LPSU choices, new contender.....

[jabbr]

28 minutes ago, Superdad said:

 

0402 size parts are really a pain to hand place and solder.  Unless you like to spend all day with you face on a microscope.  For prototyping (not large production), clever folks built their own pick-and-place machine.  Couple with a small vapor-phase reflow oven it makes for beautiful boards.  

 

 

 

Thats an awful lot of work for occasional prototypes — perhaps for a full time designer

 

For my purposes I use a “reflowster” temp controller with a toaster oven ... but it’s not available anymore ...

 

I also have a microscope which is almost essential https://www.amscope.com/applications/veterinary-zoology.html and not really that expensive. 

[jabbr]

16 minutes ago, Superdad said:

 

The challenge is getting them out of the tape without all those tiny unmarked specks flying across the floor. 

 

A microscope, knife & tweezers make this straightforward. Alternatively you need to load tapes onto the machine: pick your poison 

[jabbr]

25 minutes ago, activist38 said:

...to all comment makers here: don't discredit products without trying them. Please hold back on your criticism if you have no proof to back up your accusations. Unsubstantiated allegations against a company or individual could potentially have very serious consequences for the allegation makers and I am surprised that the admin/mods on here don't take action against this unproven backlash. 

Good point and may I say that you’ve made a splendid introduction here on AS and you are acting as a smashing brand ambassador! Carry on!

[jabbr]

13 hours ago, activist38 said:

I was only recommending a product I liked.

Wise @Jud likened this place ideally as like a pub. We are all sitting here enjoying our ales, and you’ve come in telling us about a new type of hops you’ve found. We are chatting about the best ways to grow hops. We talk about hops and different ales on a nightly basis. Some of us grow our own hops for ourselves, others sell the hops they grow, and others just want to drink. If that’s not of interest to you, we can continue our discussions amongst ourselves ...

[jabbr]

22 minutes ago, Jud said:

Because I have just enough of a hereditary tremor in my dominant hand not to be able to do fine soldering work (as mansr put it, my hands are “insufficiently resolving”), something like that (hopefully less expensive by then) would allow me to pursue an interest in DIY when I retire in a couple of years.

That may be a good argument for a home pick and place. 

 

The reality is is that some “touch up” of the baked board is often necessary, particularly with home equipment. 

 

I find a stereo microscope essential, particularly for inspection. I have used verify extensively and can tell you that there is a learning curve. I have worked with people who have hereditary tremors and although can be an issue for the most detailed work, often can be counteracted by resting the firearms and base of hands in the table, while using the fingers to manipulate the teasers. Food fir thought!

 

I can also say that the AmScope equipment is astonishingly good at that sub $1000 price point, as I’ve used products in the $40-400,000 range. 

[jabbr]

2 minutes ago, Jud said:

 

I know you meant forearms and tweezers, but this version sounds more interesting!

I’m going to leave that unedited 😂😂😂

[jabbr]

The other issue is that because of the surface tension of liquid solder, a component does not need to be placed exactly — place it “close enough” and when the solder heats, the component will “snap” in place. 

 

Like everything a little practice helps. In my experience, most DIY errors are due to errors in wiring which SMD greatly reduces. So trade offs but people should try home SMD ... has anyone used alternatives to “reflowster” ie cheap — if so, what?

 

Sorry for OT but eh.

[jabbr]

13 minutes ago, mansr said:

For boards with components on one side only, a hot plate can be used too.

Yes, both that and heat gun have uses. The advantage of the toaster oven with temp controller is that a true profile can be programmed such that the temp ramps up to a specified max, and then ramps down. It’s important particularly for more expensive ICs that they reach the proper temp for the solder but don’t get fried. 

[jabbr]

1 hour ago, mansr said:

I was thinking of this kind of thing:

 

Oh that’s nice. 

 

The cheap toaster ovens have IR bulbs on top and bottom which allows uniform heating. You place a temperature sensor so that you could control the temp by cycling the toaster on and off. The automatic device cycles the toaster on and off to set the temperature as desired, and thus can vary with time. 

 

You can also also use one of the laser thermometers to measure the actual temp on the board. 

[jabbr]

1 hour ago, 4est said:

Not to throw a wrench in the works, but Paul was discussing repairs. I would never risk the whole board to replace one damaged part. In a pinch, two irons removes a resistor or cap. For ICs, saw off the legs with a knife and use some solder wick. For that matter, with boards like Shadder's example, I've just soldered it all by hand with a pair of optivisors.

 

Absolutely and I have a small hot air gun for this purpose. I was commenting generally on techniques that hobbyists might use. 

