cafe latte wrote:
Thanks. At the moment I'm still evaluating the settings for the turntable using different protractors and experimenting with the 2-4g range for the tracking force. Initial impressions are good. I must admit that at the recommended 3g TF for this cartridge the sound is quite catchy and intense which I like. Whether this will become tiresome I'm yet to see. 2g TF, although picks up less of the motor and gives a more laid back presentation, is also a touch more sibilant. I have it tracking at 2.7g for now.
I've not paired it with the valve amps yet. I'm using my Denon AV receiver and Cambridge Audio 640p for evaluation. It would seem that the motor rumble will be below that of the valve phono stage hum so will not present an issue I don't think. As it is, I have to be 3" from the speaker to hear the motor being picked up by the arm. Getting the counter-weights as close to the yoke as possible seems to have helped.
Compared to the original, the PTP has raised the game for sure.
You should not be getting ANY rumble from an idler drive. Things to look at is what lube are you using in the main bearing, what condition is the idler wheel in and the idler bearing?
The rubbers that isolate the motor, what is there condition and has the motor been stripped and bearings cleaned and lubed?
Also the valve phono stage really should not hum at all, my feeling is there is some sort of earth loop maybe.
Thanks for your interest. The motor and bearings have all been stripped and cleaned. I used grease for their main bearings and then oil on top of the main bearing and at the end of the drive shaft. I've reduced the noise from the motor by loosening the suspension further and also by loosening the idler arm from the slider and damping it with blu-tack. Unfortunately, the motor I have seems to be noisier than can be got from other examples. It was like this from stock and at least I managed to improve it by a bit of lube and recentering the drive shaft. Further noise is coming from the spindle but not intrusive. This is probably from the notch I saw on the bearing when I stripped it, past accident perhaps. I'll replace that in the future. Now at my normal listening level, there is no audible motor noise from the listening position through the speakers. (It's there closer though)
I've been working on the phono stage in the last couple of days. I've managed to get the left channel dead quiet and reduce the hum on the right by reheating all the solder joints and re routing the b+ supply. I'm trying to find the source of this hum. It's not from the valves nor the line stage section which is quiet. Any ideas where to check? Its attenuated by the pot if that should give me a clue.
The 6mv output of the cartridge means that my phono stage is turned down which means the hum is not audible at normal listening level. (Still want to sort out the hum though for future set ups.) Question for the more experienced and tech minded, with the 2m red at 5.5mv output I can have the phono pot fully open, with the ortofon arkiv at 6mv it starts to distort past the 12 o'clock position. .5mv difference in output makes that much difference or there are other considerations?
After much fiddling with the arm and cartridge set up, I have it tracking at 3g with minimum anti skate. This produces the best all round sound and compromise for playing my predominantly charity shop and hand me down vinyls. Lower Vtf causes mistracking and other issues on the more ragged examples. Some lps I have which I rarely listened too, as I found too noisy on the other cartridges I have on another table, are quite playable on the arkiv. I suppose the bigger needle riding higher on the groove helps. I'm not now in a rush to change it in fact I'm not now dismissive about dj carts and their usefulness for certain hifi applications, I'm getting to enjoy my 'write offs' again. (My mint lps though are waiting to have more spin time on the dl103r I'm saving for...)