[HeyManslowdown97]

I hope this makes your life easier.
https://www.electrical4u.com/source-of-electrical-energy/

Moral of the story: it’s so basic just let the circuit show you, what it wants and it needs! Make the necessary changes and listen for feedback whether it’s better or worse!

Will read your article when I have a chance! I knew I was heading in the right path, I just didn’t know why certain things worked better on Zishan but I did use clues left on the board’s design and what thought about what was the mindset. Not much of a scientific approach though.

 

[HeyManslowdown97]

@HiFan
but why did they add bjt transitors on the ak4497 and not a buffer stage?? It just seems like they were like “oh crap, we ran out of power, let’s add this?”

It still baffles me!

 

[HiFan]

@HiFan
but why did they add bjt transitors on the ak4497 and not a buffer stage?? It just seems like they were like “oh crap, we ran out of power, let’s add this?”

It still baffles me!

That’s the current source. The main opamp doesn’t output enough current as HP driver. Opa1656 and muses02 can only output about +-50ma, which is rather low. Normally chips Like tpa6120, 49600 can do 200-700ma. This is crucial for low impedance phones or planar that suck current. BJTs are better in these positions than FET. FETs are better as voltage followers.

The choice of using transistor to do this, however, is a flavor thing. Many people like the sound from output stage built with discreet components. These circuits typically have slight higher 2nd order harmonic distortion (compared with chip based drivers) thus they sound "warmer". I actually like it.

 

[HeyManslowdown97]

Many people like the sound from output stage built with discreet components. These circuits typically have slight higher 2nd order harmonic distortion (compared with chip based drivers) thus they sound "warmer". I actually like it.

me too! it’s really hard to match the transitors though and they can easily distort and sound colored! I’ve tried to replacing these bjts transitors & it’s really, really hard to get them stable! I supposed that these Chinese components have odd figures since they aren’t quality controlled. They are crafty but it’s not like buying a board from TI and their components. Chinese electronics are fun though. Haha

I always wonder why some op amp makers like Sparkos?? Op amps have those discrete “opened” components and I always figured that’s what made their sound signature. It also has to be painstakingly hard to get them stable during development.

 

[HiFan]

me too! it’s really hard to match the transitors though and they can easily distort and sound colored! I’ve tried to match these bjts transitors is really, really hard to get them stable!

I always wonder why some op amp makers like Sparkos?? Op amps have those discrete “opened” components and I always figured that’s what made their sound signature.

It’s mainly distortion profile. Sparkos are good to my ears. I have a pair of singles. However i think money should first go to better headphones. Difference from sparkos aren’t as big as changing headphones.

 

[HeyManslowdown97]

It’s mainly distortion profile. Sparkos are good to my ears. I have a pair of singles. However i think money should first go to better headphones. Difference from sparkos aren’t as big as changing headphones.

I agree. Some Chinese hifi makers are proving that you can killer headphones for cheap!

I got the planar T1s off ebay barely used and they are amazing for 100!

sadly,in the west Beats and airpods on crappy smartphone DAC is where the mainstream is at.

Also, Bass in everything is dominates the sound spectrum with by bloated bass in those crappy headphones.

 

[DynamicDave]

Hi,

What are the pros and cons of driving the opamp to class A.
Do different opamps require different value resistors for constant output current?
What can I expect from doing this?

 

[HiFan]

Hi,

What are the pros and cons of driving the opamp to class A.
Do different opamps require different value resistors for constant output current?
What can I expect from doing this?

Check this out: https://tangentsoft.net/audio/opamp-bias.html

and this: https://www.audioasylum.com/audio/tweaks/messages/31186.html

 

[DynamicDave]

Thanks, I'll check them out.

 

[Shtruckk]

Hello,

I have a topping dx7 pro and i want to replace the stock op-amps (LME 47920 - headphone amp socket).
I was thinking at some discrete op-amps (https://www.aliexpress.com/item/32936027509.html) or something from SPARKOS LABS.
I'm open to any sugestions.

Thank you in advance for your help.

 

[HiFan]

Hello,

I have a topping dx7 pro and i want to replace the stock op-amps (LME 47920 - headphone amp socket).
I was thinking at some discrete op-amps (https://www.aliexpress.com/item/32936027509.html) or something from SPARKOS LABS.
I'm open to any sugestions.

Thank you in advance for your help.

Get an opa1612 and be done.

 

[morpheus620]

OPA 1656 or 1692 are also good.

 

[Rob43]

OPA 1656 or 1692 are also good.

Another vote for the OPA 1656, they sound really good !

After they burned-in they really opened up.


Rob43

 

[NCSUZoSo]

SS2590 by sparkos

Anybody tried their flagship op amp

2x SS2590 on an AudioJade Dual-DIP adapter, along with 2x Mill-Max ED58408-ND. This is shot inside of my heavily modded SMSL sAp-10. This balanced headphone amp originally used a SOIC-8 op-amp!

Personally, I recommend using the Mill-Max ED90603 or ED11083-ND for converting SMD to DIP-8. Sparkos Labs and Burson Audio, both sell their own takes on this adapter, if you'd like to consider theirs.



I have

I am in the process of writing a review between the Sparkos Labs: SS2590, SS3601| Burson Audio's V4-SS, V5-OPA, V6-OPA "Classic" & "Vivid"| Orange Amplifications Dual-DIP Discrete and a handful of IC op-amps, like the AD797, AD8597, LME4971 plus a few others.

You can find more info in the links below.

I was trying to get this done in July, but due to various reasons I had to push it back (Aug or Sep). I will be delivering a wide range of technical measurements in this review. I will try to keep it as objective, as I possibly can. Due to the large number of units to test, it is going to take a while, this is a one man show!

https://hallmanlabs.com/2020/07/20/discrete-review-update-isoregen-over-troubled-dip8-waters/

https://hallmanlabs.com/2020/06/03/sparkos-labs-pro-series-ss2590-discrete-op-amps/

 

[sorrowdragon]

lol @ 20m30s


It's always interesting to see an opamp that comes up on these forums time to time, discussed from the perspective of a professional electrical engineer in regards to its design and breaking down it's performance on an electrical engineering/circuit design level rather than on the level of amateur audiofoolery who have no real idea or clue how opamps really work or know what any of those numbers they see on the spec sheets that they parrot out of their mouths but have no real understanding or comprehension of what those numbers really mean.