What is on your workbench right now?

[Valvetubehead]

When using LED lights for photography, you should look for a high CRI value. At least 95, preferably 99.
The colors in the image are only reproduced to the extent that they are present in the light spectrum. If, for example, the red component is completely missing, a tomato will remain black in the photo.

manuf. claims equal to or greater than 95 on the one referred to… might explain why I like it

 

[pma]

This is on my workbench .

 

[dualazmak]

BTY, @Valvetubehead, you are cordially invited to my independent thread "Let's share diagrams (and photos) of our total physical audio system and the whole signal path, with a few words and/or links" if you would be interested. Your participation there with photos (and diagrams) will be much welcome.

 

[Valvetubehead]

BTY, @Valvetubehead, you are cordially invited to my independent thread "Let's share diagrams (and photos) of our total physical audio system and the whole signal path, with a few words and/or links" if you would be interested. Your participation there with photos (and diagrams) will be much welcome.

Bit of a moving target at the moment with incoming Zilch jbl c36 Frankenschpeaker project. Will circle back in a month or two.

 

[egellings]

I did taw a puddy tat!

 

[Valvetubehead]

Finally, off the bench and tested. Next, start to rework the C36 bins to receive retrofit.

 

[Berwhale]

The multimedia unit in our 2017 Skoda Yeti had a faulty touch screen. Garages quoted £1500 for a replacement unit. It's possible to buy a new touch overlay for under £20 and mount it in front of the old screen, but it's a bit a of a bodge and puts additional pressure on the fascia which can cause it to crack. I opted for a whole new screen/touch overlay for £60 from eBay. I've already changed the screen at this point, that's the old one in the background.

Works fine!

 

[Shrek6]

currently on my bench is melted black plastic splattered everywhere and dry powder chemical fire suppressant, because I was recharging a disposable vape and forgot to disconnect it.

 

[Roland68]

currently on my bench is melted black plastic splattered everywhere and dry powder chemical fire suppressant, because I was recharging a disposable vape and forgot to disconnect it.

Smoking can kill you, one way or another. Good for you that this attempt was unsuccessful...

 

[Salt]

Smoking can kill you, whereas life will kill you ...

 

[AnalogSteph]

Next patient: A Pioneer F-757 Mark II tuner

I've dragged this one back out, taken some more measurements, contemplated some possible mods for reduced standby power consumption and written about it.

Obvious casualties so far:
C703 (220µ/63V, 10xsomething mm), tuning voltage supply first filter cap. ~38 V= with 8 Vrms of AC is no good when load current is 14 mA tops. C704 (220µ/50V) still seems to be doing something as the ripple reduces to a fraction of a volt by that point, although it should be checked for leakage as it's being flanked by dropper resistors.
C713 (2200µ/25V, 16x25? mm), filter cap for the voltage that feeds the +5.6V regulator (nominal 13.0 V, real somewhat higher). Again, seeing 4 Vrms of AC (100 Hz) is a bad sign. It is possible that the LO hum I found is making its way into the PLL via this rail rather than the tuning voltage. Seeing such a relatively big, name-brand (Elna) cap with decent voltage margin fail is unusual but clearly years (decades) worth of 24/7 operation will eventually weed out the bad apples. A generally warm-running power supply section is not helping, mind you. The cap does have a private electric heating (R710) but that is only dissipating a few milliwatts as a 2 W part (no idea why it's even there).

The -7.5 V zener follower regulator is a spectacularly dumb design, I think they're frying away twice as much current as it ever supplies, and the toasty zener (80°C up) is sitting on the board right between the two electrolytics involved. No wonder its parallel cap had super crusty solder joints. I don't have high hopes for any of these parts.

By contrast, the big boy cap supplying the main relay (3300µ/35V of a different series) still seems to be decent, as maximum AC ripple remains sub-0.15 Vrms on a 22 V supply (estimated load current could easily be half an amp).

