Zishan Z4 - DAP with Dual DAC ES9038Q2M | Dual AMP OPA1622 | USB 32-bit + DSD | Bluetooth LDAC 24-bit | Balanced 2,5/4,4 | LO/PO 3,5mm

[sfrsfr]

Thanks! It seems like Zishan's stuff are a real DIY/hobbyist gateway. I do have their AD3 amp and love it to bits. With the Z4, seems like Zishan is moving forward. But at the same time, really hoping they don't take away the ease of modding with the "all SMD" components build.

Could you give a brief description of the sound performance of AD3? Did you do any mods (changing op amp or tube)?
Do you know the output impedance? Can it drive high impedance gear?
There is so little information about it, but it looks worth trying out for me...
Thanks!

 

[Setmagic]

@sfrsfr
AD3 have 850mW of power.
Probably 100 ohm output impedance.
Can drive easily 600 ohm headphones and it's very loud.
Can't drive armature IEMs in proper way for this reason.
Its for high impedance headphones best with 150+
Have audible white (background) noise but it's nice for ears.
It's quite hot due to 30V! into tube and runs about 4h.
Sound signature is focused on midrange and have quite intimate soundstage with analogue taste.

Runs best with OPA1622 (need mods to fit) because it's really stable opamp or classic
lme49720 who is easy for application.

This is super cheap and probably most compact hybrid portable AMP.
Once again I must said it's wort a price as most Zishans and very easy for modification.
It's new version 2021 (yellow caps) of this amp with little better design from factor.

I have older modded with better way and replacing capacitors who filter 30V power supply is really important.
Mine looks likes that:

 

[sfrsfr]

@sfrsfr
AD3 have 850mW of power.
Probably 100 ohm output impedance.
Can drive easily 600 ohm headphones and it's very loud.
Can't drive armature IEMs in proper way for this reason.
Its for high impedance headphones best with 150+
Have audible white (background) noise but it's nice for ears.
It's quite hot due to 30V! into tube and runs about 4h.
Sound signature is focused on midrange and have quite intimate soundstage with analogue taste.

Runs best with OPA1622 (need mods to fit) because it's really stable opamp or classic
lme49720 who is easy for application.

This is super cheap and probably most compact hybrid portable AMP.
Once again I must said it's wort a price as most Zishans and very easy for modification.
It's new version 2021 (yellow caps) of this amp with little better design from factor.

I have older modded with better way and replacing capacitors who filter 30V power supply is really important.
Mine looks likes that:

I've seen someone elsewhere mentioning replacing the opamp with Burson V5I-D. I'm thinking about trying the Muses 02.... Do you think the OPA1622 would still be a better choice?
I'm unlikely to be replacing the capacitors any time soon so hope it is still good sounding even in the original form...

 

[Setmagic]

I've seen someone elsewhere mentioning replacing the opamp with Burson V5I-D. I'm thinking about trying the Muses 02.... Do you think the OPA1622 would still be a better choice?
I'm unlikely to be replacing the capacitors any time soon so hope it is still good sounding even in the original form...

Well, it's depends on Your pocket and preferences. I was tested V5i-D and V6 classic with many more IC ones on AD3.
There was a difference that told about general opamp character. Some of them had oscilations or amplify white noise to loud. Just decided to don't place Burson because this amp is made to deal with Lo-Res Audio "sweet distortion" and it's don't worth to put expensive ones.
Every opamps are different - You can choose what You like. They are just a different circuit inside micro-chip. Newer OpAmps are usually better than old ones due to improvements in design.
If you absolutely love Bursons family just go and place one but you can't put housing because it's don't fit with V5i-D
AD3 is really fun because it's working as soft compressor and remove micro details from sound. It's only little "worse" than Little Bear B4X in general audio fidelity but much cheaper and handy.

It's a very simple tube pre amplifier circuit with OpAmps final stage amplifier.
But it can sounds better. You can modify AD3 like me or even better replacing whole power supply rail with better one. Opamp without any modification is really cosmetic change.

