GssL 20th anniversary
- Gustav (PCB Grinder)
- Jul 30, 2024
- 2 min read
Updated: Oct 6
GssL 20th anniversay edition,Gustav and Isak project, done in 2024.
Schematics rev5
Schematics - Link
Panel File
2RU version in my own design - Panel file
BOM rev 5
Bill of Materials (rev 5) - link
Reichelt BOM updated for rev 5 (Sectioned, so you can shop for the in- and output you prefer for your build)
THAT1206 Input section
NE5534 Input Section
VCA Drive
Signal Path VCA
Side Chain
Side Chain Sum
Blend
THAT1646 Output
5532 Output
PSU
Attack
Release
Ratio
Side Chain HPF
Bypass & Misc
Example:5534 in/5532 & blend
Total 82,92 euros
Mouser Parts
Standard in- and output - Cart
Total 74,27 euros
1206/1646 in- and output - Cart
Total 106,81 euros
Case example Modushop
1RU Case
55 euros
Drilling up to 20 holes x 2
70 euros
Printing (front and back)
30 euros
Total 155 euros
Pots
2 pcs 10K lin pots (threshold and make-up gain)
1 pcs 2 x 50K lin pot (blend)
1 pcs 10K log pot (Post module trim)
(You can order these from Banzai music in Europe, dont know about the US)
Calibration
R56/R57, fine tuning gain loss of unit,
Send 0dBU to unit, check output, adjust trimmer for 0dBU output (this is fine tuning, if you just leave them, youll still be within range of the classic GssL)
R59/R60, blend summing gain.
I like to dial these in, so correlating signals at 0dBU from wet and dry come out to 0dBU, some will prefer to calibrate for 6dBU, some will prefer something in between. In real use, youll never have correlated, full gain signals here, so calibrating it +6dBU make sense to every workflow, and we have a make-up gain in-circuit to control total gain anyway.
R153 - meter calibration
Send xdBU to the unit, measure output, add compression and adjust threshold until output measures x-5dBU, adjust R153 until meter reads 5. (in essense, inject signal to the unit, add a known amount of compression measuring difference between input and output, adjust the meter to that amount)
Changes from rev 4 to rev 5
Ratio switch pinout was reversed, and has been fixed
Revision was done on the ratio board, so previous builds can be fixed with a rev 5 ratio board, or you can cut and jump 6-1 to reverse, 5-2, 4-1, as well as 12-7, 11-8 and 10-9.
Isak & Gustav
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