The No.1 Website for Pro Audio
TI 5532 and TL 072 vs. BB OPA 2134 and LT 1355
Old 21st January 2007
  #1
TI 5532 and TL 072 vs. BB OPA 2134 and LT 1355

How interchangeable are 5532s with TL 072s ?

And what are the potential issues if swapping BB 2134s or LT 1355s in the place of either?



thank yous,
Old 21st January 2007
  #2
Lives for gear
 
JohnRoberts's Avatar
 
🎧 15 years
Quote:
Originally Posted by lucey ➡️
How interchangeable are 5532s with TL 072s ?

And what are the potential issues if swapping BB 2134s or LT 1355s in the place of either?



thank yous,
In general the bipolar 5532 and bifet 07x series are not interchangable. There are newer versions of both with improved performance. I am not familiar and couldn't easily google data sheets on 2134 or 1355s.. There are plenty here happy to tout their favorite new opamp, so I'm sure you'll get plenty of suggestions.

JR
Old 22nd January 2007 | Show parent
  #3
Gear Addict
 
Minion's Avatar
 
🎧 15 years
Quote:
Originally Posted by JohnRoberts ➡️
In general the bipolar 5532 and bifet 07x series are not interchangable. There are newer versions of both with improved performance. I am not familiar and couldn't easily google data sheets on 2134 or 1355s.. There are plenty here happy to tout their favorite new opamp, so I'm sure you'll get plenty of suggestions.

JR
You can switch TL072 with OPA2134 pretty safely and and sometimes you can swap NE5532 with TL074 in Low input impednace Opamp configureation....

It totally depends on the circuit....
Old 22nd January 2007 | Show parent
  #4
Gear Addict
 
svart's Avatar
 
🎧 15 years
You have to look at each part's input devices. 5532 are BJT and tl072,opa2134 are JFET input.

The bipolar inputs are very touchy concerning DC offsets and such, the JFETs are not as touchy and can be used without DC coupling caps in many cases.

A rule of thumb is that you DO NOT replace a JFET opamp with a BJT opamp but you CAN replace a BJT opamp with a JFET opamp in most cases.

you could eventually replace the JFET opamp with a BJT opamp but you must be careful.
Old 22nd January 2007 | Show parent
  #5
Quote:
Originally Posted by svart ➡️
You have to look at each part's input devices. 5532 are BJT and tl072,opa2134 are JFET input.



A rule of thumb is that you DO NOT replace a JFET opamp with a BJT opamp but you CAN replace a BJT opamp with a JFET opamp in most cases.

thanks, that's useful.

So are there any sure fire drop ins for 5532s?
Old 22nd January 2007 | Show parent
  #6
Lives for gear
 
🎧 15 years
Hi
There are no 'sure fire' drop ins for anything although many will be OK in most instances you must ALWAYS CHECK for power consumption and oscillation under all circumstances then check for all operating parameters. Newer 'whizzy' chips may just oscillate given a suspect board layout so you have to test thoroughly.
A wonder chip may look good on paper but if you can't stop it oscillating at 10MHz in your application then you are actually worse off.
Generally using a BJT type in a circuit designed for FET can suffer due to lower input impedance and a significant bias current. This will often mess up EQ sections for example (unless it was designed for BJT).
Read the 'fantasy' thread on GS, buy a few chips and try them out.
Matt S
Old 22nd January 2007 | Show parent
  #7
Quote:
Originally Posted by Matt Syson ➡️
Read the 'fantasy' thread on GS, buy a few chips and try them out.
Matt S
Thanks I'll look for that one.

In this application I've used LT 1355s in place of TL 072s with good success. Am now looking to use a 5532 alternate as well. (In the past have used the OPA 627 over 5534s with good success but it's pricey.)

thanks all,
Old 23rd January 2007 | Show parent
  #8
Gear Addict
 
svart's Avatar
 
🎧 15 years
can I ask why you are replacing 5532s?

some of the various manufacturers make a very good 5532 version.

The old Signetics/Phillips 5532 was/is a very good IC, and many are saying the JRC chip is good as well.

