Hi diyralf,
-Chris
jean-paul is right on all counts. Quality E-I cores are what I tend to use, R-cores would be acceptable too. A Toroid type transformer is the worst one to use. 40 years of experience shows me this is true. Plitron had to redesign their products to be frequency selective, now what does that tell you?
-Chris
Support from a moderator. The day can't go wrong 
BTW Rcores have way less stray field than EI types which can be useful. Although I see it as bad design practice they can be mounted ridiculously close to sensitive electronics. With smaller than 20VA types think of a few millimetres (depending on type/make). Don't do it though, clearance is a right for valuable electronics.
BTW Rcores have way less stray field than EI types which can be useful. Although I see it as bad design practice they can be mounted ridiculously close to sensitive electronics. With smaller than 20VA types think of a few millimetres (depending on type/make). Don't do it though, clearance is a right for valuable electronics.
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I'm quite sure they would be unnecessary to him. Never underestimate the power of nocebo!
I have nothing against new, expensive components. I just want to tell you that in this case, there is nothing to get 500uV less noise. The impact on the sound is 0.000. These chips have been developed for battery operation devices and for measurement technology devices.Worst reasoning ever. Like we are in DIY audio because it is cheaper to DIY
How can you state this when you haven't even tried these regulators ?
This is pure assumption..... and assumption is the mother of ****ups.
It is also not about the price which probably is even lower then LM317 when bought in volumes. Sometimes a better apart comes around, why not use that part when it performs better, is smaller, generates less heat, takes less board space etc. ? If you use that way of thinking you would still be driving a Trabant as it serves the purpose right You go from A to B exactly the same as with newer more fuel economic cars.
This is pure assumption..... and assumption is the mother of ****ups.
It is also not about the price which probably is even lower then LM317 when bought in volumes. Sometimes a better apart comes around, why not use that part when it performs better, is smaller, generates less heat, takes less board space etc. ? If you use that way of thinking you would still be driving a Trabant as it serves the purpose right
You go from A to B exactly the same as with newer more fuel economic cars.
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Good practice but not necessary with Rcore types at least I haven't experienced it with a single Rcore type. Only toroids seem to have this phenomenon in such an annoying way. In the past I have thrown away perfectly good measuring ILP/Amplimo toroids as they were unusable because of this terrible humming. I know some brands used DC blockers on large EI transformers so it is not exclusive to toroids.
Second drawback of toroids is their relatively high bandwidth which really is a showstopper in audio (well not when you use them as output transformer). They don't function as much as a filter as other types do. They let through more mains garbage than other types so to speak. I must admit that I have kept a blind eye to toroids for a long time as they indeed are easy to mount, cost a few Euro and can be found everywhere. This does not take away that they are not the best choice in audio.
Second drawback of toroids is their relatively high bandwidth which really is a showstopper in audio (well not when you use them as output transformer
). They don't function as much as a filter as other types do. They let through more mains garbage than other types so to speak. I must admit that I have kept a blind eye to toroids for a long time as they indeed are easy to mount, cost a few Euro and can be found everywhere. This does not take away that they are not the best choice in audio.
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To summarize: for these one-off projects, go on and use the nice components because if you start charging yourself even $5/hr (or Euro), your BOM is dominated by labor, and you might as well enjoy the product to its fullest and not feel a need later to tear the whole thing apart again.
I tend to scavenge my transformers, so primarily EI cores for small stuff. If I'm good, I try to keep them on the opposite side of the case from the sensitive electronics and only bring the reg board close to the circuit.
I tend to scavenge my transformers, so primarily EI cores for small stuff. If I'm good, I try to keep them on the opposite side of the case from the sensitive electronics and only bring the reg board close to the circuit.
To summarize: for these one-off projects, go on and use the nice components because if you start charging yourself even $5/hr (or Euro), your BOM is dominated by labor, and you might as well enjoy the product to its fullest and not feel a need later to tear the whole thing apart again.
Yep that's it. Also when for instance designing a PSU chances are likely it will be reused when the device itself does not please. A well designed ultra low noise PSU can and will be reused. Plain standard stuff does not belong in your shiny new high end preamp design.
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I do have a weak spot in my heart for scrounging around my parts bin, but that stems from the joy of tinkering with what's in front of me rather than any legit form of optimal effort. On the flipside, it's fun building things that are far beyond what I'd hope I could hear.
