View Full Version : DIY 'Hydra' mains lead
Inspired by an impending shortage of mains sockets I have recently made myself a one to six 'Hydra headed' mains lead(s)* and thought it may be of interest to others. I actually already use a one to four Hydra lead that I made up may years ago, but these days I need eight leads just to play a record! I have four sockets on my dedicated hi-fi spur (though it is probably a dedicated ring rather than a spur) and these are fully taken up. By adding this six way Hydra and using another double headed lead I have previously built I will end up having two spare sockets and rationalise the whole wiring. In my personal experience I have not been a fan of mains filtration or smoothing and I'm not yet convinced by mains regeneration. I could have built an extension block with plugs and sockets but I chose not to for a number of reasons. The Hydra way of wiring ones mains lead used to be recommended by Naim and I did find it to sound better with my Naim amps when I built the four way Hydra all those years ago. Back then I just used standard unshielded mains cable but this time round I thought I would try shielded and used a combination of Belden cables**
* One mains lead splitting into six others.
** All the cable and the MS HD mains plug came from Mains Cables R Us (MCRU) who are very efficient and competitively priced.
Below is a synopsis but more detail is here: http://www.audioflat.co.uk/phpBB3/viewtopic.php?f=7&t=621
I made a block to neaten up the termination where the six cables become one:
http://i62.photobucket.com/albums/h90/markemark_2006/Hydra%20Mains%20Lead/6B718901-BECA-48A6-8E2C-617F92A13363_zpshjn3afwi.jpg
http://i62.photobucket.com/albums/h90/markemark_2006/Hydra%20Mains%20Lead/4A45BEED-3BBA-4765-8985-FE51C4AB4A9F_zpswvf7eb1c.jpg
It's a sandwich of 18mm birch ply and 5mm acrylic. The ply is finished with a melamine lacquer that was given a satin finish with a Scothbrite pad.
For cable I used Belden 19364 for the tails that go to the equipment and the much stiffer Belden 83803 for the short tail that feeds the whole lot.
Previous experience has taught me that a lot of 'normal' IEC plugs and mains plugs are not really designed to be used with very thick cables like the 19364 or very stiff cable like the 83803 - as a result I decided to use an 'MS HD Power' mains plug***
The IEC connectors I used were these:
http://i62.photobucket.com/albums/h90/markemark_2006/Hydra%20Mains%20Lead/800642F3-E71D-4F36-AD9A-FF917198DB7A_zpsoiild53z.jpg
I got them from eBay (£5.00 each) and I must say they are really rather nicely made - like the MS HD mains plug they are very easy to wire thick cables to and the wires clamp very securely to the terminals.
*** This is not a cheap plug by any means at nearly £30.00 for the standard copper one (which is what I used) but it is much better, in a mechanical sense, if you are going to use thick or stiff cable. The wires clamp in a really secure way, the cable routing is easier and the strain termination is really secure and well thought through. I'm not saying it's impossible to use an 13A MK plug but it is a lot more difficult and fiddly to do a neat and safe job.
Here is an inside shot after soldering all the wires together - insulation tape was wrapped around the bundles and then epoxy potting compound was poured over the whole lot to keep it all secure (more was added after this):
http://i62.photobucket.com/albums/h90/markemark_2006/Hydra%20Mains%20Lead/3662ECAE-6C42-44D7-BEC1-53A5BD4F8CD3_zpspankl8ge.jpg
Below is a pic taken whilst I was in the process of fitting the IEC plugs:
http://i62.photobucket.com/albums/h90/markemark_2006/Hydra%20Mains%20Lead/bbef9e27-daae-4914-8bba-fb618b318e94_zps9j95an22.jpg
The rather brightly coloured Belden 83803 was covered with some 8mm mesh hose and heatshrink at the ends - the other Belden is black anyway and didn't need any further disguise.
Because of the lovely weather I haven't actually plugged any of this in yet so don't know if this project has had any impact on the sound - the options are 1/ no difference, 2/ some difference for the better, 3/ sounds worse - will report further once it is tried :).
That looks very interesting, Mark, and a great job as usual! I'm sure you'll hear some subtle sonic improvements from installation of the Hydra, but nothing drastic, as one would expect from an already well-sorted system.