SSL uses them like jellybeans with very good results, but in certain applications. they do use higher speed parts in the more important areas like summing amps though.

Also, the 5534 is a very good part as well. very neutral, stable, and low noise. Of course this is accounting for proper design, layout, etc.

Last edited by svart; 23rd January 2007 at 05:02 PM.. Reason: more info
Old 23rd January 2007 | Show parent
  #9
Gear Guru
Quote:
Originally Posted by svart ➡️
can I ask why you are replacing 5532s?

some of the various manufacturers make a very good 5532 version.

The old Signetics/Phillips 5532 was/is a very good IC, and many are saying the JRC chip is good as well.

SSL uses them like jellybeans with very good results, but in certain applications. they do use higher speed parts in the more important areas like summing amps though.

Also, the 5534 is a very good part as well. very neutral, stable, and low noise. Of course this is accounting for proper design, layout, etc.
The reason is Brian has heard better and wants better. If you heard what we have heard, you would not be happy with the sound of these 1976 dinosaurs.
Heck, even Rip Van Winkle woke up after 20 years. It's like a computer geek still using a Commodore 64. Remember, these are the parts that drove up the price for discrete consoles...

Jim Williams
Audio Upgrades
Old 23rd January 2007 | Show parent
  #10
Gear Addict
 
svart's Avatar
 
🎧 15 years
I'm on the fence about this subject.

I have parts such as lm6172s in key areas and I have parts such as the 5532 in other areas. Sometimes I like one or the other, sometimes a combination of both.

I'm not saying that the 5532 shouldn't be replaced, I simply asked why.

I went through a few years of trying every opamp in the book and for the most part I came to the conclusion that certain circuits can benefit from high speed/bandwidth and those that are simply just "good enough". I have channels full of AD825s, on little daughtercards that I made to fit the DIP sockets to replace 5532s and I have channels full of discrete opamps, some homemade, some designed by others, some purchased, but all tested.

I can't stress enough that I keep coming back to the 5532 channels for general work. I find that the others are rather good for a few things and terrible for others, but for general use I still go to the 5532 channels.

Drop in replacements are limiting to your choices. I prefer designing with CFB parts, but rarely do I have an application that I can easily drop one into an existing design without seriously thinking about it. Should I recommend that everyone dig out all their 5532s, drop them in a trashcan and jump on the AD812 for their replacements? nah, most of the time something else in the audio path will limit that potential DC-to-light bandwidth that I would have gained anyway. Remember that you can change all your opamps but one and that single part will limit all your other work.

That being said, I'll give you a little story about a recent bit of swapping fun I've had. I've been playing around with an Mx-2424, a unit that I believe you disliked Mr. Williams, because honestly it sounds like a towel is over the mic when playing back. It had opa2604 opamps on the I/O stages and 2 generation old AD/DA converters. I swapped out the opamps for lm6172, which worked without a hitch, and swapped out the AD/DA converters with the latest generation (with some minor irritation because of a new pinout, thanks AKM). I found a little more clarity but not much at all, and definately not what I was hoping for. I bypassed the input analog stages completely and found the same general tone to the audio upon playback. Further testing is slated for the outputs but it seems that the processing is doing something to the audio itself.

So I swapped out a number of parts and arrived at a conclusion that the problem is elsewhere and truly gained nothing except for some knowledge. But hey that's why I do it anyway.

So if I can offer any bit of advice, it's that do what sounds good. If you are trying to hear a cricket fart in your neighbor's garden, go for the fastest parts you can afford and then switch back when you find that the cymbals you recorded are now so painful to listen to that your dog runs for cover when you juice up the stereo.

heh
Old 23rd January 2007 | Show parent
  #11
Quote:
Originally Posted by svart ➡️
SSL uses them like jellybeans with very good results, but in certain applications. they do use higher speed parts in the more important areas like summing amps though.

