Re: arsclist Playback equipment for phonograph records

["George Brock-Nannestad" <pattac@xxxxxxxx>]

Date sent:      	Thu, 07 Jun 2001 12:42:37 -0400
From:           	Graham Newton <gn@xxxxxxxxxxxxxxxxxxxxx>
Organization:   	Audio Restoration by Graham Newton
To:             	ARSCLIST@xxxxxxxxxxxxxxxx
Copies to:      	Susan Harvey <sharvey@xxxxxxxxxxxxxxxxxx>
Subject:        	Re: arsclist Playback equipment for phonograph records
Send reply to:  	ARSCLIST@xxxxxxxxxxxxxxxx

> 
> I would caution you on the ELT, simply because if you want to cover a
> wide variety of disc types and composition, the ELT is not the one to
> do it.

I have used an LT-1XA for a period recently, and I can report that it 
is not so. There are some fundamental limitations linked to the 
principle of operation, and they obviously have to be taken into 
account when usefulness is considered.

It will reproduce any record in a shiny black material which has 
grooves created by a cutting stylus which has a straight line in its 
profile. That covers most lateral 78s, from 7" to 12", from 60 to 90 
rpm in 0.2 rpm steps, adjustable during replay. The depth of the 
tracking is also adjustable during replay, and because the channel 
separation is at least 40 dB over the whole frequency range (where 
standard stereo pickups may even go below 20 dB), the advantage 
of choosing the less worn side of the groove is immediately 
obvious. The depth adjustment corresponds to using a different 
truncated stylus, only in this case the testing wears neither record 
nor stylus. A surprising effect of the fact that no stylus touches the 
grooves is that a cracked or even Scotch-tape assembled record 
will play with just the faintest of ticks - both sides!

I have successfully played records from 1898, 1903, 1910, 1913 
and a host of other 78s, mostly shellac but a number pressed in 
black vinyl.

LPs and 45s may be played between 30 and 50 rpm with 0.1 rpm 
steps. The stereo image is extremely stable if the original record is 
properly balanced.

For both black record types cleanliness is of extreme importance if 
one wants to avoid contribution of extremely brief clicks form 
specks of dust. However, there is no problem in identifying content 
without cleaning (considering that cleaning may be invasive in its 
own right), there will simply be more noise. The disturbance from 
that is either a question of taste, or may be a simple matter for a 
noise removing unit to work on, because the distinction between a 
noise pulse and proper signal is so much greater than for 
conventional pickups.

The LT will not play Pathé discs, nor Edison Diamond discs, 
because the groove was generated by a cylinder at an angle, and 
the profile is all curves (basically an ellipse). Hence there is no line 
that can properly reflect light to the receivers. The LT will in general 
also not play ordinary acetates (lacquers, not really made of 
acetate but cellulose nitrate), because they are in a transparent 
material, and colored record materials it will also refuse. 
Sometimes the machine gets confused by the label colour, in 
which case a "label cover" is slipped over it on the spindle.

All in all this is an enviable piece of machinery, and I expect that 
the high cost is due to hand manufacture and assembly. The LT 
comes with a VPI Cleaner, which was found to be the best to fulfil 
the requirements, and a separate passive filter unit which I have not 
used. I use an Elberg preamp from VadLyd instead, and this unit 
permits simple A/B comparison.

> 
> Gilles St. Laurent at Canada's National Library in Ottawa would be
> pleased elaborate, since they have one and found that it was a nice
> idea, but there are many problems that have not been addressed. 
> 
This is also where I learnt about the ELP LT series.

Kind regards,


George Brock-Nannestad
Preservation Tactics