Gainclone heaven ?

[PeterSt]

Yea, say that.

Noise gone ? I'd say signal gone as well. So, it would be my idea that you have shortcut the leg where the DC Meters are connected to (don't ask me which one that is (hot/minus), but it will be the same the RCA output works with.

This doesn't mean you won't have sound. Only 6dB less of it (but a bit depending on how BD's amps have been setup).

[Scroobius]

For what it is worth mine are home made interconnects they are not shielded and have cotton covered silver wire loosely twisted  - no problems with interference I also tried long versions of the same with no interference problems.

Paul

[manisandher]

I don't think it has anything to do with screening noise out - I think Peter is correct.

But I've checked the cables with my meter and can't find an issue with them - there are no shorts between pins 2 and 3 on either cable. However, as I suspected, the alloy jacket is indeed connected to pin 1. So in effect, the outer body of the XLR plugs at both ends are connected to ground. Somehow, this is causing a short between pins 2 an 3. So there's either an issue in the amps or in the NOS1.

Mani.

[Scroobius]

As Peter said wonder how Bert set up the grounding? - I changed mine to be the same as Peter's and Nick's so grounding in amp not connected to PE and grounding between left and right amps not connected. Noise levels went down to barely perceptible.

P

[PeterSt]

However, as I suspected, the alloy jacket is indeed connected to pin 1. So in effect, the outer body of the XLR plugs at both ends are connected to ground. Somehow, this is causing a short between pins 2 an 3.

Maybe it needs more thinking, but at first glance I'd say it is not allowed to connect the ground pin to anything else than the virtual ground. Now it becomes vague for the workout, because you are connecting two virtual grounds that way (let the one be different than the other, and there comes the current). That is, if the BD is setup for its balanced input "floating" all the way. And if not (like signal ground is connected to the case or worse, PE), there might be another problem, because you'd be interfering with the midpoint of the signal.

Any voltage present between signal ground of the two devices (NOS1 / BD) ? (don't connect the interlinks)

Somehow, this is causing a short between pins 2 an 3.

Are you sure about this, or do you only think so because of the Offset being 0.00 ? Remember, that Offset is hooked to one of the pins only, so shorting that pin is enough to have the Offset at 0.00, while the other pin nicely will put out signal.

Thinking in a complete different direction :
When the balanced output of the NOS1 is not correctly connected to the balanced input on the other side, and one of the signal wires will sease letting through a signal, you'd have noise because of no possibility of cancelling out noise. This is a bit of a too long shot, because it would be similar to using RCA (SE), and at least in my case no noise comes from that. Now, however, it depends a lot on the shielding of the cable, and whether this is necessary in your situation. In my case I need that shield for sure (which is why I use plain coax).

Lastly, don't make yourself crazy by some cable which "cancels" noise and which further doesn't work at all (no music, or only half of it). Just use the normal cable and find the noise source. Let Paul advise you.
I think we can be sure that at Bert's place there was no noise, and otherwise he should tell you of course. But you can be sure that your amps were tested under the same condition (same NOS1, no preamp), so it can't be about things being different there. But mains setup ? you bet it will make a difference, so an advice from my side would be to try all the combinations with/without PE you can think of. You're also allowed to disconnect PE from the NOS1, if that brings the better solution, although I am sure *not* saying that it was tested OK without PE (this wasn't tested at all). It just will work without, and it is up to you whether you introduce more or a different kind of noise with it (which noa maybe can't be lead away).

HTH
Peter

[BertD]

However, as I suspected, the alloy jacket is indeed connected to pin 1.

It is because I fucked up and know how this issue can be fixed.

Could be but don't know if it helps with noise though, all was dead silent here (97dB speakers) but I do not use balanced cables (RCA).

PE is in the amps nowhere connected to the signal ground, I do not want dirty mains earth on my signal.

In my system the only mains earth (thick wire and very low resistance earth) is connected to the PC to get the dirt out from there to earth as quickly as possible without giving it a change to find another path to follow.

Bert

[manisandher]

Thanks for the thoughts Peter. Bert's given me an idea that I'm going to try later this evening. Will report back later...

Mani.

[PeterSt]

Guys, when I can help (if at all) it is nice that I can. This doesn't mean though that suddenly people's mistakes must be on a forum only to please me or something. It is okay with me (it doesn't bother) but it looks strange maybe.

Everybody makes mistakes of course, sometimes. What about my cooking eh ? haha

Peter

[manisandher]

Just a very quick post for now. My noise issues are solved. It was a simple matter of changing a wire from one pin to another on the XLR input.

Thanks to everyone who chipped in... but of course Bert who figured it out, and was actually on the phone to me just before I proceeded with the wire swap around.

