KicadJE_LFO_1
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Johansen Engineering KiCadJE_LFO_1.2 (Rev B)
Analogue LFO - minor adjustments - new jacks (PJ321 -> pj324) - remove Sine Adj
555 Based LFO - minor adjustments - new jacks (PJ321 -> pj324) - remove XXX
NAND - Footprint adj
Purpose
Fix issues with RevA
555 LFO
+/- 10V LFO Square, Triangle, Sine
2 frequency ranges
LFO
+/- 10V LFO Square, Triangle, Sine
NAND
NOT Gate (pull dn) - NAND Gate (both pull up) - AND Gate (both pull up)
0-10V output - CMOS input
D-Flip Flop
0-10V output - CMOS input
MMX
+-10V Input/output - DC couple
Top - 3 input mixer with phase reversal
Bottom - 3 mult output with phase reversal - uses mixer output as input if not applied to mult input
Status - In the mail
Initial
| Stage | Detail | Status |
|---|---|---|
| create material | sch/pcb | OK |
| gerber | OK | |
| production | OK | |
| produced | Yes | |
| delivered | OK |
Preliminary validation
| Test | Detail | Status |
|---|---|---|
| Initial Inspection | OK | |
| Initial Technical Test | LFO555 | |
| PJ321 should be 1 mm further from the front, center tap works - minor footprint twist in pj324 | ||
| Initial Technical Test | NAND | |
| cut power plane and add 20k across to fix not blowing other units due to hard pull up on tip. | ||
| Initial Product Test | LFO | |
| Initial Product Test | LFO555 | Sine and Tri not working - needs ac coupling from square - needs dc compensation |
| Initial Product Test | MMX2 | |
| Initial Product Test | NAND | Now working with 4093 - needs pull up resistors and I/O protection |
| Initial Product Test | FlipFlop |
Secondary validation
| Test | Detail | Status |
|---|---|---|
| Product Test | LFO | |
| Product Test | LFO555 | working right - tri and sine needs tweaking of waveforms |
| Product Test | MMX2 | |
| Product Test | NAND | working - see issues |
| Product Test | FlipFlop | Working as intended except for LED's |
| Quality | LFO | |
| Quality | LFO555 | |
| Quality | MMX2 | |
| Quality | NAND | |
| Quality | FlipFlop | |
| Long Term Product Test | ||
| Power Draw |
Errata
Errata - LFO
Errata - LFO555
Errata - MMX2
Errata - Flip-Flop
Errata - NAND
Hard pull up to 12 can fry other units !!! Add resistor pull up
Output protection (series resistor?)
Issues and Notes
LFO
555 LFO
AC coupling of Square should be considered - internal and at least DC adj external
bias current compensation (eg. 10k to GND)
Flip-Flop
MMX2
NAND
Pictures
MMX2
Johansen Engineering KiCadJE_LFO_1
Initial Analogue LFO
Purpose
Status - Evaluated
Initial
| Stage | Detail | Status |
|---|---|---|
| create material | sch/pcb | OK |
| gerber | OK | |
| production | OK | |
| produced | Yes | |
| delivered | Yes |
Preliminary validation
| Test | Detail | Status |
|---|---|---|
| Initial Inspection | OK | |
| Initial Technical Test | LFO555 | 555 and 072 gets warm in certain settings |
| Initial Product Test | LFO | Works well with R311 not mounted |
| Pot's should be 1 mm closer to front (or jacks further back) | ||
| Initial Product Test | LFO555 | Sine and Tri not working - RV101B should have 500R series resistor |
| Initial Product Test | MMX2 | Works nicely |
| Initial Product Test | NAND | Not working with 4093 - footprint matches 74HC00 |
| Initial Product Test | FlipFlop | Working |
Secondary validation
| Test | Detail | Status |
|---|---|---|
| Product Test | LFO | |
| Product Test | LFO555 | not working right |
| Product Test | MMX2 | Working as intended |
| Product Test | NAND | Will Never work |
| Product Test | FlipFlop | Working as intended except for LED's |
| Quality | LFO | Sounds nice - a few constraints on pot's would be nice |
| Quality | LFO555 | |
| Quality | MMX2 | |
| Quality | NAND | Will Never work |
| Quality | FlipFlop | |
| Long Term Product Test | ||
| Power Draw |
Errata
Errata - LFO555
1 - SW101 too close to P101
Errata - MMX2
1 - 1206 caps (C201+C202) are too close to the switch to mount both
Errata - Flip-Flop
1 - LED positions swapped
Errata - NAND
Will Never work - Footprint wrong so Input is directly coupled to output for some NAND's
Issues and Notes
LFO
1 - 100k should not be mounted (it ruins feedback)
2 - Sine pot should have 2k series resistor
3 - C303 could be 100nF and 1uF addon with a switch for high low
4 - Frequency pot is sensitive at low freq
5 - Chose different Jacks
6 - Consider adding series resistor to outputs
7 - mounting holes
8 - Pot's should be 1 mm closer to front (or jacks further back)
555 LFO
1 - RV101B should have series resistor (330 - 1k)
2 - All outputs should have a series resistor (470R ?)
3 - Pot's should be 1 mm closer to front (or jacks further back)
4 - RV101 footprint not matching pots
Flip-Flop
1 - LED positions swapped
NAND
Will Never work - Footprint wrong so Input is directly coupled to output for some NAND's
Pictures
Inspiration from
https://www.electronics-tutorials.ws/waveforms/555_oscillator.html
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