Pics of that high woltage opamp...

Yesterday I received that S_P_L preamp based on the high voltage opamp.
http://img.photobucket.com/albums/v292/chrissugar/GAINSTATION/DSCF6911X.jpg
opened the box

http://img.photobucket.com/albums/v292/chrissugar/GAINSTATION/DSCF6914X.jpg

a complicated PSU with many voltages. A real 250V power for the tube, not the classic starved tube thing.

http://img.photobucket.com/albums/v292/chrissugar/GAINSTATION/DSCF6919X.jpg

The preamp: a mainboard and a daughterboard

http://img.photobucket.com/albums/v292/chrissugar/GAINSTATION/DSCF6923X.jpg

chrissugar

Some datails:
http://img.photobucket.com/albums/v292/chrissugar/GAINSTATION/DSCF6925X.jpg
http://img.photobucket.com/albums/v292/chrissugar/GAINSTATION/DSCF6927X.jpg
http://img.photobucket.com/albums/v292/chrissugar/GAINSTATION/DSCF6928X.jpg
The separate boards

http://img.photobucket.com/albums/v292/chrissugar/GAINSTATION/DSCF6941X.jpg

chrissugar

As you can see they used quality components: Panasonic FC, WIMA, EPCOS, NAIS and custom discrete opamps.
The tube is 12AX7 SOVTEK

The opamps are not the ones use in the S_P_L mastering console [120V]
but some smaller SMD based circuits [60V]. There are two type of opamps, the bigger seemes to be the output stage [Four output transistors]
The circuit is an instrumentation amp topology wit DC servo based on LF411 opamp.

Here are the pics:
http://img.photobucket.com/albums/v292/chrissugar/GAINSTATION/DSCF6939X.jpg
http://img.photobucket.com/albums/v292/chrissugar/GAINSTATION/DSCF6936X.jpg
http://img.photobucket.com/albums/v292/chrissugar/GAINSTATION/DSCF6935X.jpg

chrissugar

The output transistors are 80V Uceo BCP53 and BCP56. The rest have some cryptic notations like N1, NA, N2.
I supose the N2 six pin devices are matched transistors.

chrissugar

Hm. I don't like SMD stuff... hard to identify...
and smd melf components... if they would have a face they would ROTFL (rolling on the floor laughing) :green:
where is the f***ng round melf resistore going? :twisted: :wink:

Crissugar do you accidently have a SPL* mastering console there?
I think the opamps are much easier to identify. :wink:

But the idea how the pcbs are mounted 90° to the main pcb looks good. I have to keep that in my mind.

"CHrissugar do you accidently have a SPL* mastering console there?
I think the opamps are much easier to identify. "

No, sorry I don't have one because I build my own. :grin:

chrissugar

Hi Chris,
Geat pics and info.
Thanks!

nice pics!!!

[quote author="nrgrecording"]Hm. I don't like SMD stuff... hard to identify...[/quote]No, no...look here for SMD Codes

where is the f***ng round melf resistore going?

Click to expand...

Hopefully, the endplates are all octagonal by now :thumb:

Verry nice pics too! You should be able to identify all those parts now...!