What's your opinion on opamp vs discrete? Liquid Spark description made me wondering.

[asteroth]

Is there any truth to this description?
Btw, I saw the measurements here and there are some flaws to this amp:

Review and Measurements of Monoprice Liquid Spark Headphone Amp

This is a review, detailed measurements and comparison of Monoprice Liquid Spark, Schiit Magni 3 and JDS Labs O2 headphone amplifiers. The Liquid Spark and Magni 3 retail for $99 but only the Monoprice comes with free expedited shipping. The JDS Labs O2 retails for USD $139 on US Amazon with...

www.audiosciencereview.com

 

[voodooless]

Btw, I saw the measurements here and there are some flaws to this amp

Well, that should answer your question then.

 

[levimax]

Op-amps are the best things going, especially for inexpensive high performance audio gear. It is almost impossible for discrete to match a good op-amp. The only problem with feedback for audio circuits is if you don't use enough of it. I would be suspicious of any product which tells multiple lies like this.

 

[Hemi-Demon]

If you want a discrete amp I would recommend the Topping A90D. I say this with hesitation on this forum, but I feel the bass delivery and midrange detail is worth a listen vs the standard Topping D90.

Other than that, stick to the cheaper op amp based amplifiers that measure well and have the power and features you need.

 

[Cbdb2]

The only place discretes might have an advantage is with high power. Even than, adding some power transistors to a IC OA is usually the best solution.

 

[Cbdb2]

If you want a discrete amp I would recommend the Topping A90D. I say this with hesitation on this forum, but I feel the bass delivery and midrange detail is worth a listen vs the standard Topping D90.

Other than that, stick to the cheaper op amp based amplifiers that measure well and have the power and features you need.

For the extra $100 you get much better marketing. Oh and 1db more power and the distortion goes from .000055% all the way up to .000060%. (is that much above measurement error?)

TOPPING A90 vs TOPPING A90 Discrete Comparison Chart

The upgrading of a classic is an exciting but potentially confusing event. Everyone loves quality of life improvements, but no one likes having to hack through a jungle of specs. We’ve created this comparison chart to help you quickly and easily judge the differences between the classic A90 and...

apos.audio

 

[syn08]

The common argument against ICs in audio is the under biased output stage, and hence relying on feedback to correct the crossover distortions in particular at low load impedances. Which meets the anti feedback high end audio nonsense.

Discrete op amps are generously biased, allowing them to stay mostly in Class A even in low loads, therefore providing good performance in low feedback, or even open loop, circuits. That‘s all about it. Nothing that a modern op amp cannot match, either by themselves (look at the CFA DSL driver op amps), or by buffering with a high current output stage (BUF34 comes to mind)

 

[DVDdoug]

There's more than one way to make a good amplifier... Op-amps and other ICs are the cheapest & easiest and vacuum tubes are the most expensive and difficult.

The Liquid Spark uses DC coupled topology...

There isn't supposed to be any DC (zero Hz) in audio and you can't hear it if there is. If DC somehow gets-into the audio or electronics "bad things" can happen, and worst-case you can fry an amp or speaker. Most amps (and preamps, etc.) intentionally filter it out (usually with capacitors).

Many amplifiers have DC coupled outputs (mainly to eliminate the big and expensive output capacitors) but DC is normally blocked at the input. I built an amp once and I added a protection circuit with a relay to disconnect and protect the speakers in case of a fault that put-out DC.

DC in a digital audio file creates a "click" when playback starts & stops and the DC suddenly kicks-in or kicks-out. Capacitors (or other high-pass filtering) can remove the continuous DC but the clicks will remain.

 

[syn08]

There's more than one way to make a good amplifier... Op-amps and other ICs are the cheapest & easiest and vacuum tubes are the most expensive and difficult.

There isn't supposed to be any DC (zero Hz) in audio and you can't hear it if there is.

Yes you can, maybe not voltage, but certainly current. It's the old trick to de-balance the op amp output stage bias current, by adding a DC current source at the output. This has the effect of significantly lowering the gm doubling in the output stage crossover region, and hence lowering the crossover distortions. If one audiophile insists in using 40 years old op amps (when the output lateral PNPs was one serious performance limiting factor) then the effect of this trick could be clearly audible.

Don't ask me how I find out this, I guess I'm showing my age . And BTW, caps are evil, aren't they?

 

[restorer-john]

Many amplifiers have DC coupled outputs (mainly to eliminate the big and expensive output capacitors) but DC is normally blocked at the input.

HiFi amplifier outputs in general haven't been capacitively coupled since the early 1970s. The move to split rail, direct coupling was purely for performance gains and had nothing to do with the cost of output capacitors. After all, you may remove a large output capacitor, but you need another one in the power supply- so no savings.

It was all about improving LF THD, extended response, lower output impedance and independence to loads. The only benefit of a capacitor coupled amplifier was relative freedom from loudspeaker destruction if an output stage failed.

My attitude is source components should all be capacitively coupled to their outputs as all the gain is downstream and any DC would otherwise be amplified in DC coupled pre/amplification. I certainly have little faith in DC coupled low cost D/A converters, having seen the effects in displaced woofers and protection systems tripping in power amps.

 

[MarkS]

I certainly have little faith in DC coupled low cost D/A converters, having seen the effects in displaced woofers and protection systems tripping in power amps.

Can you cite examples of DACs that have this issue (which I've never heard of before ...)?

 

[MarkS]

For the extra $100 you get much better marketing.

LOL!

This should be the truth-in-advertising motto of most of "high end" audio ...

 

[mhardy6647]

"Laser matched JFETs"... the mind boggles.

 

[DonR]

"Laser matched JFETs"... the mind boggles.

Probably means laser-trimmed to match.

 

[kongwee]

Discreet has more control on tolerance, if you take the effort to value match the components. Surface mount, I have no idea about the tolerance compare to opamps.

"Laser matched JFETs"... the mind boggles.

Properly a nicer word to used instead of DUV or something.

 

[DonR]

Discreet has more control on tolerance, if you take the effort to value match the components. Surface mount, I have no idea about the tolerance compare to opamps.

Absolutely not. Chip op amps are, by definition, made from the same silicon with uniform impurity density throughout. They are more likely to be matched in tolerance than discrete parts and definitely will temperature track better. Surface mount is a packaging technology. The internal components are generally not different from through-hole.

 

[mhardy6647]

Probably means laser-trimmed to match.

ahh, OK... I was thinkin' some sort of Jedi thing goin' on.

 

[DonR]

ahh, OK... I was thinkin' some sort of Jedi thing goin' on.

View attachment 248314

Sure, why not? Let the hate flow thru ya. I'm rooting for the red bear.

Nobody has designed using matched JFETs for maybe 20 years. Op amps are vastly superior with orders of magnitude lower offset voltages. At least that was the case when I left the business over a decade ago. Laser trimmed JFETs were a thing in the 80's though.

 

[voodooless]

Nobody has designed using matched JFETs for maybe 20 years. Op amps are vastly superior with orders of magnitude lower offset voltages. At least that was the case when I left the business over a decade ago. Laser trimmed JFETs were a thing in the 80's though.

Nelson Pass never left the 80’s, so there is that…

 

[restorer-john]

Laser trimmed JFETs were a thing in the 80's though

Laser trimmed anything was an awesome selling point.

In the late 1970s, ALPs laser trimmed the individual printed resistors in their stepped attenuators (the black beauty) to guarantee ~0.2dB gang to gang tracking. My photo from inside a Pioneer Spec 1 preamp.

Plenty of R2R multibit D/A converters has their internal resistor arrays trimmed prior to encapsulation.