I may end up taking out all the guts complete with back panel and front panel to actually work on the thing. That seems the path of least resistance to me at this point (the front panel PCB should still unclip and even the cables may be removable from there). I'll need to have all my parts and ideas ready then. When your workbench doubles as your dinner table, blocking it with a sprawling mess for extended periods of time is not really an option.

 

[tpd]

Leader LM-186a AC millivoltmeter - I thought this was broken. Turns out it's just touchy, a bit out of calibration, and I was using it wrong. Confirmed operation and touched up the calibration using what tools I have on hand.

HP 3466a multimeter - Brought this back to life, got is sort of calibrated, and buttoning back up (probably to sell because something more interesting arrived).

HP 3478a multimeter - Replaced the Rifa caps and backup battery. The battery had died long ago, so it needs a full recalibration next.

Bottlehead S.E.X. Amps (OG first version) - I somehow screwed up the first build on these ages and ages ago. Recently pulled out of storage, completely tore them down, and started rebuilding from scratch with upgrade advice from the OG Bottleheads. First monoblock is completed, tested, and working as expected. Working on the second one right now, but got distracted by above multimeter projects.

Caught a little volt nut fever and also working on some PCB designs to build my own voltage references. Haven't pulled the trigger on the JLCPCB order and keep second-guessing/revising my designs. Alas...

 

[pma]

Hi all, just received the BerryBak BVS2300 TPA3255 module and started playing with it .

 

[RickS]

I originally ordered one of the digital logger IOT power strips but the order was delayed and got fed up with Amazon. I already have plenty of spare surge protectors and may still modify one but, but a couple of 12V trigger boards for $10 and using other parts I had around, built this…

The ends are a short heavy duty extension cord and used a mono mini phone jack (upper left) for the trigger input. Added an MOV across the relay contacts for good measure. Changed the board jumper to high sensitivity and am good to go. Can either use directly for my amp or plug into a surge protector to control more devices.

 

[galeriewww]

Not on my workbench now, but it was just there. Found it at a thrift store for just over $28, a Technics SU-V620.

Thought it looked a bit boring, so I sanded off the black powder coating and did a rust treatment with salt and vinegar. Then applied a clear coat on top. I think it looks more interesting now than before

 

[Bunnyhug]

I spent a half an hour tracing why my left channel dropped out to find a wire on my cartridge came loose. Phew, I thought it was my new Fosi pre-amp that just arrived today. It's too late to play stereo, will reinstall later.

 

[Sal1950]

I spent a half an hour tracing why my left channel dropped out to find a wire on my cartridge came loose. Phew, I thought it was my new Fosi pre-amp that just arrived today. It's too late to play stereo, will reinstall later.

Solder it on so it never comes loose again, it will sound better too.

 

[DonH56]

Solder it on so it never comes loose again, it will sound better too.

Sounds funny until a guy I knew back in college actually did that. As you might guess, destroyed the cartridge, and the tonearm had to be rewired. That was back in the "straight wire with gain" days when some folk advocated (some probably still do) that every connection should be short and soldered for the best sound. He soldered the banana plugs into his speakers as well; at least those were an easier fix. Replacing all the soldered RCA jacks in his receiver was less fun.

 

[Sal1950]

Solder it on so it never comes loose again, it will sound better too.

Sounds funny until a guy I knew back in college actually did that. As you might guess, destroyed the cartridge, and the tonearm had to be rewired. That was back in the "straight wire with gain" days when some folk advocated (some probably still do) that every connection should be short and soldered for the best sound. He soldered the banana plugs into his speakers as well; at least those were an easier fix. Replacing all the soldered RCA jacks in his receiver was less fun.

Of course your right Don, I posted that in total sarcasm.
Readers, if you don't know better ABSOLUTELY DO NOT ATTEMPT TO DO THIS, IT WILL DESTROY YOUR NEEDLE AND MORE !!!

 

[egellings]

Solder it on so it never comes loose again, it will sound better too.

Can the cartridge tolerate the heat involved in soldering?