DIY DC power cables

[gstew]

2 hours ago, mourip said:

 

Excellent looking tool. Thanks!

 

Question. I am making IC's with the new Duelund 20ga wire to replace my already nice Belden IC's. These Duelund ICs continue to amaze. I am nearing the end of my ancient roll of silver "Wonder Solder" and am now considering a solder purchase.

Any suggestions? Does silver content help? Do I need rosin core and why? Is cleanup an issue with rosin core? What is a good diameter for general audio DIY?

 

Thanks!

Mourip,

 

On solders, Wonder Solder has been my go-to solder since it came out in the 80s (on something like my 7th or 8th roll now just for my DIY projects). Not only did I notice a sonic difference compared to the generic Radio Shack (RIP) stuff, but it was easier to work with and made better joints. 

 

The latest version is not quite as good from a usability perspective, but better sonically.

 

I haven't spent much time comparing different solders, but did try the Mundorf Silver/Gold solder several years back. I thought it was a bit better than the Wonder Solder, but much harder to use and making what I considered was a good joint was challenging. I've not tried a recent roll, it may be different today.

 

I am quite sure that others work as well and suspect the right 'non-audiophile' solder may work as well and sound as good. BUT I don't have as much DIY time as I need already, so I stick with the tried and true and more solder comparisons are not happening soon.

 

Greg in Mississippi

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1 minute ago, mozes said:

Congrats there you go now. Officially joined the DIY gang

+1. Way to go Rajiv!

 

Greg in Mississippi

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To get back on topic (DIY!), see attached pictures of my bench-work a few weeks ago.

I use LPS-1's (and other supplies) feeding a variety of EQ & different setups. To help me NOT plug gear in wrong, I do some standardization of plugs for types of uses and voltage ranges. For 5V-35V DC connections I use plugs borrowed from my model airplane hobby, the Deans High-Current 2-Pin.

When I first received my LPS-1s, I cut the included output cables in half & installed one of these plugs on each cut end to provide the proper adapters for my DIY'd equipment. They provided both the proper interface I needed AND reduced the cable length by half. Sometimes I'd also reuse the end from a wall-wart for a quick and dirty adapter cable.

Recently I made a bunch of cables using 'naked' Canare 4S6 at a length sized for most of my implementations. I used some fairly inexpensive these 2.1mm plugs from Ebay.

Both the Canare wire and the EBay plugs are not bad to work with, the main issue is that the insulation used in both is not very resistant to soldering temperatures. That's not an issue when soldering the cables to a typical plug, but I did ruin one of the plugs trying to solder the wire ground directly to the plug body.

Been using 4-cross (starquad) cables for many, many years just for the benefits John outlined. I first read of the benefits in an early International Audio Review, where J. Peter Moncrieff recommended a specific 4-cross Romex wire as his then near-reference speaker cable... of course this was in the days before even mid-bux interconnects and speaker wires were available. I found some and it wasn't bad for the day... it found good use as power supply umbilical and AC power cables later.

Also attached is a picture of a DIY rebuild I did to a Magnavox CD player back in the early '90s showing 4-cross power supply umbilical cables using speaker cable from Vecteur.

Thanks John!

Greg in Mississippi

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45 minutes ago, Superdad said:

 

LOL Greg.   Don't make me open my box full of handmade silver-plated, Teflon-insulated, fine-stand, strap-quad-and-greater interconnects and speaker cables--from the late 1970s and early eighties! 

And who can forget the early Litz-wire speaker cables?  I am blanking out on the brand, was not Fulton Gold, that was the pre-cursor to Monster Cable.

 

Okay, how about these beauties:

Each is a star-quad, but look closely.  The quad consists of bundles, each with 7 Teflon-insulated conductors, and each of those is something 34 strands of #38 silver-plated copper.  That little 6-inch set took my ex-Hovland partner about 7 hours to make.  We used them between the output of a high-gain, all discrete Bob Hovland FET phono stage (think John Curl Vendetta or Lyra Connoisseur level) that was bolted to the bottom of our turntables (so that the custom tonearm wires went uninterrupted from the cartridge to the PCB) and the input of a 24-postion stepped attenuator made with all series/parallel Caddock MK132 resistors--which had the same handmade wire bundles inside!  Oh, here that is--circa 1982--and at least our third generation of attenuator at that point:

 

 

Okay, I think I have dated myself enough for one day.  

DIY forever! 

 

Have a great 4th-of-July everyone!