The amps are totally silent and sound just wonderful. And the bass... what bass... I'll post more thoughts on sound quality later...

Mani.

[Scroobius]

Great news Mani - and those BG's have hardly even started to break in yet ......... it can only get better 

[Nick]

Paul Gerard, hi,

I'm going to build some of your speaker cables to give them a try. I have been reading back through the post and have a good sense of how to make them but I wonder if you could give the number of strands and wire gauge you are using. Also have you used any sheathing to protect the overall bundle ?

Paul if you have any suppliers for the wire etc in the UK that would be great.

Many thanks,

Nick.

[Scroobius]

Nick - Well first my apologies are due I have not had the opportunity to pop in to see you with my speaker cables and to have a listen to your duos. It would be really interesting to hear your system as it is the same as mine except for speakers.

You are in for an interesting time. I ended up with 4 x .8sq mm each speaker (ie 8 strands for stereo) for the bass units and 8 x .5 mm each speaker (or 16 strand for stereo) for tweeters. Connected in bi-wire configuration. They are very long runs of about 8m. They blew away my old "top end" copper speaker cables. I bought the wire from here  http://wires.co.uk/acatalog/cu_enam.html
and if I remember rightly had polyester coated wire. I suspect it does not matter what the coating is but if I was doing it again I would look at a coating that can be soldered because stripping the ends with a sharp stanley blade is a pain.
But first I would recommend you to lash up some runs of single core enamel coated wires of say 1.5 to 2.0 mm - I was blown away by the improvement in my system - if it does the same for you then it certainly be worth the time to wind up the above spec of wire. The wire is cheap enough so it is just time really.

How to wind them? check this out for a picture  http://www.phasure.com/index.php?topic=1575.msg17981#msg17981  hope this explains it if not clear let me know and I will try to explain.

As for outer sheath most of my cables have none - but near the ends at the speakers I put a sheath of techflex for cosmetic reasons - my gut feel is that techflex does not affect sound quality it is mostly air but you will only need it for cosmetic reasons transformer wire enamel coating is v tough and will withstand major battering methinks.

But these home made speaker wires were only the start of the story for me. I next tried silver cables borrowed from a friend and they were significantly better - BUT there was a question in my mind - did they sound a tad harsh? I think so but no time to properly test. But that was all blown away into insignificance when I installed the ByBee's it is difficult for me to put into words how important I think they are. They completely negated any difference between the copper and silver cables and moved the system to a whole new level.

The great thing is that transformer wire is so cheap so it is worth playing with if you have the time. 8m runs with the construction above is a lot of wire but the whole lot cost me just £30 including delivery and there is loads left.

All the best and I will be very interested to hear how you get on.

All the best

Paul

[Nick]

Paul hi,

I'm really looking forward to trying this. I cannot believe the costs  .

When you say

"I ended up with 4 x .8sq mm each speaker (ie 8 strands for stereo) for the bass units and 8 x .5 mm each speaker (or 16 strand for stereo) for tweeters. Connected in bi-wire configuration."

Do you mean ?

4 live and 4 return wires per speaker at 1mm diameter (approx 0.8mm sq) for the base

And

8 live and 8 return wires per speaker at 0.8mm diameter (approx 0.5 mm sq) for the tweeters

It just that in the picture the gauge difference looks a bit bigger than the diference between 1mm and 0.8mm diameter wires.

(Keen to get the right wires with so much making up to do. The batteries for my drill are on charge  )

Best Nick.

[Scroobius]

Nick - am away today watching Wasps hopefully avoid relegation and oblivion will check tomorrow and let you know.

[Scroobius]

Apologies for the confusion. Checking back my original calculations and order was for 0.5mm dia for the HF units but the sticker on the wire reel incorrectly shows 0.8mm dia. I mic'd them and they are 0.5mm dia. Good spot Nick. So this is what is installed: -

For each LF unit 4 x 1.0mm (dia) wires to one speaker terminal and the same to the other speaker terminal SO 8 1.0mm dia wires in total for each LF unit.

For each HF unit 8 x 0.5mm (dia) wires to one terminal and the same to the other terminal SO 16 0.5mm (dia) wires in total for each HF unit.

According to my original calcs 4 x 1.0mm (dia) wire = 3.142 sq mm equivalent and 8 x 0.5mm = 1.57 sq mm equivalent.

More thinner wires for tweeters should be better but then winding them becomes even more of a pain.

Out of interest what is the construction of your current speaker cables? For me the initial quick lash up using bare 1.5mm dia electrical (1.76mm sq) wires (i.e. the earth stripped out of lighting grade electrical wire) gave a really big improvement and if you did the same and got a big improvement then for sure all the work involved in winding the lacquer coated wires will be worth it.

Looking forward to hearing how you get on.

All the best

Paul