Also, the 5534 is a very good part as well. very neutral, stable, and low noise. Of course this is accounting for proper design, layout, etc.
I get your point about the workhorse element, yet I find them to be slow, shallow, and to have a brittle top. In a mastering eq I've used OPA627s with a great result. In this case it's a summing amp of a small console so not so huge of a deal, just asking around for ideas.

thanks,
Old 23rd January 2007 | Show parent
  #12
Gear Addict
 
svart's Avatar
 
🎧 15 years
In a mastering EQ, like the Sontec? In the original, the filter opamps were 5534, in this duty there isn't much need for speed. However, the I/O opamps were special discretes that were CFB and had a slew between 200 and 600v/us. The 5534 was part of the sound of the unit. change those and you change the sound to something different, not necessarily better.
Old 24th January 2007 | Show parent
  #13
Quote:
Originally Posted by svart ➡️
In a mastering EQ, like the Sontec? In the original, the filter opamps were 5534, in this duty there isn't much need for speed. However, the I/O opamps were special discretes that were CFB and had a slew between 200 and 600v/us.
A Focusrite 315 mkii ... which had over 60 5534s in it and sounded terribly shallow, distorted and 'colored'. Now there are all OPA 627s where audio is passed, 40 some caps removed, the output stage unbalanced and simplified with fewer parts. It sounds great ... still a slight IC quality but very pure.
Old 24th January 2007 | Show parent
  #14
Lives for gear
 
JohnRoberts's Avatar
 
🎧 15 years
I am not inclined to make sweeping statements about what opamps "sound" like. That's an incomplete statement. An opamp can only have a "sound" in a circuit application, and then how much it might color or deviate from linear depends on how hard it's working. OK, that's a simplification but IMO the reality is it all depends.

Sure some parts may be 20 years old but human hearing still only goes up to 20 kHz or so and these are adequately fast. There are newer quieter parts but we still have mix down noise floors limited by the thermal noise in microphones.

I would suggest paying attention to the difficult circuit applications (like sum bus and mic pre amps) and make upgrades there if they sound better in listening trials.

Making across the board swaps of every part with expensive SOTA opamps is wasting good money that could have been used to buy me beer(s)... or one of those new directional line cords.

JR

PS: for the record there are much improved newer subs for both the 5532 and TL07x. While not terminally flawed the old soldiers do leave room for improvement when heavy lifting is involved.
Old 24th January 2007 | Show parent
  #15
Quote:
Originally Posted by JohnRoberts ➡️
I am not inclined to make sweeping statements about what opamps "sound" like. That's an incomplete statement. An opamp can only have a "sound" in a circuit application, and then how much it might color or deviate from linear depends on how hard it's working. OK, that's a simplification but IMO the reality is it all depends.

Sure some parts may be 20 years old but human hearing still only goes up to 20 kHz or so and these are adequately fast. There are newer quieter parts but we still have mix down noise floors limited by the thermal noise in microphones.

I would suggest paying attention to the difficult circuit applications (like sum bus and mic pre amps) and make upgrades there if they sound better in listening trials.

Making across the board swaps of every part with expensive SOTA opamps is wasting good money that could have been used to buy me beer(s)... or one of those new directional line cords.

JR

PS: for the record there are much improved newer subs for both the 5532 and TL07x. While not terminally flawed the old soldiers do leave room for improvement when heavy lifting is involved.
So I "wasted my money"? Thanks.

20-20k isn't the issue, it's slew rate and distortion and bias, etc. .... and how it all plays together as a whole. That comes back to design intent, and the fundamental view of the designers. In my experince an ICs speed can easily be heard in details and distortion vs slower players ... and ICs definitely have a sound. The circuits do change but they dont change a part's intrinsic qualitites. A 5534 has a similar sound quality in everything. That sound may play well or not, with other things in the chain, but it's still there. If ICs didn't have a sound there would be no point in changing them out in the same or very similar circuits, as no one would hear anything worth paying for. The difference between 5534s and OPA627s was not subtle in the Blue 315. I'm sorry you couldn't hear it for yourself.

