Re: Power cords

Doc B. · **on:** February 02, 2011, 11:05:55 AM

We listened for about an hour today, comparing the new power cord to another prototype cord done with solid core rather than stranded wire, a sample of one of the power cords we previously sold, and one of the stock black molded cords we include with the kit. We put one new cord on our prototype preamp, and then put another into my Tube Repro on my Nagra, and then swapped back and forth between the new cord and the other cords on both pieces of gear while listening to the same track.

I expected to hear no difference and thus I have no explanation for this, but Shawn and I both thought the new power cord gave the music more bass clarity and depth, a sense of better image scale and depth, and less glare. Might be sort of a tone control effect, but it seems like there is more going on than just that. At any rate I can't figure out why it would make a diff, but the difference is audible. So now I find myself saying shoot, it worked. Now we have to make up about 20 of them for my system...

The cord came out pretty nice construction-wise. There are six wires that are done up into three twisted pairs that are then braided into a nice floppy braid. The braid gets techflex over it for style points. The AC plug is a nice clear hospital grade model and the IEC plug is a right angle model, for a clean looking connection to Bottlehead gear. We found a hunky heat shrink tube with a 4:1 shrink ratio so that we can sleeve over the necks of the plugs as well as the cable. It's adhesive lined and gets quite thick as it shrinks, which makes for what appears to be a super rugged and stiff strain relief at each end. I think one could actually grab the middle of the cable and yank the plug out of the wall without damage.

We should have the instructions written and the photos taken this afternoon, and I think Shawn has the beta kits almost completely prepped.

vladimirwolfe · **Reply #1 on:** February 02, 2011, 12:14:31 PM

Sounds like it's going to be "worth the trouble". Let me know when I can call the Queen to order!

Grainger49 · **Reply #2 on:** February 02, 2011, 12:45:11 PM

Doc,

Congratulations to you on the improved power cords.

Doc B. · **Reply #3 on:** February 02, 2011, 01:23:38 PM

You know that Shawn Phelps is our technician, right? Are you confusing him with Colin?

Jim R. · **Reply #4 on:** February 04, 2011, 05:05:31 AM

Excellent! Looking forward to receiving this. Just curious, what's the gauge of each leg?

Thanks,

Jim

Doc B. · **Reply #5 on:** February 04, 2011, 06:08:34 AM

The reason this power cord came about was that we accidentally ordered several thousand feet of 20 gauge stranded wire instead of solid core wire for hookup wire in our kits. The mistake wasn't caught until after some wire had been cut from each spool, so we were stuck with it. PB suggested we try making a power cord with it. I realized that we would need to use a couple lengths of wire for each conductor in the cord or it would really only be good for very low current applications, so we came up with a cord using twisted pairs that are braided together. It makes for a very flexible cord.

So each leg uses two lengths of 20 gauge wire. Each time you double the cross sectional are of the wire the gauge number drops by three, so that is equivalent to about 17 gauge. We use the very conservative 700 circular mils per amp rule and rate it at about 3 amps, but you could probably be safe with up to about 10 amps, however we have not tested it at that load and therefore do not condone the idea. None of our gear draws more than about 1.5 amps at startup and less than that once the power supply is charged up.

We built a couple and I figured that would be that, they wouldn't make the system sound any different than stock. I simply had three big spools of wire that would end up sitting in the lab forever. But a most unexpected and puzzling thing happened. This cord actually makes our gear sound better than our stock cords. Rather than trying to come up with some far fetched theory like most cable manufacturers I will simply state that I find that it makes our gear sound better than the stock power cord and leave it at that.

Grainger49 · **Reply #6 on:** February 04, 2011, 06:23:57 AM

(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi244.photobucket.com%2Falbums%2Fgg7%2FGrainger49%2FTipHat.gif&hash=8d9451d9e631ca52b49767759d52d7df6cfd3320)

I am particularly impressed and amused with the part about not coming up with some far fetched theory like cable manufactures.

Jim R. · **Reply #7 on:** February 04, 2011, 10:29:42 AM

Dan,

Yup, good idea giving up on the theories. If it sounds better, it sounds better and I'll just leave it in the category of mysteries that we as humans are not yet capable of understanding.

Thanks for the info on the sizing.

-- Jim

Doc B. · **Reply #8 on:** February 04, 2011, 11:28:33 AM

OK folks, instructions are done. I've simply put up a web page, as there isn't anything very top secret about how to wire an AC plug.

http://www.bottlehead.com/et/adobespc/powercord/powercordassembly.htm

shelby1420 · **Reply #9 on:** February 04, 2011, 01:14:41 PM

Quote from: Doc B. on February 04, 2011, 11:28:33 AM

OK folks, instructions are done. I've simply put up a web page, as there isn't anything very top secret about how to wire an AC plug.

http://www.bottlehead.com/et/adobespc/powercord/powercordassembly.htm

Very cool Doc, gonna try one of these beasts on one of my Paramounts and a regular plug on the other, very exciting!!!

Doc B. · **Reply #10 on:** February 04, 2011, 01:27:55 PM

We've been tying up a lot of loose ends at the office this afternoon, so the cord kits will not be shipping until Monday.

JC · **Reply #11 on:** February 04, 2011, 01:47:14 PM

Not that you're likely to be able to do anything about this, but if you get a minute, check your link to the braiding video. I have never been able to get it to play through the 3-wire braiding section; it always forwards to the next video on heat shrink.

Now, I hasten to add that this could be something at my end. This involves a PC on the internet, after all.

Doc B. · **Reply #12 on:** February 04, 2011, 02:06:00 PM

Works for me, plays through the braiding video to the end and then goes to the next video.

JC · **Reply #13 on:** February 04, 2011, 02:23:20 PM

Thanks for checking, Doc. I'll try to figure out what is going on at this end, then.

One of the odd features is that it loaded in its entirety, and truncated at a slightly different point each time.

EDIT: Yup, Ad Block Pro issues, again. Something in the clip was apparently just enough like an "ad" to trigger it and tell it to go to the next video. After it had played a little more than half the clip!

The real laffer, of course, is that I naturally have ABP disabled on your site. So, I didn't even think to check whether it had re-enabled itself when I went to your link.

Very helpful indeed, when you get to see the whole thing! Thanks again for checking it!

Grainger49 · **Reply #14 on:** February 04, 2011, 04:16:38 PM

When I read you had trouble with the video I tried the link. The site loads then there is an add on that loads to play the video. I have it, but don't know which one it is. It plays for me. Took a second look. It is Adobe Flash Player 10.