Kofi Annan in: "B+... PLUS!!!"

[ThorstenL]

Konnichiwa,

I'm wondering if the bit of white noise I've got maybe the valves.. What do you think?

Yes, there is some variability for both ECC83 & ECC88. The ECC83 is the more relevant one for noise, but it will mainly generate "Tube rush", with a stromg LF emphasis. The ECC88 will contribute "white" noise as it is after the RIAA and high frequencies are not attenuated.

The noise will be more than from a CD Player but should not be much more.

Also, unshielded valves attract hum....

Sayonara

 

[Kofi Annan]

"they believe that any portion of power confided to me, will be exerted in opposition to their schemes. And they believe rightly; for I have sworn upon the altar of God, eternal hostility against every form of tyranny over the mind of man. . ."

Hey-- I just said that in my recent address to the UN! What a rip off!!! You tell me where this Jefferson guy is and I'll go fix his wagon. Did he also steal my one-liner about the Swiss Special Envoy to Bulgaria? That one killed in closed session...

Looks like what you've drawn is series. You want parallel:

electronics star: anode cathode :chassis ground
: cathode anode :

OK, taking this explanation down to the level of your average UN Secretary General:

There are two diodes that we'll call Frank and Boutros. Frank's anode is connected to Boutros' cathode and Boutros' anode is connected to Frank's cathode. The PSU star ground is connected to Frank's anode / Boutros' cathode and Frank's cathode and Boutros' anode are connected to the chassis.

Right?

I would think something like the common-as-dirt 1n400x should do fine.

Will these do?

Interested to hear how quiet you can make the phono stage, if you get it dead quiet then I'll do a rewire on mine to try to get rid of that last bit of noise.

I'll give a full report one I'm done rewiring. In case you haven't noticed, I kinda suck at this. Most of my projects involve the prefix "re-" at some point, but I'm taking it slow on this particular "re-" so hopefully it will yield better results. As Grandpa Annan always says, "Plan your work, then work your plan so you won't have to rework it, you stupid schmuck".

Grandpa calls it like it is.

What valves are you using?

I'm using a JJ / Tesla E88CC and a Telefunken 12AX7 that I pulled out of an old Pilot tube amp. I'm actually using the center tap of the power transformer that I pull out of that same amp for the phono stage.

Keep us posted on the thread for the Swans. They may be my next project, my Maggies are a bit insensitive for my valve amp.

Well, I'll post the full details on the FR forum, but in short, you may want to consider another full range design for your tubes. I ran the Swan D-101a with the 108EZs off a SET 2A3 and hated them. Running off a GainClone they sound really sweet, however. Someone made the comment that the ML-TL / BLH design of the Swans may be causing havoc with impedence for the 2A3s and so, may be negatively affecting the sound.

Also, unshielded valves attract hum....

I'll probably shield them as well.

Thanks again!

Kofi

 

[ThorstenL]

Konnichiwa,

There are two diodes that we'll call Frank and Boutros. Frank's anode is connected to Boutros' cathode and Boutros' anode is connected to Frank's cathode. The PSU star ground is connected to Frank's anode / Boutros' cathode and Frank's cathode and Boutros' anode are connected to the chassis.

That's it. Or as I like to call them, diodes doing then 69....

Will these do?

Yes, but being safety concious i tend to use high current bridge rectifiers (simply short out + & - and connect one ~ terminal to ground and the the other ~ terminal to the chassis which in turn is earthed. I just like to make sure fuses really blow first. The 1N400X series of diodes are a bit skinny for all that current.

Sayonara

 

[Kofi Annan]

That's it. Or as I like to call them, diodes doing then 69....

Hey now. Frank and Boutros are just friends. Friends working toward a common goal. Sure, maybe they're a little curious, but they know that they can't let their empty, animal urges get in the way of ensuring a proper ground for my PSU.

being safety concious i tend to use high current bridge rectifiers (simply short out + & - and connect one ~ terminal to ground and the the other ~ terminal to the chassis which in turn is earthed.

How about this motherfather?

So you mean that I would connect the + and - terminals together and go SPG to to ~ and other ~ to chassis, right?

Thanks a blahblahblah...

Kofi

 

[ThorstenL]

Konnichiwa

How about this motherfather?

Yeah mon, da motherfunker ez jus right.

So you mean that I would connect the + and - terminals together and go SPG to to ~ and other ~ to chassis, right?

Yup, that's what I do normally.

This one will do (as there are two diodes in parallel) around 20A continous and withstand sureges of up to 400A. If that one blows out open circuit any normal wire would have ben vaporised too....

Sayonara

 

[Sch3mat1c]

...You DO realize that there IS a ground, where one is defined....right?

 

[ThorstenL]

Konnichiwa,

...You DO realize that there IS a ground, where one is defined....right?

Ground remains pure fiction. No matter how you define it.

Commonly ground is thought of as having zero impedance and resistance, the result is that many people (even experienced EE's) make mistakes when laying out this "ground". Even traditional star grounding arrangements have problems.

I prefer to consider ground a signal connection with undefined impedance and to arrange my current loops such that said undefined impedance, regardless of magnitude produces the least possible error voltages for the signal (static error voltages for DC from the PSU are acceptable BTW within reason).

Sayonara

 

[Sch3mat1c]

Ground remains pure fiction. No matter how you define it.

Ok, so why is the word used if it doesn't exist, and how is it that millions of EEs have been "fooled" by this false information?

Chuckle.

Commonly ground is thought of as having zero impedance and resistance, the result is that many people (even experienced EE's) make mistakes when laying out this "ground". Even traditional star grounding arrangements have problems.

