Re: Straight Wire Test
Try the 20 741 opamp test. Unity gain vs. straight wire
like Richard Clark does. Make sure you correct any FR variations
caused by input/output impedance, let us know if this test is
valid. Sounds like a fun project -> can you distinugish between
20 cascaded opamps vs. straight wire. Imagine the implications
if you can fool people who listen to your test ? Maybe you
can make some money by gambling with folks? /hehe
Dave S said:Regarding KYW and his "straight wire test":
Why do most people seem to prefer an active preamp to a passive (even using the same volume control)?
This would appear to be a case where active devices (= signal manipulation, distortion etc) is preferable to straight wire.
Maybe I should try 20 X 741 is series??? Or maybe my wires are not straight enough? The electrons have a lot of corners to turn in op-amps, maybe vintage opamps with larger geometries do not have such tight corners?
BTW, I have not listened to NE553X for a while but I seem to recall it adds a fuzzy edge to the music and is a bit thin sounding compared to something like OPA627.
Try the 20 741 opamp test. Unity gain vs. straight wire
like Richard Clark does. Make sure you correct any FR variations
caused by input/output impedance, let us know if this test is
valid. Sounds like a fun project -> can you distinugish between
20 cascaded opamps vs. straight wire. Imagine the implications
if you can fool people who listen to your test ? Maybe you
can make some money by gambling with folks? /hehe
Don't think I'll bother, thanks.
I cannot get any op-amp circuit to sound as good as my scratch built grounded grid tube preamp and many op-amps sound better than straight wire with a pot (i.e. passive pre). I've seen the 12AU7A used in the GG described as a "tizzy little fart bottle" so where does that leave the straight wire?
I cannot get any op-amp circuit to sound as good as my scratch built grounded grid tube preamp and many op-amps sound better than straight wire with a pot (i.e. passive pre). I've seen the 12AU7A used in the GG described as a "tizzy little fart bottle" so where does that leave the straight wire?
Mr. van de Gevel's 5534 pre-amp design
Has anyone built up one of the "dynamic impedence" pre-amps that Marcel van de Gevel published in his October 2003 "Electronics World" article on cartridge noise? It looks like he is addressing some of the key issues regarding 5534 (or Op27) op amp limitations in his circuit--things hashed over repeatedly in this form and elsewhere. ...Just wondering if the thing sounds as good as one would expect from the throughtful design.
van de Gevel, Marcel, Noise and moving-magnet cartiridges. Electronics World, October 2003, pp 36-43
http://www.highburybiz.com/publications/publication.asp?headerID=ele&pubID=ewo
Has anyone built up one of the "dynamic impedence" pre-amps that Marcel van de Gevel published in his October 2003 "Electronics World" article on cartridge noise? It looks like he is addressing some of the key issues regarding 5534 (or Op27) op amp limitations in his circuit--things hashed over repeatedly in this form and elsewhere. ...Just wondering if the thing sounds as good as one would expect from the throughtful design.
van de Gevel, Marcel, Noise and moving-magnet cartiridges. Electronics World, October 2003, pp 36-43
http://www.highburybiz.com/publications/publication.asp?headerID=ele&pubID=ewo
"Originally posted by thylantyr
'Try the 20 741 opamp test. '
I don't think there will be a lot of takers of that good piece of advise.
because people are afraid of discovering how poor their hearing really is, "
Audio is full of those tests we would rather not do, whether is is B. Carver making a SS amp sould like a tube and, the guy who used coat hanger for interconnect wire or whatever. The nice thing about DIY is that even if I can't really hear the difference, knowing I built it myself is the big kicker.
'Try the 20 741 opamp test. '
I don't think there will be a lot of takers of that good piece of advise.
because people are afraid of discovering how poor their hearing really is, "
Audio is full of those tests we would rather not do, whether is is B. Carver making a SS amp sould like a tube and, the guy who used coat hanger for interconnect wire or whatever. The nice thing about DIY is that even if I can't really hear the difference, knowing I built it myself is the big kicker.
Folks, we have had these series IC tests for decades. As I remember a designer made one about 30 years ago to convince Mark Levinson that IC op amps were not audible. Oh well!
It seems, as we add more IC amps in series, the damage has been already been done with the first IC, and the rest don't count for much.
I have personally never heard an op amp IC beat an open loop discrete design, but I am told that the AD797 is darn good! And in many cases, superior to many discrete designs.
It seems, as we add more IC amps in series, the damage has been already been done with the first IC, and the rest don't count for much.
I have personally never heard an op amp IC beat an open loop discrete design, but I am told that the AD797 is darn good! And in many cases, superior to many discrete designs.
because people are afraid of discovering how poor their hearing really is
There is too much audio voodoo everywhere.
What is taboo in one audio industry is heaven in another
and visa versa.
