How come the "Super Hard-On" crackles?

[The Tone God]

talk is cheap, kid.  8^)

I'll back it up old man. Don't worry about that.

Andrew

[zachary vex]

i got nothin' to worry about.  8^D

[The Tone God]

i got nothin' to worry about.  8^D

Not for alittle while. Besides I have more intersting things to do with that bit of technology then copy someone else.

Andrew

[zachary vex]

glad i could be of help!  8^)

[The Tone God]

glad i could be of help!  8^)

Oh sorry about that. I was referring to my own switcher designs from long ago. I just read your description to determine what parts from my designs would be needed to satisfy your needs. I could shrink it down more if needed but I feel some features should not be left out (i.e. safety features). Anyways I'm sure that others have found that tidbit an interesting piece so thanks for sharing.

Thanks is all for this thread-jacking.

Andrew

[zachary vex]

feel free to send it off to me and i'll take a peek at it.  9-15VDC in, 230VDC out, regulated within 5% over the input range, and from 0 to 15mA.  mine goes to 17mA but it doesn't need to.

[The Tone God]

removing a fuse from the "mains" on any high-powered circuit is always a terrible idea.  what if there's a direct short of the +12VDC supply to ground inside the nano head?  can you imagine the current levels a gel-cell can achieve under direct short conditions?  i wouldn't trust your fuse-free design any further than i could throw it.

I would never remove a safety feature to keep cost or complexity down. With that in mind that safety issue is addressed plus many others as is required by CSA. An yes I have shorted a gel cell. It was umm...impressionable.

feel free to send it off to me and i'll take a peek at it.  9-15VDC in, 230VDC out, regulated within 5% over the input range, and from 0 to 15mA.  mine goes to 17mA but it doesn't need to.

PM or email me.

Andrew

[Torchy]

Priceless.

Where else would two grown men argue "mine is smaller than yours" ...

[puretube]

the point being... question everything, and try your own methods, and you may drag some new truth in out of the dark.

right on!
I can sign that, too.

[no one ever]

PM or email me.

Andrew

ooh, a collaboration.

[rocket]

The "Crackle OK" pot is an intermixed gain/bias control. There is no practical way to elminate the crackle without more circuitry, and as zv as notes in this forum, even though lots of his customers complain about it, it's so "elegant" that he'll never change it. I can look up the tread if you like, it's in the last week or so.

The "Cracke OK" pot is the source resistor that does both biasing and gain for the active device.

I understand the gain control part of that - but why would you want to adjust the bias together with the gain - shouldn't the bias be fixed?

[zachary vex]

why should the bias be fixed?

[Meanderthal]

 Try deliberately mis-biasing a tranny once... it'll do wierd things. Some of which can be interesting and useful. Kinda like the dying battery thing...

[markm]

The "Crackle OK" pot is an intermixed gain/bias control. There is no practical way to elminate the crackle without more circuitry, and as zv as notes in this forum, even though lots of his customers complain about it, it's so "elegant" that he'll never change it. I can look up the tread if you like, it's in the last week or so.

The "Cracke OK" pot is the source resistor that does both biasing and gain for the active device.

I understand the gain control part of that - but why would you want to adjust the bias together with the gain - shouldn't the bias be fixed?

Noooooooo!
Lot of great tones available with this control

[R.G.]

I understand the gain control part of that - but why would you want to adjust the bias together with the gain - shouldn't the bias be fixed?

The bias - and distortion from that - and gain change are intermixed in the same control.

[puretube]

just for the record:
c.p.-pots are not a one-for-all guarantee for cracklefreeness;

IIRC, I had mixed experiences ~35 years ago with LDRs as variable
plate- and/or cathode-resistors in certain HV tubecircuits;

(dunno whether the SHO pots are voltagedividers or variable resistors,
but the LDRs, which I thought to be cracklefree in my circuits, didn`t
work as good as intended...).

give it a try!

[R.G.]

I don't think LDRs go to low enough resistance for the really high gains. Other wise an LED/LDR pair controlled by a pot would be fine.

[markusw]

I don't think LDRs go to low enough resistance for the really high gains. Other wise an LED/LDR pair controlled by a pot would be fine.

Suppose it would consume a bit more current than a simple pot.
Here are some values I measured from a home made LED/LDR combo (bright green LED):

I (mA)     R (ohm)

1,279        5180
1,376        4760
1,515        4260
1,730      3660
2,840      2130
4,060      1480
17,500     453
20,200    417


Markus

[puretube]

NSL got optocouplers guaranteed for <60 Ohm @ 20mA IF;

not to be misunderstood:
I encouraged Z to check out a c.p. pot - not an opto-control;

despite the chance,
that in some circuits
any variable resistors that usually are supposed to be free of crackle-noise
still can cause unwanted behaviour.
(at least they did in those times when we didn`t light LDRs with LEDs,
but with bulbs...).

[markm]

I understand the gain control part of that - but why would you want to adjust the bias together with the gain - shouldn't the bias be fixed?

The bias - and distortion from that - and gain change are intermixed in the same control.

Just how well would this type of control work in various other circuits......it maybe worh a couple of experiments!