Look forward to reading about your impressions in due course :)
Marco.
Thanks Marco, I suppose any benefits would be down to a lower impedance cable to the power amps and/or the shielding (which most of my power cables didn't have before). I must admit I'm not expecting much (if any) difference, but we shall see :) - I'll definitely report back whatever the outcome.
brian2957
08-06-2016, 10:48
Very nice work Mark . Thanks for posting this with pictures . I'll stick my neck out and say you will get a very nice improvement in SQ , particularly in the bass :)
Got a link to the IEC plugs please ?
here you go:
http://www.ebay.co.uk/itm/261606656667?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
The ones above are rhodium plated - if you don't want any plating I see you can get the same thing for only £4.00 each!
Edit: I notice some of their IEC plugs have Oyaide embossed into the strain relief.... all look exactly like the ones I bought.
brian2957
08-06-2016, 12:33
Thanks Mark . I've just ordered a couple as they're handy to have in the old spares box :)
I'll be watching this thread with interest .
I'll stick my neck out and say you will get a very nice improvement in SQ , particularly in the bass :)
I'm not so sure Brian as the bass duties are handled by a separate amp and that already had a Belden shielded mains lead feeding it. You never know though :).
brian2957
08-06-2016, 14:55
Aye you never know in this game Mark . Just thinking , would silicon not do the same job as the epoxy compound ?
Hmm...yeah, it may do, but I already had some of the epoxy to hand (I had bought it for something and not used it - can't remember what now).
brian2957
08-06-2016, 15:37
Nice one . I'm thinking of building one of these . Won't be as nice as yours cosmetically though .
Nice bit 'o craftsmanship there, oddly attractive as well.
Seems as a whole lotta work though
I'm lazy and just buy/use these.. 2 for 10$
17172
Nice one . I'm thinking of building one of these . Won't be as nice as yours cosmetically though .
Well the cosmetics do nothing for the sound :). Actually, I'm not sure silicone is such a good idea as it will take a very long time to set. You can buy the potting compound quite easily from eBay.
brian2957
08-06-2016, 16:29
OK thanks Mark .
Nice bit 'o craftsmanship there, oddly attractive as well.
Seems as a whole lotta work though
I'm lazy and just buy/use these.. 2 for 10$
17172
You are quite right, it is a whole lot of work - bit of fun though :).
The problems with the extension lead you show are 1/ the neon indicator is considered a no no and is often removed, 2/ there are more connections in the line and 3/ it isn't star earthed/wired. A lead like the one I have built is specifically intended to overcome these points.
Colin Wonfor
09-06-2016, 12:14
What epoxy did you use? What is it dielectric breakdown voltage ? What is it fire retardant spec like ? is it self extinguishing ? And what is it temperature working range ?
I am just think of safety and home insurance problems.
So the CE specs would be useful, also note some Epoxy not only produce heat when setting can also give of gasses so ventilation is recommended, and just another point you covered the connections in tape some tape reacts with other plastic to become brittle and even in rare cases liquid, so the tape spec would be cool to have. The next thing is the epoxy Hydroscopic some are so water ingress may happen.
Reaction between plastic like Polystyrene and PVC as in power cable in polystyrene boxes and loft insulation striping the cover of in time another fire risk.
Take care Col
I used a product called PX-700K-1 made by Robnor Resins. You can find the Technical data and material safety date here if you really want to:
http://www.robnor.co.uk/robnor-products/epoxies-for-electrical-and-electronic-application.html
Manufacturers summary description:
High electrical insulating characteristics
High adhesion
Low shrinkage
Good thermal conductivity
UL94 V-0 @ 1.5mm
Excellent chemical & water resistance
Does not contain halogens
As you can see, water ingress is not an issue but why would it be - a bunch of 13A sockets in a plastic box is more likely to suffer water ingress.
Some info on the electrical tape used (prior to being encased in the above resin):
http://www.hellermanntyton.co.uk/site/products/electrical-tapes/htape-flex15-15x10/710-00104
I'm quite happy that my cable is at least as safe as any other - but thanks for the concern.
