hI,
I am just looking for thoughts on my upgrade of my system going from ad712 opamps to either opa2134 or 2 opa627. Is there a big difference in sound quality through these two?
(I already have 4 of each so cost is not a big deal, although finding the right adapter might be.
Thanks for your thoughts.
God bless...
Mark
I am just looking for thoughts on my upgrade of my system going from ad712 opamps to either opa2134 or 2 opa627. Is there a big difference in sound quality through these two?
(I already have 4 of each so cost is not a big deal, although finding the right adapter might be.
Thanks for your thoughts.
God bless...
Mark
2134
Hi Mark,
The two are very different designs. The OP 627 is an updated op 27. That was a very good low noise design. It was good also in IC based RIAA amps. The 2134 is a more modern design, with beefier output and much higher speed. I use it in place of NE 5532's, it is always better. What was the original chip in which instrument? What was the job of the chip you want to replace?
David
Hi Mark,
The two are very different designs. The OP 627 is an updated op 27. That was a very good low noise design. It was good also in IC based RIAA amps. The 2134 is a more modern design, with beefier output and much higher speed. I use it in place of NE 5532's, it is always better. What was the original chip in which instrument? What was the job of the chip you want to replace?
David
The GBW and Slew Rate of the 627 is higher than that of the 2134 (GBW of 16mhz versus 8, and a Slew Rate of 55 V/us versus 10). Furthermore, the noise performance of the 627 is about 50% better than the 2134.
I would say that if you want a quick drop in replacement to try out the Burr Brown/TI sound, pop in the 2134. If you would like to see what BB's best chips have to offer, get a browndog single-to-dual opamp adapter.
In my personal opinion, the 2134 is pretty mediocre, while the 627 sounds really nice. I can't spew audiophile words over it, just that the 627 sounds a lot better to my ears and there's really no comparison. This seems to be inline with most folks opinions on those two opamps. (And even against the "better" version fo the 134/2134, the 132/2132)
The brown dog adapters can be purchased here:
http://www.cimarrontechnology.com/index.asp?PageAction=VIEWCATS&Category=5
I'm sending the link because it's not fun to google for, and doing site searches on most forums won't yield the site
Good luck and welcome to the wonderful world of op-amp rolling!
I would say that if you want a quick drop in replacement to try out the Burr Brown/TI sound, pop in the 2134. If you would like to see what BB's best chips have to offer, get a browndog single-to-dual opamp adapter.
In my personal opinion, the 2134 is pretty mediocre, while the 627 sounds really nice. I can't spew audiophile words over it, just that the 627 sounds a lot better to my ears and there's really no comparison. This seems to be inline with most folks opinions on those two opamps. (And even against the "better" version fo the 134/2134, the 132/2132)
The brown dog adapters can be purchased here:
http://www.cimarrontechnology.com/index.asp?PageAction=VIEWCATS&Category=5
I'm sending the link because it's not fun to google for, and doing site searches on most forums won't yield the site
Good luck and welcome to the wonderful world of op-amp rolling!
OPA 627
Hi.
I have just had a good look through the 627 datasheet. I was reffering to the OP 27 when I said the 2134 is better. The 2134 is not as bad as someone said here, it just likes good bypassing, etc, to work well.
The 627 could well be a better sounding device. But you will need an adapter if you replace a 5532 or any dual opamp. I am interested how your experiment works out, I may get some of these 627's myself..
David.
Hi.
I have just had a good look through the 627 datasheet. I was reffering to the OP 27 when I said the 2134 is better. The 2134 is not as bad as someone said here, it just likes good bypassing, etc, to work well.
The 627 could well be a better sounding device. But you will need an adapter if you replace a 5532 or any dual opamp. I am interested how your experiment works out, I may get some of these 627's myself..
David.
opa 627 and 2134...
Hi Everyone,
Thanks for all the great advice and opinions. Today I installed an 8pin dip adapter into my Parasound preamp so I can swap opamps out easily and quickly. I tested the opa2134 vs the ad712 that were stock. (Opa2134 is not broken in at all, so it will most likely get better w/time) The base is much better from the 2134, but it does not seem to be as powerful on the output side, but could just be the break-in needed.
