What is wrong with op-amps?

[morinix]

Outside audio this approach is not a valid one. Things like design, simulation and test are required. In the wacky world of hifi as long as you are not starving and you customers are happy then its the norm.

Did you notice the name of this forum?

 

[morinix]

How about the OPA1612? It's not as fast ( 27v/uSec) as the LT1358, but it has better THD, noise, and CMRR specs.

Interesting device 😎. SMD only! So I will have to do a bit of solder gymnastics.

 

[morinix]

here's the "non-discrete" BA640...

...you want to use this?

Note the nice soupy sounding tantalums? 😀

Hoveland used a tant cap at the output of the HP100. Without that cap it sounded like any other "back of the concert hall" unit.

 

[morinix]

Morinix, did you OPA134 or not? I'm curious of your impressions. And no I won't ask for ABX THD or anything. You can even PM me as to keep out the numerologists from the discussion.

No I haven't yet. I will though. I've been looking through my parts. I think I have a tube of those from I grabbed when Alesis went BK.

 

[DPH]

And we've regressed at least 75% of the way back up the thread.

Please find me on homeopathy forums discussing dose response curves. They seem a more reasonable lot.

 

[scott wurcer]

EDIT: apparently Dick Burwin predated the Deane Jensen use of the inductors - but I do think it is a very clever thing to do.

Loves op-amps and horns too.

 

[Kirchhoff]

No I haven't yet. I will though. I've been looking through my parts. I think I have a tube of those from I grabbed when Alesis went BK.

Let me motivate you with post 867 in this thread.

Despite the idiotic comments that ensued, you can notice that Jay:

- nailed right Esmeralda as the 4562
- ruled out Blodwyn and Ethel as the worst and attributed them to TL072 and 4558, although he mistook one for the other
- he declared Gladys as the best overall however since his favorite opamp is 5532 he declared this to be 5532; it actually was the OP275
- he liked closely Mabel which was the real 5532

BTW Gladys was the only recent generation opamp with FET input there. You just have to try one. OP275, or whatever if you can't find your tube of OPA134. Just avoid the TL072, eh?

 

[DPH]

Let me motivate you with post 867 in this thread.

Despite the idiotic comments that ensued, you can notice that Jay:

- nailed right Esmeralda as the 4562
- ruled out Blodwyn and Ethel as the worst and attributed them to TL072 and 4558, although he mistook one for the other
- he declared Gladys as the best overall however since his favorite opamp is 5532 he declared this to be 5532; it actually was the OP275
- he liked closely Mabel which was the real 5532

BTW Gladys was the only recent generation opamp with FET input there. You just have to try one. OP275, or whatever if you can't find your tube of OPA134.

Go ahead and look on Google for "anomaly hunting". Ask yourself which explanation makes more sense.

 

[famousmockingbird]

Loves op-amps and horns too.

Dick squeezed highest performance from the many hundreds of integrated circuit operational amplifiers.....

Dick Burwen's Sound System


I repeat, hundreds.

Flame on haters..............

 

[scott wurcer]

Dick Burwen's Sound System


I repeat, hundreds.

Flame on haters..............

Dick spent a year tweaking its frequency response so that a recording of his son, Russell,
playing drums in the front center horn, became difficult to distinguish from the real drums.

Bear, I have the connections to possibly get a visit.

 

[DF96]

Changing the Q of a typical AM ferrite loop antenna will have no effect on the received bandwidth.

Simply untrue, unless by "no effect" you actually mean 'some effect'. Unclear to me whether your sentence contains a mistake in English or electronics.

 

[morinix]

Let me motivate you with post 867 in this thread.

Despite the idiotic comments that ensued, you can notice that Jay:

- nailed right Esmeralda as the 4562
- ruled out Blodwyn and Ethel as the worst and attributed them to TL072 and 4558, although he mistook one for the other
- he declared Gladys as the best overall however since his favorite opamp is 5532 he declared this to be 5532; it actually was the OP275
- he liked closely Mabel which was the real 5532

BTW Gladys was the only recent generation opamp with FET input there. You just have to try one. OP275, or whatever if you can't find your tube of OPA134. Just avoid the TL072, eh?

That test that Mooly made up, the level of circuit refinement is about where I was with the first LCR (MK1). The LCRMKI used OP275. I know this part well, used to be my goto op-amp. The best short description I can give for Mooly's circuit is; a mass of average speed opamps applying various degrees of smearing to average passives being powered by reverse recovery haze and 3 terminal regulator compression.

I don't care to stoop that low anymore.

But I will give the op275, 5532 and 4558 a try in my new layout of LCRMKIII just for kicks.

 

[Kirchhoff]

Go ahead and look on Google for "anomaly hunting". Ask yourself which explanation makes more sense.

Why don't you google for "denialism" instead.....

 

[Kirchhoff]

That test that Mooly made up, the level of circuit refinement is about where I was with the first LCR (MK1). The LCRMKI used OP275. I know this part well, used to be my goto op-amp. The best short description I can give for Mooly's circuit is; a mass of average speed opamps applying various degrees of smearing to average passives being powered by reverse recovery haze and 3 terminal regulator compression.

I don't care to stoop that low anymore.

But I will give the op275, 5532 and 4558 a try in my new layout of LCRMKIII just for kicks.

It was amazing though to see Jay ranking them in a manner that made sense.

Thanks for trying the test, I am interested to see how FET fares against your bipolar favourite(s).

 

[DPH]

Why don't you google for "denialism" instead.....

How the heck did you make it through engineering school (ostensibly) since you obviously have zero intellectual rigor? Occam is your worst enemy, I realize. And, denialism of a completely null result? Never. Impossible.

 

[Kirchhoff]

How the heck did you make it through engineering school (ostensibly) since you obviously have zero intellectual rigor? Occam is your worst enemy, I realize.

I chose a school where the ranking criteria wasn't the number of insults you could spit per minute and/or sentence.

 

[DPH]

I chose a school where the ranking criteria wasn't the number of insults you could spit per minute and/or sentence.

Wow, that is assuredly some rich irony.

 

[Kirchhoff]

Wow, that is assuredly some rich irony.

You must have been the valedictorian at yours, didn't you?

 

[DPH]

You must have been the valedictorian at yours, didn't you?

No, in fact I learned that extracurricularly. Only from the best, yours truly. 😉

 

[Wavebourn]

MM cart to 40db to 600 ohm RIAA to 20db.

I use the LT1358 now. Most of the number crunchers here think the slew rate is meaningless. I differ.

So I tried the LM4562 (one of the touted opamps on this thread). It couldn't resolve like the LT1358. So since there seems to be a cloud of test and measurement heavies here I throw out the request. I'm just seeing if anyone can come up with a better device since most here are quick to dismiss my 6 years of perfecting my design.

With RIAA feedback slew rate of MOST of modern opamps is plenty. Something else may be different that affected the sound. Non-linearity of an output impedance?