unknown arm

[disco]

Recently I finished a headphones amplifier and I auditioned a lot of records last week. I found the phones reveal much more than the loudspeakers. On half of the few dozen records surface noise was noticable. At first I had the impression it was because of tip wear but tonight I found out a known good cart does it too, whatever the adjustments. Can it be the unipivot plays a role here?

Until two years I used an isopropyl alcohol mixture on the vacuum cleaner. Someone mentioned the IPA to subtract softeners from the vinyl, is this a myth or a fact? There's a lot of 'homebrew recepies' on the web containing alcohol.

[brianco]

DISCO,

If you think that only some records are 'noisy' it is possible that they have been played with very poor equipment in the past.

Play with the damping level. Most of the MMs need very little - in fact we used to use 'STP' engine additive as it is thinner than silicon and it made a big improvement in many cases. The main problem we had with this arm was that the counterweight - the early ones had no locking screw - would rotate and alter the azimuth.....that was the main reason for getting rid of it!!

[kevinkr]

Originally Posted by disco

Recently I finished a headphones amplifier and I auditioned a lot of records last week. I found the phones reveal much more than the loudspeakers. On half of the few dozen records surface noise was noticable. At first I had the impression it was because of tip wear but tonight I found out a known good cart does it too, whatever the adjustments. Can it be the unipivot plays a role here?

Until two years I used a isopropyl alcohol mixture on the vacuum cleaner. Someone mentioned the IPA to subtract softeners from the vinyl, is this a hoax or a fact?

No, the unipivot is not the culprit, your records are. All records have surface noise - some more than others, condition, (i.e. you ruin records by playing them with bad cartridges) cleanliness, and sylus geometry all play a role in how much noise you hear. In some cases poorly damped platters and mats may result in tracing energy being reflected back to the stylus which may result in higher noise levels and some echo as well (Not to be confused with tape print through or pre-echo due to overcutting.)

Low levels of surface noise are usually masked by the program material except at very low signal levels. The stylus on your cartridge is being dragged through the groove as the disk spins and this generates some noise - if the vinyl has significant levels of contamination or is impropery formulated it may be inherently noisy regardless of program signal levels.

I listened to vinyl through headphones a lot as a teen-ager as it was the only high quality source available in those days. I heard plenty of noise through the headphones. Low frequency & some aspects of tracing noise can be greatly reduced by summing the LF below a couple of hundred Hz to mono.

If you are used to digital headphone listening you will quickly notice that vinyl does not begin to approach the snr achievable even in the cheapest mp3 player.

[kevinkr]

I use a mix of 90% distilled water, 10% IPA and a couple of drops of Kodak photo-flo in a mix of a couple of liters to clean my records - I have used this for a very long time, and have noted no deleterious effects. Note that it doesn't always seem to do the job either.

[brianco]

Originally Posted by disco

..............Someone mentioned the IPA to subtract softeners from the vinyl, is this a myth or a fact? There's a lot of 'homebrew recepies' on the web containing alcohol.

Firstly, IPA will if too strong make the vinyl 'brittle and dry'. The plasticizers will migrate over time and this process will also cause an increase of noise as the record will present an increase in friction to the stylus. Kevin is totally right to dilute with distilled water to a 10% mixture as this is enough to soften normal muck before vacuum cleaning.