awty Posted August 17, 2014 Share Posted August 17, 2014 I made quite a few of these over the years based on the CMoy schematic. Where did you get the PCB? 1 Link to comment Share on other sites More sharing options...
mwhouston Posted August 17, 2014 Share Posted August 17, 2014 Where did you get the PCB? These are small prototype brds. from Stiff Dicks. No longer available but I still have a few left. 1 Link to comment Share on other sites More sharing options...
niss_man Posted August 17, 2014 Share Posted August 17, 2014 Yep. Show me that you can actually hear the difference between two modern types in the same application without knowledge of which you are listening to. Post #19. opamp shootout was performed blind. Just download wav files of mysterious opamps labeled after fruit. Certainly can hear differences. I used a decent pair of cans for this. 1 Link to comment Share on other sites More sharing options...
A9X Posted August 17, 2014 Share Posted August 17, 2014 Post #19. opamp shootout was performed blind. Just download wav files of mysterious opamps labeled after fruit. Certainly can hear differences. I used a decent pair of cans for this. It was a very poor test to determine differences especially as the question was asked to pick a preference: this doesn't mean anyone actually heard a difference (and look at all the comments saying how hard it was) but simply believed they did, which is not the same thing. There was poor level matching, channel flips and some of the opamps were overloaded. There were no controls and easily available software to allow people to cheat by visually examining the files. It was of no more benefit than reading 6loons to determine the sound of something. If someone had done an ABX and reliably picked say the 5532 vs the 4562 when there was no possibility of cheating, I might believe you. And when I see it done, I will, but I haven't yet in some decades. https://www.youtube.com/watch?v=MHx6BX3HZJc 1 Link to comment Share on other sites More sharing options...
TMM Posted August 17, 2014 Share Posted August 17, 2014 (edited) Also you get the 'bandwagon effect' as people who are unsure just vote for the most popular option. Edited August 17, 2014 by TMM Link to comment Share on other sites More sharing options...
ArthurDent Posted August 18, 2014 Share Posted August 18, 2014 AFAIK the transconductance op amps AD844/OPA861 used as dac outputs are free of neg feedback. George should know for sure. They sure dont have that closed in sound I hear with every other opamp i've heard. Was there much work involved in changing all the op-amps in the DEQX to these. Link to comment Share on other sites More sharing options...
statman Posted August 18, 2014 Share Posted August 18, 2014 Was there much work involved in changing all the op-amps in the DEQX to these. ???? I dont think they would work in DEQX and I respect the DEQX engineering too much to "fiddle" with it. I used transconductance op-amps behind 1541 and 9018 dac chips. Link to comment Share on other sites More sharing options...
Rej Ma Posted February 24, 2018 Share Posted February 24, 2018 Reviving an old thread : I've just changed the Opamp on my asus essence stx. This time for the not so expensive OPA2134 ..... I've had many years to listen to the standard JRC 2114 and I find the opa2134 to be quite a great change. More precise, more punch, wider sound stage...pretty much what I was expecting to get. So for those of you who don't want to spend too much, try those 2134 if you have some very good headphones. I've 5 headphones and IEMs to compare the new sound with and it's quite obvious. I only deal with the opamp 8 PDIP anyway, I just don't want to solder. Cheers from Québec , Boys! 1 Link to comment Share on other sites More sharing options...
Addicted to music Posted February 24, 2018 Share Posted February 24, 2018 (edited) 17 minutes ago, Rej Ma said: Reviving an old thread : I've just changed the Opamp on my asus essence stx. This time for the not so expensive OPA2134 ..... I've had many years to listen to the standard JRC 2114 and I find the opa2134 to be quite a great change. More precise, more punch, wider sound stage...pretty much what I was expecting to get. So for those of you who don't want to spend too much, try those 2134 if you have some very good headphones. I've 5 headphones and IEMs to compare the new sound with and it's quite obvious. I only deal with the opamp 8 PDIP anyway, I just don't want to solder. Cheers from Québec , Boys! Going SOIC and converting them isn’t that hard. You are leaving yourself short of other opamps If SOIC devices aren’t sampled. If you are sticking to PIn8 then you should also check out the LME devices. Edited February 24, 2018 by Addicted to music Link to comment Share on other sites More sharing options...
mwhouston Posted February 25, 2018 Share Posted February 25, 2018 For an $8 chip from Jaycar they are hard to beat. A good fall back chip. I have used more expensive chips but find in the end there is little improvement. I have found some of the more expensive easier to destroy where the 2134 is far more tolerant. Link to comment Share on other sites More sharing options...
catman Posted February 25, 2018 Author Share Posted February 25, 2018 G'day all, yes I concur! The OPA2134 is a very hardy and 'tough' dual op amp. Regards, Felix. Link to comment Share on other sites More sharing options...
Addicted to music Posted February 25, 2018 Share Posted February 25, 2018 8 hours ago, mwhouston said: For an $8 chip from Jaycar they are hard to beat. A good fall back chip. I have used more expensive chips but find in the end there is little improvement. I have found some of the more expensive easier to destroy where the 2134 is far more tolerant. All OPA series are compensated. Link to comment Share on other sites More sharing options...
LogicprObe Posted February 25, 2018 Share Posted February 25, 2018 I may have a couple of old Burr Browns around somewhere................. Link to comment Share on other sites More sharing options...
oohms Posted February 25, 2018 Share Posted February 25, 2018 Back when i was building headphone amps and op amp rolling, I remember that the OPA2134 was nice and slightly warm and bass heavy. Going to a LM4562 was more sterile and a little more detailed, the LM6172 even more so. If you use them directly to power headphones in a CMOY like setup, then current driving capacity is more important 1 Link to comment Share on other sites More sharing options...
Rej Ma Posted March 7, 2018 Share Posted March 7, 2018 On 8/16/2014 at 10:43 PM, A9X said: It was a very poor test to determine differences especially as the question was asked to pick a preference: this doesn't mean anyone actually heard a difference (and look at all the comments saying how hard it was) but simply believed they did, which is not the same thing. There was poor level matching, channel flips and some of the opamps were overloaded. There were no controls and easily available software to allow people to cheat by visually examining the files. It was of no more benefit than reading 6loons to determine the sound of something. If someone had done an ABX and reliably picked say the 5532 vs the 4562 when there was no possibility of cheating, I might believe you. And when I see it done, I will, but I haven't yet in some decades. This subject is so controversial . My 2 cents on this one is if I use a good pair of IME= (earphone) like the RHA CL750 or any other ones with the Knowles Balanced Armature, you will hear the difference if you listen to some electronic music, in Flac or aiff ( 24 bits) , The music is more direct than with some normal headphones. At the same time, we have to admit that many opamp will sound the same. Only once in a while we can really hear a real difference, if we know the song very well. Link to comment Share on other sites More sharing options...
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