Hi everyone,
I have a CD63ki, and running my finger along the chassis I can feel a buzzing sensation, presumably some current is running through it. (the buzzing is not there when unplugged)
I talked to an owner of a CD63se who had exactly the same thing with his machine. He grounded the chassis to his house earth and the buzzing went, he also felt there was a small increase in SQ.
Is this totally safe to do?
Why do I and others experience this phenomenon?
What else can I do to check and improve the players earthing arrangements?
Should I ground the 'ground' of my home-made clock PSU to the house earth too?
TIA,
-Simon
I have a CD63ki, and running my finger along the chassis I can feel a buzzing sensation, presumably some current is running through it. (the buzzing is not there when unplugged)
I talked to an owner of a CD63se who had exactly the same thing with his machine. He grounded the chassis to his house earth and the buzzing went, he also felt there was a small increase in SQ.
Is this totally safe to do?
Why do I and others experience this phenomenon?
What else can I do to check and improve the players earthing arrangements?
Should I ground the 'ground' of my home-made clock PSU to the house earth too?
TIA,
-Simon
Hi Alf,
Thanks for the advice!
I have mains polarity correct - tested with an EMI meter for lowest field strength (unless it's different plugged in where it is now compared with where I tested it - never thought of that!!).
When you say "test the current to earth" do you mean one probe on the chassis and one on my house earth? And is that voltage or current setting on my DMM? (my electronics knowledge is basic, sorry!)
So should I be earthing it? You didn't say if I can...
-Simon
Thanks for the advice!
I have mains polarity correct - tested with an EMI meter for lowest field strength (unless it's different plugged in where it is now compared with where I tested it - never thought of that!!).
When you say "test the current to earth" do you mean one probe on the chassis and one on my house earth? And is that voltage or current setting on my DMM? (my electronics knowledge is basic, sorry!)
So should I be earthing it? You didn't say if I can...
-Simon
Hi,
I tested for current by putting an electrode to ground and one on a chassis screw. I measured fluctuating current from 0-4uA, mainly staying on 1 or 2 uA.
Interesting thing: when I put the probes across the buzzing went, and took them off it came back again.
I guess I should just earth the thing, I shouldn't get any ground loop hum as my amp has no earth connection...
-Simon
I tested for current by putting an electrode to ground and one on a chassis screw. I measured fluctuating current from 0-4uA, mainly staying on 1 or 2 uA.
Interesting thing: when I put the probes across the buzzing went, and took them off it came back again.
I guess I should just earth the thing, I shouldn't get any ground loop hum as my amp has no earth connection...
-Simon
(just in case anyone is following this thread...)
I've temporarily earthed the player now, just using a piece of speaker wire from a screw to a ground terminal I fitted to my power strip.
Buzzing is gone and the sound seems slightly improved. I could be imagining this of course, but I hear a quieter background and better coherance.
Thanks for reading.
-Simon
I've temporarily earthed the player now, just using a piece of speaker wire from a screw to a ground terminal I fitted to my power strip.
Buzzing is gone and the sound seems slightly improved. I could be imagining this of course, but I hear a quieter background and better coherance.
Thanks for reading.
-Simon
I find earthing is extremely important in many audio systems, so I'll post some comments and ideas on what I have done in the past..
First off, I find that by putting an isolation trafo between the power and my amp makes a huge difference in sound, just because it cleanes up the signal a lot. After doing this I grounded the amp to its own exclusive ground rods. This made quite an improvement.
Next thing, I put a saturation isolation transformer on the CDP. To do this, I put the trafo in the line like a normal iso transformer, then ran a ground directly to the CDPs transformer primary winding, this way, the CDP trafo is grounded, but not the whole CDP except for using its connection to the amp, this way there isn't a ground loop.
I did the same things with the other sources, such as turn table, VCR, other transports, reel to reel, whatever I had.
On the VCR I used an iso transformer for the cable input, that way there isn't a ground loop to the cable system, which for some reason has really lousy grounding.
As for the darn computer. There's iso trafos about to go between it and the amp cause it's causing all kinds of problems...
First off, I find that by putting an isolation trafo between the power and my amp makes a huge difference in sound, just because it cleanes up the signal a lot. After doing this I grounded the amp to its own exclusive ground rods. This made quite an improvement.
