APP992 thread

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I'll get you voltages tomorrow. When I did pull them I was getting continuity between 2 of the legs on the 140s and 139s that went bad.

Thanks!

Paul
 
Pier,

On a working 992 in the Baby Animal running at 24V, the outside legs of the BD139 is 24V and the middle leg is 48V. I found one more working 992 that I put in there so now all the channels are working great, but I still have the handful that still need to have the 139 and 140 both replaced, and possibly more, which I don't know. I may also add heat sinks to the ones that are working in this unit just to be safe.

Thanks!

Paul
 
Hi, I’m just working on a pair of app992’s.

A generous diy’er on here sent me them free with another PCB I bought so I don’t know how old they are.

Just about to install the mounting pins, I see on post 7 that the PCB will be mounted solder side up, but on post 30 the PCB is mounted component side up.

Is this the difference between version 1 and 2?  In which case, my PCB’s don’t say v2, so should I just assume I have the first version and I should mount them solder side up?

Cheers

Ste
 
steves.mastering said:
Hi, I’m just working on a pair of app992’s.

A generous diy’er on here sent me them free with another PCB I bought so I don’t know how old they are.

Just about to install the mounting pins, I see on post 7 that the PCB will be mounted solder side up, but on post 30 the PCB is mounted component side up.

Is this the difference between version 1 and 2?  In which case, my PCB’s don’t say v2, so should I just assume I have the first version and I should mount them solder side up?

Cheers

Ste


Hi Steve,

thanks for posting
the first APP992's (less than 5% of the total ) were put on the socket with their PCB on the top, the other ones have to be put on the socket with their PCB on the bottom. The schematic is quasi the same for all versions, so pratically there are no  differences on their sound.
As Volker said is possible to see the PCB to know the version of it. Than, If you want, you can post a photo of this PCB (of the top layer), please.
Cheers
Pier Paolo
 
 
Thanks for your replies.

I zoomed in on the pic on post 7, seems the same PCB as the one I have so I soldered the pins same as that. Going to install it in my diy sontec tonight :)

Thanks again :)
 
Hi guys,
Does anybody know where I can buy a few DIY kits for APP992s that I can run in 2 channels of TheDon 250EQs using 16V rails?

My goal would be to enrich the low-mids harmonics, would they be good for that?

Thank you for any tips! I’m in California btw.

Stefano
 
baslotto said:
Hi guys,
Does anybody know where I can buy a few DIY kits for APP992s that I can run in 2 channels of TheDon 250EQs using 16V rails?

My goal would be to enrich the low-mids harmonics, would they be good for that?

Thank you for any tips! I’m in California btw.

Stefano

It's not designed for adding harmonics/color. It's designed for very fast transients and clean. It sounds amazing for mastering applications and similar type situations, but if you want character you might want to use something else.

Thanks!

Paul
 
Hi Everyone,
Just wanted to chime in with my experience with Pier's APP992 v2.1 (!).

v2.1 seem fairly straightforward to build, but I chose to have them pre-assembled to avoid any additional troubleshooting.

Similar to a few users here, I used the APP992 v2.1 in both the In and Out position on my Don Classics 250EQ in a 500 series rack. Simply put, these opamps sound nothing short of stellar and are a massive step up from the OPA134 in this application. Like Udo noted, these are VERY clean and open. The sound is detailed with an almost effortless quality to their operation, and have an ability to highlight music in a very flattering way. The APP992 also handled higher gain without feeling as pushed or contained as the OPA134 in this situation.

I am very happy with the APP992 v2.1, the audible improvement was definitely worth it!

Grazie Pier!

Best,
Brian
 
Hi Brian,

many thanks for your comments, I really appreciated them.

BTW is possible to upgrade the APP992  ver 1 to ver 2.1.

best regards
Pier Paolo
 
ppa said:
Hi Brian,

many thanks for your comments, I really appreciated them.

BTW is possible to upgrade the APP992  ver 1 to ver 2.1.

best regards
Pier Paolo

Hi Pier Paolo,

could you please PM me how to upgrade my ver 1 to ver 2.1?

Thanks!
 
Falk said:
Hi there,

does anyone have the built documents for the app992? I received the kits but do not have any assembly instruction. Could someone help me out?

Thank you,
Falk

Hi Falk,

docs just sent, I avoid to send papers with the parcels to reduce (a lot) the shipping costs.
I sent you by email, manual, schematic and BOM.
If you have questions contact me, please.
thanks
Pier Paolo

EDIT: schematic and BOm are upgraded for the ver.2.1.

 
Pier Paolo,
I received the APP992 and install them as discussed.  one word: WOW !

My Mastering EQ has come to live, heavily computing with my other 2 Sontec EQs in transparency. Simply beautiful.  Thank you tank you for making it available and your excellent service. It was worth the wait.

I will try to attach some pictures for my feedback.
 
Hello Pier,
I found a handful of APP992. Bought them in 2012 (?) but boxed back then for lack of time, and then forgotten. The kits have resurfaced after moving twice now. So time to put them to use  :)

Need documentation please, as I had not printed it out back then. Not sure which version it is and whether upgrading is possible and/or makes sense.
 

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