luvdunhill

Awesome! I tried a “remote” thermistor (Murata NCP18XH103) and ended up just using a LM234 and some resistors.

I ended up using the LT1021 - in haven’t tested that circuit yet, but it’s soldered in waiting to get some juice.

Actually, no but good question! I have three of these identical looking PSUs now - keeping the simple aesthetic. The PCB could be mounted that way though, but in my “case” it won’t. I plan on logging hours the TT is on (to estimate stylus wear) and how accurate the speed control is. I will retrieve that data off the USB port if needed. Here it is in action. The top display is the actual platter speed. Next to write the auto adjusting code. https://imgur.com/gallery/UXOn6R9

Woo, looks like the CPU board is working! Currently set at 20.29 Hz for 33.33rpm output. Got the front panel also working and now just need to solve the issue of the reflective IR Sensor (or go back to a magnet) - which I think might take a shroud to try and reduce stray light. The second display will then read out the actual platter speed as measured by the tach. Then I can adjust the speed in a feedback loop (PID). Still smells like a busted cap though

Soo.. what you are telling me is the white stripe on that black square thing is positive, not negative? Ok, that released some smoke and fire…

I dunno, is it okay with Larry if we use that? We haven’t asked permission after all.

This has been a handy device for me - even has pads to control it from a micro controller: https://www.amazon.com/DROK-Adjustable-Electronic-Discharge-Resistance/dp/B07KQS74C6/ref=mp_s_a_1_16?dchild=1&keywords=programmable+battery+load+tester&qid=1619718835&sr=8-16

I have been continuing to play with turntable motors. I have two projects, one a controller with platter speed feedback for 3-phase AC motor and another controller for DC motors, which is an ultra-compact version of the one in swt61’s turntable to drive the Maxon motor. Here are some photos, just got things soldered up and have a whole lot of very tedious testing and software writing to do in addition to the SAMD microcontroller, that cutout is org castellated pads will also fit the new Raspberry Pi 2040 chip, which I am hoping to play with a bit. I hope they work!

Ok, who logged back into Huddler-Fi? Come clean.

Nice work! So I see you removed the door and window trim and then somehow fancied it up?

I got the code working to measure the platter speed! The sensor is still wonky - maybe I need to build a shroud around it.. Maybe I just built a ghost sensor! That would explain a lot... maybe this is the newest fad in audio accessories

The optical based sensor seems much more fiddly compared to the magnet. It’s influenced by ambient light (for example record needs to be on the platter) and I am using a small craft mirror on the platter but not sure if just a white dot would work better? The part is VNCT2020. IMG_2400.MOV

That’s pretty special.

Off topic - but I am also working on a battery controller. Spent an embarrassing amount of time troubleshooting and replacing parts to find out that I had incorrectly labeled the “charging” and “error” LEDs

It looks like you wouldn’t have an issue with the double thickness but would have to put a cutout if you wanted to keep parts on both sides of the sub-assembly. I also don’t have any idea how thin of a PCB you can go with and have enough plating on the castellations...

What about a castellated sub board with the smaller parts and the USB connector?

Splicing up some new fancy blocks for the weekend

Do you typically stop the platter before you change records?

It’s fun getting to know a new setup. I don’t have the VPI really dialed in yet, but already don’t like the threaded clamp. I am trying just a heavier weight that places over the threaded spindle. I also don’t know why VPI didn’t better match up these foam discs when adapting their newest footers to older designs. I think I will have a go at designing a replacement.

Yes, that’s an option. I see Analogue Seduction wants 276£ for one (@swt61 the 309 doesn’t use the old style bayonet connection, in fact due to the offset angle the 309, 310 and 312 aren’t compatible with each other) and I am wondering if that’s close to what SME will charge..

With a bit of rigging, look what’s making music:

Woo... finally found a SME 309. Now I need an extra head-shell that isn’t a zillion dollars.

I think I am going to try to use a reflective sensor - looking at Vishay VCNT2020. I need a mirror or similar, assuming the acrylic platter won’t be IR reflective. Maybe a foil sticker? http://www.farnell.com/datasheets/2614502.pdf added a comparator to the board to adjust the sensitivity

Maybe just buy the house as well - will solve your space problems.

Ok, tach seems to be working - enough done today where I am going to try and rig up a tonearm and do some listening before I go back to working on the software for the controller IMG_2369.MOV