Dark Side Of The Moon,and bass

Hi saab,


Saab said:
and when I tap the rack,TT off,and volume at normal levels,with cart lowered onto record,i get flap,so this means its to do with the arm?

I suppose a new arm will be a decent upgrade
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I missed this reply. I would go along with Paul Ranson & Steve M (7V) and say it looks like feedback. The sound from the speakers will resonate your rack and also resonate your turntable. Also the vibrations from the rack will go into the turntable.

Where is the turntable with respect to speakers? What sort of floor have you got? Have you tried moving the deck? How about a wall shelf.

We will get to the bottom of this.


SCIDB
 
Curently on a Project rack,but will be using an Ash Designs rack soon when i move

the floor is unknown being rented,but in the new house its wooden boards,suspended

the rack is offset and only a foot from the right speaker,but if i'm getting flap when neverything if off,as you suggest,it can't be the speakers can it?

I will wait and see what the new rack and floor does
 
Saab said:
just played a few CDs,whilst reading the Sun,and then popped on DSOTM on vinyl,as i do at least once a week,but noticed something I had never noticed before,the main driver was going ten to the penny,like it was on speed.I thought something was wrong so popped a bass heavy cd on,and nope nothing out of the ordinary,popped Time on again and the speakers again looked like they were about to blow up

must be some crazy low bass on that record,although ive heard it weekly for 25 years and still never noticed what is happening to the main driver

spooky,or is it just me?
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Saab,

It could be low frequency noise or rumble on the disc. Although the start of 'Time' does have some seriously deep bass in the recording. My main floor standers never seemed to pick this up. When I bought my REL sub, I recall the first time I dug out and played the LP. The bass revealed by the sub is truely subterranian at the start of this particular track, I could feel it vibrate my whole body. Top stuff!

KXF
 
Does anyone know the difference between Static v Dynamic compliance - and vertical v lateral compliance (I can guess this one I think)? :confused:

Mantra quote the Ortofon at 25µm/mN Dynamic compliance. HiFiStore quote it as 25µm/mN Dynamic Lateral Compliance as do Ortofon themselves

SCIDB quoted a figure 16 for the Goldring BUT Mantra quote a Static Compliance of 24µm/mN. Delving deeper Goldring themselves quote 16µm/mN
Static Vertical and 24µm/mN Static Lateral compliance.

If its the latter figure which is relevant then by my calculations if arm resonance is the issue then the Goldring would actually be marginally worse than the Ortofon with a figure of 7.5Hz against the Ortofon's 7.7

If the cone flap was because of an arm cart mismatch before, you've replaced the cart with another which may theoretically be equally or perhaps even more mismatched.

Now all that said I've run an Ortofon 530 on an RB250 without problem.

So we are left with a possible arm/cart mismatch (still), though I'm not sure given that there seem to be different ways of measuring compliance and given that on a very similar setup (but different deck) I didn't suffer the same problem.

Or feedback as a result of poor isolation.

One last thought. When was the last time you oiled your bearing? Might be worth replacing the oil and seeing if that helps before throwing any more cash at the problem - if its rumbly and their is a mismatch it might help. Or borrow a test record and see what the arm resonance actually is.
 
I've used a Goldring 1042 in an RB300 in the past with no problems, I would guess Goldring/Rega combos are extremely common. I suspect something else is causing the problem.

-- Ian
 
right,its not isolation,I have stuck the TT on a high-end Ikea Lack and indeed,the cones vibrate like a good 'un

don't get me wrong,it still sounds great (got Great Gig In The Sky On for 3 millionth time now as it happens)

but,there must be something amiss.I have changed the cart and i am now using a Michell Technoweight,and nowt has changed.Will try an Origin Live 250 and see what happens

who knows,i bought it s/h and maybe the previous owner did some botched diy?
 
it must be the arm,the cones vibrate as the cart is running through the first grooves,ie with no music
 
Dave,

Did you try the suggestions for loosening or tightening the nut that holds the arm onto the deck, adding a home-made cardboard gasket (or similar) or putting a piece of bluetac onto the arm to try to damp any arm resonances?
 
nope,will try that lot now i have changed the cart,problem with a techoweight i woont know how many turns to allow for the blu-tack,so i will have to forget that one
 
Saab said:
I would if she lent me hers,but she won't:)

UncleAnts

how do I do that?
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Not sure on a Rega - others can probably advise better, but every deck I've ever had the platter (or sub platter in your case) lifts out. In principle you should see a spindle and a hole. Clean them both with some lint free cloth and isopropyl alcohol (if you have any). replace the old oil - Mobil 1 is good but the oild supplied by Rega porbably best - as to amount, I can't advise - again another Rega owner may be able to help. If you've never oiled it, there's a good chance it needs it. A dry bearing will rumble and grumble at a low freq. I'm guessing if you have a potential arm resonance prob, then this may be the culprit. Even if it isn't, you should do it anyway

Found this on the Rega site:

http://www.rega.co.uk/html/F.a.q.htm

According to them it shouldn't need it unlee the table has been on its side - unless you've had it from new, you may not know.

May or may not help, but probably a good thing to do anyway
 

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