Colin Wonfor
09-06-2016, 13:58
As you can see, water ingress is not an issue but why would it be - a bunch of 13A sockets in a plastic box is more likely to suffer water ingress..
But the 13Amp socket is in free air without the possibility of osmosis but encapsulation can and does cause problems we had that on the Euro Fighter, fixed now phew. So sometime low shrinkage can add problem when use other plastic as the epoxy heats and the cools gaps become apparent , a slight problem.
You basic idea is bloody good I was just being over careful.
The Robnor products are very good good choice.
This is worth noting on there spec:-
Causes skin irritation. May cause an allergic skin reaction. Causes serious eye irritation.
Harmful to aquatic life with long lasting effects.
http://www.robnor.co.uk/images/safety-datasheets/Epoxy/H__S_RX700K-1_BK.pdf
http://www.robnor.co.uk/images/technical/epoxy/Updated/PX700K-1.pdf
Colin, each joint is fully soldered, wrapped in insulating tape and then fully potted - hopefully that is sufficient (it will only ever be used indoors and unlikely to see combat :)).
Colin Wonfor
09-06-2016, 14:06
Combat, it would win I am sure, I will duck quickly he he :)
sq225917
09-06-2016, 16:28
Mmm glossy and mattness in one toy.
I managed to avoid skin and eye contact (I didn't ingest it either) and no aquatic life was harmed during the construction of this small project.
Anyway, I added the last of the epoxy this evening so the whole termination point is now entirely potted. I've screwed the top cover on and the whole thing is finished. In a couple of days the potting compound will be fully cured and completely solid. To be honest, the electrical insulation tape, the insulation on the cables and the potting compound are all absolutely as one would expect and there are no technical surprises.
Colin Wonfor
10-06-2016, 05:35
I am glad you have not burnt eyes out and the house is in tacked so now what improvement do you hear compare to a MK type extension box.
I didn't have an MK extension box before Colin. I had a four headed hydra cable made from standard cables (unshielded and smaller gauge), another standard cable fitted with MK and Martin Kaiser plugs and a Belden 19364 shielded cable fitted with silver plated MK Tough Plug and Martin Kaiser IEC.
I've only had a chance to have a very brief listen but it does seem better in some respects. My only concern regards overall dynamic but it's too early to come to any conclusions really. I should get some free time on Sunday.
(I should clarify that there is also another two headed cable (feeding my phonostage) made up the same as the six headed cable - but I was using that before this update)
I've only had a chance to have a very brief listen but it does seem better in some respects. My only concern regards overall dynamic but it's too early to come to any conclusions really.
Be aware, Mark, also of these things showing up any underlying issues in your system, which the new set up could be highlighting, and that perhaps before were masked by the old set up, especially as you'll have made decisions up until this point, in terms of 'tuning' the presentation of your system, with the old set up in place...
My experience of working with the mains supply is that genuine improvements succeed in further 'opening the window' in systems, which can be a good and/or bad thing.
Good, from the point of view of allowing one more 'insight' into recordings and what your system is *actually* like, in terms of its overall sonic signature/tonal qualities, and bad (albeit temporary), in terms of highlighting any deficiencies, until you fix them and thus regain the balance you prefer, and marry them with those genuine improvements.
That, however, is the only way you make genuine progress! Sometimes on the journey towards building a good system, you have to take a temporary step 'backwards', in order to go three steps forwards.... :)
Marco.
Hmm... well I wouldn't say dynamic contrast was in shortage before, quite the contrary in fact. As I say, I've only had a very brief listen and quite late in the evening, both records I listened to are quite gentle too. Shielded cables do have a reputation in some quarters for limiting dynamics though (that knowledge may also be colouring my view). Anyway, as I said, I've only had a very short listen so far.
Sure, I get that. All I'm saying is don't conclusively judge any negatives heard as being genuinely such, until you get a proper handle on things, and know where you want to go :)
Marco.
The dynamic thing is just a question mark and in no way a conclusion (I may yet conclude completely the opposite). I did think instrumental texture, tone and separation was very good. Space around the musicians was really pronounced on the Eno album I played and vocals were excellent.
The dynamic thing is just a question mark and in no way a conclusion (I may yet conclude completely the opposite).
