LG Ultrafine 4K daisy chain with 34WK95U-W

After my last post comparing these two monitors, I wanted to see if you could daisy chain the two and still only have to connect one cable to the MacBook, as the LG Ultrafine 4K supports 40gbps and has a thunderbolt out port as well.

Turns out that you can! Thunderbolt 40gbps from MacBook -> LG Ultrafine -> 20gbps to LG 34WK95U-W at full resolution on both monitors.

LG UltraFine 4K 24″ (Mac) vs. LG 34WK95U-W 5K2K 34″ Monitor

For a while now I’ve been using an LG UltraFine 4K (24MD4kL) monitor with my Apple MacBook. However I’ve wanted to have a little more desktop space and was able to get an LG 34WK95U-W UltraWide at a discount, so I thought I would share the differences between these two high pixel density monitors.

Comparison:
– Higher pixel density on the UltraFine, but the UltraWide is still retina like
– Clearing sounding speakers UltraFine, but the UltraWide is louder and much more useable than the built in 14″ MacBook’s
– Ultrafine is slightly brighter, and the semi-gloss screen is slightly more premium
– 3 USB-C ports on the UtraFine compared to 2 USB-A, but the UltraWide has HDMI/DisplayPort inputs and can display two sources at the same time
– UltraFine wakes from sleep faster
– Thunderbolt on the UlatrFine allows daisy-chaining to another 4K monitor
– Native Apple controls for volume an brightness on the LG UltraFine although you can use MonitorControl with the UltraWide
– Some people are annoyed by the fan noise on the UltraWide, but I couldn’t hear it
– About 1.5x more desktop space on the UltraWide
– UltraWide is almost twice the price

Overall, some people might be better off getting two UltraFine 4Ks instead of a single UlatrFine, since it’s almost twice the price, but I got my used and I already use the monitor on my MacBook as a second display as well as Touch ID and the webcam, so having 3 monitors was just too clumsy and took up too much space. I tend to work on just 2/3rds of the UltraFine, as I find two windows optimum as a programmer. But the extra third allows me to have space for email or a video without having to constantly cover my main work.

I had to do a few things to get my UlatrFine to work at high DPI resolutions.
– Update the monitor firmware using the LG OnScreen Control software downloadable here.

– Using the display menu on the monitor itself, change the Display Port version to 1.4. Again it wouldn’t show up as a 5120×2160 monitor without doing this.

More tips can be found on this MacRumors thread. I did not need to use SwitchResX or BetterDummy in order to run at 3840×1620 resolution.

Also while the UltraFine 4K is made for Mac, people have got it working on Windows machines with Thunderbolt, and the brightness can be controlled with one of these apps:
https://apps.microsoft.com/store/detail/lg-ultrafine-brightness/9N5MJ2FQ4GWW
https://github.com/motamed/LG-UltraFine-Brightness-Control

Small Improvements to the M1Pro MacBooks

The 14″ M1Pro MacBook is the best Mac I’ve ever owned. Having used one for some time now though, I would have liked to see a few small improvements:

  • Half size function keys but a larger touch pad
  • Menu bar come to exactly the bottom of the webcam notch
  • HDMI 2.1 and SDUC (SD Express Card)
  • Ethernet on the MagSafe charger (like the iMac)
  • USB-A Port (please just give us one Apple)
  • More key travel on the keyboard (it’s better than the butterfly keyboard, but I still prefer my old unibody MacBook keyboard)

The M1 iMac Should Have Been USB-C Powered

The new M1 iMac is sure to be a hit, but given its lower power processor, it would have been great to make it USB-C powered, so a power supply could be shared between the iMac, MacBook, and iPad, now all running the M1 processor. USB-C supports power along with data, so the ethernet on the power supply (which is a great idea.) could still be included and made available to the MacBook and iPad. It would have also allowed USB-C wall power sockets to start becoming a standard, which could also start including the ethernet connection, wired internally in the wall. At the very least it should have done a MagSafe connector which was the same as the MacBook, which is rumored (leaked!) to be on the M1X 14″ and 16″ models, scheduled for release mid-2021, but it looks like the connector for the iMac is far too big to work on a laptop.

M1 Mac Mini Internal Storage

Was looking at the M1 Mac Mini and wondering if you could fit some extra internal storage inside all that empty space. I’d love to see someone do this:

  • Add a USB to M.2 SSD in the extra space.
  • Take slim right angle cable out through the fan vent and plug it in a USB-C port out the back.
  • For the extra brave, maybe they could desolder one of the USB sockets, and attach the cable directly to the motherboard.

