[JamesL]

Has anyone tried hand-soldering series SMD to those?
Would it be worth the trouble?

 

[cotdt]

Quote:

Originally Posted by JamesL /img/forum/go_quote.gif Has anyone tried hand-soldering series SMD to those? Would it be worth the trouble?

not worth the trouble...

 

[Navyblue]

Nikongod,

Thanks for your wonderful explanation.

Quote:

Originally Posted by nikongod /img/forum/go_quote.gif There are some inexpensive sources for 24-step switches in Asia, Il edit this post later.

Yep, would greatly appreciate that. VT4C is selling at $14.80-24.00 depending on whether if I want that few microns of gold.

Quote:

Originally Posted by nikongod /img/forum/go_quote.gif What you are describing has been done. It works out very well if you need LOTS of range or very fine control with a stepper.

So, I'm not that smart after all.

Quote:

Originally Posted by nikongod /img/forum/go_quote.gif I really like the shunted log pot. link It is an elegant solution when using inexpensive parts or if you need more attenuation than a standard pot can provide. If you are using open-loop tube stuff (or open loop SS stuff with naturally high gain), it is a very nice way to get the HIGH attenuation you may need while still using a well matched section of the pot. The output stages in most sources are somewhat indifferent to load impedance as long as it is not BELOW a certain point. IME an input impedance which varies from 100K to 110K is not a problem for most sources that require 100K. I suppose that the arguments of "high VS low" input impedance (noise and stuff) applies when you design something with really wide variances in input impedance, but you can get around it well.

The shunt mod to a standard pot does sound like a really happy ending. No carbon in the signal path, no steps, cheap, and next to no effort required to implement. May be except for the psychological effect on me with regard to the variable impedance.

I am using it on a default 8x gain Beta 22, since I'm not getting K1000 anytime soon, I guess I could easily live without the "maximum" volume.

 

[Navyblue]

Quote:

Originally Posted by holland /img/forum/go_quote.gif VOLUME CONTROL TO 12AX7 6SN7 ECC88 ECC82 ECC81 EL34 6V6 - eBay (item 320300801499 end time Dec-16-08 09:29:15 PST) I like those, no real problems other than break before make. That's not a big problem though. If you want carbon, change the resistors and hand match to 0.1%. The MF resistors in the package work better than most cheap pots, but could also be better matched.

Thanks, I used to have that bookmarked but lost it.

Sounds like it's the best deal around, but all that soldering made me cringe.

 

[nikongod]

Quote:

Originally Posted by Navyblue /img/forum/go_quote.gif Yep, would greatly appreciate that. VT4C is selling at $14.80-24.00 depending on whether if I want that few microns of gold.

link
$4.50 or $6 depending on exactly what you want.

 

[stixx]

Quote:

Sounds like it's the best deal around, but all that soldering made me cringe.

Have a look at this one...
DACT Type 23 Stepped Attenuator Potentiometer 100K el34 - eBay (item 300268952921 end time Nov-25-08 07:49:11 PST)

Looks to be decently made and saves you the hassle of fiddling with small resistors while trying to solder them...
Last year I purchased a very well made ladder attenuator using the same rotary switch and Dale resistors all around from a seller in Taiwan (kyc111)...but he doesn't seem to be doing business anymore.