[Guy 13]

Hi neobp and Quiet Earth.
Thanks for that exchange of opinion and knowledge, interesting it is, however,
I am very happy with the sound of my Rega Exact mm cartridge
with the Bellari VP-129,
well before it started to play unwanted FM Vietnamese music.
It's not what some would call hi-end or the best or the best,
but it's enough for me.
You can keep arguing, exchange, fight if you want,
that's O.K. with me, even if it's MY topic.  

Guy 13

The Rega RB301 arm and the interconnect should be right now
in the hands of the Vietnamese technician.
I am crossing my finger that he does not screw up the whole thing.
If he does, after I will take care of him,
he will not be sleeping in his bed, but in a coffin.

[neobop]

Hi Neo,

I respect your opinion and your experience too. How could I be "more wrong" by actually selecting the input capacitance value of my phono stage, and then listening to decide which sounds more correct? That is what I do at home in real time and real space. Listening is not a simulation. I choose the value of C that sounds best while I am playing the record, not what the math tells me to choose. In my case either 470 or 220 pF sounds the best, with 470 being the most often used. If I go by theory alone then I cannot stand to listen to most of my pop/rock collection.

Thanks for the link. I have read that article before (and many others) and I know what you are getting at. Those are nice simulations and calculations but they don't tell the whole story. Did you notice that they also play with the input resistance as well as the capacitance? Not that it matters ....... the proof is in the listening, not the simulations. The calculations are good for getting a general understanding of how the load might react, but they do not really represent what is actually happening while the cartridge is talking to the load, and the load talking back. You have to play the record to get that data. (You have to listen to it.)

Well, we will have to agree to disagree on this one. I know that I am way outnumbered on this topic, (which should be another thread anyway) and I can only speak for my own cartridge and system, and what I hear at home. 


But to recap, the main reason I brought up the capacitance is that I noticed there was none (zero) in the front end of the Bellari. I think there should be some, especially if you are picking up a radio station. Or perhaps if you hear way too much sibilance in those Paul Simon records. It's just one more thing to explore and you can decide for yourself if it helps or it hurts. I think experimenting is ok, isn't it? Sure it is.

Cheers everyone! 

Curious what cart and phono stage sounds best with > 600pF ?  It's possible.  I had a MI cart where recommended capacitance was > 400pF, but no modern MM/MI cart comes with such recommendation.

As I said in my post, you couldn't be more wrong refers to the following:
"But beyond that I also believe the rule of limiting capacitance to 220 pF for a MM cartridge is more of an urban myth than a hard and fast truth. The modeling for that 220pF capacitance situation is theoretical and static. It does not represent what will actually happen when the cartridge is playing music into the load.  In other words, it's an approximation or a starting place. A base line."

There is no such rule. Capacitance is loaded to compliment the output of the cart.  220pF was used as default capacitance in many phono sections in yesteryear, but it was never a standard and not total capacitance.  I stated in my initial post on this subject, that it depends on the cart and phono stage.  HO cart resistance loading can be very beneficial, but you're right, that's a subject for another thread.  If you're really interested you are welcome to join in here:
http://www.audiocircle.com/index.php?topic=88878.msg1317722#new

The TNT article wasn't just theoretical.  Along with the calculations there were actual response plots with the cart playing a record.  Those findings have been verified by hundreds of end users.  We had a thread on this here on Vinyl Circle.  With that cart 250pF (total) had to be maintained to keep treble from drooping, but increasing to 370pF caused a pronounced peak (the thing you're trying to avoid) and sharp roll-off at 14KHz.  That's a relatively high inductance cart, but it's about the same as the Ortofon 2M series which has rather different response.  Yes, by all means tune by ear, but watch those "characterization" statements.  I use HO carts often, and capacitance can make a dramatic difference.  Hopefully, Guy won't need excessive capacitance to block RF. 
neo

[neobop]

Guy,
If your arm comes back and it works but you still get radio interference, Quiet Earth's suggestion might fix it.  Lets hope it goes away.
neo   

[neobop]

I was wondering about the self capacitance or miller capacitance of the tube and op amp.  Wouldn't that tend to limit bandwidth and help block RF ?
Guess it wasn't enough to stop that local radio station.

neo

[Guy 13]

