Based on Diyaudio's comments, ESS Technology's "Sabre Aplication Note" and Douglas Schrodeder's articles, I have decided to try the following op-amps:
OPA2604 (I/V conversion and LPF filter) + AD797 (output)
LME49720 ou LM4562 (I/V and LPF) + LME49710 (output)
dual mono OPA627 (I/V and LPF) + OPA627 (output)
I would like to thank all of you who made those helpful contributions in this thread.
Greatings!
http://www.esstech.com/PDF/Application_Note_Component_Selection_and_PCB_Layout.pdf
UPDATE 1/18/2011: Eastern Electric Minimax DAC - upgrading op-amps Review - Equipment Reviews - Dagogo
Audio Blast: Eastern Electric Minimax DAC Opamp Rolling - The Columns - Dagogo
OPA2604 (I/V conversion and LPF filter) + AD797 (output)
LME49720 ou LM4562 (I/V and LPF) + LME49710 (output)
dual mono OPA627 (I/V and LPF) + OPA627 (output)
I would like to thank all of you who made those helpful contributions in this thread.
Greatings!
http://www.esstech.com/PDF/Application_Note_Component_Selection_and_PCB_Layout.pdf
UPDATE 1/18/2011: Eastern Electric Minimax DAC - upgrading op-amps Review - Equipment Reviews - Dagogo
Audio Blast: Eastern Electric Minimax DAC Opamp Rolling - The Columns - Dagogo
The AD797 is one that needs care... it might have stability issues as a drop in replacement.
Keep it simple... the OPA2604 and LM4562 should be fine. For a single opamp for the output I would have an OPA604 to hand.
I have also used the AD845 with excellent results.
If the original is an NE5534 you need to check if an external compensation network (cap) is fitted between pins 5 and 8 and remove it.
Keep it simple... the OPA2604 and LM4562 should be fine. For a single opamp for the output I would have an OPA604 to hand.
I have also used the AD845 with excellent results.
If the original is an NE5534 you need to check if an external compensation network (cap) is fitted between pins 5 and 8 and remove it.
AD827 $10-$40 on eBay.
http://www.ebay.com/sch/i.html?_trk...7&_sticky=1&_trksid=p3286.c0.m14&_sop=3&_sc=1
http://www.ebay.com/sch/i.html?_trk...7&_sticky=1&_trksid=p3286.c0.m14&_sop=3&_sc=1
I am thinking of purchasing the op-amps on eBay. Is there any risk of buying fakes ones? I mean, does it exist fake op-amps (LM4562, OPA627, AD797)?
Basically, IC OPAMP NE5532/NE5534 is nothing wrong. Both Musical Fidelity in UK and MBL in Germany currently use it in audio amplifier design and sell it at many $$$bug. They do not solely plug and play, but use a set of “jig and fixture” to perform testing, sorting and component matching of IC OPAMP before use. Thus, it sounds good. However, the methodology of component matching may be secret to the company.
Alternatively, IC OPAMP LM4562, OPA627, AD797 are good choice, but higher price in comparing to NE5532/NE5534. I do not comment eBay, but recommend more reliable suppliers such as Digitkey, Farnell or Mouser, etc… in which the component must not be fake.
Try Digikey, Mouser, Avnet...
LM4562 is some 3$ for DIP, 1.5$ for SMD. The metalic can is expensive - some 20$ - and I don't think it is worth it.
Try also AD8599 - really a good OpAmp, on par with LM4562.
http://www.eetimes.com/design/audio...rt-1--Op-amp-history--properties?pageNumber=3
LM4562 is some 3$ for DIP, 1.5$ for SMD. The metalic can is expensive - some 20$ - and I don't think it is worth it.
Try also AD8599 - really a good OpAmp, on par with LM4562.
More from it:
http://www.eetimes.com/design/audio...rt-1--Op-amp-history--properties?pageNumber=3
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When you've installed the sockets, get somebody to swap the opamps without letting you know which ones they've put in. See if you can reliably identify any of them over a number of swaps.
