Pars

Ok stupid question time [emoji4] I hadn’t seen this kind of symbol used on a silkscreen before for a polarized cap (the 100uf caps): Which end is +? I’m guessing the closed end of the symbol? I suppose I could figure out which rail is which and then I’d know for sure Sent from my iPhone using Tapatalk

Yes, I understood what johnwmclean meant when he said soldering this board felt like it was sucking the life out of his soldering iron. I had no trouble with the pads under the regs, which are also connected to ground. Just the small pads. Sent from my iPhone using Tapatalk

As for cutting the output resistors in half, I guess it would double the current? Not sure if that is advisable though oftentimes more is better. I would think you would need to re-bias it however. Group buy mini board question: Noting the trouble I had getting some of the LDO pads to tin, is any special cleaning of these boards required? I only scrubbed the area with rubbing alcohol/toothbrush. Do I need to take some scotchbrite or something else to these boards before building? Sent from my iPhone using Tapatalk

Tried my hand at soldering a pair of the regs on, using a Hakko 936 with a 3.2mm chisel tip. Had a hard time getting some of the pads to tin on the neg reg, used plenty of flux. Switched to my smallest point tip and ran around the outsides of the chip (from the YouTube video). My hot air station hasn't arrived yet, nor have the Meanwells. I'll put the associated components on tomorrow night and probably use my bench supply and see what happens. Sorry for the crappy photo, but let me know what you think.

I know, bad form quoting myself Order arrived on time today. It appears to have been picked correctly, as long as everything was in the correct bin. Didn't ohm anything out (will do that when I assemble). Damn, is Mouser back on their game? It did take me about an hour to go thru everything against the packing slip.

Thanks, and yes I had found them on Mouser myself. Order was already placed at that point and I would have been concerned about the height. The Vishay cap T55D107M025C0060 has very similar specs to the Kemet, is less than half the price ($1.27 vs $3.56), is the right footprint (2917/7343) and is short at 2.8mm. I should have ordered those instead. Not sure what the reputation of that Vishay division (Polytech) is though. Sent from my iPhone using Tapatalk

Nice Kerry! Loving the SiC rectifiers. Would love a GRLV done like this (both std. LT1021 and your lower voltage version here... not sure if a single PCB could support both?), with 1) 3 output terminal blocks (2.54 and 5.08mm pitch) 2) Dispense with the 3rd bridge support 3) Support up to 35mm main caps This of course doesn't fit with your less/smaller goals above... might be great for the next GB

Yes, I see your point from that perspective

Where do you find said Panasonics? I can't find 100uf/25V anywhere. 20V maybe, or 68uf/25V? EDIT: was searching tantalum. Found them; yes a bit tall, not sure how much of a problem that would be. I don't find $3.80 ea in 10 or more reasonable. I've paid less for BlackGates Arrow wants $6.76 ea in 10 or more, and they have over 12,000 in stock. I wonder why?

<Mouser rant, pt2> Not holding my breath, but perhaps a change for the better. Placed a large order on Sunday, being careful to either change parts to in stock SKUs or find elsewhere. Contacted them yesterday to change shipping to insured (duh... my mistake), so they changed it to UPS with decent rate. Get an email today that I had gotten the free upgrade to UPS Next Day. Low and behold, order actually shipped today, complete, and is supposed to arrive tomorrow... this assuming the email or article I had read regarding UPS' Louisville hub having shit going on because of the weather. Now for the fun of checking it all in (something I'd never had to do before recently). Much of it being surface mount, it might take until I start ohming shit out to determine whether they actually shipped all the right stuff or not. 60 some line items, oh joy

There’s the cash grab Stax should go for... a “Spritzer Signature” line Sent from my iPhone using Tapatalk

The opamp in the GRLV runs single supply, so it will only see V+ or V- to gnd. OPA134, etc. is fine as long as it’s total max voltage is high enough, 36V in this case. The 9.1V zeners are fine for this as well. Sent from my iPhone using Tapatalk

Wow! RIP Dolores... and Dan and Eddie

Happy Birthday!

Mini BOM part question: For C4, C5, C6, C7, a tantalum polymer 100uf/25V cap is indicated. Not sure what is with these caps, but they seem rather expensive. All the usual suspects at Mouser run from $4-$6 each, with a couple running up to $16 ea. The ones in my BOM are all on backorder (one which was $2.91 in qty of 10 or more). Then I run across Vishay-Polytech, which is $1.79 ea, and $1.27 in qty 10 or more. Something wrong with these compared to Kemet, AVX, etc.? Just looking for something reasonably priced and IN STOCK. EDIT: wound up ordering the ones (Kemet T521X107M025ATE060) in Kerry's original BOM... figured he or Kevin chose them for a reason.

Happy Birthday Frank!

Happy Birthday John! I hope you have a great one!

I might be interested in a case group buy. I would need 3.

Yes, that is fantastic work! Sent from my iPhone using Tapatalk

The THAT chips aren't between the regs and the power input for the amp sections. The input section of the amp obviously wouldn't work without something being in there. From what I'm seeing in a sim, nothing bad would happen. The outputs won't be biased, etc., but only seeing low-level voltages where I looked.

Ehhh, something sounds very wrong... the mini shouldn't load that supply that much, and it shouldn't be running that hot. Even with the PSU being plugged into the offboard reg holes, the onboard regs are still in circuit, with no easily removed component to isolate the amp channels from them (short of cutting traces). I would carefully go over the board, making sure that everything is in the right place and correctly oriented, and no solder bridges that you can see. You might also post some good pics of both sides of the board at sufficient resolution and maybe one of us might spot something.

Maybe something like this https://plugable.com/2011/07/12/installing-a-usb-serial-adapter-on-mac-os-x/ Not sure if monoprice has anything

RIP Ray and John

The schematic I have says OP27. diffinput3.PDF.pdf

How fucking intuitive .08" = 2.032 mm. .05" = 1.27mm I also take it this doesn't have anything to do with the "Resistor - European Style - 0805" in Kerry's BOM?