Next thing, I put a saturation isolation transformer on the CDP. To do this, I put the trafo in the line like a normal iso transformer, then ran a ground directly to the CDPs transformer primary winding, this way, the CDP trafo is grounded, but not the whole CDP except for using its connection to the amp, this way there isn't a ground loop.
I did the same things with the other sources, such as turn table, VCR, other transports, reel to reel, whatever I had.
On the VCR I used an iso transformer for the cable input, that way there isn't a ground loop to the cable system, which for some reason has really lousy grounding.
As for the darn computer. There's iso trafos about to go between it and the amp cause it's causing all kinds of problems...
Mains tweaking
Good stuff, thanks for the ideas.
I've been thinking about getting a nice big isolation transformer for my cd player, and putting it in a box with some transient suppressors, x and y caps, and maybe some large caps too, but money is a little tight right now, so it will have to wait. I don't see how this solution could be much worse than some rather expensive line filters commonly for sale.
Currently, I use a Russ Andrews Silencer, and a box I put together with some caps including a 10uf lighting cap across L+N, and some transient supressors. (Gives a richer, more mellow sound)
When I have (much) more money I will get a very big transformer just for my amp, but I don't want to choke it with anything smaller or even the same size as it has inside.
I added a .33uf cap to my cd player, as well as a series choke for both L+N. These helped the sound a little.
Also, I totally modified my Belkin power strip by removing the circuitry, cleaning the power rail connectors, and changing the lead for a thick braided beast I made. (these made the sound cleaner and less distorted, and the bass loads better!)
Lots of fun is power! I have no time for people who don't believe power tweaking will make a difference - it does!!
-Simon
Good stuff, thanks for the ideas.
I've been thinking about getting a nice big isolation transformer for my cd player, and putting it in a box with some transient suppressors, x and y caps, and maybe some large caps too, but money is a little tight right now, so it will have to wait. I don't see how this solution could be much worse than some rather expensive line filters commonly for sale.
Currently, I use a Russ Andrews Silencer, and a box I put together with some caps including a 10uf lighting cap across L+N, and some transient supressors. (Gives a richer, more mellow sound)
When I have (much) more money I will get a very big transformer just for my amp, but I don't want to choke it with anything smaller or even the same size as it has inside.
I added a .33uf cap to my cd player, as well as a series choke for both L+N. These helped the sound a little.
Also, I totally modified my Belkin power strip by removing the circuitry, cleaning the power rail connectors, and changing the lead for a thick braided beast I made. (these made the sound cleaner and less distorted, and the bass loads better!)
Lots of fun is power! I have no time for people who don't believe power tweaking will make a difference - it does!!
-Simon
Oh, believe me, power is very important.
For my amp's isolation transformer, I use a 5KVA delta isolation transformer and run it 220 most of the time. This puppy will handle about 25 times the power of my current amp, which is a Harman/Kardon A402. It is 40W per channel. I have however run much much larger amps off this transformer with great performance and improvement over the usual setup.
I find that with good isolation transformers, you don't need much other filtering (inductors and caps). This is because the transformer becomes almost resonant at 60hz it takes a great deal of energy to push transients and high frequency noise through the core. Almost all of this noise ends up being dissipated as heat since the core is very inefficient for transferring it. I find a little tiny bit of noise can get through, but some proper grounding usually finishes that off and maybe putting some small caps to ground from the secondaries.
As for the CDP, it's using a saturation transformer. These use a cap to cause great saturation of the core. This generates much heat, but the result is a very accurately regulated output voltage with very clean power. Noise is even harder to get through these transformers since the cap and transformer creat a resonant circuit that will eat noise up like nothing else. The input voltage can vary a great deal with the output generally staying within 1% of 117V. This makes the CDP sound very detailed and with less stress.
If you can stand the transformers running very hot, this is a good idea to use the saturation type. The only other problem is that they are very expensive. I get mine from retired aircraft ground management equipment and obsolete cable TV distribution systems. This stuff is easy to get your hands on if you're in the local ham radio club of a town that's upgrading stuff. I've recieved all kinds of used equipment in almost perfect condition from the airport, including a sperry RVR computer and a complete ILS system.
