All the little things you can do to improve your amp

[Bricolo]

Hi all

What do you think about making a thread that resumes all little tips, good parts to use, and such things?


Like the kind of wire that sounds good fot internal wireing, how to place parts "optimaly".


My first question: what resistors do you all use? On all the posted photos, I've never seen classical resistors with coloured rings, like the ones I ever used. Are mine not good?

[gni]

Resistors are color coded for identification. Some are stamped. . .
some are even custom. It is what is inside that makes the difference.
They are designed to slow the current. . .some do it with more noise
that others. . .all introduce noise. Metal and Carbon are the standard
types used. . .Bi-directional also. Some parts of the circuit are not
as critical as others as far a noise characteristics. Most people would
not hear the difference between carbon and metal. . .although many
on 'this' forum would state the difference is night and day. The only
thing that matter in the end it what you hear. . .you listen to your
system! Unless you want to impress your neighbor!

Let's keep the post alive!

Chris

[john blackburn]

Capacitors are another area of confusion for newcomers to electronics (my own experience is very limited)
Should it be mylar, polystyrene, polarised or axial? and why does capacitor X cost 15 times as much as capacitor Y for the same value, and is it worth it for my needs?
Many hours of trawling this forum has found the answers to many of my questions, though generally prompting a question of their own in the process.
Its a learning curve!

[Johan Potgieter]

Not even trying to try (oh well then) to answer Bricolo's original question, but I think it is a little vague to suggest that one should use what "sounds best". That surely is an undertaking! Often the difference will not be audible, and at any rate how many combinations would have to be tried?

I think it is fairly generally accepted that metal film and metal oxide resistors are more stable and have lower noise than carbon types. Depending on the design this will often not be audible, but materials science wise there can be little doubt. Listening is extremely subjective and I don't want to open that debate; let us just say there has been development in materials over the last decades.

Again very generally there is little to quibble regarding poly-ester capacitors, with tantalum doing well with large values and where polarised can be used. (A well researched series on capacitors some 4-5 years ago by Cyril Bateman in "Electronics World" provided excellent information.)

Other questions: The smaller dimensions of radial capacitors favours them - also more readily available, but electronically no difference. Contrary to what some believe, non-polarized electrolytics are better that polarised (again referenced the above series).

Lastly, perhaps, new folks must beware of qualitive claims that "this" type is better than "that" type. Very often the claims are theoretical and of no practical consequence in audio. (E.g metal film resistors are inductive - yes they are .... making a possible difference only in the MHz region, etc.)

Regards

[john blackburn]

Thats so often the problem. You read one article where capacitor type A is the bees knees but you shouldn't use type B if it was free, then you read an article which says the exact opposite. They both have evidence to support their case but its so far beyond my fledgling understanding that it means little.
I'm on with my first chipamp currently, an LM3875 kit from Mad about sound (Superb service on every front, highly recomended!)
I want to give it the active preamp featured here on Decibel Dungeon.

http://myweb.tiscali.co.uk/nuukspot/...clonepre2.html

Its the most complex project I've tried so far as its going to have to be stripboard, I dont have the kit for making pcbs and cant find anyone in my area doing this kind of thing.
I'm putting it in a large case as it will make stamping the flames out easier.