oscilloscopes?

[BobbyBubblehead]

Think I already have a spare 555timer from my amiga days... I made a push to break/long hold variable rapid fire button on my Kempston pro joystick... //// Nope just looked and I threw it out a few months back thinking no use for it lol

I did just find two aquarium thermometers though... So not entirely a wasted trip into the cellar



That will be handy to monitor the case ambient and usb pcie card temps

At least the 555 timer and such are cheap enough to obtain.

Scope, spec analyser, eddy current sensor... Growing shop list

 

[Bobnova]

Yeah 555's are nice and cheap

 

[BobbyBubblehead]

You don't want to use a switching load for testing loaded ripple. Every time the switches inside the inverter fire you'll give a lovely ripple jump. Not helpful.

RF work != testing PSUs, which is what we're talking about here.

Linear power supply, the ripple the pico puts back into the dc after convertion and the filters that help remove the ripple after is the focus bob & myself are talking here.

But yes to RFI investigations also.



Edit: awesome... I can see how warm that 40watts gets at least... Time to shove on an album.



Looks like they are still calibrated... 30.7 left sink... 30.1 right sink



Left channel is a little higher... Room acoustic fight

Excuse the androids clueless orientation... I tried to rotate the pics...

 

[NiHaoMike]

For testing audio PSUs, play a 1kHz square wave at high volume (somewhere between 1/2 to 3/4 volume) into a dummy load (don't try using the speakers - you'll go crazy very quickly!) and scope the supply rails with the scope set to AC coupling. Then repeat with a 100Hz square wave. That's the accepted way to check the transient response of the PSU. If the amp has variable supply rails, repeat the test at higher and lower volumes. (Hint: if the PSU is well designed, you'll have to turn the sensitivity on the scope way up to see anything.)

Also note that many modern chipsets can detect and automatically cancel out effects of ripple on the supply voltage, especially low frequency ripple.

 

[BobbyBubblehead]

Noted Mike.

Long throw speakers could never replicate a square wave and yes I'm sure I wouldn't want to hear it.

Not sure on the power amps supply though it is separate. The pre amp has something like 16 independent power rails.



Some crazy ribbon power cable action. Lol

So sensitive if any pop out slightly it effects the sound.


I will study up on the amps psu. I can always phone the guy who designed it.

I have four high end linear psu to test out... No5 is on its way. I helped him decide to make a hybrid with linear for the final stages and switch mode to handle the dirt and draw.

so I hope that No5 will make a good compromise between handling a computer and clean output.

Also the company took it to automated build.
(the first looked like it was soldered by a blind physically challenged rhesus monkey) cheap labour...

Dnm in contrast use Swedish jewelers... Because their the only people with the time consuming skills to build to their spec.

Dnm boards are truly immaculate.

I will take the power amp apart some day and photo the 3 dimensional boards. Only bit of electronics I know of with 3d design. Obviously at 4k each I'm in no rush to rush in and break it. I heard the noise from the phone last time a rep told him I had killed something really expensive

Edit: yeah the amp is $6,700 USD 4K in UK £ and excuse the building dust... Renovation either side of this house. Drill and hammer all day then ask me to turn my massive 40watts down... Naturally I complied first time then the police came and asked me not to kill them all the second time. I plan to move