And yes, line level voltages aren't moving around too much from design to design, so component portability and confidence that things work are nice features.
And yes, line level voltages aren't moving around too much from design to design, so component portability and confidence that things work are nice features.
I wouldn't rely too much on specific brands or part numbers.
Time is big issue. A 741 build today is unlikely the same part as it was 50 years ago. A 5534 may have been a cutting edge design difficult to build with lots of out of spec units in the 1970s, but processes and materials have improved since then.
I really doubt that companies like Ti have production lines for hundreds of different opamps. Instead they would print any part number on their devices, whatever their sales department tells them to do.
Good info regarding the transformers, thanks.
I don’t understand stand the ne5534 cult status, besides it being generally well balanced. I keep some around for testing out new circuits where I don’t want to risk losing better parts, or the possibility of faster parts oscillating.
I replaced the ones I had last used with some fet input, discrete op amps. I pretty much forget that they are in there.
I don’t understand stand the ne5534 cult status, besides it being generally well balanced. I keep some around for testing out new circuits where I don’t want to risk losing better parts, or the possibility of faster parts oscillating.
I replaced the ones I had last used with some fet input, discrete op amps. I pretty much forget that they are in there.
a. The original 741 is not made anymore. All current 741 versions are different but mimic the original one.
http://www.ti.com/lit/ds/symlink/lm148-n.pdf
b. you know that TI used to publish pictures of the different dies in their datasheet books ? I know some companies rebrand their own IC's but this can not count for hundreds of types.
Modern production is indeed often designing one final design and then downgrade it to create different versions. This strongly depends of the final purpose aka audio is the usual suspect. Industrial stuff that needs special features like ultra low input current etc. ARE different IC's. That some of those may also be remarked as audio type only seems logical. Any company likes to produce volumes and audio is not one of the largest markets. Simple.
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I would dispute that, car audio and portable audio are massive production quantity markets. What is niche are the enthusiast segments of the markets.
That's far from the truth, there are actually very few cases where this is true. Often downgraded specs for the audio/consumer market where no DC precision, etc. are needed. There are dozens of mask sets in any major op-amp portfolio.
I agree, it's logical, and healthy for us when the 'audio' part is more accessible too. Although in the modern era that is hardly an issue.
I bought one of these BA1 LM3886 2.1 channel amplifier.
Now, This amp is connected to a small 8" subwoofer in 4 ohms and 2 bookshelf speakers in 8ohm. This is the only amplifier I could find that does 2.1 channel and has a crossover to properly separate the frequencies. You can get the crossover cutoff set to whatever you like, I do believe it is 18db but not sure. Anyway, I digress....
The result is far better than I had imagined. In fact of all the amplifiers I have owned, this is a close 2nd. Among many brands and models from Nad to Sony ES, the brand and Models that stood out most was Harman Kardon HK-990. The comparison was not close. This small chinese amp is much better. Surprisingly! I then had the HK-3490 which replaced the HK-990. Big difference. HK-3490 won and still is best sound I have heard on my speakers. However, this small Chinese amp is close second and im not even remotely joking. On my speakers, this little amp is amazing.
Why am I stating all this?
Cause is uses the 5532 op amps. It has 2. I am trying to figure out what is a drop in replacement without any modification to the circuit. So far I suspect
the OPA2604, LM4562, LME49860.
Id like clarification before trying this procedure.
Thank you
Now, This amp is connected to a small 8" subwoofer in 4 ohms and 2 bookshelf speakers in 8ohm. This is the only amplifier I could find that does 2.1 channel and has a crossover to properly separate the frequencies. You can get the crossover cutoff set to whatever you like, I do believe it is 18db but not sure. Anyway, I digress....
The result is far better than I had imagined. In fact of all the amplifiers I have owned, this is a close 2nd. Among many brands and models from Nad to Sony ES, the brand and Models that stood out most was Harman Kardon HK-990. The comparison was not close. This small chinese amp is much better. Surprisingly! I then had the HK-3490 which replaced the HK-990. Big difference. HK-3490 won and still is best sound I have heard on my speakers. However, this small Chinese amp is close second and im not even remotely joking. On my speakers, this little amp is amazing.
Why am I stating all this?
Cause is uses the 5532 op amps. It has 2. I am trying to figure out what is a drop in replacement without any modification to the circuit. So far I suspect
the OPA2604, LM4562, LME49860.
Id like clarification before trying this procedure.
Thank you