|Standard intro and disclaimer|
High resolution digital recordings of hifi system upgrades can be used for subsequent comparison to provide a more reliable method of assessment than trying to apply and assess the update at the same time. Other benefits are the possibility of external validation of conclusions, and letting others hear the kind of changes that are possible for a given level of effort or expenditure.
It should be understood that no assessments are being made with regard to the relative performance of analogue vs high-resolution digital.
To avoid any copyright issues I’m restricting my recordings to 1 minute for vocal work, and 2 minutes for classical. My test recordings are as follows.
Female vocal, easy listening
Male vocal, pop
The necessity of accurate arm and cartridge alignment is widely accepted. In this test I am assessing the differences in tonal balance when the vertical tracking angle (VTA) is changed. I have assessed the differences due to approximately 1 degree of VTA change, with both values lying close to 24 degrees (it is hard to accurately measure VTA values).
The analogue front end under test was comprised of a Pink Triangle Export with Funk Firm V-drive DC motor upgrade, SME IV tonearm, Dynavector DV10x5 high output MC cartridge and Graham Slee gram amp 2 SE phono stage.
Before each test session, the turntable was warmed up by playing one side of an album.
The phono stage was left running for 30 minutes before the start of the test.
Recordings hve been captured as 24bit, 96kHz WAV files using a SoundBlaster X-fi PCMCIA soundcard and a Dell Inspiron laptop.
For each alignment :
- Measure the distance between the record surface and the centreline of the arm tube at two reference points. All measurements were taken on the same side and position on a specific LP.
- Measure the downforce, and adjust as necessary to ensure the same value is used for both alignments.
- Make the recordings listed above.
- After taking the recordings, calculate the relative change in the heights of the front and back of the arm tube, from which the change in VTA can be calculated.
Caveat: these are high resolution recordings taken from a high performance audio system, and are intended for download. The differences are unlikely to be audible through the embedded player and typical computer speakers.
front 12.5mm, rear 10.5mm
|dont know why 1-tt1|
|cold cold heart 1-tt1|
|Im allright 1-tt1|
|paper walls 1-tt1|
Alignment 6 (I tried a number of others but these two give the best contrast)
front 13.5mm, rear 13.5mm
|dont know why 6-tt1|
|cold cold heart 6-tt1|
|Im allright 6-tt1|
|Paper walls 6-tt1|
- front change in height : 1mm
- rear change in height : 3mm
- distance between measurement points = approx 100mm
so I’d expect the angle change to be tan^-1(2/100) = 1.1 degrees, let’s say 1 degree.
Measurements from photographs agree with this calculation.
This small change in VTA produced clearly audible changes in the tonal balance of the system. The brighter sounding recordings were taken with the tonearm level, the other set with the back lower.
A one degree change in VTA produced clearly audible changes in the tonal balance of the system. For reference, the relative change in the positions of the front and back of the tonearm required was 2mm. This clearly indicates that careful setup and listening tests pay dividends in the overall sound from a hifi system.