Actually, all audio companies tend toward having a family sound as well. I'm not sure how company culture and intentions and design variations become a 'family sound' but it's always there. ( And as in life, there are always exceptions.)
Old 24th January 2007 | Show parent
  #16
Lives for gear
 
JohnRoberts's Avatar
 
🎧 15 years
Quote:
Originally Posted by lucey ➡️
So I "wasted my money"? Thanks.

20-20k isn't the issue, it's slew rate and distortion and bias, etc. .... and how it all plays together as a whole. That comes back to design intent, and the fundamental view of the designers. In my experince an ICs speed can easily be heard in details and distortion vs slower players ... and ICs definitely have a sound. The circuits do change but they dont change a part's intrinsic qualitites. A 5534 has a similar sound quality in everything. That sound may play well or not, with other things in the chain, but it's still there. If ICs didn't have a sound there would be no point in changing them out in the same or very similar circuits, as no one would hear anything worth paying for. The difference between 5534s and OPA627s was not subtle in the Blue 315. I'm sorry you couldn't hear it for yourself.

Actually, all audio companies tend toward having a family sound as well. I'm not sure how company culture and intentions and design variations become a 'family sound' but it's always there. ( And as in life, there are always exceptions.)

I do not debate with people about what they hear, it irritates them and wastes my time. If you're happy with your decision, relax and enjoy.

I was offering general advice based on my personal experience and not trying to comment on any specific choices you made. I was only addressing you directly with my earlier post that NE5532 and TL07x series are not interchangeable, but again that was based on my experience too so YMMV.

JR
Old 24th January 2007 | Show parent
  #17
Gear Addict
 
svart's Avatar
 
🎧 15 years
Quote:
slew rate and distortion and bias
Yes sometimes they are used as buzzwords, that's a terrible fact these days.

Yes these can have a huge impact on sound but so can the noise on the voltage rails, RF noise on the ground system, impedance mismatching between stages and between channels and bussing, caps between stages, etc.

There is more to the sound than opamps. Sometimes you get lucky and swapping parts sounds great, sometimes it's a placebo.

60 opa627s is close to 600$ in opamps alone!

While we may trust that the opa series was designed with audio in mind, does that change the fact that I find the 604 series nasal while the 134 series is very scooped in the mids? Nope, I hear what I hear. For someone else in another situation, they sound great. I have a large amount of modified equipment that has 627's, some of them have identical units with the 5534 installed. While each one has a very slight sonic flavor, once married to a particular duty, it's impossible to tell which is which. Again, this is limited to other parts/forces in the audio chain. The least common denominator determines your performance.

I still think that what you are hearing might be an "effect" of sorts, not necessarily because of the slightly increased bandwidth, slew, etc. I've always found that a slight boost in HF gives the sense of higher fidelity without actually giving a higher quality.


Quote:
digital eq
As great as the Weiss stuff seems to be, you are comparing apples to oranges.

EDIT:

As a side note to explain my thoughts (and ones that agrees with your path as well as Mr. Williams), I work in RF engineering these days, primarily analog. In my own studies I have found that to truly replicate any signal, an opamp should be spec'd with at least 100 times more slew than needed. While most disagree with me, I have found that the micro transients riding on the audio carrier waves are generally flattened by anything less than 100v/us. This includes most if not all "audio" opamps. These tiny transients are indeed heard by our ears as definition in the audio. These transients also have a habit of making the audio harsh as well. Most audio opamps ignore these in order to make the audio more listenable and smooth. Controlling the slew is more important than just carelessly slamming back and forth into the rails.
Old 24th January 2007 | Show parent
  #18
Quote:
Originally Posted by svart ➡️

I still think that what you are hearing might be an "effect" of sorts, not necessarily because of the slightly increased bandwidth, slew, etc. I've always found that a slight boost in HF gives the sense of higher fidelity without actually giving a higher quality.
Yep, that's Basic IC Listening 101 ... and not my course of study at this pont.