I plan to get the brown dog adapters and try the opa 627's soon. I will update this page in a week or two when they're in.
God bless...
Mark
Hi Everyone,
Thanks for all the great advice and opinions. Today I installed an 8pin dip adapter into my Parasound preamp so I can swap opamps out easily and quickly. I tested the opa2134 vs the ad712 that were stock. (Opa2134 is not broken in at all, so it will most likely get better w/time) The base is much better from the 2134, but it does not seem to be as powerful on the output side, but could just be the break-in needed.
I plan to get the brown dog adapters and try the opa 627's soon. I will update this page in a week or two when they're in.
God bless...
Mark
Re: OPA 627
I love the 627 and the 637. They're great sounding chips. I also like the AD8610/8620. The easiest way to go dual with the 627/637 is to buy a dual SMD opamp to single DIP adapter from browndog, and solder down the two SMD 627/637's. This keeps the traces shorter than doing a dual-DIP to single-DIP swap.
I'm still waiting to try my AD8065/8066 chips as well. They're supposedly far better than the 8610/8620.. I'm just lazy and haven't given them a critical listen yet.
I have to say that one of the OP amps I'm surprised by at the quality is the AD746. It's an older Analog Devices one. It's comparable to the 627, but it's slightly slower, faster slew rate, and a little higher noise. Still pretty good sounding though, with a beefy PSU.
Brian: I also agree -- With the exception of mechanical devices, I don't think parts really "break-in" .. if anything, their specs drift to worse than when they were brand new. I've always thought that it was more of your brain getting used to the changes in the sound. But I'm gonna drop out of that convo, since it'll stir up a firestorm
David Nessim said:
I love the 627 and the 637. They're great sounding chips. I also like the AD8610/8620. The easiest way to go dual with the 627/637 is to buy a dual SMD opamp to single DIP adapter from browndog, and solder down the two SMD 627/637's. This keeps the traces shorter than doing a dual-DIP to single-DIP swap.
I'm still waiting to try my AD8065/8066 chips as well. They're supposedly far better than the 8610/8620.. I'm just lazy and haven't given them a critical listen yet.
I have to say that one of the OP amps I'm surprised by at the quality is the AD746. It's an older Analog Devices one. It's comparable to the 627, but it's slightly slower, faster slew rate, and a little higher noise. Still pretty good sounding though, with a beefy PSU.
Brian: I also agree -- With the exception of mechanical devices, I don't think parts really "break-in" .. if anything, their specs drift to worse than when they were brand new. I've always thought that it was more of your brain getting used to the changes in the sound. But I'm gonna drop out of that convo, since it'll stir up a firestorm
Re: Re: OPA 627
Parts do "break-in" -- and I was a skeptic -- every chipamp I have built I test on a scope -- the very first turn-on you get some nasty oscillations for perhaps a second or so -- all subsequent turn-ons are fine -- I don't know whether it's the chip itself, the electrolytics etc.
Certain resistors absorb moisture and drift through time -- they will have different values depending upon the amount of time they are in use AND the relative humidity --
i don't think that opamps get better or worse with age.
motherone said:
Brian: I also agree -- With the exception of mechanical devices, I don't think parts really "break-in" .. if anything, their specs drift to worse than when they were brand new. I've always thought that it was more of your brain getting used to the changes in the sound. But I'm gonna drop out of that convo, since it'll stir up a firestorm
Parts do "break-in" -- and I was a skeptic -- every chipamp I have built I test on a scope -- the very first turn-on you get some nasty oscillations for perhaps a second or so -- all subsequent turn-ons are fine -- I don't know whether it's the chip itself, the electrolytics etc.
Certain resistors absorb moisture and drift through time -- they will have different values depending upon the amount of time they are in use AND the relative humidity --
i don't think that opamps get better or worse with age.
breakin...
Hi Guys
I do think that electronics do break in and sound better with a few hours of use. I think the that 2134's are sounding better, louder at same vol setting, louder tighter bass etc.
I ordered the brown odg adapters, so I should be able to test the opa 627 by the end of the week or next week. Can't wait.
God bless...
Mark
Hi Guys
I do think that electronics do break in and sound better with a few hours of use. I think the that 2134's are sounding better, louder at same vol setting, louder tighter bass etc.