Oh. You're talking about ground as the wire. Wire is just wire, and yeah, if you put current through the far end of a ground line, it will elevate slightly with respect to the main ground potential.

I prefer to consider ground a signal connection with undefined impedance and to arrange my current loops such that said undefined impedance, regardless of magnitude produces the least possible error voltages for the signal (static error voltages for DC from the PSU are acceptable BTW within reason).
[/B]

Ok, makes sense, so how does ground not exist?

Tim

 

[Kofi Annan]

Not that I'm trying to add fuel to the fire, mind you. A guy like me should be helping build agreements and cooperation. Oh well... just this once:

Looks like we have another vote for "there is no ground". Look here.

Heh heh heh....

Kofi

 

[ThorstenL]

Konnichiwa,

Ok, so why is the word used if it doesn't exist, and how is it that millions of EEs have been "fooled" by this false information?

Any seriously practiced EE will know that "ground" is a convenient fiction for simplified drawing of circuits and for easier understanding, but in reality they know that "ground isn't".

Ok, makes sense, so how does ground not exist?

Correction, ground exists in the same way unichorns, mermaids and firebreathing dragons exist. Within a lore common to a tribe, better not taken too literal.

Sayonara

 

[Sch3mat1c]

Now I'm really confused. It's like you're violating a law of physics or something, without violating one. The letters "G", "R", "O", "U", "N" and "D" spell a word AFAIK, which has some sort of meaning in the English language.

Kofi: that page appears to be very thorough and a good read for anyone concerned about grounding. Err, I mean... uh... not-grounding? Geez, if the word "ground" doesn't exist, what is it called now?

Tim

 

[SY]

"Earth."

If you set up your system on Mars, it's "Aries."

If there's no such thing as ground and it's all a convention, then I have nothing to fear about playing golf during a thunderstorm.

 

[CraigBuckingham]

How about the terms common and ground.

Do they make it a little clearer?

 

[CraigBuckingham]

"Earth."

If you set up your system on Mars, it's "Aries."

If there's no such thing as ground and it's all a convention, then I have nothing to fear about playing golf during a thunderstorm.

Make sure you tell the lightning first.

 

[Frenchman]

The Earth is a pretty poor approximation of a PEC (Perfect Electric Conductor) which is what you generally think of as a perfect ground. Kuei is quite correct, and it's all relative.

Of course, the Midwest USA is better then most places in approximating the ground. That means we generally get better antenna patterns

 

[ThorstenL]

Konnichiwa,

If there's no such thing as ground and it's all a convention, then I have nothing to fear about playing golf during a thunderstorm.

Well, there may not be any ground, but there are still opposite poles and the conductivity of the pole you stand on has a lot to do with where lightning strikes (though not all, lightning is unpredictable enough to make scientists pull their hair out).

So, try to stay out of the Bunkers and keep to places high & dry....

Sayonara

 

[Kofi Annan]

Geez, if the word "ground" doesn't exist, what is it called now?

Tim

Let's call it "Jimmy the Hat"!

Jimmy the Hat was I guy I went to grade school with who always wore a you-guessed-it and was clearly the biggest loser in school. Zits at age 11, allergic to milk, had BO, hand-me-down knapsack, spit when he talked-- you know, all the loser acoutrements.

Anyway, the reason I recommend this is that we always used to use him as a reference point when we did something embarassing to refocus the ridicule. If I spilled milk on my pearl-buttoned polyester shirt during lunch, for example, I might say, "that's a Jimmy the Hat move if I ever saw one."

You see, he was used as the ultimate reference point. Now sometimes he would do something good, like anot fail a test (how, I'll never know), so he wasn't always an absolute reference point (to Kuei's point), but still one that was good enough to approximate a reference point when necessary.

In conclusion, I propose that all engineers begin replacing "ground" with "Jimmy the Hat" on the basis that this moniker seems to appeal to the engineering sensibilities pertaining to the concept of the "ground myth".

Please let me know your thoughts.

You finally made it, Jimmy...

(sniff)

Kofi

 

[CraigBuckingham]

Why ground???????????????????????????????

http://www.leminstruments.com/grounding_tutorial/html/start.shtml

 

[KevinTams]

gilding the lily

I've decided to break into it to rewire the "Jimmy the Hat" earthing arrangement to try to get rid of that last bit of hum. While I'm at it I may try to tweak it a bit. Inveterate fiddler that I am I'll try to "gild the lily"

Reading Morgan Jones book there may be some benefit in adding a ccs to the cathode of the ECC88. Farnell do a 1ma diode http://uk.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=371040&N=401 . Is it a benefit to add a ccs to this stage, if so would the ccs diode be OK or should I go for something like the Gary Pimm design? This may sound to some as if I know what I'm talking about, trust me I don't

This stage goes into a TX102 TVC then into my KT88 pp valve amp input impedance is 47k, would there be any benefit to add another gain stage or cf stage between the TVC and the power amp?

TIA
Kev

 

[ThorstenL]

Re: gilding the lily

Konnichiwa,

Reading Morgan Jones book there may be some benefit in adding a ccs to the cathode of the ECC88.

Don't, just simply don't. Leave the circuit as is.

This stage goes into a TX102 TVC then into my KT88 pp valve amp input impedance is 47k, would there be any benefit to add another gain stage or cf stage between the TVC and the power amp?

There is no true benefit adding stages anywhere, EVER. If you have insufficient gain, you will NEED to add a gainstage, even if it would be better to do without. If you have enough gain, you have enough gain.

Sayonara