1176 REV E - F Hybrid

[ilfungo]

Hi
I'm working on real 1176 REV  F layout from a real comp  '70 era.
I want to try to make an hybrid version between REV E  and F.
REv F with output stage of rev E or simply REV E with IC meter circuit.
Could work?
Thanks!
Attacked the Hybrid schematics .

 

[ilfungo]

???

 

[JW]

Howdy,

I wish you'd received some advice on this, as I'm interested as well.

I wonder if nobody has replied because the schematic changes you made are a little difficult to make out? Looking at the JBL scheamtics http://www.jblproservice.com/pdf/vintage%20jbl-urei%20electronics/urei-1176lnmanual.pdf it's not quickly  obvious (to me anyway) what all the differences are in the outputs between E and F. It would take a bit of studying them.

And in your attachment, I can't quickly tell exactly where you're changing what. For example, I see C10 is enlarged. But C10 is the same cap in E and F. ???

 

[JW]

I've been tinkering with my Mnats J boards (which are actually rev F/G) for quite a while and I think I want to try just tapping the circuit at the output pot like it looks like you're doing and perfboarding the Rev D output circuit. I did notice that there is a 250K output pot in the Rev D.

I need to study how the meter circuit is hooked up though. I don't understand quite yet if anything needs to be changed if what I have in there already is working (IC meter)

Here's a legible D schematic on mnats site: http://mnats.net/files/1176REVD_VOLTS.pdf
Here's an F/G schematic from gyraf: http://www.gyraf.dk/gy_pd/1176/1176sch.gif
Here's the JBL scans of the original schematics: http://www.jblproservice.com/pdf/vintage%20jbl-urei%20electronics/urei-