Yes, we are redesigning for a 350mm deep chassis. That’s 50mm deeper than before. Need to update name to A50…
I have also started to totally redo the internal layout with both trafos vertical (lower EMI noise pickup) and more room on chassis floor.
I have also started to totally redo the internal layout with both trafos vertical (lower EMI noise pickup) and more room on chassis floor.
Something I didn't expect tonight:
Doing some measurements with REW: disconnect the Laptop PSU and I get more distortions in RTA, not less.
I checked my Power Savings Options, and I was on Performance Mode for both battery and Powered. I tested some more with AMD Ryzen Balanced, same thing.
Went into More Advanced Options and changed some of the detailed settings there for Battery vs Powered. Still nothing found that could explain it.
The output used in the internal 'Headphones' out and what I noticed is that it takes around 6s for the distortions to appear in my setup on unplugging the charging cable. In addition, if I plug the cable in again, RTA doesn't remove the distortions although I have no averaging, until I stop the playback on the Generator and start it again.
Very odd.
Doing some measurements with REW: disconnect the Laptop PSU and I get more distortions in RTA, not less.
I checked my Power Savings Options, and I was on Performance Mode for both battery and Powered. I tested some more with AMD Ryzen Balanced, same thing.
Went into More Advanced Options and changed some of the detailed settings there for Battery vs Powered. Still nothing found that could explain it.
The output used in the internal 'Headphones' out and what I noticed is that it takes around 6s for the distortions to appear in my setup on unplugging the charging cable. In addition, if I plug the cable in again, RTA doesn't remove the distortions although I have no averaging, until I stop the playback on the Generator and start it again.
Very odd.
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Try using an external oscillator like an Akitika or a Victors and see if it changes. Your laptop may have some sort of background audio processor app running and it uses fewer clock cycles in battery mode to save power.
The HP did come with loads of bloatware, including a Bang & Olufsen output section apparently, and related software to manage that. Will give it a try with external Sig Gen and perhaps the hacked Behringer again. Thought the latter had developed a problem, not so sure anymore. But if it's indeed out then the REW automation can't be done.
Having inconsistent results seriously diminishes the value I would get in measuring in my setup. There have been a few changes as well: commissioned an old HP w1907 monitor to use with the laptop as secondary screen via HDMI. This monitor sprays a lot of interference at the bottom of the screen. One of my lamps also does something like that, except even bigger.
In addition, it could be interesting to scope the USB power rails when the battery mode kicks in and see if there's an issue there too, or even if it is THE issue rather than the analogue out which was my initial conjecture.
Having inconsistent results seriously diminishes the value I would get in measuring in my setup. There have been a few changes as well: commissioned an old HP w1907 monitor to use with the laptop as secondary screen via HDMI. This monitor sprays a lot of interference at the bottom of the screen. One of my lamps also does something like that, except even bigger.
In addition, it could be interesting to scope the USB power rails when the battery mode kicks in and see if there's an issue there too, or even if it is THE issue rather than the analogue out which was my initial conjecture.
On the bench tonight is testing the new TPA3255 amp boards from the GB that just arrived. Installed it into the test chassis and it works great. Sound is superb. The new external 15v connection works well too.
Edit: more like 'crapware' instead of bloatware, and lots of it. That's on top of Windows' own crapware/bloatware.
I recently got a Lenovo P16S workstation laptop and I impressed that it has no bloatware at all and performs so smoothly out of the box without requiring a ton of changes to the operating system settings like the old HP I have. Runs much quieter too even though it has a much more powerful CPU. I am a convert now. My previous laptops have been HP, Dell, Acer, Toshiba and Lenovo is my favorite thus far.
I've heard very good feedback about them, even recent YT videos regarding older ones. They bought the laptop designs from IBM at one point and must have some of that DNA still there.
I went thru a half dozen 14 & 15" ThinkPads that I picked up on ebay for $35-75 each and cleaned and outfitted them w/ ssd's and resold them. Excellent machines. I even edited photos and music on them. Full service manuals online down to the last screw. Even tried a new machine with Ryzen cpu for a while. It was killer fast but I didn't relly need it as much as sound gear 😏 ThinkPads rock.
