DAC AD1862: Almost THT, I2S input, NOS, R-2R

[weissi]

don't let that opamp discussions be your *religion*. Use any of the newer/better opamps recommended everywhere here:

-for low impedance sources (>6kOhm)
NE5532(-4)/NJM5532(-4)/NJM2068//OPA161xx/OPA162x/Ad8022

-for high impedance sources (>6kOhm)
(OP275), OPA164x, OPA1656, OPA627, AD86x0, AD8066, ADA4627-x

-for higher output current (headphone drive) - Voltage feedback
AD8397, OPA1656, OPA161x, OPA162x, newer TI Audio opamps


There are other, more specific applications - these opamps are more difficult to implement:
- extreme low source impedance (AD797/LT1028/ADA4898-x)
- high current drive (AD8397, TPA6120, AD815, ...)

This is just my personal list, but take it as a starting point.
Try reading the datasheets for the differences between each part falling into one of my classifications (e.g. OPA1642 vs. OPA1656)
There are other parts of a DAC-system that should be considered, apart from the listed opamps to increase the performance of a DAC.

 

[MrSlim]

If anyone is looking for boards, I can do another run in the group buy going here: miro1360 AD1862 DAC Board Group Buy

 

[miro1360]

... I will also test with Burson Audio V6 classic/vivid but fitting them along with the side caps will be tricky. Lets see how it goes. Also by the way is there any initial setup steps like using the trimmer to set the offset etc.,

take an inspiration from @Vunce, his posts: #141, #339, #525
he installed the capacitors from bottom for a wider range of opamp packages

there is no setup for dc offset, normally there is not a problem with this, these opamps have negligible dc offset

 

[diyiggy]

I like the Ada, but I haven't made many tests as I'm very busy to refurbishing my home...so few time. More later. Not tried the LM yet.

 

[manniraj]

take an inspiration from @Vunce, his posts: #141, #339, #525
he installed the capacitors from bottom for a wider range of opamp packages

there is no setup for dc offset, normally there is not a problem with this, these opamps have negligible dc offset

Thanks Miro, yes I have gone through Vunce posts. Need to desolder the caps nearby and place them underneath but that is for another day. As I am going to try the regular NE5534 and LM6171 which are through hole 8 leg opamps for now.

 

[diyiggy]

With the tegular cost nothing 5534 oap, one can also use the old NJR 4580DD...very well suitedfor headphones...neutral. needs no less than 0.1 uf decoupling...cheapand dip 8 casing but good. Though for the cost the oap 1656 should be hard to beat..as the oap861...

 

[diyiggy]

I m looking forward to hear from Miro with the 627 as it s a bi.cmos...few are.

 

[Paddy Garcia]

I am not a golden ears type, not a tweaker or opamp/tube/capacitor roller, and am cheap so I really wanted to like the 5532s I put in to smoke-test the finished DAC. They were fine, but not nearly as fine as the 627, which sounded much richer and had a deeper LF response. Dammit.

 

[pistollero]

Just to share my experience. Tested opa627 and ad825. I liked more opa627.
Very good sound, very pleasent. Vocals are real.. very good in my opinion.. i listen in past in other circuits and never liked much.. but in miros dac it sound very good... have to admit.

 

[Joseph K]

I m looking forward to hear from Miro with the 627 as it s a bi.cmos...few are.

I am afraid.. So few are, that not even the OPA627..
Is "bi. Cmos"

 

[diyiggy]

Damned ...bi.fet ? Di.Fet ??? Cmos only?

 

[Joseph K]

The OPA6x7 is fabricated on a high-speed,
dielectrically-isolated complementary NPN/PNP process.

Jfet

 

[TNT]

I hear less bass in drums etc. But i think i dont have the perfect setup of power supply around ada4627-1.

Or your speakers... it's a system game ;-)

//

 

[TNT]

Damned ...bi.fet ? Di.Fet ??? Cmos only?

Doesnt matter, yore only guessing anyways eldamn.

//

 

[miro1360]

The only issue with 627 is the price Otherwise is sounds really very good across the whole spectrum. I'm a little more on the side of LM6171 or ADA4898 - but your ears may be different so the only way is your own test

 

[miro1360]

Damned ...bi.fet ? Di.Fet ??? Cmos only?

627: input is jfet (difet technology)
the rest and output is npn/pnp
(difet technology - advanced geometry dielectrically-isolated FET, which can achieve very low input bias current by eliminating isolation-junction leakage current)

 

[Joseph K]

I would suggest to test it's 'siblings' - - ADA4627, OPA827, OPA828, too. All of them are aimed to 'better' the OPA627, and would say that they do something worthwile, indeed.
I did not try in this position, I/V, but did try thoroughly in the MyRef designs. And preferred the more modern versions.

Ciao. (all this if one can not get an OPA1656.. )

 

[miro1360]

exactly, try more opamps ... be sure you get them from a trusted source, only trusted source for opamps!

 

[pistollero]

Or your speakers... it's a system game ;-)



//

Yes you are right, i though about that also.

 

[diyiggy]

You know TNT is only guesting anyway...wet powder.