 

I see that there are $200 range reflow ovens now but haven’t used one. There are a number of great SMD packages which are super low inductance but the contacts are all under the package and the temp controlled  oven is so much better for that!

[jabbr]

6 hours ago, Jud said:

 

Very nice work.

 

With this type of tremor, as @jabbr knows but others might not, it's a little more complex than just bracing.  This tremor is what's called "postural," which means that having the hand in certain positions triggers it.  Bracing would be helpful (and thanks for the idea), but I'd also need to try to ensure that my hand, wrist and forearm aren't in a bad position (one that triggers tremors) during soldering.

 

Yes absolutely! Actually everyone has some degree of tremor and what you say is true for everyone. The key is to arrange your hands and arms in a relaxing position. One reason I love the microscope is that you can arrange so that the head is at a comfortable level for your neck and you can look straight ahead. You then place your arms and hands in a relaxed position. What you have to learn is to look straight ahead even though the view is down (rotate 90 degrees around x axis)

[jabbr]

18 hours ago, psjug said:

I don't get the argument over parts packages.  Just use what works for you

More important to look at ESR/ESL particularly if we are talking about bypass caps and high speed digital — so the application is important — basically SMD beats through hole in “lead” inductance, also it’s harder and harder to find old style jfets but the little critters are cheap and a roll will last a lifetime.

 

Some of the new packages have much lower inductance.

[jabbr]

3 hours ago, 4est said:

Although I do not disagree with these statement, I do not see how this is apropos through the meter long cable from this external power supply to the load. This seems especially true considering that not only are we fighting the lead network IRL, but that there is likely some sort of regulation between this power supply and the load as per your example. Perhaps I am daft, but it would seem to me that an external power supply cannot react at these frequencies.

 

Perhaps that’s the point. An external supply is only so important, often doesn’t need to be tightly regulated (or regulated at all) and the design that we are most interested in is the quality of the transformer, as well as solid capacitance and properly filtered diodes so that Hf spikes aren’t introduced. 

 

There seems to be an an obsession with external supplies, but an external supply can’t make up for a poorly designed board, nor a poorly designed local power distribution network. 

[jabbr]

10 minutes ago, 4est said:

OK then, just checking to be sure. I know you and he are beyond me in this stuff.

No you are right on. When I build my own supplies, I spend my $$ on good transformers, and then old fashioned filtering caps, or cap multipliers and good snubbers on the diodes. ... then a cable ... on the board board being supplied is where you place the LT3045s otherwise SMD versions of the Salas shunt etc... ie on board second stage regulation

 

I don’t always want to build my own because it’s work ... so I look for cost effective external supplies ... the main issue is that they are often too whimpy ... sorry low powered ... in the wattage dept. Some basic specs are expected. 

[jabbr]

21 minutes ago, jaaptina said:

Not having the knowledge but thinking from this point. Is there a point in having a power supply, (long) cable, MPAudio SD-HPULN LT3045 dc-dc converter, very short cable, dac/streamer configuration? 

 

 

It depends on what is being supplied, but if tighter regulation is helpful then yes. This is called a “pre regulator” and the design pattern might be to step down a supply and allow LDO which reduces the heat generated in the final board. In other cases on board LT3045s might be cascaded to generate the full complement of needed voltages. On board is best.

[jabbr]

2 hours ago, Tomslin said:

Yes, I agree to this. I am quite convinced that the LTO cells I use and Supercaps can meet these requirements.

 

To bypassing any voltage regulators directly on the cards are probably not completely impossible, and possibly improve them if I should do something like that. But I have no intend to do it. Moreover the JCAT cards are already close to perfect in that aspects.

 

 

 

Ah but the latency of that card is trashed by the Solarflare, haven’t you measured that!?

[jabbr]

20 minutes ago, sandyk said:

 I was asking what actual equipment you are using in your own Audio system.

Still using something like a SBT ,without even a decent Linear PSU such as designed by John Swenson and used by numerous DIY Audio members ?

 

 

Careful ... one could call your non networked system primitive if you want to go down that road. Are you using a real upsampling server or still listening to CDs?

 

Id be very careful about getting high and mighty with whatever other people listen to. 

[jabbr]

1 hour ago, sandyk said:

I never said it was. The shot was aimed at me, and I simply made it clear that I (along with many other members) only need easily accessible high quality audio without the need to use physical media. The fact that in my case at least, it ALSO sounds way better than simply playing physical media is an added bonus !

 

Nothing personal but we’ve been hearing about the “need” to do all sorts of contorted tweaks to our computers to allow them to produce good audio when interfaced to a DAC. LPSUs on the memory banks, SSDs, special cables etc and a new tweak of the week for now years when all this can be solved using a good cheap isolating network.So no I don’t wrap my speaker cables around toroids etc because it’s just not necessary.