Update:
I realized this was probably more trouble than it’s worth when you could just stick a tiny 512GB USB, or maybe in in an M1X Mac Mini Pro use a 1TB SD card.

Buffer With Relay Bypass

Just a quick schematic of a buffer with relay bypass. The relay bypass means that if you lose power, the relay switches back to bypass and you still get a signal like the TC Electronics Bonified Buffer.

  • Based on JHS Little Black Buffer
  • The value of R will depend on what voltage/spec relay you have
  • Most opamps are in 2 in 1 chips. The unused side is wired to prevent noise/oscillations

Train Wreck Type-2 Lar-Mar on a Victory V40

I’ve been looking at doing a post phase inverter master volume mod to my ’68 Fender Vibrolux. I was wondering about using what was on the Victory V40, since it is a American-style tube amp. It turns out they seem to use a Type-2 Lar-Mar but with a larger value pot, and smaller value safety resistors.

I think the advantage of this setup is that with the resistors in parallel, the lower resistance makes more difference when calculating the total resistance. The better tolerance of the fixed resistors keeps the total grid leak resistors more consistent between the two power tubes, as pot tolerances can be ±10% of the stated value.

Here’s a comparison:
1) 10% tolerance 250K pot in parallel with 1M resistor:
Min = 225K x 1.0M / 225K x 1.0M = 184K
Max = 275K x 1.0M / 275K x 1.0M = 216K

2) 10% tolerence 1M pot in parallel with 250K resistor:
Min = 0.9M x 250K / 0.9M + 250K = 196K
Max = 1.1M x 250K / 1.1M + 250K = 204K

As you can see, even though the pot tolerance is the same, the end result is a much smaller deviation between the 2 grid resistors with a 1M pot vs a 250K pot.

PRS Piezo Options

I’ve been looking at modding a PRS singlecut with a piezo pickup and a middle single coil. Models I’ve been looking at are:
– S2 Starla
– SE Zach Myers
– SE Tremonti
– SE Singlecut Trem

These all have a different bridge but are all a bit non-standard, so I’m documenting a little of my research as it took a little time and emailing to come across.

1) TonePros AVT2P
TonePros make a wraparound bridge that use standard tune-o-matic saddles. You can then get some piezo saddles from RMC Pickups

2) PRS Trem with RMC saddles
RMC also make some Piezo saddles to retrofit PRS tremolo bridges

3) Replace PRS Tremolo
You might be able replace the PRS tremolo with a 6 screw piezo, but the screw spacings might be slightly different, so might be hard to make it work:
PRS seem to be 52.4mm (2-1/16″)
LR Baggs (Vintage 6 screw) 53.98mm (2-1/8″)
Fishman 56.38mm

4) Graphtech Wraparound
Graphtech make a complete replacement, but it’s pretty expensive and has 6 separate piezo leads that need to be fed to the cavity and joined using their circuit board.

5) Replace Tune-o-matic
If you have tune-o-matic bridge like the Starla or 245, there’s a pretty affordable bridge available on eBay, along with more expensive solutions from Fishman and LR Baggs.

6) Modify a PRS Trem
Because the tremolo block can be unscrewed from the top plate, you may be able to wedge an element between them like the video below. This might be worth experimenting with since it’s completely reversible and the elements themselves are only about $5.

7) ABM Piezo Wrap Around
AMB in germany used to make a wrap around piezo bridge, but when I contacted them said they no longer did due to low demand.

8) Q-Tuner Magnetic pickup
You may be able to add an additional Q-Tuner magnetic pickup, which has a large dynamic range and more capable of capturing an acoustic sound, especially when combined with something like the Fishman Aura Imaging DI.

Flip-Flop Loop Switcher / Dual Pedal Switcher

I have a couple of DIY overdrive pedals that I never have on at the same time. So I wanted to house them as a dual overdrive and then add Flip-Flop switching so that to go from one pedal to the other, instead of having to turn one off and the other on, you just turn on the one you want, and it automatically turns the other off. Could be used for a true bypass looper as well to switch pedals in the same manner externally.

So far I’ve done this with counter ICs. I planned to try and do it with a single dual J-K Flip-Flop with asynchronous reset, but I couldn’t get the clock debounce to work with that. Eventually, I came up with a clock circuit that works with a dual counter chip:

Schematic using dual counter chip:

Schematic using 2 counters. This uses a different debounce circuit which I’ve found to work with that chip:

I also chanced upon a debounce circuit that worked, when all the other types I found on the internet didn’t work that well with this particular IC chip. I’ve drawn out just that portion incase it’s useful to anybody else struggling with a chip clock timings. Even though both the 9V and GND should be AC ground, I found it would only work if I decoupled to both the positive and negative of the power supply: