Review and Measurements of Massdrop THX AAA 789 Amp

[Roen]

A different power supply definitely improve the THX sound quality according to my experience.

There is no noise heard with the original power supply come with THX.
But the imaging is big and not condensed.

Spoiler

In fact I am also confused to the issue I heard. Since the measurement is inaudible and near perfect.
But I have lend THX to my friend for over a week. And I didn't told him any thoughts about this amp.
It turns out that he has notice the same issue.

headphone mainly use: Z1R, A2000Z, SRH-1840, TH-X00
compared amp: Jotunheim, Gustrad H20, iFi Pro iCAN
DACs: Grace m9xx. Pioneer N70A

The issue persists with and DACs and headpones. And only with THX.
I thought THX is just tuned like this.And everyone just love it.So no one complains.
Until I go power supply change for fun as usual.

I tried a probably poor quility 24v 0.5A LDO for other device.
cost $60
View attachment 21613
(YES I aware 0.5A is low.buy i don't believe THX consume that much
since the machine is no heat coming out )

This improve some image issue.But bass texture was fucked up.
So I figure out the image issue comes from power supply.

I give iFi DC iPurifier2 a shot .
View attachment 21617
This stuff is some how expensive.but I am too busy to
DIY stuff recently.And this stuff is full refundable in my
place.
View attachment 21615
Finally the sound imaging condensed.just like making the focus right in photo.
But one thing must aware is iFi DC iPurifier2 gets very hot working and even with THX shutdown over night.
Probably 60~70 degrees Celsius.Might need to find transformer with switch to use with this.

You know we're going to have to ask for measurements right?

 

[AresHarvest]

Yep, I'm immediately skeptical of any claim that swapping the power brick results in a wider sound stage or more precise imaging.

 

[Rojaran]

v200 or any a-z clone of it.

I know only two:
- Accurate Audio HPA-A200
- Gustard H10
Is something else?

 

[JohnYang1997]

I know only two:
- Accurate Audio HPA-A200
- Gustard H10
Is something else?

Gustard is not clone rather a mimic/mod in my book. A200 is a cheaper clone than af200. They guy who makes af200 also makes fiona3 which is lisa3 clone.

 

[Rojaran]

OK thanks

 

[Rojaran]

Gustard is not clone rather a mimic/mod in my book. A200 is a cheaper clone than af200. They guy who makes af200 also makes fiona3 which is lisa3 clone.

Where did you buy af200?

 

[JohnYang1997]

Where did you buy af200?

I am from China. So..

 

[Rojaran]

It looks like you have a little better access to these things

 

[Rojaran]

You compared Accurate Audio HPA-A200 with the original Violectric HPA V200. Are there big differences in sound?

 

[JohnYang1997]

You compared Accurate Audio HPA-A200 with the original Violectric HPA V200. Are there big differences in sound?

I don't think there's anything big but there should be. I don't buy into the original being the best stuff. If it measures well then it is. Before i modified o2, a200 and af200 are my recommendations for my friends. So a couple of them bought a200 and happy. af200 is more expensive but i think it's better built, closer matched transistors. So yeah. But it's twice as expensive tho. about 2400 cny.

 

[Rojaran]

I think so too. Can you recommend a safe store from where I could order Accurate Audio HPA-A200?

 

[JohnYang1997]

I think so too. Can you recommend a safe store from where I could order Accurate Audio HPA-A200?

Why not just get a jds atom? Unless you are powering very high impedance headphones, atom will outperform a200.

 

[Rojaran]

Atom is a great amplifier, but I do not like clinical sound. I read somewhere that Atom sounds like that. Hence the direction of V200

 

[JohnYang1997]

Atom is a great amplifier, but I do not like clinical sound. I read somewhere that Atom sounds like that. Hence the direction of V200

Amplifiers imho do have sound. But the difference is still rather small comparing to headphones. If you get a pair of great sounding headphones to your liking it will sound good.

 

[ReAlien]

I think so too. Can you recommend a safe store from where I could order Accurate Audio HPA-A200?

I bought my A200 on Taobao, manufacturer refurbished version, for 1000 CY, it's around 155 USD.

 

[JohnYang1997]

I bought my A200 on Taobao, manufacturer refurbished version, for 1000 CY, it's around 155 USD.

The refurbished ones are essentially second handed ones. The seller/builder discontinued the a200 so he bought back some second hands and resell them. Not bad deal especially for the price. And you can swap some opamps for better measurements.
opa827 for input and opa227p for the ones nesr the output transistors.

 

[Rojaran]

I bought my A200 on Taobao, manufacturer refurbished version, for 1000 CY, it's around 155 USD.

How is your impression? Satisfied with the purchase?

 

[ReAlien]

The refurbished ones are essentially second handed ones. The seller/builder discontinued the a200 so he bought back some second hands and resell them. Not bad deal especially for the price. And you can swap some opamps for better measurements. opa827 for input and opa227p for the ones nesr the output transistors.

Great advice! I'll write PM to you on the matter now.

 

[JohnYang1997]

How is your impression? Satisfied with the purchase?

V200 is very good sounding, clean sounding amp. It will have some noise with super sensitive iems like final heaven v. Other than those, it's very competent. You can go reference audio analyzer for measurements.
https://reference-audio-analyzer.pro/en/report/amp/violectric-hpa-v200.php

 

[Rojaran]

V200 is very good sounding, clean sounding amp. It will have some noise with super sensitive iems like final heaven v. Other than those, it's very competent. You can go reference audio analyzer for measurements.
https://reference-audio-analyzer.pro/en/report/amp/violectric-hpa-v200.php

Thanks. Do you know any similar sounding amplifiers with very low impedance output?