Member @bloqhed just completed his build of the FH9HVX and has a new review of his listening impressions here:
https://www.diyaudio.com/community/...w-class-ab-for-lean-times.353512/post-7249920
https://www.diyaudio.com/community/...w-class-ab-for-lean-times.353512/post-7249920
On the bench tonight is EP600 and my job is to make a set of sample of each set of cable assemblies for production to copy.
Soon to hop up on my bench is my trusty old Harman Kardon DVD player.
Purchased new in 2006, it's been great for movies and the occasional audio CD.
Fantastic video performance, and has the acclaimed Wolfson 196/24 DACs in it.
However, it's recently got the "bad caps" issue and takes a while to power up.
Being manufactured in 2005, at the time when "bad caps" were being put into everything, I have to suspect this DVD22 is one of the victims.
The 2 "PH" branded 1000u/16v caps are apparently the reason for the low PS 3.3v/5v issue, but just in case, all the "PH" labeled caps (220u/25v) will be checked and changed just in case.
My soon-to-get-here Mouser order today has some Panasonic and Nichicon caps for this.
Who the hell is "PH" brand? anybody know?
Purchased new in 2006, it's been great for movies and the occasional audio CD.
Fantastic video performance, and has the acclaimed Wolfson 196/24 DACs in it.
However, it's recently got the "bad caps" issue and takes a while to power up.
Being manufactured in 2005, at the time when "bad caps" were being put into everything, I have to suspect this DVD22 is one of the victims.
The 2 "PH" branded 1000u/16v caps are apparently the reason for the low PS 3.3v/5v issue, but just in case, all the "PH" labeled caps (220u/25v) will be checked and changed just in case.
My soon-to-get-here Mouser order today has some Panasonic and Nichicon caps for this.
Who the hell is "PH" brand? anybody know?
I had a whole parallel processing Dell server rack (the kind used for numerical simulations of Navier Stokes equations) go bad after 2 years with oozing caps. This was circa 2004. I think the back story on the “Capacitor Plague” as it was called, was that an electrolytic solution formula was stolen (but miscopied in the process) by a defector from a Japanese company to a Chinese company who later moved to start his own company in Taiwan. Unwittingly propagation the bad formula over many companies. The bad formula develops pressure and blows up the cap after sustained use (typically 2 years of 24x7 use) but by then, millions of caps had been manufactured and used in equipment all over the world.
The bad thing about the 2 year timing is that most standard manufacturers warranties expire around then.
The bad thing about the 2 year timing is that most standard manufacturers warranties expire around then.
There's at least one whole forum dedicated to this - expanded greatly from initial considerations IIRC.
Well, the Harman Kardon DVD 22 is now back in top shape!
Those two 1000uF 16v caps had slightly high ESR, but one of them measured 2100 uF!
I also replaced numerous 220u caps and a 470u as well - all secondary caps in the SMPS.
At any rate, the unit powers up instantly now and reads promptly.
Those two 1000uF 16v caps had slightly high ESR, but one of them measured 2100 uF!
I also replaced numerous 220u caps and a 470u as well - all secondary caps in the SMPS.
At any rate, the unit powers up instantly now and reads promptly.
Was on Air Frying duties tonight (I asked), so brought the laptop and the hacked Behringer interface to the kitchen prep area to do some tests while frying some sausages. At first I had horrible, horrible measurements. Turns out it was just the wrong Cal. file...
All sorted, now it's interesting to look at what was hiding. The interface seems to be impervious to Battery Mode shenanigans seen on the laptop analogue outs.
What remains seems to be USB Packet harmonics and their interactions with the test Sig.
Heck, even mains pickup seems less than on Electronics Lab A's Desk, which is funny as hell.
All sorted, now it's interesting to look at what was hiding. The interface seems to be impervious to Battery Mode shenanigans seen on the laptop analogue outs.
What remains seems to be USB Packet harmonics and their interactions with the test Sig.
Heck, even mains pickup seems less than on Electronics Lab A's Desk, which is funny as hell.
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