A phono preamplifier is not a FM receiver !

0 Members and 1 Guest are viewing this topic. Read 5954 times.

I.Greyhound Fan

Re: A phono preamplifier is not a FM receiver !
« Reply #160 on: Yesterday at 04:57 am »
I am sure that you have done this but just in case.  Did you connect the ground?

Also, I have a Bellari phono preamp that had a hum until I hooked it into a different surge suppressor from the TT as I have 2 of the same circuit.  You could try this too.

Guy 13

Re: A phono preamplifier is not a FM receiver !
« Reply #161 on: Yesterday at 06:55 am »
I am sure that you have done this but just in case.  Did you connect the ground?

Also, I have a Bellari phono preamp that had a hum until I hooked it into a different surge suppressor from the TT as I have 2 of the same circuit.  You could try this too.

Hi Greyhound.
Yes, I have connected the ground wire and disconnected and re-connected.
I even tried different location.
I've check t make sure I had a good ground on the 120V outlet and I did.
It's strange, because in my other house, the Bellari did have any hum at all and it did not have any ground wire between the Rega RB301 arm and the Bellari unit.
In the new house, next door, with the same set up and Bellari I had lots of hum, plus FM radio interference.
Now, I don't have anymore the FM interference, but I do have some residual hum.
I will try a few more things and report back my findings.
By the way, with my new set up, the PDR linear arm,
I have no ground wire. See the pictures in the earlier posts.

Guy 13

Guy 13

Re: A phono preamplifier is not a FM receiver !
« Reply #162 on: Yesterday at 09:25 am »
Hi all.
Just reverse the walwart without any success, still the same level of hum.
Any more suggestions other than scrap the whole vinyl rig... :lol:

Guy 13

neobop

  • Full Member
  • Posts: 2612
  • BIRD LIVES
Re: A phono preamplifier is not a FM receiver !
« Reply #163 on: Yesterday at 10:48 am »
Guy,
What did you do about this mess? 





Guy 13

Re: A phono preamplifier is not a FM receiver !
« Reply #164 on: Yesterday at 11:05 am »
Guy,
What did you do about this mess?
Hi neobop.
What mess ???
Haaaa.... The mess with the tiny cartridge wires.
I tried to twist them together, but did not work,
even if their are small they are a little stiff.
I try to put them closer together and use little pieces of Scotch tape,
the result was so, so...
My next trial will be to lower the wires support
and then shorten the small wires.
Each new trial is done on my only free day, which is Sunday.
Therefore, probably by the end of this year,
I will have found an ideal way to route the wires so they look good
and don't interfere with the movement of the arm.
Does that make sense ???

Guy 13

neobop

  • Full Member
  • Posts: 2612
  • BIRD LIVES
Re: A phono preamplifier is not a FM receiver !
« Reply #165 on: Yesterday at 12:07 pm »
"Does that make sense ???"

No, not really.  It's not the look that concerns me.  I suspect it's the source of your hum, RFI or whatever.  Maybe you could shorten it and try an aluminum foil shield like Bacobits suggested. 

I just saw this statement:  "By the way, with my new set up, the PDR linear arm,  I have no ground wire."  Good grief.   :duh:

C'mon now Guy, you can't break the rules all the time and get away with it.  You need to solder or somehow attach a ground wire to the arm.  It might be easier to use a ground post and a set of RCAs like the VPI set-up I posted earlier.  You just need to leave enough slack so the arm can travel across the record unencumbered.  I'm guessing you could lower that coat hanger about a foot or more. 

Once you have a ground to the phono stage the hum might go away.   If you still have some residual hum you could try an additional ground wire between the phono stage and (pre)amp, but that might not be necessary. 









I.Greyhound Fan

Re: A phono preamplifier is not a FM receiver !
« Reply #166 on: Yesterday at 03:51 pm »
What Neobop said!  You should have a ground wire unless the ground is built into the IC's of the TT like my old Thorens TD-145.  With that being said, I would try a ground wire attached to the tone arm and your preamp and see if this fixes the problem.

Guy, what Bellari do you have?  If it is the VP-130 it could be the crappy walwart as there is a known problem with the DC power supply.  Radio Shack sells a DC power supply wall wart that has filtering and can fix the problem if that is the cause.  I have the Bellari 129 and it uses an ac walwart.

The hum can also be due to appliances in your house.  Try unplugging the AC, Refrigerator,etc and see if the hum goes away.

