My table is a Technics SL-1200, quartz-PLL servo speed-controlled with a low-rpm DC motor, so the comparison isn't exactly straightforward. The capacitors in yours could be there simply for powerline filtration. |
OK, let me rephrase. Is your motor DC or AC? Mine is AC synchronous, and as such uses the 60 Hz frequency of the AC from the wall to regulate the speed. I don't really have a power supply per se, just the power cord and the caps. I think that if I change the value of the caps, I will change the speed. |
Ait: Now you're getting in over my head, I didn't engineer the upgraded power supply that I added to my TT, I just bought it and did the listening tests. I guess I owe Undertow an apology, as much as his actual words seemed off the mark, it's true he was writing in answer to your question about improving capacitor *quality* alone, not quantity, and though it's not inconceivable that this could have some effect as well, in that context I can see why he'd make the remark about the cap not being in the (electrical) signal path. Yours is a question for those with expertise I don't have. |
Zaikesman,
You state that you increased the capacitance, I'm just curious why. I was intending to just replace the cap with a better one of the same value, is there a benefit to increasing the capacitance, and if so, what is the benefit? |
Undertow: In my experience (which is admittedly limited to one example, but I don't think this a controversial statement), increasing the capacitance of the motor regulation can indeed have a direct impact on the audio signal, as you put it (irrelevant that the cap is not within the electrical signal path -- a TT/cart, as a transduction system, also has a mechanical signal path which is equally important), and not only in the case of the regulation being overtly faulty beforehand (mine wasn't). I have no idea whether this particular table would benefit (or yours), mine did. However, my comment was more on a theoretical level, just to point up that what you wrote came out sounding wrongheaded IMO, perhaps unintentionally, but still it couldn't be further from the truth to imply that motor regulation in a TT doesn't directly bear upon the resulting audio signal. |
06-13-06: Zaikesman
"Does not have direct bearing on the actual audio signal, just how the power is regulated to the motor"
That's classic.
Zaikesman (Reviews | Threads | Answers)
I think you know what I meant, and am not trying to give out false help or anything.... However, yes of course speed regulation and overall performance of the motor is important to the final sound, but my point was different, as the caps in the motor will not change the audio signal like something connected in-line with the tonearm wire down to the phono amp. And I did explain which you cut out of the quote being if he had a lot of vibration or speed problems of some sort than it could be a worthy replacement, but then again the cap in my motor is simply for the kick start so you don't have to start the platter by hand.
So whats classic about it? Just curious, If I am wrong than I believe you! |
I realize it was never a top-of-the-line unit, but it's a challenge to try to make it into something good, that I can use for a year or so until I buy a top notch TT. I think that the changes I'm making will elevate the performance to at least middle-of-the-pack among TTs.
So, back to the Caps - the small ceramic disk is to drain the RFI generated on motor startup to eliminate the turn-on thump, and the other is used to regulate the motor speed. I'll probably leave the ceramic disk alone, since they last forever, and replace the other with a good quality mylar film cap - any reasons not to use a mylar film, other then it probably being a bit of overkill? |
"Does not have direct bearing on the actual audio signal, just how the power is regulated to the motor" That's classic. |
It's a 25 year old BSR!!!! Do what you want with it as it was never much of a TT and anything you can get from it (either in performance or fiddling) is worth a try. |
The motor does vibrate a bit when running, so I will probably replace the caps and see if that helps. I am isolating the motor from the sub-chassis in order to minimize vibration, so I might as well go a little further and get new caps. |
Honestly very little, unless your motor speed or something seems to struggle... Does not have direct bearing on the actual audio signal, just how the power is regulated to the motor.. I would say it could be a waste if it is working fine, if not I would still not go to some kinda audio costly quality cap, but you could replace if you want. But I could be wrong, my table has a isolated motor that simply has nothing to do with the turntable accept turning the belt at perfect speed, beyond that it does not Hum or cause any ill effect, so if it makes noise or does not run smooth then I guess you could freshen the caps. |