I ordered the brown odg adapters, so I should be able to test the opa 627 by the end of the week or next week. Can't wait.
God bless...
Mark
Radian,
I have to disagree with your assertion on Carlos's methods "improving" the sound. Carlos prefers to state things based on what he thinks he hears, rather than actually taking out a 'scope and measuring them.
If you are REALLY interested in seeing work done with opamps correctly, please check out the head-fi message boards. PPL, Tangent and others have been designing very high end headphone amplifiers around all sorts of various op-amps.
I only state this because I have tried it. I have a small headphone amplifier 4x 470uF cerafines on the power rails, 2x 3.3uF bypassing it, and 2x .1uF ceramics on the pins of the opamp (it's a "dual" socket). I heard absolutely NO difference between any of the chips that I tried in the socket (OPA2132/4, 627/637, AD8620, etc.).
I also want to state that bypassing Op-amps IS critical to prevent oscillations. On lower-speed opamps (2132/2134), it is far less critical than on the new-fangled high-speed tech that's out. I'm just trying to state that I believe in proper bypassing, but I disagree with Carlos's assertion that the only way to get "proper sound" out of any opamp is to put the bypass caps directly on the pins, otherwise they "sound horrible".
I'd be much more inclined to listen to him if he actually bought an oscilloscope and posted graphs on how he tested. This is what a lot of the head-fi folks do. Furthermore, I would say that headphones will be far more sensitive to any problems with an opamp than a speaker would be.
I have to disagree with your assertion on Carlos's methods "improving" the sound. Carlos prefers to state things based on what he thinks he hears, rather than actually taking out a 'scope and measuring them.
If you are REALLY interested in seeing work done with opamps correctly, please check out the head-fi message boards. PPL, Tangent and others have been designing very high end headphone amplifiers around all sorts of various op-amps.
I only state this because I have tried it. I have a small headphone amplifier 4x 470uF cerafines on the power rails, 2x 3.3uF bypassing it, and 2x .1uF ceramics on the pins of the opamp (it's a "dual" socket). I heard absolutely NO difference between any of the chips that I tried in the socket (OPA2132/4, 627/637, AD8620, etc.).
I also want to state that bypassing Op-amps IS critical to prevent oscillations. On lower-speed opamps (2132/2134), it is far less critical than on the new-fangled high-speed tech that's out. I'm just trying to state that I believe in proper bypassing, but I disagree with Carlos's assertion that the only way to get "proper sound" out of any opamp is to put the bypass caps directly on the pins, otherwise they "sound horrible".
I'd be much more inclined to listen to him if he actually bought an oscilloscope and posted graphs on how he tested. This is what a lot of the head-fi folks do. Furthermore, I would say that headphones will be far more sensitive to any problems with an opamp than a speaker would be.
jean-paul said:
Unbelievable. You are one of the few in this galaxy that don't hear differences
Apologies Jean-paul. I should have added "I could tell no difference between them in the board WITH the decoupling caps on the pin and the one without" to that sentence.
Looking back at the post, I didn't make my point clearly. I wasn't comparing those opamps to each other, rather I was comparing those opamps with the bypasses on the pins versus without.
There was no audible difference with the bypasses versus without. The only bypassing on board was the pair of 3.3uF caps listed above, and they were approximately 1" away from the opamps (a rough guesstimate -- i haven't measured)
Mike
I really thought you meant what I read ! I could have known if I had taken the time to read your previous posts.BTW break-in of opamps is not that strange. Most sound better after having been under voltage for a few days. Just as caps.
About Carlos decoupling scheme; I do not know what he cooked up for OPA2134 but in casus OPA627 and several other types I can tell that a 100 to 220 nF cap from + to - directly on the chips makes a difference. OPA627 likes the decoupling caps a bit bigger than usual, say 100 uF Panasonic FC or so.
motherone said:
You must be very hard at work !
I have OPA627's on a Stokes SDS class A headphone amplifier, before those i tried lower priced opamps.
I do hear a difference between two different Burr Brown numbers.
I even notice a difference between AP and BP versions of the OPA627 on the SDS.
Sounded like you had a cheap hobby, Motherone !
But i did read you first posting earlier, thank goodness.
Those little critters are so sensitive, an inch can be a long way.
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