Many people insist they can hear differences, but many others think that there's no audible difference; TI, who manufacture highly regarded DACs, recommend NE5532s and NE5534s for use in the very applications where you are intending to replace them. Most of the people making recommendations NEVER undertake the unsighted comparisons, they rely on swapping the chips themselves... ...and stuff that people write in threads like this one.
Many people insist they can hear differences, but many others think that there's no audible difference; TI, who manufacture highly regarded DACs, recommend NE5532s and NE5534s for use in the very applications where you are intending to replace them. Most of the people making recommendations NEVER undertake the unsighted comparisons, they rely on swapping the chips themselves... ...and stuff that people write in threads like this one.
AD827 - $12.47:
Digi-Key - AD827JNZ-ND (Manufacturer - AD827JNZ)
By the way, using a socket in this type of circuit may have a detrimental effect on sound because of stray reactance conflicting with high frequencies and fast rise times, it's best to solder the opamp directly into PCB. Afterwards, proper circuit performance needs to be verified using an oscilloscope.
Mike
Digi-Key - AD827JNZ-ND (Manufacturer - AD827JNZ)
By the way, using a socket in this type of circuit may have a detrimental effect on sound because of stray reactance conflicting with high frequencies and fast rise times, it's best to solder the opamp directly into PCB. Afterwards, proper circuit performance needs to be verified using an oscilloscope.
Mike
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Alant4321, Sonic_Real_One, Counter Culture and Michael Bean,
Thank you very much indeed for your contributions! I'd like to say I relly enjoy this forum. Some time ago I got unexpected results with an ordinary Radio Shake integrated amp due to precious info given here. That encourages me to go further and modify my new DAC.
MiniMax DAC comes with IC socket but after choosing the best op-amp, I'll solder it on the PCB. I haven't got a scope and I don't plan to buy one, but I may pay a guy who modifies audio gears to test the reability of the chosen op-amp before soldering it.
I'm quite ceptical as regards some audio tweeks, such as "magic" power and digital cables and I'm certainly performing blind audition tests to avoid "placebo effect".
Thank you very much indeed for your contributions! I'd like to say I relly enjoy this forum. Some time ago I got unexpected results with an ordinary Radio Shake integrated amp due to precious info given here. That encourages me to go further and modify my new DAC.
MiniMax DAC comes with IC socket but after choosing the best op-amp, I'll solder it on the PCB. I haven't got a scope and I don't plan to buy one, but I may pay a guy who modifies audio gears to test the reability of the chosen op-amp before soldering it.
I'm quite ceptical as regards some audio tweeks, such as "magic" power and digital cables and I'm certainly performing blind audition tests to avoid "placebo effect".
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Personally I did a test replaced on My Denon only ONE OpAmp. That was taking care of the front and rear R channels (they kept the L and R separated - good job).
At that point I really wasn't sure which speaker is that channel and I was able to pick up a "winner" after a few songs that I knew very well (to make sure). The channel that sounded best was the one with the new OpAmp.
Denon uses better OpAmps in the end-of-line players, receivers. Is a way for them to make a marketing difference and ask for twice the price.
A lot of companies used the 5532 simply because it was (and still is) the best CHEAP OpAmp that you could get - good for the beancounters.
TI recomands that for some DACs because they knew that japanese electronics design people (culture) would be inclined to pick up a DAC for their designs if it did have 5532/5534 shown. But is not the only one shown in their data sheets...
At that point I really wasn't sure which speaker is that channel and I was able to pick up a "winner" after a few songs that I knew very well (to make sure). The channel that sounded best was the one with the new OpAmp.
Denon uses better OpAmps in the end-of-line players, receivers. Is a way for them to make a marketing difference and ask for twice the price.
A lot of companies used the 5532 simply because it was (and still is) the best CHEAP OpAmp that you could get - good for the beancounters.
TI recomands that for some DACs because they knew that japanese electronics design people (culture) would be inclined to pick up a DAC for their designs if it did have 5532/5534 shown. But is not the only one shown in their data sheets...
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