-
Interacting Input Stage Issue
09/08/2023 at 22:59 • 0 comments- Design flaw, the first stage resistors connected to Vsig of the Sub-Bass, L-Mid, U-Mid, Presence and Brilliance filter have a topology that make that appear in parallel with each other when the resistance is measured between Vsig and ground. As a result this significantly lowers the resistance measured by those resistors as shown in the following diagram.
- This means that the spectrum filters are not isolated from each other and will affect each other's signal responses
- ****************To prevent this problem, I am going to use the fourth op-amp in each IC package as a buffer amplifier for each spectrum filter
- The first stage resistors of the Bass and midrange filter connect to Vsig and a capacitor as shown in the following diagram. Therefore the measured resistance was unaffected as shown in the following image
- T
- Design flaw, the first stage resistors connected to Vsig of the Sub-Bass, L-Mid, U-Mid, Presence and Brilliance filter have a topology that make that appear in parallel with each other when the resistance is measured between Vsig and ground. As a result this significantly lowers the resistance measured by those resistors as shown in the following diagram.
-
Troubleshooting!!!!!!
09/06/2023 at 06:27 • 0 comments- Some resistors are giving values that giver by over 50% of ideal values when measured by oscilloscope after being soldered
- Documented the soldered
resistors that are and aren't defective
- 7 were defective
- -----R1, R2, R20, R21, R58, R39, R40
- 43 were not defective
- -----R13, R18, R31, R36, R51, R41, R50, R22, R35, R53, R23, R24, R28, R29, R30, R34, R48, R4, R11, R65, R43, R45, R47, R54, R61, R66, R67, R68, R69, R70, R71, R72, R73, R74, R75, R76, R77, R78, R79, R80, R81, R8, R82
- Interesting, the resistors that appear to be defective are at the first stage of their respective spectrum filters and connect either directly to Vsig or via one resistor
- ***Figured out the issue, this resisters are not defective, this is a design mistake, need input buffers will go into more detail tomorrow
- Analyzed measured capacitor values, will go into more detail tomorrow
-
Solder Update 2
09/06/2023 at 06:23 • 0 commentsD2
- 1kohm: R66,R67,R68,R69,R70,R71,R72 - soldered
- 143kohm: R23 - soldered
- 48.7kohm: R34, R58 - soldered
- 26.7kohm: R40 - soldered
- 35.7kohm: R8 - soldered
- 95.3kohm: R54 - soldered
- 118kohm: R13 - soldered
- 137kohm: R20 - soldered
- 4.32kohm: R61 - soldered
- 57.6kohm: R37 - soldered
- 576kohm: R28 - soldered
- 107kohm: R45 - soldered
- 453kohm: R47 - soldered
- 68kohm: R17 - soldered
- 56kohm: R33 - soldered
- 4.7nF: C13,C14 - soldered
- 0.1uF: C51,C60,C61,C62,C63,C64,C65,C66,C67,C68,C69,C70,C71,C72,C73 - soldered
- 47uF: C1, C2 - soldered
- 2nF: C56 - soldered
D3
- 20kohm: R73 - soldered
- 102kohm: R74 - soldered
- 620ohm: R82 - soldered
- 45.3kohm: R21 -
- 1nF: C21,C22,C25,C26,C27,C28,C29,C30,C31,C32,C33,C34,C35,C36,C37,C38,C39,C40,C41,C42 -soldered
- 13nF: C7, C8 - soldered
-
Solder Update
08/27/2023 at 05:31 • 0 comments- 680ohm: R75, R76, R77, R78, R79, R80, R81 LED brightness control LEDS - soldered
- 270kohm: R22, R35, R53 - soldered
- 90.9kohm: R4, R11, R65 - soldered
- 19.1kohm R24 - soldered
- 59kohm: R42 - soldered
- 100kohm: R29, R30 - soldered
- 160kohm: R2, R41, R50 - soldered
- 78.7kohm: R39, R48 - soldered
- 84.5kohm: R1 - soldered
- 11.5kohm: R57 - soldered
- 1.6nF: C19, C20 - soldered
- 6.2nF: C17, C18 - soldered
- 6.8nF: C9, C10 - soldered
- 1uF: C47, C48, C49, C52, C53, C57, C58 - soldered
- 3nF: C23, C24 - soldered
- 24nF: C11, C12 - soldered
- 100u: C43, C44 - soldered
-
Ordered!!
08/04/2023 at 04:48 • 0 comments- Verified correctness and availability of components
- Ordered components on Digikey
- Ordered PCB on JLCPCB
-
Order Preparation
08/03/2023 at 03:58 • 0 comments- Moved R82 closer to the power LED
- Physically verified the 9V power jack connection to adapter
- Verified pots connected to nets properly
- Made list of components that still have left over from previous build and therefore don't need to re-order
- Created new updated BOM
-
Design Adjustments
08/03/2023 at 01:00 • 0 comments- Increased the value of R82 (9V indicator) to 620 ohms (chosen for availability)
- Added 3.5V label to output of LDO in Rhi-Control
- Added Signal and Ground labels to screw terminal audio input
-
Design Adjustments
03/15/2023 at 03:31 • 0 commentsCorrected Spectrum filter mistakes
- In KiCad, op amp filters were connected as positive feedback, changed to negative feedback
- Corrected R5 and R8 values in FinalLowMidrange LTSpice file
- Corrected R2 and R3 in FinalUpperMidrange LTspice file
- Corrected R2 in FinalPresence LTSpice file
- Changed C39 and C40 in KiCad Brilliance Filter from 1nF to 820pF
-
Design Adjustmets
03/02/2023 at 04:17 • 0 comments- Corrected the LT1054 -5V regulator inverter power output label and retraced the signal
- Finished sourcing replacements for 0201 components, will use 0603 minimum from now on
- Changed 0603 footprint to hand solder version, and changed 0402 footprints to 0603 hand solder version
- Decided to keep the two
parallel 1uF capacitors instead of replacing them with one 2uF capacitor
- The 2uF cap is $3.78, just for one
- Using parallel caps in power supply circuit to achieve equivalent capacitance is fine, in fact there are advantages https://eepower.com/capacitor-guide/applications/capacitors-in-parallel/#
- Created Bill of Materials
-
Solder Progress 11
01/26/2023 at 03:36 • 0 comments- Attempted to solder capacitor
onto area with broken pad by soldering to the trace after scrapping the
protection off
- Was able to scrape protection off, but was not able to get solder to stick to the exposed copper
- Ended up making the situation worse
- The whole point of soldering
myself was to:
- Save money
- To be accurately claim that I can solder surface mount devices
- The above two are no longer issues
- **SOLUTION: Redesign the board
- Don't use components smaller than 0402, use 0603 if space permits
- Fix negative voltage regulator output and feedback mistake (would have to cut 2 traces and connect 2 traces...)
- Re-check every other circuit for mistakes
- This works out as I can easily solder 0402 sized devices now, a lot of my 0201 components got damaged and have values that deviate greatly from the ideal value, so the filters were not gonna work properly anyway
- I have all of the tools I need this time, should be able to finish soldering aspect within a week
- I will spend the rest of this week and the weekend redesigning and working on the BOM, aim to order new board by Sunday or Monday
- ***Incorporate component availability into design - check if JLCPCB has component before selection, will use soldering
- Will buy new IC's as well, large chance of damaging components with hot air rework station, do not wanna take the time and risk with a board with this many components
- Attempted to solder capacitor
onto area with broken pad by soldering to the trace after scrapping the
protection off