I was wondering about the self capacitance or miller capacitance of the tube and op amp.  Wouldn't that tend to limit bandwidth and help block RF ?
Guess it wasn't enough to stop that local radio station.

neo

Hi neobop.
As I mentioned in an earlier post,
when the system was in our other house,
it was on the ground floor and with exactly the same components,
I had no interference what so ever.
Now, I am on the forth floor and I have nice musical interference.
I guess it's because I am now at the same level as the FM emitting antenna
of the Vietnamese FM station.
What else could it be ? ? ? 
In about a week or so, I will know if the problem was with the black tiny ground wire, if that was not the problem, then I am back up the creek without a paddle and my turntable/phono stage will be as useless as a pair of tits on a leg horn.
(I like to use those expression, for me they fit well the situation, but if they don't please suggest something better.


Guy 13
The French Canadian that likes to use some English expressions.
By the way: I am not sure if I want to modify my Bellari ? ? ?
I hope I won't have to.

[Quiet Earth]

Guy,

You don't have to modify your phono stage to see if a little more capacitance helps (or hurts). Put a RCA barrel type adapter on the input of your Bellari. Now you have two inputs. Plug your regular phono cable into one of the RCA jacks. You can solder a small capacitor on a RCA plug and plug it into the other end of the RCA adapter.

You can get inexpensive 100 220 330 pF capacitors and make your own capacitor loading plugs to play around and listen for yourself. If you don't like it or it doesn't help  your phono stage is still like new.

Hopefully the rewire will fix your problem and you won't have to try it.

Here is a picture of the style of adapter : http://aphroditecu29.com/ViaBlue/Image/XS%20Series/xs_cinch_adapter_y_2.jpg

[Guy 13]

Guy,

You don't have to modify your phono stage to see if a little more capacitance helps (or hurts). Put a RCA barrel type adapter on the input of your Bellari. Now you have two inputs. Plug your regular phono cable into one of the RCA jacks. You can solder a small capacitor on a RCA plug and plug it into the other end of the RCA adapter.

You can get inexpensive 100 220 330 pF capacitors and make your own capacitor loading plugs to play around and listen for yourself. If you don't like it or it doesn't help  your phono stage is still like new.

Hopefully the rewire will fix your problem and you won't have to try it.

Here is a picture of the style of adapter : http://aphroditecu29.com/ViaBlue/Image/XS%20Series/xs_cinch_adapter_y_2.jpg

Hi Quiet Earth.
Thanks for the info.
I will only do it, if I still have interference.
I don't have any 100 - 220 - 330uf capacitors,
therefore I will have to go the electronic flea market to buy some,
which is only 10 minute drive from my work.
Thanks again.

Guy 13

[MightyG]

Hi Guy;

I read through your thread and was wondering if you have successfully resolved your problem? You've received some excellent suggestions from other helpful members...In the event you're still experiencing the radio interference issues with your analog setup, perhaps these tips may be helpful to you...

Generally speaking the majority of RF broadcast interference usually affects analog audio circuits in the longer wavelength lower frequency AM bands but RF interference in the VHF and UHF frequencies of FM broadcast transmitters can also be problematic, especially if the FM transmitter is line of site or in close proximity to your location. In your instance the length of wires and/or interconnects may not always be the cause. As I understand, your components are the same as you had set up previously with no issues. In this case another area which could be causing your RFI problem is with the 12AX7 tube or with the low voltage wall power supply module. If it's not the cartridge or tonearm causing the problem, it sounds like you have a connection or component which is acting as a diode detector and/or overloading in the input grid circuit of the 12AX7 tube in your phono pre.

Ideally it would be nice to simply borrow another phono preamp and see if that exhibits the same problem. Perhaps you've done that. If you haven't done this...pull the tube from your phono pre and either try another new 12AX7 or clean the tube pins and the tube socket very thoroughly with something like "DEOXIT" or a quality contact cleaner using a Qtip. Insert the tube a few times to clean the socket contacts. Do the same with all of your interconnect plugs. Slight corrosion or dirty contacts of the tube and socket can cause a very high resistance point which can act as a diode rectifying the RF from the FM station. Another area would be the low voltage power module (wall wart) with your phono pre. These units can also act as a diode detector picking up the FM interference. Either replace that unit or you can use a small toroidal choke core and wrap as much of the low voltage power cord around the toroid core. I would start with a #43 core material ferrite toroid. You don't have to cut any wires, simple wind the power cord around the toroid on the wire end that plugs into your Bellari. Amazon or ebay are sources for the ferrite toroid if you can't find them local. I hope your interference is gone so you can enjoy the music. Take care.

