Is there a THX AAA comparison?

[jbeez]

I'm trying to find some difference between these things, I did find a link/graphic on thx.com found here-> https://www.thx.com/wp-content/uploads/2020/01/AAA-Chart-Updated-9.23.19.jpg

But its not complete or I don't understand it. I see THX 888, where is 887? Where do the numbers that aren't on this chart from THX actually land? What is the history of the different releases, are all 800 series released after all 700 series or is that not how that works?

Regards

 

[JohnYang1997]

A search on the forum would help.
Anyway.
let's start with 789
789 is the original(but cut down) version of thx 888
789: opa1602 + opa564
888: opa1612 + opa564 + flying supply
flying supply adds headroom and voltage swing without exceeding the operation maximum of the opamps.
887 is the upgrade/optimized version of 789
887: opa1612 + opa564 + low noise optimization
887 has lower noise than 888
788 is opa1602 + ad8397 so it's very different from 789
789 is essentially "886" in a sense.
Another story is that the original brochure didn't have the flying supply. New thx 888 works at +-18V. Originally only at +-12V which is the operation voltage for 789 and 887.

 

[JohnYang1997]

Oh. I forgot. All models in the brochure are released at the same time. Different models are for different purposes, different power consumption, different pcb area. 887 is designed after the release of the models. 789 is designed before the models are finalized.

 

[jbeez]

Thank you so much, most of my searching is bombarded with just amplifier info instead of specific info around these different chips themselves. This is very useful!

 

[jae]

The numbers surely aren't intuitive.

 

[Rotary Transformer]

A search on the forum would help.
Anyway.
let's start with 789
789 is the original(but cut down) version of thx 888
789: opa1602 + opa564
888: opa1612 + opa564 + flying supply
flying supply adds headroom and voltage swing without exceeding the operation maximum of the opamps.
887 is the upgrade/optimized version of 789
887: opa1612 + opa564 + low noise optimization
887 has lower noise than 888
788 is opa1602 + ad8397 so it's very different from 789
789 is essentially "886" in a sense.
Another story is that the original brochure didn't have the flying supply. New thx 888 works at +-18V. Originally only at +-12V which is the operation voltage for 789 and 887.

The PCBs of 789 and 887 look identical. Is there any chance to simply upgrade 789 to 887? Such as just replacing the 1602 with 1612?

 

[JohnYang1997]

The PCBs of 789 and 887 look identical. Is there any chance to simply upgrade 789 to 887? Such as just replacing the 1602 with 1612?

Unless you have measurement equipments to verify changes, I don't recommend doing so.

 

[raistlin65]

Any thoughts on how the new THX AAA One that is available on drop.com for preorder? How does it fit in with the rest? Or just an entirely new design capitalizing on the brand?

https://drop.com/buy/drop-thx-aaa-one-linear-amplifier

Looks interesting.

 

[JohnYang1997]

Any thoughts on how the new THX AAA One that is available on drop.com for preorder? How does it fit in with the rest? Or just an entirely new design capitalizing on the brand?

https://drop.com/buy/drop-thx-aaa-one-linear-amplifier

Looks interesting.

I'm 99% sure it's the 788(with flying/boot strapped supply).