PDR

  • Full Member
  • Posts: 591
  • May the best man win, you with the ponytail...OUT!
    • Renex Arabians
Re: A phono preamplifier is not a FM receiver !
« Reply #167 on: Yesterday at 11:33 pm »
I've had at least 4 variants on this type of arm and have never ground it.....never had a hum.
The 195 page thread from Diy Audio has dozens of builds on this type of arm, or a close clone....metal bearings
rolling on glass tubes.
None have grounded the arm....http://www.diyaudio.com/forums/analogue-source/238027-diy-linear-tonearm.html
The arm that Guy has worked with no hum here with my AT13e cart on my P3, but my wires were shorter and
are set back in a tube like this pic of the Cantus Opus 3



I've also had luck with longer wires hung overhead, this pic is of another I built.....no hum



Not that grounding the arm wouldnt help in Guys set up.....just havnt needed it before.
I hope you get this sorted Guy...  :(



Guy 13

Re: A phono preamplifier is not a FM receiver !
« Reply #168 on: Today at 04:01 am »
"Does that make sense ???"

No, not really.  It's not the look that concerns me.  I suspect it's the source of your hum, RFI or whatever.  Maybe you could shorten it and try an aluminum foil shield like Bacobits suggested. 

I just saw this statement:  "By the way, with my new set up, the PDR linear arm,  I have no ground wire."  Good grief.   :duh:

C'mon now Guy, you can't break the rules all the time and get away with it.  You need to solder or somehow attach a ground wire to the arm.  It might be easier to use a ground post and a set of RCAs like the VPI set-up I posted earlier.  You just need to leave enough slack so the arm can travel across the record unencumbered.  I'm guessing you could lower that coat hanger about a foot or more. 

Once you have a ground to the phono stage the hum might go away.   If you still have some residual hum you could try an additional ground wire between the phono stage and (pre)amp, but that might not be necessary. 






Hi neobop.
Since I have replaced my Bellari with the Pro-Ject,
I have no more Radio Interference and a lot less hum.
I already tried s long time ago wrapping everything with aluminum foil
and tried different grounding scheme.
My problem with the grounding of the arm is that I need a tiny wire
and they are sold by sets of four, O.K. they are around 10USD,
no need to break my piggy bank. I will see if I can buy/find one only.
As for the coat hanger, I've already lower it and made the cartridge wires shorter.
I did try to ground different ways the phono and main amplifier, no change.
My last trial will be DC power supply with two batteries (12V + 6V)
Please give me some time to catch my breath...

Guy 13



Guy 13

Re: A phono preamplifier is not a FM receiver !
« Reply #169 on: Today at 04:07 am »
What Neobop said!  You should have a ground wire unless the ground is built into the IC's of the TT like my old Thorens TD-145.  With that being said, I would try a ground wire attached to the tone arm and your preamp and see if this fixes the problem.

Guy, what Bellari do you have?  If it is the VP-130 it could be the crappy walwart as there is a known problem with the DC power supply.  Radio Shack sells a DC power supply wall wart that has filtering and can fix the problem if that is the cause.  I have the Bellari 129 and it uses an ac walwart.

The hum can also be due to appliances in your house.  Try unplugging the AC, Refrigerator,etc and see if the hum goes away.

Hi Greyhound.
My Rega P3 turntable has no ground what so ever.
Even the Rega RB301 arm did not have a ground wire, I had to add one myself.
I have put aside my Bellari VP-129 with Ruby and a spare Sylvania 12AX7.
I've tried two different walwart, the original 220V. and another original for 120V.
both of them did not change/improve anything. Both of them gives 15VAC output.
So, no change to power the VP-129 with DC power supply or batteries.
My listening room is on a separate/upper floor of the kitchen
and my listening room as it's own main breakers.

Guy 13

Guy 13

Re: A phono preamplifier is not a FM receiver !
« Reply #170 on: Today at 04:13 am »
I've had at least 4 variants on this type of arm and have never ground it.....never had a hum.
The 195 page thread from Diy Audio has dozens of builds on this type of arm, or a close clone....metal bearings
rolling on glass tubes.
None have grounded the arm....http://www.diyaudio.com/forums/analogue-source/238027-diy-linear-tonearm.html
The arm that Guy has worked with no hum here with my AT13e cart on my P3, but my wires were shorter and
are set back in a tube like this pic of the Cantus Opus 3


I've also had luck with longer wires hung overhead, this pic is of another I built.....no hum


Not that grounding the arm wouldnt help in Guys set up.....just havnt needed it before.
I hope you get this sorted Guy...  :(

Hi Perry.
Thanks for your comments.
The more I try things, the more I think your PDR linear arm is not responsible for the hum.
Like I mentioned earlier I will try a battery power supply with 18VDC battery set up and see.
Those (Lead/gel) batteries are motorcycle batteries and are available at each street corner
and are about 10 USD each.
This is not a life or death thing, therefore, I will look into it, when I have more free time,
because it not because I'm soon to be 67 that it means I am retired.
Thanks.