 

 

Alex,

 

You were probably thinking of Polk speaker wire. Moncrieff's top recommendation for speaker cable in that review was a multiple-paralleled run of Polk, his 2nd best was a Polk/Columbia Romex pair, with 3rd best Columbia alone. Interesting stuff that Polk... based on the design, I thought it'd make pretty good power umbilicals... They were ok, but after awhile shorts developed where the enamel insulation wore through and made messes in my hard-build gear. Still have some short pieces of that stuff around in a junk box somewhere.

 

Hovland was my kind of manufacturer! Those jumpers remind me of the multiple conductor twisted pair looms I made for my super-modified Hafler DH-200s back in '81-'82 based on the Audio Amateur Pooge articles... 1st set with Kynar insulation, 2nd set with Teflon, ultimately both sets were too bright in that application (that was true for me for any silver-plated copper wire) & I went to Mogami hookup wire. Real pain to build those looms up, just to discard them for the much simpler to implement Mogami!

 

And that stepped attenuator reminds me of the one I built up about that same time for my preamp... possibly a better switch (Shallco), definitely poorer resistors (Corning). It stuck with me for several years before I discovered ladder and then shunt attenuators (with Daven switches & nude Vishay resistors).

 

Ah, the memories!

 

Take care my friend... thanks for the trip down memory lane! 

 

And great July 4th's for all in the states... and same to those in Canada for the Canada Day holiday. Some also to ya'll outside the states, though it isn't a holiday for you!

 

Greg in Mississippi

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2 hours ago, Cornan said:

Does this mean that even if the two LT3045 boards are completely matched (voltage and amperage) from the maker they still need resistors in series with each board?

 

I understand that a single board is optimal, but does that neccessarily make two separate boards a bad idea? Better without it completely if you use it in the DC cable path (close to the powered device)? The only thing you want to acheive using two boards is for devices requiring more than 1A. 

Cornan,

 

Have I got a solution for you! A fellow in Germany made up some paralleled LT3045 boards and is selling them on DIYAudio here:

 

http://www.diyaudio.com/forums/vendor-s-bazaar/310402-fs-ultra-low-noise-power-supply-lt3045-based-pcb-post5227003.html

 

He has both boards with 2 sections of 3 paralleled LT3045 each (1.5A / section) and boards with a single section of 6 paralleled LT3045 for 3A. He'll sell raw boards (what I got), boards with the LT3045 already installed, or finished & tested boards

 

I just built one of the dual section boards up and it is working swimmingly powering my SDTrans384 SD Card player (which really only pulls 400mA max). I used .1% resistors to set the V-outs instead of the pots he shows and the 2 sides measured a measly .01V difference (4.92V & 4.93V). Each side is fed from an LPS-1 & are paralleled for 3A output max, overkill in this application.

 

Problem solved!

 

Greg in Mississippi

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Jean-Michel,

 

You are very welcome. & I had planned to start out this set of replies with an apology on implying that one could get 3A out of 2 LPS-1's in this setup. You are very correct... and I apologize for not being clearer. The dual 3||LT3045 boards each have a max output of 1.5A and in parallel (when tightly matched) will provide 3A. BUT the system current will be limited by the LPS-1's 1.1A max each, so total out available is 2.2A. All very sufficient for a device that draws less than 500mA, but I'm an overkill kind of audiophile! 

 

As for improvement, I have AFAIK the only pair of LPS-1s that have been output-matched for paralleling (thanks again, Superdad!).  I tried them in parallel to power either a Raspberry Pi I2S-output renderer or an SDTrans384 SD card player. I describe my initial experiences here: 

and an update after trying a dual 4||LT3042 board (800mA max per side, 1.6A max when parallelled)  with each side powered by an LPS-1. That has been my reference for both of these applications since then.

 

My gut feel is that the lower noise provided by these boards along with the additional energy storage (there's about 36,000uf on each board) are what make them better than raw LPS-1s for this application.

 

I should add that in some other applications (such as Ian Canada's R-Pi Isolator board and Allo.com's R-Pi Isolator board and Kali reclocker board), I have tried both an Acko AKR75 regulators (his previous version using an ADM715x chip... next best chip regulators I know of after the LT3042/45s) and an older generation Belleson regulator between the LPS-1s and the load board. In these applications, I preferred directly powering them from the LPS-1 without the intervening regulator boards. That MIGHT change if I try an LT3045-based regulator board, but that is my experience so far.

 

Pix of a couple of the AKR75 reg boards attached...

 

 

12 hours ago, agladstone said:

Greg:

I will start by saying that I don’t understand at all really what these LT3045 boards do at all and I’m completely confused by all the talk here about them! 