 

[sfrsfr]

Well, it's depends on Your pocket and preferences. I was tested V5i-D and V6 classic with many more IC ones on AD3.
There was a difference that told about general opamp character. Some of them had oscilations or amplify white noise to loud. Just decided to don't place Burson because this amp is made to deal with Lo-Res Audio "sweet distortion" and it's don't worth to put expensive ones.
Every opamps are different - You can choose what You like. They are just a different circuit inside micro-chip. Newer OpAmps are usually better than old ones due to improvements in design.
If you absolutely love Bursons family just go and place one but you can't put housing because it's don't fit with V5i-D
AD3 is really fun because it's working as soft compressor and remove micro details from sound. It's only little "worse" than Little Bear B4X in general audio fidelity but much cheaper and handy.

It's a very simple tube pre amplifier circuit with OpAmps final stage amplifier.
But it can sounds better. You can modify AD3 like me or even better replacing whole power supply rail with better one. Opamp without any modification is really cosmetic change.

Thank you, it is very helpful.
So what was the effect of replacing the capacitors for better ones?
And where do you suggest I look to get better capacitors if I decide to replace them?

Comparison with the Little Bear B4X would be indeed great.

Btw. would it be still good with earbuds of common impedance and sensitivity, let say 32 ohm and sensitivity 110dB/mW?

 

[Amos Isaac]

Could you give a brief description of the sound performance of AD3? Did you do any mods (changing op amp or tube)?
Do you know the output impedance? Can it drive high impedance gear?
There is so little information about it, but it looks worth trying out for me...
Thanks!

I played around with the opamps and the capasitors. I've used it with the Muses 8920, Muses 02, OPA2134. Best sounding one to my ears are the Muses 02 followed by the 8920. With the 2134, it sounded very good as well but I felt like there was more impact on the Muses. Sound bigger in terms of power....? Also, bigger soundstage on the 8920, just more umph on the 02.

As for the caps, i just traded it with a pair of Nichicon with the same values. I didn't do too much of cap rolling as i don't want to mess up the traces on the board, and also i don't have too many caps to mess around with.

After changing the opamp from the stock one, I can power higher impedence headphones without the bass/sub bass farting. The original opamp couldn't handle the delivery on the lower register. I love this amp, I velcroed it to my Fiio M6 and powers almost everything I have at 45% power. It can power Sennheiser 6XX lower than 45%. As for sound, it bring the sub bass up but no muddiness (must change opamps), the highs are sparkly but siblilance is contained (I don't what magic that is), you also get 3D like soundstage and imaging.
I know it may be hard to believe such cheaply made device can have such affects, but these results are what I experience and heard. I am also a professional sound mixer and studio engineer, I do have a little experience on sound.

 

[Amos Isaac]

@sfrsfr
AD3 have 850mW of power.
Probably 100 ohm output impedance.
Can drive easily 600 ohm headphones and it's very loud.
Can't drive armature IEMs in proper way for this reason.
Its for high impedance headphones best with 150+
Have audible white (background) noise but it's nice for ears.
It's quite hot due to 30V! into tube and runs about 4h.
Sound signature is focused on midrange and have quite intimate soundstage with analogue taste.

Runs best with OPA1622 (need mods to fit) because it's really stable opamp or classic
lme49720 who is easy for application.

This is super cheap and probably most compact hybrid portable AMP.
Once again I must said it's wort a price as most Zishans and very easy for modification.
It's new version 2021 (yellow caps) of this amp with little better design from factor.

I have older modded with better way and replacing capacitors who filter 30V power supply is really important.
Mine looks likes that:

This I agree, it will get hot after a long session.

 

[sfrsfr]

I played around with the opamps and the capasitors. I've used it with the Muses 8920, Muses 02, OPA2134. Best sounding one to my ears are the Muses 02 followed by the 8920. With the 2134, it sounded very good as well but I felt like there was more impact on the Muses. Sound bigger in terms of power....? Also, bigger soundstage on the 8920, just more umph on the 02.

As for the caps, i just traded it with a pair of Nichicon with the same values. I didn't do too much of cap rolling as i don't want to mess up the traces on the board, and also i don't have too many caps to mess around with.

