
These won't work for my DAC - too low voltage supplies. Including the topic of this thread - we're drifting aside. These THS40.. probably won't work, either. They have pretty high input currents. When I tried the AD8022 or a pair of the AD8021's, I heard noise only. They were high input current op-amps, too. The Audio-gd discrete op-amps have the advantage of JFET inputs which is very low input current.
post #36 of 393
Thread Starter 
AD826 worked well besides it's nothing special, AD8022 was noisy, and yes, I have decoupling capacitors on all op-amp inputs. Might be these were oscillations because the AD8019 produced no noise, neither did the AD8397.
post #37 of 393
Thread Starter 
Our experiences differ a lot. I never liked the LT1364 and for me it's roughly the AD826 class, the AD8022 is one of the best for output buffers. I installed them there in my CDP, many guys did it in their Audiotrak Prodigy HD2 soundcards and confirmed that it was better than any other popular op-amp besides maybe AD8599 which is slightly different, much easier to use and very likeable.
post #38 of 393
Thread Starter 
I evaluated the AD8022 once as sounding pretty similar to the AD797ANZ, maybe a bit more tubey.
post #39 of 393
This thread has already gone astray, so I might just as well ask you, syllabus and majkel, how are you using AD797? What resistor values etc. Are you using the 47 pF decompensation (distortion cancelling) cap? I find AD797 to sound darker and more neutral with it, but when simulating it this way in LTSpice, it looks like hell.

Majkel, I'll send you a PM regarding the discrete amps.
post #40 of 393
Quote:
Originally Posted by NelsonVandal View Post
This thread has already gone astray

yeah... it has.
post #41 of 393
Out of interest, I tried the OP27GP in my test Compass as they were in my local electronics shop and they give a very good first impression, better than the 627s do, managing to be seductive with the music in the mid range, reminding me somewhat of the Moon, but with some of the punch you get from the Earth in the upper ranges. Quite interesting.
post #42 of 393
hi guys.
anybody knows why audio gd don`t answer emails?
post #43 of 393
remember audio-gd is in china. they are not there to answer email till 4pm pst. i did encounter a delay with them and then emailed again usually around 4pm pst and they got back to me quickly.
post #44 of 393
I get very prompt replies from Kingwa whenever I email, but my timezone isn't a lot different from his.

Back: The time of your post would have been about 5 or 6am his time or thereabouts.
post #45 of 393
guys i have sent him emails before and he responded very fast.

this time it`s 4 days and still no answer.
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