Guy 13


I.Greyhound Fan

Re: A phono preamplifier is not a FM receiver !
« Reply #171 on: Today at 05:56 am »
Guy, I would still tape a wire to the tone arm and ground it to the phono preamp just to see if it fixes the problem.  It is something that will take 30 seconds.

Guy 13

Re: A phono preamplifier is not a FM receiver !
« Reply #172 on: Today at 09:30 am »
Guy, I would still tape a wire to the tone arm and ground it to the phono preamp just to see if it fixes the problem.  It is something that will take 30 seconds.
Hi Greyhound.
I found a jumper wire with alligator clips and I tried it and....
No difference. Perry was right.
Anyway, thanks for the suggestion.
If I try nothing, I cannot fix the problem.
If I try something and it does not work.
Well at least I know it does not work.
Thanks.

Guy 13

By the way:
I took me more than 30 seconds, more than 600 seconds. :lol:
I had to find that jumper wire, that took 95% of the 600 seconds.


neobop

  • Full Member
  • Posts: 2612
  • BIRD LIVES
Re: A phono preamplifier is not a FM receiver !
« Reply #173 on: Today at 11:23 am »
Is this the same system you're using without hum with other sources?

What else is hooked up to the same AC line?  You could try unplugging everything except the phono system and see if it goes away.

Reconnect the ground wire and connect another ground wire between the phono stage and amp.  You can use an unpainted chassis screw on the amp.  You need bare metal.  If the hum goes away leave that wire on and disconnect the one from the arm and see what happens.

Even though you have a dedicated line it could be going to a mains box with other lines?  That could be the source of the hum. 
If nothing works after Halloween is past, call Ghostbusters.

Final suggestion - move back to the old place.
neo

Guy 13

Re: A phono preamplifier is not a FM receiver !
« Reply #174 on: Today at 12:43 pm »
Is this the same system you're using without hum with other sources?

What else is hooked up to the same AC line?  You could try unplugging everything except the phono system and see if it goes away.

Reconnect the ground wire and connect another ground wire between the phono stage and amp.  You can use an unpainted chassis screw on the amp.  You need bare metal.  If the hum goes away leave that wire on and disconnect the one from the arm and see what happens.

Even though you have a dedicated line it could be going to a mains box with other lines?  That could be the source of the hum. 
If nothing works after Halloween is past, call Ghostbusters.

Final suggestion - move back to the old place.
neo

Hi Neo.
My system is the following:
Rega P3 Turntable with (Now) PDR linear arm with Rega Exact MM cartridge.
Pro-Ject Phono Box DC (MM/MC compatible) walwart 120V. in 18VDC out.
Decware SE84C+ SET amplifier 120V.
Rega Apollo CD player 120V.
Bottlehead Crack headphone amplifier 120V.
Omega 7F Open Baffle Dipole.
GR Research SA-1 ss plate amplifier 120V.
PI Audio Majik Buss line filter/conditioner 120V.
All power cords are stock and as short as possible
and away from speakers and interconnects cables.
Interconnects are Signal Cable OFC and shielded.
All power cords are the grounded type.
Everything is 120V. and connected to the Majik Buss.
The wall outlet is dedicated to my system.
I just finish unplugging each item that is not related to vinyl playing. 
I tried a ground wire from the arm and the phono stage to the amplifier inside ground buss bar (Cannot find more grounded than that.)
I've tried all kind of ground connection arrangement,
even the one you mention above.
I've switch off all the breaker in the house except the one for my system
and still hum...
Your final suggestion is not good, because the old place is now rented and pays for the mortgage of the new house and kick out the people would be asking for trouble, plus I like my new listening room, because it's on the forth floor, therefore away from the street noise and God knows how noise the streets of Vietnam are.
Tomorrow, I will ask to borrow 12 + 6 V batteries to replace the walwart and see/hear if the hum is gone.
Thanks anyway for the suggestions.
Two heads are better than one, with that hum problem, my head is like scrabble eggs.

Guy 13