For the 5KVA delta, that I took off my uncle's boat when he was re-building it. I got the old radar and a pile of other stuff.
For my amp's isolation transformer, I use a 5KVA delta isolation transformer and run it 220 most of the time. This puppy will handle about 25 times the power of my current amp, which is a Harman/Kardon A402. It is 40W per channel. I have however run much much larger amps off this transformer with great performance and improvement over the usual setup.
I find that with good isolation transformers, you don't need much other filtering (inductors and caps). This is because the transformer becomes almost resonant at 60hz it takes a great deal of energy to push transients and high frequency noise through the core. Almost all of this noise ends up being dissipated as heat since the core is very inefficient for transferring it. I find a little tiny bit of noise can get through, but some proper grounding usually finishes that off and maybe putting some small caps to ground from the secondaries.
As for the CDP, it's using a saturation transformer. These use a cap to cause great saturation of the core. This generates much heat, but the result is a very accurately regulated output voltage with very clean power. Noise is even harder to get through these transformers since the cap and transformer creat a resonant circuit that will eat noise up like nothing else. The input voltage can vary a great deal with the output generally staying within 1% of 117V. This makes the CDP sound very detailed and with less stress.
If you can stand the transformers running very hot, this is a good idea to use the saturation type. The only other problem is that they are very expensive. I get mine from retired aircraft ground management equipment and obsolete cable TV distribution systems. This stuff is easy to get your hands on if you're in the local ham radio club of a town that's upgrading stuff. I've recieved all kinds of used equipment in almost perfect condition from the airport, including a sperry RVR computer and a complete ILS system.
For the 5KVA delta, that I took off my uncle's boat when he was re-building it. I got the old radar and a pile of other stuff.
Excellent stuff duo,
Makes we very eager to start messing with transformers, but I am a little unsure of this 'saturation' type and method of connecting them, but as neither my amp or cd player come 'earthed' as stock I will not worry about ground loop.
Thanks for the technical explanation, it often goes above my head, but it's nice to know how stuff works.
I was thinking of something like a 300va transformer for the CD player... though searching Farnell for 'isolation transformer' has given me some ideas - they have industrial type jobs up to 5000va, now seen as my amp only has a 350va transformer inside, surely a 1000va job would do nicely... £68 with tax, hmm, interesting. Actually, some of these yellow beasts seem to step down to 110v That's not very useful for me! It's not clear that any are 230v>230v. Ah well, can't afford one right now anyway
-Simon
Makes we very eager to start messing with transformers, but I am a little unsure of this 'saturation' type and method of connecting them, but as neither my amp or cd player come 'earthed' as stock I will not worry about ground loop.
Thanks for the technical explanation, it often goes above my head, but it's nice to know how stuff works.
I was thinking of something like a 300va transformer for the CD player... though searching Farnell for 'isolation transformer' has given me some ideas - they have industrial type jobs up to 5000va, now seen as my amp only has a 350va transformer inside, surely a 1000va job would do nicely... £68 with tax, hmm, interesting. Actually, some of these yellow beasts seem to step down to 110v
That's not very useful for me! It's not clear that any are 230v>230v. Ah well, can't afford one right now anyway -Simon
I would say that even 300VA is quite large for a CDP. Most CDP's don't go over 50W, in fact, I haven't seen one that did unless it was tubes.
1000VA seems like a practical choice for the amp though.
none of my CDP's or other equipment came grounded originally, however, If you ground an amp, usually the RCA or XLR connectors will be grounded as well, this way your input sources will be grounded only when connected to the amp and not with their own power connections.
saturation typ transformers originated at a company called SOLA.
I'm not sure who actually invented the topology, but the theory is somewhat simple. In a transformer, you can insert special cores that cross the magnetic flux and limit the current output. This can be seen in any microwave oven transformer because there must be some way to limit the magnetron current. This is because, being a diode type tube without grids, the magnetron will drawas much current as it can to a certain point until it fries. The transformer will limit the current, and thus the power output simply via the little spacer cores.
In a saturation transformer, there are also these little slabs. In this case they may limit the transformer from overload, and also play a role in proper saturation. The capacitor that goes with the transformer is usually a large oil cap that is connected accross its very own winding. The cap will cause current to lag voltage which in turn saturates the core because of a loading effect. I believe the little core slabs are actually in there mostly to keep the capacitor from over-saturating the transformer.