 

(good old fashioned heavy iso transformers to supply the audio area remains a good idea, and avoid really crappy SMPS) 

[jabbr]

2 minutes ago, sandyk said:

Yet you seem to believe that you can correct everything after the horse has bolted ! 

 

Yes, as long as the bits remain identical, any sort of noise on the digital line can be corrected. I don’t care to argue this point, particularly with anecdotes about what someone else heard 30 years ago.

 

The fact that music is now distributed over the Internet dies nothing to reduce the quality of such music (files) in any way. I’m not going to respond to any anecdotal experiences of what people may claim to have heard otherwise.

 

As you say you are not a qualified engineer.

[jabbr]

9 hours ago, Tomslin said:

 

Oh shit! I didn't think about that 😉

 

Ha ha! I don’t have experience with the so-called Femto Ethernet cards, but I have extensive experience with Solarflare, Intel & Mellanox ... all of which have “femto” class clock oscillators. In fact the 100Gbe Ethernet NICs are said to have a jitter tolerance of “zero” and the latest NICs are 200 Gbe and 400 Gbe (Mellanox is current leader) 

 

Note that these all have their own on card power distribution networks and are all intended to be supplied by PCI-e / ATX type server supplies and ALL have extremely low jitter so my opinion is that for Ethernet NICs the resources and proven track record of Mellanox, for example, vastly outweighs any audiophile manuf.

 

I think this is what @marce is getting at: non-audio, space, defense etc etc designers are looking at the same low noise, low jitter, low latency parameters that are being discussed for digital audio. At least for Ethernet etc we are decidedly on the high speed digital side of this equation.

[jabbr]

6 hours ago, marce said:

F Off its getting monotonous, I have to defend my self to counter your endless putdowns, you are the grumpy old man I have mentioned previously. I have posted no put downs just some relevant info, I stopped posting because of endless putdowns, off topic comments aimed at a person, back to my bass, I can't be bothered. Goodbye.

 

Don't take it personally. His sole argument style is argumentum ab auctoritate. 

 

He is forced to put down an opposing authority, because otherwise his argument can’t stand on its frail leg.

 

But don’t let him run you off because there are those of us who “only know what they have read in dusty old textbooks” and so we are dependent on the experiences of people like yourself. I know that those waves don’t know whether they are carrying a sound or a code 😉

[jabbr]

2 minutes ago, marce said:

Found it, its the Ladder DAC. Will have a look, my initial comment would be that I would use resistor packs with matched resistors, easier assembly, thermally connected resistors etc.

Not a ladder DAC, a pure DSD input DAC described by @Miska DSC-1 and modified as 1) balanced and 2) output transformers as the analog filter.

[jabbr]

10 hours ago, sandyk said:

 

 That's laughable coming from somebody who claims that he can cure all digital audio's ills without needing to improve the source device,

 

We are talking about digital electronics, and this should be understood by anyone who has even a slight knowledge of the relevant physics. My “claim” is the standard accepted position. 

 

(The statement I made is that noise from the source digital stream can be reduced to an arbitrary level such that bits have no “memory” of where they came from.

 

Quote

 

and refuses to accept what he calls "anecdotal "evidence from others, no matter how many report the same thing, even the results of DBTs , when that is exactly what he expects others to do when he makes his unsubstantiated claims without even any confirming reports from others or verification by way of DBT.

 

 

My claims are hardly unsubstantiated. I am talking basic math & physics, really at an undergrad introductory level. Really old chap you ought to pick up a freshman textbook — this is basic — also read up on what “anecdotal” means.

[jabbr]

3 minutes ago, sandyk said:

Typical " Father knows best" type BS.

 Your claims ARE unsubstantiated, but apparently your rules don't  apply to E.Es ,ONLY those without appropriate qualifications.

 E.E.s are no more infallible than  anyone else .

 

 

You don’t need to be an EE or have a degree, rather the ability to read & understand basic physics. Basic. I am not talking about qualifications nor appealing to authority, rather referencing the shared understanding about electronics. Try Khan Academy — it’s terrific.

[jabbr]

6 minutes ago, sandyk said:

Well, how does your " Basic Physics" explain the attached ?

 

You are now changing the topic. My claim is that it is possible to scrub any noise from a digital stream down below an arbitrary level. 

 

I’ve also said that sending such a stream across, for example, my own fiberoptic Ethernet segment will remove any such noise on the source and eliminates source effects. 

 

I also suspect that, for example, new products such as Sonore’s opticalRendu will also be impervious to the original source stream. 

 

These are specific setups that other readers can test for themselves so no one needs to take what I say at face value.