The only thing that seems constant is speakers, people can
easily distinuish one from another, but they will spend
their whole lifetime trying to figure out what transistor
sounds better, eventually they have to pick something
as the winner.
Build an opamp circuit and socket the printed circuit
board. Insert the opamp that makes you happy
There is too much audio voodoo everywhere.
What is taboo in one audio industry is heaven in another
and visa versa.
The only thing that seems constant is speakers, people can
easily distinuish one from another, but they will spend
their whole lifetime trying to figure out what transistor
sounds better, eventually they have to pick something
as the winner.
Build an opamp circuit and socket the printed circuit
board. Insert the opamp that makes you happy
This will obviously be application specific but a good test is to insert an opamp in a chain where no gain is needed, adjust its gain for unity (possibly by input divider) and compare to a piece of wire. This will give you a good handle of the opamp intinsic sound.
If you cannot distinguish it from the wire you're probably using some very crappy wire or are blessed with Richard Clark's hearing syndrome. The average middle age male generally rates around 20-30 milliClarks (mC).
"It is my recollection that the preferred 5534 was from Raytheon actually, and someone used to test them for distortion and rebrand them. I think MA332, but google shows only a few obscure references. "
I've heard this as well. The company that rebranded them was Analog Systems, in Arizona. I used the Ma332, and other parts (MA336, dual FET in) in rechipping mixing consoles and audio processing boxes in the radio stations I worked in in the '80's. These chips were expensive, but sounded much cleaner than their counterparts. I still have some of each, and have rechipped a couple of cd players and again, the difference is not subtle.
There was a listing for them in the IC master, but I'm not getting any response via email or telephone.
I've recently come across some RC5534's, which I assume are Raytheon made. If they do sound different/better in circuit, I will post the info here.
I've heard this as well. The company that rebranded them was Analog Systems, in Arizona. I used the Ma332, and other parts (MA336, dual FET in) in rechipping mixing consoles and audio processing boxes in the radio stations I worked in in the '80's. These chips were expensive, but sounded much cleaner than their counterparts. I still have some of each, and have rechipped a couple of cd players and again, the difference is not subtle.
There was a listing for them in the IC master, but I'm not getting any response via email or telephone.
I've recently come across some RC5534's, which I assume are Raytheon made. If they do sound different/better in circuit, I will post the info here.
analog_sa said:
you need to be extra careful about those "crappy wires". a lot of them aren't "electron friendly" and force the electrons to jump up, down or spin in the wrong direction, adversely impacting the sound and creating way too much "jitters" from abrupt electron movements.
That is horrible for audio.
I wish someone can invent "electron carriers" that can smoothly transport electrons through those wires, much like a 1960s Buick Roadmaster crusing down I95. Then you will hear truly smooth music, not those crappy wires.
>It is my recollection that the preferred 5534 was from Raytheon actually, and someone used to test them for distortion and rebrand them.<
I have also experienced that "drop-in replacement" designs may sound (and sometimes behave) differently, depending on who the manufacturer is. For example, the OP37 from PMI/AD has a different tonal balance (among other things) from the nominally compatible OPA37 by BB/TI. I suppose that the semiconductor processes are different, and possibly the internal schematics as well.
I don't mean to claim that either device sounds "better" than the other, but depending on which '37 you start with, the rest of the circuit may possibly benefit from being voiced using different componentry, and in some cases, different component values to get a similar-sounding final result.
It has also been my experience that the same device type from the same manufacturer may sound different, depending on the choice of package. A plastic package can sound different from a ceramic one. A metal can seemingly sounds different again, but it is not really possible to _properly_ compare a metal can against any sort of DIP8 package, due to the different shape and the resulting impact on the pcb layout.
All of the above is subjective, and will depend on the rest of the design, operating environment and individual listener. OTOH, I would imagine that the preference for a Raytheon 5534 started out as a subjective choice, too.
jonathan carr
I have also experienced that "drop-in replacement" designs may sound (and sometimes behave) differently, depending on who the manufacturer is. For example, the OP37 from PMI/AD has a different tonal balance (among other things) from the nominally compatible OPA37 by BB/TI. I suppose that the semiconductor processes are different, and possibly the internal schematics as well.
I don't mean to claim that either device sounds "better" than the other, but depending on which '37 you start with, the rest of the circuit may possibly benefit from being voiced using different componentry, and in some cases, different component values to get a similar-sounding final result.
It has also been my experience that the same device type from the same manufacturer may sound different, depending on the choice of package. A plastic package can sound different from a ceramic one. A metal can seemingly sounds different again, but it is not really possible to _properly_ compare a metal can against any sort of DIP8 package, due to the different shape and the resulting impact on the pcb layout.