After changing the opamp from the stock one, I can power higher impedence headphones without the bass/sub bass farting. The original opamp couldn't handle the delivery on the lower register. I love this amp, I velcroed it to my Fiio M6 and powers almost everything I have at 45% power. It can power Sennheiser 6XX lower than 45%. As for sound, it bring the sub bass up but no muddiness (must change opamps), the highs are sparkly but siblilance is contained (I don't what magic that is), you also get 3D like soundstage and imaging.
I know it may be hard to believe such cheaply made device can have such affects, but these results are what I experience and heard. I am also a professional sound mixer and studio engineer, I do have a little experience on sound.

Excellent!
So is it still usable with normal impedance (~ 32 ohm) and sensitivity (~ 105 dB/mW) gear?
I would like to use it primarily with earbuds, from 30 ohm impedance up.
Btw. what is the difference between Muses 8920 and Muses 02 regarding sound?

 

[Amos Isaac]

Excellent!
So is it still usable with normal impedance (~ 32 ohm) and sensitivity (~ 105 dB/mW) gear?
I would like to use it primarily with earbuds, from 30 ohm impedance up.
Btw. what is the difference between Muses 8920 and Muses 02 regarding sound?

Yeah it would be usable. In my experience to have the better tube effect, I would suggest running your source at a lower signal. But if you are running line level out, it would be best to keep the output level at a safe listening level. Cause it gets loud. Like LOUD. If I'm not mistaken, the volume potentiometer is in the input stage so I think it is still best to protect your ears and gears rather than to have signal at perfect line level. As long as you enjoy your music.

As for the Muses opamps, I can say that the sound quality or the "sound" is still dependant on the architecture of the circuit implemented. But if I were to generally put it out there as to how it sounds, both give greater impact. Both have better control of current swings that allows greater and maybe cleaner dynamics. I can't fully nor professionally explain how it works, but sound changes. Maybe its speed, maybe its the amount of voltage supplied. But Muses to Muses, the 02 is a bit more superior in almost every device i tried it on. It has bite, you hear kicks slap better, reverbs dies off slower, the bassist doesn't have their amps-in-front-of the-band sort of tone. The 8920 has similar qualities but maybe lesser control. Like the 02 at 80%. Hope that helps.

 

[Amos Isaac]

Excellent!
So is it still usable with normal impedance (~ 32 ohm) and sensitivity (~ 105 dB/mW) gear?
I would like to use it primarily with earbuds, from 30 ohm impedance up.
Btw. what is the difference between Muses 8920 and Muses 02 regarding sound?

Regarding the sensitivity:impedence, I don't know whether its just a placebo or not, but it seems like some higher impedence drivers tend to sound more lush with the amp.

 

[Setmagic]

Thank you, it is very helpful.
So what was the effect of replacing the capacitors for better ones?
And where do you suggest I look to get better capacitors if I decide to replace them?

Comparison with the Little Bear B4X would be indeed great.

Btw. would it be still good with earbuds of common impedance and sensitivity, let say 32 ohm and sensitivity 110dB/mW?

Better signal to noise and imagine.
I don't have professional equipment. This is my mesurment:
stock - white, green - maxed mod.
Higher distortion in 50Hz in green is just interference with my generic zoom audio recorder sound card.
My modded DSDs is waaay better but I don't have mesurments due to to bad sound card.


Yes just go for better capacitors
It's really worth.

 

[Setmagic]

Regarding the sensitivity:impedence, I don't know whether its just a placebo or not, but it seems like some higher impedence drivers tend to sound more lush with the amp.

Yes, now days high output impedance is a problem, because most high end and generic headphones have 32ohm.
So ~100ohm output impedance is way to big to keep them in good. It means they have unnaturally extended and rolled off bass on low impedance headphones.
On my 250 ohm old studio golden standard DT150 it's ok to have that much impedance.

 

[Amos Isaac]

Yes, now days high output impedance is a problem, because most high end and generic headphones have 32ohm.
So ~100ohm output impedance is way to big to keep them in good. It means they have unnaturally extended and rolled off bass on low impedance headphones.
On my 250 ohm old studio golden standard DT150 it's ok to have that much impedance.

Thanks for clearing that up! So great to learn more things.

 

[Syncaine]

Don't scare people. Here are normal measurements with a 30 ohm load.

 

[Setmagic]

Don't scare people. Here are normal measurements with a 30 ohm load.

Of Stock AD3?