However, I THINK what you’re saying in your post is that by using 2 LPS-1’s and your LT3045 boards as configured, that you’re able to get 3A current output? Is that correct? 

So if I’m correct, the next question, is there a way (perhaps it would require 3 or 4 LPS-1’s?)

to use these boards in conjunction with multiple LPS-1’s to get 12V 3A ?? (I’m thinking this would be an incredible power supply for my Mytek Brooklyn DAC)? (Although if 4 LPS-1’s are required plus the boards, it may not end up being a good cost to value ?

 

agladstone,

 

See my comments and apologies above. Powered from 2 LPS-1s, the max current you get from that setup is 2.2A. AND it takes care to match the board outputs (and should be done under load, as John Swenson said). So not easily today. For what is out there now, I'd look at the Vinnie Rossi supplies. Hopefully we'll see some new products soon that will make this more easily done.

 

Also see Cornan's comments below on the real-world current draw of that DAC.

 

I should add that I run a DIY Soekris DAM1021 DAC from the I2S output of the SDTrans384 SD Card Player. It is my reference setup. I have set it up to be powered either from a pair of very good DIY'd linear power supplies OR a pair of LPS-1's set to 7V. While the LPS-1's exhibit some fine qualities in this setup, I've stuck with the linear supplies due to slightly greater dynamic impact and shading. You have to understand I LOVE LPS-1's and have 10 of them around here currently. They are ground-breakingly great supplies. AND I have found some situations where I either find them better augmented (such as feeding the dual 3||LT3045 or dual 4||LT3042 supplies) or where I prefer a different solution. Still, in MOST cases, I can't beat them!

 

7 hours ago, Cornan said:

 

Thanks Greg! @tapatrick have showed me this beautiful board a couple of times before on my "True experimental tweak thread". I am definately interested to give it a try on my Brooklyn DAC which reguores 12v/~1.5A if I not DIY my own parallel board. Do you have a picture of your parallel boards you could share? It would be very interesting to see a picture! ?

 

7 hours ago, Cornan said:

I am planning to use the LT3045 post Brooklyn DAC as well. However, it does'nt really require more than 2A. To be sure I'll recommend that you monitor the current draw during 10-15 min incl power on/off. My bet is that it will only draw max 1.5A.

 

Pictures attached...

 

 

I should add that I use different input and output capacitors than what is listed in the BOM... these are the same line as those used in the dual 4||LT3042 boards that have also worked very well where I've used them, but alas are no longer available. I also:

 

1. Added an additional 5,600uF capacitor at the output of each side.

2. Omitted the rectifier diodes and jumpered as appropriate to make them DC input.

3. Left out the heat sinks for this application due to both the low current draw of the driven device AND a fairly low input voltage (7V out of the LPS-1s).

4. Used .1% resistors instead of a pot to set the output voltage for each side.

 

6 hours ago, jean-michel6 said:

Hi Greg ,

 

 

Thank's for the good info .

 

Several questions :

 

LPS-1 output 1.1 A max so two in parallell is 2.2A max ? Correct ?

 

The German DIY shows only the AC-DC version , does he has also DC-DC version , which is needed to work with LPS-1 ?

( question for you and John S ) This LPS-1 is already a very good PS , what improvement bring the LT board ?

 

Jean-Michel, I left out the Shottky rectifiers & jumpered across traces to make these DC input... see pix of my unit.

 

Greg in Mississippi

[gstew]

14 hours ago, sandyk said:

Hi Greg

 You need to be careful here. The text book implementations of these ensures a very low ESR, which favours upper HF detail. Unless you change a few input capacitor types and values you may end up with overly etched HF detail.

 

This shouldn't  happen with Digital, but it does ,  even with SATA filters. The later SATA filters use much larger value electros which help to ensure a more balanced sound. (Previously I had a good play around with DIY SATA filters using L & C.)

 

Regards

Alex 

 

 

Alex,I totally agree with your point. While I didn't have that in mind when I first tried one of the paralleled LT304x boards, I suspect the reason they've worked so well is that they are really designed as small power supply units with AC input from a transformer and a significant amount of capacitance (~18,000uF) on each half. AND they do retain good small hi-frequency bypass capacitors before and after the regs as suggested by the datasheets. 

 

Thanks for pointing this out!