All of the above is subjective, and will depend on the rest of the design, operating environment and individual listener. OTOH, I would imagine that the preference for a Raytheon 5534 started out as a subjective choice, too.
jonathan carr
scott wurcer said:
I have a tube of 50 Raytheon RC5532N that I picked up on eBay a couple of years ago. Their part number on the chip and the tube is RC306. The tube in addition has a DO44134-000 number on it. Assembled in Philippines. I don't have anything with socketed dual opamps to use as a comparison vehicle other than a Rolls unbalanced to balanced converter box. It has some BA4560's in it.
janneman said:
How can you tell if the package is ceramic? the ones I have are black and have 532 3C1 stampped in white on the bottom.
Bernhard said:
Thanks Smarty Pants,
Sometimes things are not as obvious.
Are you saying that the ceramic chips are red with "I love Buffalo" on them? That's what some ceramic tea cups I have look like.
But seriously, ceramics come in different colors. Black could be one of them. Plastics come in different densities too. Without going into scratch tests I wanted to know how to tell. I don't think it was that stupid of a question.
Maybe there are different types of ceramic packages, but all the
ones I have seen look quite different from the plastic ones.
They are built somewhat like a sandwich, consisting of two thin,
flat, rectangular pieces of ceramic with the chip in between
these and the pins also coming out between at the side. You
should clearly see that there is some kind of sealing compound
between the two pieces of ceramic. Further, I think all the ones
I have seen have been grey, rather than black like the plastic
packages.
ones I have seen look quite different from the plastic ones.
They are built somewhat like a sandwich, consisting of two thin,
flat, rectangular pieces of ceramic with the chip in between
these and the pins also coming out between at the side. You
should clearly see that there is some kind of sealing compound
between the two pieces of ceramic. Further, I think all the ones
I have seen have been grey, rather than black like the plastic
packages.
Thanks, I ws hoping for that kind of answer.
I looked around and found a couple of images of cerdip
My Raytheons are not ceramic dip. Still, the difference in appearance is not that big.
I looked around and found a couple of images of cerdip
An externally hosted image should be here but it was not working when we last tested it.
My Raytheons are not ceramic dip. Still, the difference in appearance is not that big.
OK, for what it's worth, my opinion of 5532
I just took my Rolls Matchbox apart and compared 3 different op amps including the Raytheon RC5532N back to back. The other two were the stock Rohm BA4560 that came in the Rolls and a Burr Brown OPA2134. The application was balancing and driving a 20' line in to a JBL LSR25P nearfield studio monitor. The source- Toto IV SACD on a Philips SACD1000 player thorough a db preamp.
The stock opamp sounded a bit edgy and shallow. It made the SACD sound like a cheap CD player. The RC5532 sounded much more detailed and laid back in the midrange/treble (can't really compare the low end using a 5.25" woofer). The BB2134 had the same basic smooth and laid back character as the 5532 but with a touch more definition. The difference was not obvious as whe switching from the Rohm to 5532. I had to listen much more carefully and switch back and forth many times before grasping the differences. Both made the qualities of SACD come through.
In this particular setup the 5532 took the Matchbox 95% of the way to the performance of the 2134. I wonder why Rolls decided to save maybe $0.50 and went with the cheap opams. Maybe they preferred the more aggressive character of the cheap stuff. It does make the music cut through a background noise and exaggerates the midrange. I can see how it could be perceived as "good" in a project studio situation.
I have 47 of the RC5532 left and see no problems using them in some future projects. The money that otherwise would go toward $3.00 op amps can be spent upgrading caps and other parts.
I just took my Rolls Matchbox apart and compared 3 different op amps including the Raytheon RC5532N back to back. The other two were the stock Rohm BA4560 that came in the Rolls and a Burr Brown OPA2134. The application was balancing and driving a 20' line in to a JBL LSR25P nearfield studio monitor. The source- Toto IV SACD on a Philips SACD1000 player thorough a db preamp.
The stock opamp sounded a bit edgy and shallow. It made the SACD sound like a cheap CD player. The RC5532 sounded much more detailed and laid back in the midrange/treble (can't really compare the low end using a 5.25" woofer). The BB2134 had the same basic smooth and laid back character as the 5532 but with a touch more definition. The difference was not obvious as whe switching from the Rohm to 5532. I had to listen much more carefully and switch back and forth many times before grasping the differences. Both made the qualities of SACD come through.
In this particular setup the 5532 took the Matchbox 95% of the way to the performance of the 2134. I wonder why Rolls decided to save maybe $0.50 and went with the cheap opams. Maybe they preferred the more aggressive character of the cheap stuff. It does make the music cut through a background noise and exaggerates the midrange. I can see how it could be perceived as "good" in a project studio situation.
I have 47 of the RC5532 left and see no problems using them in some future projects. The money that otherwise would go toward $3.00 op amps can be spent upgrading caps and other parts.
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