Indeed, which is why I said:
Don't conclusively judge any negatives heard as being genuinely such, until you get a proper handle on things...
:)
Marco.
Colin Wonfor
10-06-2016, 12:42
Quote from Marco "That, however, is the only way you make genuine progress! Sometimes on the journey towards building a good system, you have to take a temporary step 'backwards', in order to go three steps forwards.... "
God I have done that so many time select one cap with a great spec and it like going backwards 10 pace, so refit old cap and the magic is back crazy. Data sheet are ok but practice and a inquiring mind is often better. And now back to my favourite soldering iron it is only 40yrs old but the best the Maplin etc ones are just junk Weller every time.:lolsign::lolsign:
Quote from Marco "That, however, is the only way you make genuine progress! Sometimes on the journey towards building a good system, you have to take a temporary step 'backwards', in order to go three steps forwards.... "
God I have done that so many time select one cap with a great spec and it like going backwards 10 pace, so refit old cap and the magic is back crazy. Data sheet are ok but practice and a inquiring mind is often better.
And that, my friend, is today's truism! Try telling it to the 'text book/stats, uber-alles', boys ;)
It's certainly how I built the type of system I've got now, although I let others, more skilled than I am, use the soldering iron... :eyebrows:
Marco.
Colin Wonfor
10-06-2016, 13:05
Marco Quote "It's certainly how I built the type of system I've got now, although I let others, more skilled than I am, use the soldering iron... "
Coward, burning hair and flesh is my daily treat he he:lol:
Marco Quote "It's certainly how I built the type of system I've got now, although I let others, more skilled than I am, use the soldering iron... "
Coward, burning hair and flesh is my daily treat he he:lol:
Wrectum...? Damn near killed um
Coward, burning hair and flesh is my daily treat he he:lol:
Aye, she likes that too, but only in the bedroom (or dungeon)! :eyebrows: :whippin:
Marco.
Even though I seem to have done a lot off it I actually find making up cables a massive PITA - all the fiddly wire stripping etc.
Virtual-Symmetry
11-06-2016, 14:29
5 Pin Din leads i just love making up. Amazing how many people make a complete mess of them including melting the connectors :rolleyes:
I spent an hour and a half having a listen tonight before I went out and I'm really very thrown by the differences. I don't think dynamic is less but the whole sound does show more grip and more impact.
brian2957
11-06-2016, 20:17
Sounds like it was worth the effort then Mark :)
5 Pin Din leads i just love making up.
Good character building stuff, especially soldering the two earths to a single pin.
I spent an hour and a half having a listen tonight before I went out and I'm really very thrown by the differences. I don't think dynamic is less but the whole sound does show more grip and more impact.
Nice one, mate. Sounds like all your effort was worth it :thumbsup:
Enjoy the music!
Marco.
Hi Marco - more of a short distraction from work than an effort :). I tell you what though, I have to (very reluctantly) admit that not only has this cable(s) made a difference but a very worthwhile one at that! I say 'very reluctantly' because a/ it doesn't make much sense, b/ it opens a proper Pandora's box of implications.......
Intriguing... Could you expand a little on that? Anyway, based on what I've done myself in that area, your reaction isn't surprising ;)
Marco.
Hi bud, you mean expand on the sound, the logic or the Pandora's box?
The sound mainly, but all three would be nice :)
Marco.
Sorry bud:
Well, the logic first I guess....
The essential problem with the logic aspect is that there is very little technical difference in what I had before compared to what I have changed to. Yes the thickness of the cable has increased but that was technically more than sufficient before, none of the plugs I had before made vague or intermittent quality etc. What I didn't have before is cable shielding. However, foil shielding isn't worth a lot and only half a metre was a braided shield. Damping? does that do anything - rhodium plate on the IECs, does that do anything?
The big thing is that I have true ground and signal star earthing now - but I had that already over four of my components and all I did was extend it over my TT power supply and sub-woofer.
Ultimately, all these things 'might' make a difference but the cable loom I replaced had considered many of them and already had a fully soldered MK mains plug with polished pins, decent quality IEC plugs etc.
The Pandoras Box?
