TLN-862 Lag Processor


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Last updated: March 17, 2013


The TLN-862 Lag Processor is a MUUB implementation of Harry Bissell's Morph Lag circuit. The Morph Lag has independent controls for setting the rise and fall times, and a shape control to vary the response between linear and logarithmic. Lately I've found I am needing lots of lag processors to smoothen control voltages (particularly from crappy 8-bit MIDI to CV boxes). The MOTM-820 is a fabulous lag processor with voltage controlled everything (I have several) but it is overkill for some of my needs. The TLN-862 is a good way to get lots of lag processors in as small a space as possible.

The TLN-862 features two independent channels (A & B) with the following controls:
  • UP A/B: sets lag time for positive (increasing) voltages.
  • DOWN A/B: sets lag time for negative (decreasing) voltages.
  • SHAPE A/B: sets the response from linear to logarithmic.

Note that the panel layout for this module (and the rest of my MUUB utility modules) uses the smaller type of knob found on Encore Electronic's UEG and Frequency Shifter. Most people will probably hate this, but I wanted to get the most functionality in the least amount of space while still maintaining some semblance to the MOTM standard. To this end, all of my MUUB utility modules use a new layout grid that allows up to 6 pots with 4 jacks, or 4 pots with 8 jacks, on a 1U wide module.

The TLN-862 Lag Processor can be built using MUUB daughterboards.

Contact me if you wish to purchase PCBs.

Total current draw for a two channel TLN-862 (as shown at left) is 38 mA @+15V and 38 mA @-15V.


The User Guide does not contain detailed explanations on how to install parts or which kinds of solder to use. The intended audience is the experienced kit builder who is quite comfortable building a circuit from a description, a parts list, and a schematic. Calibration routines are included.

View the TLN-862 User Guide rev 1.0 (pdf)

Graze over the TLN-862 Schematics rev 1.0 (pdf)

Detailed panel cutout diagram (pdf) with notes for those who want to build their own panel.

MOTM-style front panels for this module can be ordered from The Bridechamber.


TLN-862_prototypes.jpg TLN-862_final_panels.jpg
Prototype with Plexiglass Panel Final Version with Bridechamber Panel

Construction photos.

Richard Brewster's version with Bridechamber panel.