Any transformer that is saturated will have a great deal of eddy current in the core, this is because the core is being energized as much as it can handle. The core will thus get very hot in most cases. Also, don't expect much power from a saturation transformer. They are about 10 times larger than their ordinary counterpart for the same power throughput. A 5KVA saturation transformer would probably be a little larger than a 15" computer monitor, however, a normal 5KVA transformer like the one I have is about a 10" cube and weighs 61lbs.
As for connecting the saturation transformers; they have exactly the same connection setup as a normal transformer. Two pins for primary and two for secondary usually, unless you have multiple primary/secondary connections, which still remain the same as usual. The saturation transformers usually come inside a chassie with the cap inside so you don't have to worry about how to connect it. Mine is just a convenient
I hope this helps explain a bit about the types of transformers I'm talking about.
1000VA seems like a practical choice for the amp though.
none of my CDP's or other equipment came grounded originally, however, If you ground an amp, usually the RCA or XLR connectors will be grounded as well, this way your input sources will be grounded only when connected to the amp and not with their own power connections.
saturation typ transformers originated at a company called SOLA.
I'm not sure who actually invented the topology, but the theory is somewhat simple. In a transformer, you can insert special cores that cross the magnetic flux and limit the current output. This can be seen in any microwave oven transformer because there must be some way to limit the magnetron current. This is because, being a diode type tube without grids, the magnetron will drawas much current as it can to a certain point until it fries. The transformer will limit the current, and thus the power output simply via the little spacer cores.
In a saturation transformer, there are also these little slabs. In this case they may limit the transformer from overload, and also play a role in proper saturation. The capacitor that goes with the transformer is usually a large oil cap that is connected accross its very own winding. The cap will cause current to lag voltage which in turn saturates the core because of a loading effect. I believe the little core slabs are actually in there mostly to keep the capacitor from over-saturating the transformer.
Any transformer that is saturated will have a great deal of eddy current in the core, this is because the core is being energized as much as it can handle. The core will thus get very hot in most cases. Also, don't expect much power from a saturation transformer. They are about 10 times larger than their ordinary counterpart for the same power throughput. A 5KVA saturation transformer would probably be a little larger than a 15" computer monitor, however, a normal 5KVA transformer like the one I have is about a 10" cube and weighs 61lbs.
As for connecting the saturation transformers; they have exactly the same connection setup as a normal transformer. Two pins for primary and two for secondary usually, unless you have multiple primary/secondary connections, which still remain the same as usual. The saturation transformers usually come inside a chassie with the cap inside so you don't have to worry about how to connect it. Mine is just a convenient
I hope this helps explain a bit about the types of transformers I'm talking about.
Thanks again Duo,
I only suggested 300va as the number is one I've probably seen for sale, and want some degree of overkill. Also, a larger one would let me connect my clock psu (yes, small) and anything else digital wise that may get bought in the future. The one in my CD player is a tiny toroid, must be about 50va, but I may build a psu from scratch one day, but thats a big maybe!
If I ground anything I'd rather make it my CD player as it's worth less money and feel more comfortable tinkering with it, as I have done lots already.
Thanks for the explanation on those transformers.
One more thing though... are 'saturation transformers' more commonly called something else? I ask, because searching Farnell, then Google doesn't find anything/much.
-Simon (needs cleaner power)
I only suggested 300va as the number is one I've probably seen for sale, and want some degree of overkill. Also, a larger one would let me connect my clock psu (yes, small) and anything else digital wise that may get bought in the future. The one in my CD player is a tiny toroid, must be about 50va, but I may build a psu from scratch one day, but thats a big maybe!
If I ground anything I'd rather make it my CD player as it's worth less money and feel more comfortable tinkering with it, as I have done lots already.
Thanks for the explanation on those transformers.
One more thing though... are 'saturation transformers' more commonly called something else? I ask, because searching Farnell, then Google doesn't find anything/much.
-Simon (needs cleaner power)
Hi SimontY,
isolation transformers are quite common on the second hand and surplus markets in the UK (and elsewhere). 240V/240V primary/secondary are obtainable and are used, for example, by TV technicians to isolate live chasssis and by people working on switch mode power supplies. Amp builders will also find these useful along with a variac.