[neobop]

Hey Guy,

 

 

    

[Speedskater]

Now theoretically a phono pre-amp can't pick-up FM transmission. But real world FM transmitters also have an AM component that can be de-modulated by nearby sensitive circuits.

This Jim Brown paper has more about EMC (EMI/RFI interference) than most need to know.
Don't let the title fool you.

"A Ham's Guide to RFI, Ferrites, Baluns, and Audio Interfacing"

by Jim Brown K9YC
Audio Systems Group, Inc.
http://audiosystemsgroup.com

The basis of this tutorial is a combination of my engineering education, 55 years in ham radio, my
work as vice-chair of the AES Standards Committee working group on EMC, and extensive research
on RFI in the pro audio world where I’ve made my living.

http://www.audiosystemsgroup.com/RFI-Ham.pdf

[Guy 13]

Hi MightyG, neobop and Speedskater
and whoever is interested in my (Let's call it) FM problem.
I just got my Rega RB-301 tone arm from the operating room
and it's sitting on my office desk waiting for me to remove the bandages.
(Packing bubble wrap.)
I've been a little busy this week, but tomorrow (Sunday)
I will put it back on his final resting place which is the Rega P3 turntable.
The doctor has installed a grounding wire that is supposed to be welded to the tone arm interior body.
We will see what will happen and if the interference (Unwanted Vietnamese boring music) will be gone,
certainly hope so, otherwise I will kill myself or kill that turntable which ever is the easiest.
Will get back to you as soon as possible.
Thanks for inquiring about my #$$%^&*(&^%$#@$% problem.

Guy 13

[Guy 13]

Now theoretically a phono pre-amp can't pick-up FM transmission. But real world FM transmitters also have an AM component that can be de-modulated by nearby sensitive circuits.

This Jim Brown paper has more about EMC (EMI/RFI interference) than most need to know.
Don't let the title fool you.

"A Ham's Guide to RFI, Ferrites, Baluns, and Audio Interfacing"

by Jim Brown K9YC
Audio Systems Group, Inc.
http://audiosystemsgroup.com

The basis of this tutorial is a combination of my engineering education, 55 years in ham radio, my
work as vice-chair of the AES Standards Committee working group on EMC, and extensive research
on RFI in the pro audio world where I’ve made my living.

http://www.audiosystemsgroup.com/RFI-Ham.pdf

Hi Speedskater.
Wow... That's over 60 pages of reading...
Holy smoke, that's a lot of reading.
I had to practice my fast reading skill, which was very rusted.
I will read again what I have misted in my first reading.
Very interesting, but a little too technical for me, even with my basic in electronic diploma.
Thanks.

Guy 13

I might try to install mt tone arm this evening.
(Saturday night... live...)

 

[Guy 13]

Hi all.
I've installed my Rega RB301/Exact mm combo on my Rega P3 turntable,
I've connected the interconnects and the new ground wire to the Bellari VP-129 and guess what?
Keep in mind that my name is Guy 13, therefore, thirteen means bad luck, well...
The FM interference is almost gone, I have to turn the volume control to maximum and put my hear against the speaker to hear it, but it's still there.
However, there is a fairly loud hummm... At maximum level, which is not where I set it to listen to music.
And, the sound is a little thin and the output level of the cartridge is not what it use to be.
I suspect the the re-tipping by Soundsmith as changed something to the output of the cartridge, that don't seams to be possible/logical, but that's what I hear.
I did a switcharoo between my Rega and my cheap automatic Sony turntable and guess what ?
No interference whatsoever, no hummm with my 175 USD Sony,
but a very cheap sound, almost none listenable...
For now, I will listen to CDs and try not to look at my turntable until I come up with a solution...
At 66 years old, I don't need frustrations like that, I have enough frustrations living in Vietnam. Do I need more from my audio stuff.
I think not.

