SL1200.....

[jky999]

I've got a modded SL1200 which is generating some hum when I turn the psu (Time Stamp) on. I've got a battery phono stage (Ray Samuels F-117) which is dead quiet. I've also properly grounded the turntable chasis according to the directions on this site. I'm also using the Oyaide MJ12 which I thought would reduce interference.

So, is there a way to quiet things down? I'm a vinyl newbie here.

[6L6]

Is this a newly mounted cartridge? It might be just that, or a cart/cable combination that doesn't have good synergy. I have 2 cartridges that my SL-1200 just doesn't seem to like, that my Rega does fine with... and vice-versa.

I guess I am asking what have you recently changed, if anything?

[jky999]

I'm not sure if others would consider it an acceptable amount of hum or I'm just delusional. I can crank my preamp way up with my phonostage on and it's dead quiet. As soon as I plug the Time Step psi in, I get a bit of hum. I thought the 1200s had a reputation for being completely quiet which is why I'm asking.

I'm using a Lyra Delos on a SME 309 arm. I disabled the strobe which reduced the hum. I grounded the chasis according to a lengthy post I saw detailing it on this site. This also reduced the hum.

Again, I don't know. Others might consider what I have to be a more than acceptable level of hum. It's not that significant. I'm just hoping to get better sound out of the table which already sounds very, very good.

[6L6]

Aha.

(Maybe...)

Did you do your turntable grounding procedure before the addition of the Timestep PSU? You might have introduced a ground (probably mains safety earth) loop somewhere.

[jky999]

Nope, I did it after the Time Step psu.

[Sonority]

How close is the PSU to the T/T?

[jky999]

It's abt 3' away.

[chris@panteg]

Hi Joe

I used a Timestep psu with my 1210 for a couple of years , I also use a 309 , I had no issues with hum whatsoever ! Is the the pitch control earth connected to the arm base ?

[synsei]

Was the hum apparent before the PSU was fitted?

[jky999]

Hi Joe

I used a Timestep psu with my 1210 for a couple of years , I also use a 309 , I had no issues with hum whatsoever ! Is the the pitch control earth connected to the arm base ?

I did not do anything at all with the pitch control earth that I'm aware of. I also can't comment on the hum prior to the Time Step psu since I put that on as soon as I got the table.

[chris@panteg]

I did not do anything at all with the pitch control earth that I'm aware of. I also can't comment on the hum prior to the Time Step psu since I put that on as soon as I got the table.

When I installed the 309 , I clamped the pitch control earth tag to the arm base , no problems with hum .

[jky999]

OK, problem solved! I think I had the Time Step PSU too close to my phono stage and my phonostage too close to my tubed preamp and psu. I went through an insane number of permutations trying to fix things and the final solution involved putting the Time Step PSU as far away from the tt and phonostage as possible and also maximizing the distance of the phonostage from everything else. Damn, this vinyl stuff is finicky.

Thanks everyone.

[RobbieGong]

Finicky for sure, but experiences followed by member solutions are a big assist to others so that's a plus :). My new psu carries a hum although slight it bugs me so when my system is back up and running (long story) I'll try moving it around - It currently sits on top of my cd player, middle shelf of hi fi rack. Maybe that is the problem, it is also very heavy too, so maybe not in the best place :rolleyes:

[Macca]

if the add on PSUs are supposed to improve the sound how is it that they hum so badly when the stock PSU is completely silent?

[synsei]

I don't have any hum issues with mine, mind you it is a Paul Hynes PSU. Either there is a shielding issue with the PSU or an earth problem in the deck. I'd still go with what Chris advised ;)

[jky999]

OK. I'd like to make sure I've got this grounding thing down. I've got an MK2 and I see where the original tonearm had a ground cable. Unfortunately, I don't remember where that ground cable attached to the table/pcb board.

Right now, I've got my tonearm grounded to my phonostage and the table itself grounded separately. I used the lower left ground point on the PCB based on Mike New's instructions and ran a ground wire out from the table.

So, I guess the ideal thing is to have one ground. Would it be acceptable to take the ground wire from the table and connect/clip it to the arm? Is this how people generally do it when they're using aftermarket tonearms?

[Mike_New]

I'm not sure if others would consider it an acceptable amount of hum or I'm just delusional. I can crank my preamp way up with my phonostage on and it's dead quiet. As soon as I plug the Time Step psi in, I get a bit of hum. I thought the 1200s had a reputation for being completely quiet which is why I'm asking.

I'm using a Lyra Delos on a SME 309 arm. I disabled the strobe which reduced the hum. I grounded the chasis according to a lengthy post I saw detailing it on this site. This also reduced the hum.

Again, I don't know. Others might consider what I have to be a more than acceptable level of hum. It's not that significant. I'm just hoping to get better sound out of the table which already sounds very, very good.

Hi Joe,
When you say "as soon as you plug the PS in" you get a bit of hum;
I presume you have a two pin plug which connects the PS to the SL1200.
So the PS is switched on when you crank up the gain?
The reason I ask is that the time step PS is not absolutely shielded from hum propogation, I had the same problem with my KAB unit some time ago when doing exactly what you are doing. I have my setup against an outer wall of my house and when it rained heavily the hum increased!!
The thing is where do you stop in detecting hum when you have turned up the wick to what probably amounts to about 500W of output.

Try moving the cabling about or even move the PS to a different location, Hum is funny stuff it pops up where you don't expect it.