Quote:
As a side note to explain my thoughts (and ones that agrees with your path as well as Mr. Williams), I work in RF engineering these days, primarily analog. In my own studies I have found that to truly replicate any signal, an opamp should be spec'd with at least 100 times more slew than needed. While most disagree with me, I have found that the micro transients riding on the audio carrier waves are generally flattened by anything less than 100v/us. This includes most if not all "audio" opamps. These tiny transients are indeed heard by our ears as definition in the audio. These transients also have a habit of making the audio harsh as well. Most audio opamps ignore these in order to make the audio more listenable and smooth. Controlling the slew is more important than just carelessly slamming back and forth into the rails.
thumbsup
Old 24th January 2007 | Show parent
  #19
Lives for gear
 
ulysses's Avatar
 
🎧 15 years
What a lot of people fail to understand is that slew rate is only audible or relevant when it's inadequate. It's kind of like the octane rating of gasoline - once it's above what is needed for the engine in question, any further increase has no value.
The slew rate needed from any particular amplifier is a function of the maximum signal level at the maximum frequency that will be encountered, and the load on the amp. That's it. You can calculate what the slew rate needs to be, and so long as you use an amp that has a slew rate higher than that, you're fine. If you do this, you will not get slew-induced distortion. "Upgrading" from a chip that does 20V/µS to 130V/µS will almost never offer any improvement by itself. Maybe the faster chip will also be better in some other parameter, but that's beside the point.
Here's a great article that gives a real-world example involving line driving amplifiers. It effectively conveys the variables and calculations involved, and can be applied somewhat to other circuits.
Old 25th January 2007 | Show parent
  #20
Lives for gear
 
JohnRoberts's Avatar
 
🎧 15 years
Quote:
Originally Posted by ulysses ➡️
What a lot of people fail to understand is that slew rate is only audible or relevant when it's inadequate. It's kind of like the octane rating of gasoline - once it's above what is needed for the engine in question, any further increase has no value.
The slew rate needed from any particular amplifier is a function of the maximum signal level at the maximum frequency that will be encountered, and the load on the amp. That's it. You can calculate what the slew rate needs to be, and so long as you use an amp that has a slew rate higher than that, you're fine. If you do this, you will not get slew-induced distortion. "Upgrading" from a chip that does 20V/µS to 130V/µS will almost never offer any improvement by itself. Maybe the faster chip will also be better in some other parameter, but that's beside the point.
Here's a great article that gives a real-world example involving line driving amplifiers. It effectively conveys the variables and calculations involved, and can be applied somewhat to other circuits.
While I don't want to add fuel to the all XYZ opamps sound like crap thesis, I'm afraid your slew rate is like octane is a bit of an over simplification. That said I find SVART's 100x headroom rule a bit too much in the other direction.

My personal thesis on this is that slew limiting along the rate of change axis is kind like an old tube amp voltage clipping along the amplitude axis. The tube amp starts getting progressively worse X dB before actual saturation. However even this is a simplification, since slew rate is routinely measured in an overdriven, input stage saturated mode. What would be useful is a measure of linearity of the rate of slew rate change over it's useful range. Some opamps designed for say S/H applications can have incredible slew rate in transition but horrible slew linearity in a useful range for audio.

While there is no existing metric that I am aware of that simply measures this slew linearity characteristic I have long been a fan of two-tone in band IMD testing. I rolled my own 19:20 kHz test set back in the '70s and found it's IMD measurements correlated better than THD, etc in audio design with sound quality.

Another consideration wrt slew rate, IMO any properly designed audio path will LPF the very front end so you can't approach slew limiting for any valid (not clipped) audio input. In these IMO properly designed audio paths there is no meaningful slew rate spec, but instead a rise-time spec. Marshal Leach described this in an AES paper about an improved power amp front end, but this doesn't have to be incorporated into active stages to work and could be a simple passive filter.

I did a phono pre back in the '80s where I applied the RIAA playback EQ's 75uSec pole before any negative feedback. You couldn't possibly slew limit that unit and it would shrug off a 2V 20kHz or higher frequency square wave, but I digress.