Guy 13

[neobop]

"The FM interference is almost gone, I have to turn the volume control to maximum and put my hear against the speaker to hear it, but it's still there.
However, there is a fairly loud hummm... At maximum level, which is not where I set it to listen to music."

What about that hum at normal listening levels, can you hear it?

If you had the cartridge rebuilt with a new tip and cantilever, it might take a few hours or more for the suspension to settle in. 

neo

[Guy 13]

"The FM interference is almost gone, I have to turn the volume control to maximum and put my hear against the speaker to hear it, but it's still there.
However, there is a fairly loud hummm... At maximum level, which is not where I set it to listen to music."

What about that hum at normal listening levels, can you hear it?

If you had the cartridge rebuilt with a new tip and cantilever, it might take a few hours or more for the suspension to settle in. 

neo

Hi neo.
I was so upset that I forgot to see/hear if the humm was present
at mid setting volume.
I will do that later on this morning.
I had a good night sleep to calm down,
because yesterday I was really, super up-set.
Yes, you are right, I will have to put some millage on the re-tipped cartridge
before I can appreciate the work of Soundsmith re-tipping.
(With my Sony automatic cheap turntable I have not FM and no humm...)
I have a few more things to try before I put to sale or throw in a corner my Rega/Bellari combo.

Guy 13

 

[G Georgopoulos]

Hi Guy13

if you have such problems it's got to do with the phono preamp...not the tt...

good luck in finding the fault...

[Guy 13]

Hi Guy13

if you have such problems it's got to do with the phono preamp...not the tt...

good luck in finding the fault...

Hi Georgopoulos.
The more I circle around the combo (Rega RB301 arm + Bellari VP129 phono stage) the more I think the problem might be the Bellari, because the Rega arm is sheilded properly and connected to the Bellari grounding lug.
I will do more investigation, even if it makes me more aggressive...

Guy 13
 

[neobop]

Hi Georgopoulos.
The more I circle around the combo (Rega RB301 arm + Bellari VP129 phono stage) the more I think the problem might be the Bellari, because the Rega arm is sheilded properly and connected to the Bellari grounding lug.
I will do more investigation, even if it makes me more aggressive...

Guy 13

Guy,
This doesn't make sense.  Unless I misunderstood, you substituted an old Sony and it was dead quiet?   Did you plug the Sony into the Bellari? 

Without an antenna the RF isn't a problem with the Sony, and now with Rega you have to crank it all the way and put your ear next to the speaker?

" I think the problem might be the Bellari, because the Rega arm is sheilded properly and connected to the Bellari grounding lug."

Really?  Why are you getting hum? 

I can tell you right now, either
1) you have a ground loop - the tech didn't disconnect the the arm ground from the channel ground, OR,
2) the "welded" ground connection inside the arm doesn't make a good enough connection.

It's unlikely the wire itself is bad, so where does that leave us?  You can install a couple of small caps inside Bellari like Quiet Earth suggested, to deal with radio remnants.  It might make it sound better anyway, but the problem is still with the arm.

If you want to test for a ground loop, disconnect the arm from preamp.  With your meter check at minimum resistance setting between the end of the ground wire and the outside of each channel plug.  Move it around and make sure you have good contact.  You should get nothing.

To make a proper ground connection inside the arm pillar the area must be sanded down first.  The anodized finish has to be removed.  Instructions were in an earlier post.
neo

 

[neobop]

Guy,
It's probably just a little older than advertised.  Do you think it would be worthwhile for them to copy the entire table?  It's a shame you sold the Linn, but all you can do now is move on.

Okay, that looks better.  Now, the question is, where does that black ground wire go to inside the arm, and is it still connected in there?  It should be connected to a ground inside the arm, if it wasn't pulled out.  If that black wire is disconnected inside, then you would have to make a ground connection on the aluminum part of the arm tube or pillar.  Lets assume (at least for now) that it's still connected inside.

Now, what you have to do is disconnect that bridge between the bottom ground connector for the black wire, and connector for the left channel ground (blue).  Don't worry about that brown strap.  It shouldn't matter.

Here are instructions for a complete DIY rewire job, including making a new ground connection inside the arm.  Hopefully, you won't need it:
http://www.vinylengine.com/hotwiredrega.pdf
neo

[yeldarb]

If you have a spare tube, roll it into the Bellari.