Prefered type of components

[JDeV]

What are the prefered type of components to use in tube amps?

For instance:
For resistors use Cracked carbon rather then metal film.
For caps use metalised polyester rather then electrolytic.
(Only examples)

[analog_sa]

Hi

There are no universal preferences, it's pretty much a question of taste which may also develop and change. Seeing you're in SA there are not that many choices locally. Readily available (and reasonable) are WIMA MKP4 polyprops from AVNET, LCR elcos from AP, Welwyn resistors from RS components, ERO MKP caps from RS electronics, various motor-start caps. This will at least give you a comparison point for better components.


cheers

peter

[Tube_Dude]

HI

There are no universal preferences, it's pretty much a question of taste

1oo% agreed with you...is like the food...everyone have is one preferences...that even change during life.

when i ear..."that sound best than..." for me that doesn't mean nothing...weel, in reality only mean that listener A prefer the sound of the component B in relation of component C....no more no less!

regards

jorge

[Bas Horneman]

Generally MKP are better than Electrolytics though..soundwise and specwise. MKP don't age as fast as electrolytics...

But electrolytics can't be beaten in uF per $.

For that reason the tube output stage in my cd is going to use lytics in the psu for a change. My poweramps only use MKP and MKP in oil (motor start)
Except as bypass cap for the cathode resistor where the size was important as well there I used a BG lytic.

[Brett]

My <i>preferences</i> are (not totally in order)

PSU
-PP in oil
-PP
-Electros, if, they are the first in CLCLC only (cost & availability) or in DC filament supplies. Panasonic TSHA and TSHB are good for $$

Coupling / bypassing etc
-Audyn PP film/foils
-Arcotronics PP f/f
-Silver mica in low value positions
-Russian Teflons

Cathode bypasses (prefer none)
-Elna Starget (cheap at RS)
-PP esp arcotronics and ASC

Resistors
-Beyschlag / Philips MF (cheap and available)
-Mills NIWW (excellent)
-Kiwame Carbon film
-Vishay bulk foil
-Caddocks

Build it with whatever decent components you have at hand, then change components and see whether the difference is important to you. Whatever is in series with the signal usually has a bigger sonic affect than something in shunt. Same with low signal level components like in phono stages. Anode and cathode resistors are the first R's I would change, with Mills being excellent for higher power apps (so are some of the Vishay power foils) as well as Caddock and Kiwame for lower power (preamp) anode, and cathode. I don't like carbon compositions much, though I have some vintage items that are full of them and sound great.

Coupling caps and PSU caps are in the signal path, so I use the best I can. PP in oils will last forever if treated well, so the expense can be recycled into later projects too.

Topological changes will have a bigger effect than some component changes and vice versa with the topology usually being the biggest, and passives being maybe 10% (-20%) *sometimes* more in some instances. Don't get too hung up on the part itself, or the hype. Get the amp working.

Also don't limit yourself to what you can get locally. If you have a CC and a fax, mail order from Europe or the US. Apart from a few things I get surplus or from RS/Farnell, I import almost all of it because it's not available anywhere near where I live. Postage for small parts is very reasonable, and there are a heap of reputable sellers of quality parts out there. Suggestions later if you like.

Enjoy

[EC8010]

It's easy to get hung up on component differences. Get the circuit absolutely spot-on, then tinker with components. Every so often (not usually on this forum), we see designs that flout the rules of good electronic design that are stuffed full of "designer" components.

In general, foil capacitors are better than metallised, but they're much bigger and more expensive. Ranking of plastic dielectrics (least leaky to most): PTFE, styrene, propylene, carbonate, ester. Mica is variable because there are lots of different types.

Electrolytics designed for use in switch-mode powere supplies are usually better than standard (lower ESR and inductance).

Inductance in wirewound resistors is only an issue <1k. There is no significant inductance in any wirewound resistor above this value. Nevertheless, Mills W/W NI are popular. (I haven't tried them yet.)

PTFE and ceramic valve bases are best (less leaky). Try to avoid phenolic if possible.

In the end, "It ain't what you do, it's the way that you do it."

[SY]

The question is rather meaningless. The "best" component depends on what it's being used for and where it's being used. For example, a low ESR cap which is better to use in a switching regulator can be a disaster used on the output of a series regulator. A cap which is lousy for coupling or EQ may be the best choice in a spot where RF bypassing is needed. And so on and so on. Stop worrying about universals and concentrate on the specifics.

If what you want to know is what's fashionable, the question makes sense and please ignore everything I've said. If you want to know what the trade-offs are in selecting components for actual performance, a good start would be Bob Pease's book.

[analog_sa]

Inductance in wirewound resistors is only an issue <1k. There is no significant inductance in any wirewound resistor above this value.

surely you mean the opposite?

[Tube_Dude]

Hi analog_sa

surely you mean the opposite?

EC8010 is right!

regards

Jorge

[analog_sa]

Hi Jorge, EC8010

Please explain. I've always assumed that the more wire you have, the bigger the loop and inductance. Don't really have much experience with WW.

thanks

peter