 

Greg in Mississippi

 

[gstew]

19 hours ago, sandyk said:

 

Hi Greg

 

Not bad !
Were they Naked Bulk Metal Foil Resistors, or a less expensive item ?
For the less experienced members, the results are of course governed by the actual reference voltage of the voltage regulator I.C. used, not so much by the actual measured resistance values of the close tolerance resistors (1% or better) when used with a less precise voltage regulator. (Most DMMs don't have enough resolution to accurately measure close tolerance low value resistors)

Kind Regards

Alex

Warning - Information Overload.
(An  experienced DIY person can  also further reduce the voltage difference of the higher voltage output regulator by retro fitting a parallel metal film resistor of > 100 times the value across the higher value resistor of the 2 voltage setting resistors, usually under the PCB.

If the Voltage regulator uses through hole resistors, it is possible to slightly increase the output voltage of a voltage regulator by replacing the lower value of the 2 resistors used, with a 1% resistor that measures a fraction lower than the original.

You can also reduce the output voltage slightly by slightly increasing the measured value of this resistor, or decreasing slightly the value of the higher value resistor of the 2 voltage setting resistors. With the latter, you can  also use a very high value (>100 times) resistor in parallel with it instead of replacing it.)

Susumu SMD. Very reasonably priced & my 'Tweak Mentor' says they approach nude Vishays in SQ. 

 

Later!

 

Greg in Mississippi

 

P.S.  Great tip on adjusting regulator output V. 

[gstew]

5 minutes ago, sandyk said:

 

 

http://www.davehilldesigns.com/smt_resistror_distortion_rev1.pdf

Alex,

 

Thanks for that... very interesting. Useful to see he found Susumu to work ok.

 

When I first tried some SMD resistors in the interest of keeping leads short in a feedback loop (I could solder them right across the device's pins), I tried some 'thick film' ones thinking they'd be better. Not so, the thin-film ones turn out to be the SMD metal films. 

 

The particular Susumu line I tend to use are the RG. Generally when I'm building something using SMD R's, I'll sub them in even if the BOM shows something else. 

 

AND occasionally I scratch build SMD circuits on protoboards... so far good results, I'm waiting for one to oscillate into oblivion!

 

Greg in Mississippi

[gstew]

Deleted, supposed to be a PM.

 

Greg Stewart

 

 

[gstew]

 

20 hours ago, sandyk said:

 

 It's hard to tell from the photo, and a search for what you quoted gave no results.

It appears to be a Surface Mount Electrolytic capacitor. However, it is highly likely that there is other damage, including the I.C.s due to the incorrect voltage  polarity.

This is a very different situation to when you are constructing something and inadvertently insert an electrolytic capacitor around the wrong way and blow the crap out of it. (Been there, done that )

 

I was going to make a comment similar to Alex's (though less eloquently). 

 

1 hour ago, Forehaven said:

Any way to check for other damage Alex?  Otherwise I guess I'll just toss it.

 

Forehaven, if you are in the US, I'd be happy to check it out for you & repair/rebuild for a small fee. PM if interested. I just  built up 2 more of the 2x 3||LT3045 boards yesterday with 100% success (and have done a fair number of other SMD-board builds and mods successfully), so I  am comfortable doing this. 

 

6 hours ago, tapatrick said:

for sure  I wouldn't win any awards for the looks of my diy stuff.. and often when you add up the parts cost and time, a ready made piece can be a no brainer 

 

20 hours ago, sandyk said:

 

 Yes, it can be quite time consuming, especially making the correct size holes in metal for AC mains sockets etc.

 

I DIY much of my gear so I can do things I have found to be 'better' or that can't/won't be done commercially. For example, I use a good 'audiophile' solder.. which happens to be leaded, where almost all commercial products are now ROHS compliant. I structure the gear to minimize wire lengths, number of connections, and non-soldered connections. I'll use what I consider 'better' parts/components where appropriate. I build-in or add vibration damping & control. I use wildly overbuilt power supplies. While many of these only make small differences by themselves, in my experience, you put them all together and they can can make significant differences.

 

Of course, I have to observe my limitations. That's when I buy a piece of gear. For example, I use PS Audio P10 AC Regenerators and BHK-250 amps. I could not effectively duplicate either of these... I don' t have the audio design and engineering experience and training  nor do I have the appropriate test gear.

 

But from cables to power supplies up to phono stages & DACs (where I can work with other's designs or pre-made modules such as those from Soekris or Twisted Pear Audio), I can do some pretty good components, at least to my ears. This is worthwhile to me, as I can't buy gear that addresses all of these (and other) areas OR can't afford the gear that does.

 

And ALL of my DIY'd gear is MASSIVELY ugly. IMHO, doing it 'right' rarely means doing it 'pretty'. 

 

Greg in Mississippi