4mm speaker cable blocks

David.
Just for the record I am not a geek who carries this all around in my head. I happen to have a spare pair of NAIM speaker terminal blocks. so out with the ruler:

Spacing of plug stems (c to c) is 19mms
Thickness of plug stem (with spring) is 4mms

I don't understand exactly what you are planning but good luck

GEOFFP

Geoff,

Thank you.

I am planning to substitute the Samson power amp into the system whilst the 250 is away for a service, but I don't want to have to make up more speaker cable sets.

DS

OTD - Computer Jockeys - Pot Headz

Geoff,

I believe that the spacing is "supposed to be" 18mm, although I also believe that my Isobariks had either 19mm or 3/4 inch (18.3mm) because they never really sat well in the sockets with the plastic blocks in place.



David,

don't worry about the spacing. If the cables don't fit, remove the plastic block (the two halves are only held together with a small philips self-tapping screw).

I believe that some people prefer the cables without the block in place, anyway.

cheers, Martin

E-mail:- MartinPayne at Dial.Pipex.com

“I believe that some people prefer the cables without the block in place, anyway.”

Would you say some more about it? I’m just that curious because I’ve realized the Naim plugs fit only loose at the speaker end and especially so at the amp (old 250) end. Moving the items I used to hear contact errors (errrrrrrors). Maybe the contacts can be made more safe by plugging some thin copper wires parallel with the plug, I wonder. Or might it be better removing the black plastic and applying a (simple) spring mechanism that keep the contacts tight?

graphoman

Graphoman,

If I understand your problem correctly...remove the black plastic banana plug blocks altogether. They have a tendancy to grip the bananas to tightly which transfers vibration into the plug assemblies (and ultimately microphonics into your crossovers). If you must use them, work the banana plugs around in them until they are an extremely loose fit.

Next, take a small cartridge screwdriver (or similarly small tool) and gently pry the worn spring up on your existing male banana plugs (restoring the "tight" contact with it's corresponding female connector and hopefully improving sound a bit).

hth,

dave

thank you, hopefully it’ll work. May it concern not only the input at the sbl’s crossover but even the input of the tweeter and the main driver as well, I wonder.

Regards
graphoman

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May it concern not only the input at the sbl’s crossover but even the input of the tweeter and the main driver as well, I wonder.

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Good question Graphoman,

I'm sure it wouldn't degrade performance. Might be a question for emailing Naim.

regards,

dave

it was no way to restore the plugs. Temporarily (?) I tried the most simple solution. Removed the black plastics, inserted the twin plugs and twisted then outer portion of the plugs some 6-8 times with insulation tape around. The tape ring is elastic and makes little tension but can fix the contacts for a while.

Having done this at the amp out/speaker inputs (=4 place) sound quality improved. Then I made this “mod” at the tweeter and woofer inputs (=4 place more) and I felt an improvement again.

However, since my system is far from being perfect and my listening room is a Haunted Castle I can never be that sure. Would you make any comment to my acts? (Or, for the better: do somebody want to try my solution and report back?)

graphoman

Graphoman,

quote:

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Would you make any comment to my acts?

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Not sure if I understood you correctly...did you use pieces of copper wire to improve the "grip" between Naim Banana plug and its female connector and totally do away with the Naim black plug (spacers)?

If I'm understanding this correctly, I'd say it's OK as a short-term solution until you can replace those worn male bananas with new ones. You might want to power down your 250 first to prevent these loose bits of wire from shorting out the amp if they fall out during routine plug cleaning procedures.

Personally I'd throw the black plastic spacers away entirely and not replace them. The effort to check for correct polarity with each reconnect is minimal (and your SBLs might perform better without the microphonics).


regards,
dave

Hello All,

There seems to be a parallel here with the DIN plug locking rings, too rigid a connection is a bad thing.

Regards Robert

quote:

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Naim plugs fit only loose at the speaker end and especially so at the amp (old 250) end.

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I've been considering buying Furutech locking Banana plugs (discussed here or over at PFM), and discussed this with a man in a Hi-Fi shop. He seemed to think that they shouldn't be used at the amp end because they' couple the amp to the heavy cable too tightly which might introduce vibrations whatever that Naim doesn't like. (I'm not sure that's why we loosen our DIN locking rings - I thought that was because the ring forces the pins slightly off true and so reduces the contact?)
However, he seemed to think that it might work at the speaker end. I'm probably going to try them (though they aren't exactly cheap at £50 for the required set of four).

Paul Rowlands

funny, funny.

I have to reconsider. Listening to the sbls plugs (at the tweeter and the woofer level) without the black plastics but fastening the plugs with insulation tape, makes a Hi-Fi-ish sound that may be describe as “clear” but not as good to listen to. The two channels begin to work independently, and gone the well-known Naim bass and rhytm playing ability.

It seems to me that the black plastic things are not hazardously designed. Maybe they are bad – but necessarily so. They help to tune the system into balance. The main speaker input and the amp output is not as sensitive but I’ve decided to change all the worn bananas to new.

graphoman

Well, back to the original purpose of the question...

I made a converter box (plastic) 2 x 1/4" jacks to 4 x 4mm banana sockets and it works fine.

I can now use my Samson Servo 260 power amp in place of my 250, and can even use the balanced inputs.

Surprisingly little downgrade on sound quality, given the price differential.

DS

ITC - Karl Bartos - I'm the Message

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funny, funny.

I have to reconsider.

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Graphoman,

Perhaps a case of masking effects? Maybe your tight black plastic plug holders compensated for a less-than-tight metal-to-metal electrical contact between male and female bananas(due to plug wear)?

quote:

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but I’ve decided to change all the worn bananas to new.

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I'll bet this is the best sonic solution (along with dispensing with the black plastic plug holders entirely).


regards,

dave

“Perhaps a case of masking effects? Maybe your tight black plastic plug holders compensated for a less-than-tight metal-to-metal electrical contact between male and female bananas(due to plug wear)?”

Sorry, Dave, I don’t think it’s that simple. At the tweeter and woofer levels the plugs are not worn (or could be restored). I think the plugs WITHOUT the black plastic housing sounded microphonic while WITH the plastic I came away with a little more distortion but a better balance.

At the amp out and X-over in the plugs seem to work properly with/without the plastic as well, supposed the contacts can be made tight. You see I’m not scholastic.

graphoman

Graphoman,

Hmmmm...no idea what's happening with your rig then. Naim seems to think that the plastic plug holders trash the sound with naim suspended xovers if tightly gripping the male bananas...but if your experience is different....


regards,

dave