So yes, slew rate can matter when you don''t have enough, but IMO not a huge issue for a couple of decades now. It's not how fast it goes but how well it goes fast in the range you use it. There are newer better opamps around but I am more impressed with other metrics that are improved.

JR
Old 25th January 2007 | Show parent
  #21
Gear Addict
 
svart's Avatar
 
🎧 15 years
Sure, I agree that it's a bit over the top for audio, my findings were actually based on RF work that I have done, namely studying small signals riding on RF carriers. So far it's application to the audio field is working just fine. Overkill? maybe, but upper harmonics are what make audio sound more realistic and those take bandwidth. the new generation of opamps is faster, quieter and all-around more pure to the input signal, 100x bandwidth is not expensive anymore.

But in closing, you are still absolutely correct that it's much more important for an opamp to faithfully replicate the signal+gain than blind slew banging back and forth between the rails.

Old 25th January 2007 | Show parent
  #22
Gear Guru
Quote:
Originally Posted by svart ➡️
As a side note to explain my thoughts (and ones that agrees with your path as well as Mr. Williams), I work in RF engineering these days, primarily analog. In my own studies I have found that to truly replicate any signal, an opamp should be spec'd with at least 100 times more slew than needed. While most disagree with me, I have found that the micro transients riding on the audio carrier waves are generally flattened by anything less than 100v/us. This includes most if not all "audio" opamps. These tiny transients are indeed heard by our ears as definition in the audio. These transients also have a habit of making the audio harsh as well. Most audio opamps ignore these in order to make the audio more listenable and smooth. Controlling the slew is more important than just carelessly slamming back and forth into the rails.
One other note: As far as the transients making the audio sound harsh, I've found that if there are any non-linearities upstream these faster, clearer parts tend to reveal them, not cause them. This is important, read it again, please.

I've been working with a customer with a very nice, highly modified 112 input MR-4 with the usual moving faders, etc. They are now "selecting" opamps for sonics and the ability to make Pro Stools sound OK. Although they prefer the more open sounding parts for tracking, the mix buss and monitoring is part selected to offer the best sonics without exposing the pro stools artifacts. This is a very involved decision as I keep trying to get them to open up the system but they are very sensitive to the digital "uglies" they have to deal with in this format.

They are now using 4 modified (I did one, they did the rest) Alesis HD24XR's with AI-4's to feed the AES data out of the 192 digital box. They have sold all their analog pro stool converter boxes. Still, the mix buss uses a Texas Instruments THS4051 opamp due to it's class A design and it's huge blooming low end and midrange. It's in a custom summing amp "trans-Amp" design with great transistors and passives. They claim it's closer to analog tape than any other digital fixes they have done. Best yet, they can work with this without the usual digital flatness and minimizing the artifacts created by Avid.

It's the biggest band-aid I've ever seen.

Jim Williams
Audio Upgrades
Old 25th January 2007 | Show parent
  #23
Lives for gear
 
JohnRoberts's Avatar
 
🎧 15 years
Quote:
Originally Posted by Jim Williams ➡️
One other note: As far as the transients making the audio sound harsh, I've found that if there are any non-linearities upstream these faster, clearer parts tend to reveal them, not cause them. This is important, read it again, please.

I've been working with a customer with a very nice, highly modified 112 input MR-4 with the usual moving faders, etc. They are now "selecting" opamps for sonics and the ability to make Pro Stools sound OK. Although they prefer the more open sounding parts for tracking, the mix buss and monitoring is part selected to offer the best sonics without exposing the pro stools artifacts. This is a very involved decision as I keep trying to get them to open up the system but they are very sensitive to the digital "uglies" they have to deal with in this format.

They are now using 4 modified (I did one, they did the rest) Alesis HD24XR's with AI-4's to feed the AES data out of the 192 digital box. They have sold all their analog pro stool converter boxes. Still, the mix buss uses a Texas Instruments THS4051 opamp due to it's class A design and it's huge blooming low end and midrange. It's in a custom summing amp "trans-Amp" design with great transistors and passives. They claim it's closer to analog tape than any other digital fixes they have done. Best yet, they can work with this without the usual digital flatness and minimizing the artifacts created by Avid.

