Minimizing pops and clicks with vinyl

[Brett]

Measured across the pre i/p via a buffer and into a Tek storage scope. Continuous signal were much lower.

Deccas are at the high end of the ouptut range anyway.

[Aleksunder]

Originally posted by Brett

Headroom. One of my carts is a Decca, and I've seen that put out 2V on click transients on a storage scope. The last pre I built for it ran on very high HT and had a lot of swing on the front end and only in the most extreme damaged / dirty discs would it clip. The noise, whilst still present was as you said 'on a different level' and didn't make itself known.

I've heard it said that one of the reasons Deccas are so hated by some people is that they were listened to in systems where their unique 'speed' often overloaded the RIAA networks, with unsurprisingly nasty results.

Graham Slee, for one, pays partilcular attention to input headroom on his MM phonos.

[federico moreno]

I have heard something about lead sheet mats... they should be acoustically inert, and conductive too. But the downside is that lead can be poisonous.

If you are concerned about static charges -I suspect that, because of your question about a conductive mat- , some people reported good results by placing some wet sponge or similar next to the TT. It helps to drain static succesfully.

I live in a very humid location, next to -at least- 3 rivers, so static charges of the type so common in dryer climates are not a problem.

I actually use a 4 mm glass mat, ¨decorated¨ with some transparent adhesive silicone spots (very thin ones). It works well: the background of music is dark, pops are minimized, and the lp rests solidly over the spots, with no slippage (I use non-slip circular spots, of the kind used below light home appliances to avoid movement).

You must avoid to put spots in the label zone (center) and the lip zone(periphery). The disc, for what I know, should only be sustained in the recorded surface.

[AndrewT]

Posts 28, 30 & 32 finally got to the heart of minimising the audibility of clicks from debris in the grooves.
Exceptional headroom in the pre stage both before, during and after the RIAA stage helps enormously.
The longer you can preserve the signal without clipping it, the less damaging you are to preserving the information near or in the click waveform. Finally let the RF filter roundoff the very fast transient that gets past all the earlier stages including your pre-amp that also requires a high headroom for this and any other clicks that come through with the signal.
30db of overload margin is about the minimum headroom that works adequately. 40db is near the maximum headroom that seems to be reported as offering benefit.

Clean or keeping clean, removes the clicks, headroom minimises audibility.

[federico moreno]

Yes; as stated in the cited posts, and in AndrewT´s one, I have noticed that the RIAA preamp stage is notoriously important in impulsional noise minimization; I noticed that for the first time when I made a version of Thorsten Loesch ¨Analogue Addicts¨ phono stage (aka ¨El Cheapo¨), based on opa637 opamps.

The first thing that caught my attention when I first auditioned the unit was the lack of surface noise. In a first instance I was fooled, thinking that the preamp was somewhat ¨treble shy¨... but no: all the treble was there.
It was myself, so accustomed as I was to HF garbage (clicks, hiss and assorted nasties).

That unit is performing flawlessly since then, a couple of years ago, and nothing seems capable of uncivilize the sound quality, even very hot output cartridges (shure m44c), garage sales records and, sometimes, less than optimal styli.

[Jeb-D.]

Andrew, is that 40dB headroom using which reference Vin@1kHz or Vin@20kHz?

[AndrewT]

+40db ref Vin @ 1kHz.