audio-talk

No as a anode load instead of a resistor of choke.

Nick wrote:No as a anode load instead of a resistor of choke.

Don't know anything about anode CCS ! I must read up on it. Does anyone here use them ? And how do they compare with anode chokes ?

ooo I built em (C4S) and never used them, I have Kevin Carter ones for Amity, they worked in Andrew L's lovely little phono stage and I am of the opinion that on the whole they can be the dog's bits; they make a PSU for the driver stage independent of the PSU for the output stage, the sharpen up things the way but even better as a constant current is guaranteed, a choke does, only cheaper (well, not cheaper than Tim but!), deffo worth a try!

I could use the C4S going spare on a 6DN7 - where's the soldering iron, drill, bits etc?

Nick wrote:What B+ have you got. Why not try a CCS, either a C4S or a IXY part would be happy at those sorts of voltages. If you want to try a couple of the 10M45's I will send you a couple to play with.

Hi Nick - Yes please !

No prob, PM me your address again.

Thanks Nick. The regs came in the post just now.

Is there a particular way to implement the CCS or do I just use the data sheet ?

PS The spider in the packet was dead on arrival.

Oh dear, I do hope he was dead when he left. I will feel bad about that now.

yes, just use a 470R to 1k carbon stopper on the "gate" and use the graph on the spec sheet to bick the sense resistor. And if needed heat sink them (being aware the anode is at b+ voltage).

What current are you intending to run at? What B+ are you starting with?

Nick wrote:Oh dear, I do hope he was dead when he left. I will feel bad about that now.

yes, just use a 470R to 1k carbon stopper on the "gate" and use the graph on the spec sheet to bick the sense resistor. And if needed heat sink them (being aware the anode is at b+ voltage).

What current are you intending to run at? What B+ are you starting with?

HT is at the moment 260V and I was thinking of 5.5ma

EDIT Is the "formula" for the resistor 3,000 divided by the current in ma ?

Thinking again.

Do I set the anode CCS current at the same level as the cathode is set for ?

And does the cathode resistor & cap stay as is ?

I'm off out for this afternoon so will catch up tonight.

You set the anode current to be the value you want to pass through the valve. You set the cathode resistor to give the bias point you want to operate at for that current.

I would try a 560R sense resistor for 5.5ma. So yep, I think your formular is right.

260v on b+ and I guess 120v or so on the anode, thats 140v across the device, so thats a dissipation of just under a watt, a small heatsink should be more than enough.maybe 20 C/W or so would be good.

Excellent.

So will the 560R set the voltage and current ?

No, 560R will set the current. The voltage on the grid will be set by the voltage across the cathode resistor. So Ohms law will set the grid voltage. Then the valve will set the anode voltage as the point on the plate curves where the grid voltage line crosses the horizontal current line set by the CCS.

pre65 wrote:PS The spider in the packet was dead on arrival.

A free dead spider with every order


Is that something I should consider doing?

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Mike H wrote:
A free dead spider with every order,


Is that something I should consider doing?

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No.

You should consider 2 free 10K 100mA o/p TX's and a pair of GM70's with every order or if the order is over £20 maybe a quartet of NOS 211's.



DTB

Hmm, nice idea, but bet I know what the bank manager will say



Actually I might tell him that just to watch him blanch

E-evil...

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