Be careful you don't pick up the slightly more common 240/120V type which is used to run 120V gear and by builders to run 120V power tools.
Good condition used isolation transformers can be picked up for a fraction of their value - try ebay.co.uk or one of the industrial auction houses such as www.dovebid.com or www.henrybutcher.com. As always caveat emptor and also beware - both online and real life auctions can become a pain in the wallet.
James
isolation transformers are quite common on the second hand and surplus markets in the UK (and elsewhere). 240V/240V primary/secondary are obtainable and are used, for example, by TV technicians to isolate live chasssis and by people working on switch mode power supplies. Amp builders will also find these useful along with a variac.
Be careful you don't pick up the slightly more common 240/120V type which is used to run 120V gear and by builders to run 120V power tools.
Good condition used isolation transformers can be picked up for a fraction of their value - try ebay.co.uk or one of the industrial auction houses such as www.dovebid.com or www.henrybutcher.com. As always caveat emptor and also beware - both online and real life auctions can become a pain in the wallet.
James
Hi everyone,
I got myself one of those transformers from Ebay. Unfortuantely, I was barbequing dead animal and missed the two 3kva jobs (they went for just over £30)... however I did catch myself a 2kva for £17.56!!! (the 2nd one went for £36!) Amusingly, this is the same sized transformer as is found in the Isotek Qube 2k, which sells for £1500!!!
The description says it can deliver over 8amps of current, which is more than enough for my Roksan Caspian integrated, which uses a paltry 350va toroid.
Obviously, I'm very happy with my purchase, and I will let you all know when/if it works and what it does for my sound...
Laters,
-Simon
I got myself one of those transformers from Ebay. Unfortuantely, I was barbequing dead animal and missed the two 3kva jobs (they went for just over £30)... however I did catch myself a 2kva for £17.56!!! (the 2nd one went for £36!) Amusingly, this is the same sized transformer as is found in the Isotek Qube 2k, which sells for £1500!!!
The description says it can deliver over 8amps of current, which is more than enough for my Roksan Caspian integrated, which uses a paltry 350va toroid.
Obviously, I'm very happy with my purchase, and I will let you all know when/if it works and what it does for my sound...
Laters,
-Simon
Hi,
I'd like to ask a quick question about my transformer and setup:
I want to add some varistors before the transformer to stop spikes reaching it, I have used them before across L+N.
Question is, can I/should I use them across L+E and N+E too?
I want to buy:
http://uk.farnell.com/jsp/catalog/v...IV1MLSXRY4DRQFIAEWSFE4AVAAS0IV3?prodId=318644
Also, are 'Y' caps the ones specifically meant for use across L+E and N+E?
(Might aswell turn this thing into a full blown Isotek Qube 'clone', bar the cool aluminum case, blue LED, and £1500 price tag )
Cheers,
-Simon
I'd like to ask a quick question about my transformer and setup:
I want to add some varistors before the transformer to stop spikes reaching it, I have used them before across L+N.
Question is, can I/should I use them across L+E and N+E too?
I want to buy:
http://uk.farnell.com/jsp/catalog/v...IV1MLSXRY4DRQFIAEWSFE4AVAAS0IV3?prodId=318644
Also, are 'Y' caps the ones specifically meant for use across L+E and N+E?
(Might aswell turn this thing into a full blown Isotek Qube 'clone', bar the cool aluminum case, blue LED, and £1500 price tag
)Cheers,
-Simon
Are you talking about MOVs (metal oxide varistors)?
If so, you can put them from L+N, and from L+E and N+E but
then you must use a fuse on the L because those varistors will short right out in a spike.
I'm not sure exactly what you mean by 'Y' cap.. Is it just a cap with three leads and essentially two caps inside? If so, I don't believe they are specifically designed for the intent of transformer filtering. (Anyone else have ideas on this?)
If so, you can put them from L+N, and from L+E and N+E but
then you must use a fuse on the L because those varistors will short right out in a spike.
I'm not sure exactly what you mean by 'Y' cap.. Is it just a cap with three leads and essentially two caps inside? If so, I don't believe they are specifically designed for the intent of transformer filtering. (Anyone else have ideas on this?)
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