Thank you very much Alex ! Very kind !
But I don't want to bother you and take up your time.
I think I will handle a little additional circuitry so you don't has to reprogram the firmware.
But I wanted information on what exactly is going on with the trigger board. I haven't assembled the boards in the enclosure yet, so I haven't measured the signals of the trigger board. I only flashed the firmware and checked the processor board and displays.
But I don't want to bother you and take up your time.
I think I will handle a little additional circuitry so you don't has to reprogram the firmware.
But I wanted information on what exactly is going on with the trigger board. I haven't assembled the boards in the enclosure yet, so I haven't measured the signals of the trigger board. I only flashed the firmware and checked the processor board and displays.
I have a question about input impedance matching (muses 72320).
I use selected 7230 with very small differences in input resistance. 8 ohms between R and L input in left 72320 and 12 ohms in right.
Differences between two 72320 - 22 ohms. The average input resistance about 19950 ohms.
With this matching network I reduced the input resistance to 13k. Why?
I can match close to 1-2 ohm these 72320 while keeping the input resistance high. Almost 20k. Is this wrong? Why looking for an input resistance of 10-12k?
input impedance matching
I use selected 7230 with very small differences in input resistance. 8 ohms between R and L input in left 72320 and 12 ohms in right.
Differences between two 72320 - 22 ohms. The average input resistance about 19950 ohms.
With this matching network I reduced the input resistance to 13k. Why?
I can match close to 1-2 ohm these 72320 while keeping the input resistance high. Almost 20k. Is this wrong? Why looking for an input resistance of 10-12k?
input impedance matching
Question on grounding: I'm wiring stuff up right now, starting with the shunts from the logic supply board, and I realized that the L and R analog PSU grounds aren't tied together anywhere? I'm thinking they should be? See the red arrow on the logic supply schematic, below. I can't think of anywhere they would already be connected, other than possibly if using a SE source or two, they would be thru the RCA shells to the source component.
^ Hmmm, OK, thanks. Does this involve connecting via the chassis? Also, I don't know if I will use the triggers, sub board, etc. I also do not have schematics for either of those cards, and haven't been able to find them. Most of that type of link is broken in all of the AI version threads both here and on homecinema.fr (any link to psykok's stuff).
Getting the wiring done and ran into an odd problem. I'm building 2 of these, one for myself and the other for DrizztDo in France.
I connected everything except the R preamp board. The L preamp board seems to work fine (I hear relays switching, etc.), but if I connect the R preamp board, the processor won't start up. Either one. The other R preamp board is the same. I do not have any of the FB jumpers (1, 3, 6-9) in place yet. The board addresses are set correctly (R12, 14, 16 for the L and R12, 14 and 15 for the R), but I believe those are only for the Muse chips. I'll recheck my control cables, but pretty certain they are correct. If I unplug the R preamp board control cable, the processors start up fine. Same behavior if only the R preamp board is cabled (and not the L).
I'm just starting to build the UGS modules. I noticed the UGS boards have a spot for a couple of C FB caps, but don't see this on the BOM, so I assume these aren't used.
I connected everything except the R preamp board. The L preamp board seems to work fine (I hear relays switching, etc.), but if I connect the R preamp board, the processor won't start up. Either one. The other R preamp board is the same. I do not have any of the FB jumpers (1, 3, 6-9) in place yet. The board addresses are set correctly (R12, 14, 16 for the L and R12, 14 and 15 for the R), but I believe those are only for the Muse chips. I'll recheck my control cables, but pretty certain they are correct. If I unplug the R preamp board control cable, the processors start up fine. Same behavior if only the R preamp board is cabled (and not the L).
I'm just starting to build the UGS modules. I noticed the UGS boards have a spot for a couple of C FB caps, but don't see this on the BOM, so I assume these aren't used.
Thanks Alex. I haven't looked at the reset yet. That is pin 14 on the STM32 (NRST signal)?
I did work on it briefly today and noticed some odd behaviors. I checked both cables I made and did the following:
I presume that in order to look at much on the processor board, I will need to remove the OLED displays? Thanks for any thoughts.
I did work on it briefly today and noticed some odd behaviors. I checked both cables I made and did the following:
- Hooked the right preamp board to the left I/F on the processor. Other I/F disconnected. Worked fine.
- Moved the connection on the processor board to the right I/F. Worked fine.
- Ohmed out both cables. Wired straight thru, no shorts or anything between pins.
- I could get it running if I connected one board at startup, and connected the other while it was up and running. I could shutdown via the long encoder press and it would come back up OK.
- If I switched power off at the IEC, it would not come back up. Disconnect one preamp board and it came right back up.
- Measured voltage at the processor board and it is fine at +5.995Vdc.
I presume that in order to look at much on the processor board, I will need to remove the OLED displays? Thanks for any thoughts.
Hey Alex,
Nevermind. I hadn't installed the ferrite beads yet (1,3,6-9). I put those in, and it works fine now. Might have been the Muse chips not being powered, etc. causing that issue. Starts up fine and consistently now. Now on to further testing and building the UGS modules.
Is there any guide around showing what the various test points on the preamp boards are for? Thanks again, and for such a great project!
Nevermind. I hadn't installed the ferrite beads yet (1,3,6-9). I put those in, and it works fine now. Might have been the Muse chips not being powered, etc. causing that issue. Starts up fine and consistently now. Now on to further testing and building the UGS modules.
Is there any guide around showing what the various test points on the preamp boards are for? Thanks again, and for such a great project!