It's the biggest band-aid I've ever seen.

Jim Williams
Audio Upgrades
I would second your approach for open/linear path. The duality of what works best for tracking vs. mix down has long been addressed in monitor speakers often with different models. The difference there IMO is mostly frequency response.

I am not a fan of using an opamp for some IMO negative consequence, despite that negative mitigating some other negative. Sounds like the wrong tool for the job. I would attempt to better understand what is going on (perhaps a simple, or not so simple LPF). There may be another more linear and well defined way to get the same result.

Of course the customer is always right, and interested in results right now. Surely not concerned with my design philosophy, and they shouldn’t be.

JR

PS: What happens later if/when Pro tools or the source du jour cleans up their act?
Old 25th January 2007 | Show parent
  #24
Gear Guru
Quote:
Originally Posted by JohnRoberts ➡️
I would second your approach for open/linear path. The duality of what works best for tracking vs. mix down has long been addressed in monitor speakers often with different models. The difference there IMO is mostly frequency response.

I am not a fan of using an opamp for some IMO negative consequence, despite that negative mitigating some other negative. Sounds like the wrong tool for the job. I would attempt to better understand what is going on (perhaps a simple, or not so simple LPF). There may be another more linear and well defined way to get the same result.

Of course the customer is always right, and interested in results right now. Surely not concerned with my design philosophy, and they shouldn’t be.

JR

PS: What happens later if/when Pro tools or the source du jour cleans up their act?
They have the clearer parts ready for the change. For them, it's about making the system they use (protools) sound as good as they can. For me, I don't have artifacts to deal with so I use the most open stuff I can. I can only hope that the protools system is replaced, the sooner, the better, for all of us.

Jim Williams
Audio Upgrades
Old 25th January 2007 | Show parent
  #25
Gear Addict
 
🎧 15 years
Quote:
Originally Posted by Jim Williams ➡️
...to make Pro Stools sound OK...
Hehe, good one! I must be living in a cave, that's the first time I heard that one and I imagine it's not new...
Old 25th January 2007 | Show parent
  #26
Gear Addict
 
svart's Avatar
 
🎧 15 years
Well, I agree that there are certain areas that need higher speed/bandwidth like input stages to recording devices especially if they interface directly to those high dollar preamps, like an API312 and it's honorable opamp, the 2520, and it's 2-4v/us slew rate...

However my thoughts about channel gain/buffer stages are different, the bus interfacing part needs to be high speed but also low noise( and much more that I could get into later if asked). The buffer stages and gain stages that follow are much less in need of speed and benefit from a "good" sonic signature rather than blazing speed. With that said I do keep all my opamps socketed and can change them at will to suit the music so my opinions are not necessarily relevant here.
Old 26th January 2007 | Show parent
  #27
Lives for gear
 
JohnRoberts's Avatar
 
🎧 15 years
Quote:
Originally Posted by svart ➡️
Well, I agree that there are certain areas that need higher speed/bandwidth like input stages to recording devices especially if they interface directly to those high dollar preamps, like an API312 and it's honorable opamp, the 2520, and it's 2-4v/us slew rate...

However my thoughts about channel gain/buffer stages are different, the bus interfacing part needs to be high speed but also low noise( and much more that I could get into later if asked). The buffer stages and gain stages that follow are much less in need of speed and benefit from a "good" sonic signature rather than blazing speed. With that said I do keep all my opamps socketed and can change them at will to suit the music so my opinions are not necessarily relevant here.
A very input stage and to some extent also the outputs, could benefit from more than audio gain bandwidth to reject and or filter any HF interference present at interfaces.

JR
Old 26th January 2007 | Show parent
  #28
Gear Addict
 
svart's Avatar
 
🎧 15 years
that's why you should only use iron on the I/O..

JK, Of course you are right John.
📝 Reply
Post Reply

Welcome to the Gearspace Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and Reverb.com listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.


 
 
Slide to join now Processing…

Forum Jump
Forum Jump