Well the issue here is 'if there is an accepted difference then how far should you go along that path'? MCRU do a cable better than the one I used for double the money etc. - do you need fancy solder / do you need fancy fuses etc.,...
Sound : performance
It's a bit life everything has been focussed a bit better. It's like excess reverberation has been soaked up - it's more damped and more focussed at the same time.
Starterman
22-06-2016, 12:42
Interesting little project!
I messed about with mains cables quite some time ago and came to the conclusion that it made a significant difference to the sound - not just the materials used but the relative lengths of the "tails". I discovered this by accident when trimming the tails of my original Hydra to make them all the same length (1m) and noticed a marked improvement in sound quality. Nelson Pass wrote that all mains leads should be the same length - now I'm not a Pass fan, but this does seem to be correct.
My entire system is fed off a 4-tailed (headed?) Hydra so it's a bit easier to compare things than in your (Mark's) system. I occasionally try out my Belden screened Hydra and/or my rubber insulated version, but always seem to end up preferring the one built with ordinary 6A mains flex. I also tried ferrite rings on each tail (actually only on the Belden Hydra) with minimal effect and think I prefer the lead without.
My suspicion is that the mains cable configuration affects the grounding/earthing of the equipment. I must admit I haven't tried the other Hydras since changing most of my mains transformers to EI types (toroids will couple everything together at HF much more, only my bass amps use toroids now), so might get a different result if I could be arsed to try again now.
Interesting idea about cable lengths. In my case the cables of the Hydra I built aren't the same length at all. Two are about 0.8 of a metre, two are about 1.2, one is 2 metres and the sixth is 2.5.
Starterman
22-06-2016, 18:18
Interesting idea about cable lengths. In my case the cables of the Hydra I built aren't the same length at all. Two are about 0.8 of a metre, two are about 1.2, one is 2 metres and the sixth is 2.5.
Oops sorry for sowing those seeds when you've just completed your project.
OTOH if it isn't practical in your system then so be it. Some things just are not worth worrying about, especially when the sun if shinning. :)
It's OK, those particular seeds fell on pretty stony ground :). It just wouldn't have been at all practical to run a six headed Hydra with each cable 2.5 metres in length.
I used the commercial version of this many years back, saw someone selling similar on the Bay last year in various configurations.
In principle I like it, one word of caution regarding your joining method though.
Soldering of mains connections is not usually the done thing and probably doesn't meet some safety spec or other. Joints are usually a mechanical fixing, especially for safety earthing, so if there is a short the solder wont melt and release the lead.
I don't know how much protection the fuse would be, as to which would melt first and being encapsulated SHOULD keep everything in place, but its something to bear in mind when dealing with mains voltages.
On one occasion, I used mechanical (crimped) connections and soldered them as well, to reduce contact resistance while still meeting safety requirements. I've not bothered since and just used mechanical fixings.
Well I guess that about wraps the thread up. A great deal of 'advice' has been proffered with regard to construction minutia and I will leave it to those who come after to weigh. I don't in any way invent this concept of 'hydra' mains lead termination but I would, in my experience, recommend it to others and in preference to a mains block and multiple sockets+plugs arrangement; if you can handle a bit of minor DIY I strongly recommend it. I'm personally quite happy with the construction method I have used and I wouldn't write that if I felt it endangered others (or myself) in any way - however, please don't attempt any construction that you are not confident in or if you have any doubts.
Well I guess that about wraps the thread up. A great deal of 'advice' has been proffered with regard to construction minutia and I will leave it to those who come after to weigh. I don't in any way invent this concept of 'hydra' mains lead termination but I would, in my experience, recommend it to others and in preference to a mains block and multiple sockets+plugs arrangement; if you can handle a bit of minor DIY I strongly recommend it. I'm personally quite happy with the construction method I have used and I wouldn't write that if I felt it endangered others (or myself) in any way - however, please don't attempt any construction that you are not confident in or if you have any doubts.
+1
Have a similar hydra block wired up to my balanced mains unit feeding my system and sounds noticably better than mains blocks, even than the foo ones Ive tried.
Those looking to get into even more detail about maximising your mains cor the hifi, google someone called Roy K. Riches.
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