Idiots guide to understanding electrical flow through a set of hifi components

[pbroido]

This post started out as a question on component matching / understanding impedance and voltage inputs and outputs/ etc as I am considering diving into my first DIY project - a simple passive pre
I quickly realised I did not know how to even phrase my first post and rather than asking the forum questions like will this work with that and hope for the best I thought it best I get the hang of the basics.

So the question is : Is there a simple guide/book to understanding the electrical flow through a traditional set of hifi components?: source components > pre amplification (phono and pre) > power amp > speakers with an explanation on the variables (impedance, voltage, power, gain etc) and the formulas that can be used at each point to calculate theoretical values. Pictures would be nice and not the definitive guide to hifi DIY as Im looking for basics now :)

I feel that armed with this Ill be building by design rather than just following diagrams and hoping for the best.

My system will be as follows and many of the components are in place - now that most of its there I need understand it better :)


TT > Phono Stage > Pre Amp or Passive > Power > Speakers

CD and Squeezebox > DAC ^

[struth]

decent article here that may help

https://www.soundonsound.com/sos/jan03/articles/impedanceworkshop.asp

[Arkless Electronics]

"The Art of Electronics" by Horowitz and Hill is a really good book on general electronics ;) Then you'll know why there isn't an "electrical flow through a traditional set of hifi components" :)

[pbroido]

Cheers Guys,

Ill start with the article and consider the "The Art of Electronics" - looks impressive, almost as expensive as some of my components (second hand) and certainly bigger;)
Feels like back to school.

Hopefully some semi intelligible questions to follow soon.

Gnight

Peter

[Colin Wonfor]

"The Art of Electronics" by Horowitz and Hill as alway been put up as the electronic designers Bibble. It is not , but it is a good reference book but the real action and learning can only come from learning on the job and with experience. It like another set books by another self publishing Guru which I will not mention, but I had to clean the mess some of his designs have left behind.

K.I.S.S. is and always will be best from me. Learn from real humans doing the job not some academic who thinks he understands all.


Thing like these sites:-

http://www.satsleuth.com/Schematics.aspx?Category=Misc

http://sound.westhost.com/projects.htm

There are many many more.

[agk]

By all means read a few books and gain some knowledge at the same time but the best way is to get stuck in.

When you get to a place where you need help there are plenty of folk on here who can help and diyaudio is another great forum for diy.

A passive pre is a nice easy starting point requiring only basic soldering and some assembly.

[awkwardbydesign]

Learn from real humans doing the job not some academic who thinks he understands all.

Unfortunately there are no real humans here, just words on a screen. So picking which ones to believe is pot luck. And some have an agenda.

[clack]

By all means read a few books and gain some knowledge at the same time but the best way is to get stuck in.


I happily quote you, Andrew.
First because making things is the best way to understand the way they work.
And more than all because the most amiss comments usually come from who doesn't try anything but is convinced he has the right to pontificate from the higher peak of his ignorance.
Moreover the latter is something that in this fast food age is scientifically sought after, so fellows are able to get more rich convincing people to eat sausages which have ammonia as their main ingredient.

Having tried many preamps, tube, solid state, passives, modded even more and recently built one that easily goes well beyond many products of the most rewarded brands, I feel like to give some advice to Peter.

A well made passive can be surprising about the amount of audio informations it is able to deliver to the main amp.
So, it can be very rewarding trying to DIY one.
The biggest issue is regarding the volume control, that is the nightmare of any preamp designer, because the amount of degradation involved with it can be very high and downgrade the best design.
So, be sure to choose a very good logarithmic one, of a correct value.
If the value (kohms) is too low, it will load too much the output stage of the source, avoiding it to obtain the best performance in sound quality.
A value too high, instead, will probably result in a screamy sound.
50 kohms can be a reasonable value to start with.
Ladder type controls can give an advantage in transparency when used instead of the traditional potentiometer, because they have only two resistors connected in series to the output, but have their shortcomings as well. 24 steps can be not enough, resulting in having always a too loud or too low sound level.
Someone has reported malfunctioning of the cheap chinese ladder controls, something able to blow speakers, when better ones can easily cost more of a whole production passive preamp.
So, maybe, beginning with a 15 euro Blue Alps pot can be the most convenient choice.

More than all I would build for sure a DIY passive, but allowing the room inside the cabinet to be equipped with an active circuitation in the future.
Not only because when the choice of a fine pot and an equivalent source selector is made and they are placed inside a cabinet with all the RCA sockets of the quality needed, the amount of money spent is not so far from the one involved in an active preamp.
But mainly for the following reason. Even if a passive can be very detailed and rewarding, chances are that sooner or later the solidity, the power and the driving abilities of an active preamp will be regretted.
There is no main amp, even the most powerful and well sounding, able to show the whole of its qualities, mainly for dynamics, timbric fullness and ability to send power to the speakers, that can do without a preamp that drives it in the best way.
A main amp that seems rather thin and weak can show an unexpected strength when driven by a preamp able to make its duty in the way it should.

[Reffc]

I learnt from the Radio Designer's Handbook by Langford-Smith (4th Ed 1953!) which I still use as a reference today and for loudspeakers, I started off with Gilbert Briggs book, the Loudspeaker and the later 2nd Edition. It may be over half a century old but the basics are all there. There's more modern publications such as The Art of Electronics and many other textbooks (take your pick, most introductory ones will teach you the basics) plus loads of websites (a few mentioned above). As Col mentions, they need to be supplemented by experience in order to learn more fully.

[awkwardbydesign]

After 45 years of faffing about I have just bought Morgan Jones's "Valve Amplifiers". And now I have a headache! Although I have made stuff for years, my technical knowledge is inadequate, but my brain seems to have fossilised. And my memory is definitely going!
Learning as you go is all very well, but there comes a point when some theory is necessary. Unfortunately.

[anthonyTD]

Still have my copy too! Great book.:)
I learnt from the Radio Designer's Handbook by Langford-Smith
PS, please excuse my latest Avatar, seems i have been interfered with,:scratch: hopefully, normal service will resume shortly.:)

[Arkless Electronics]

"The Art of Electronics" by Horowitz and Hill as alway been put up as the electronic designers Bibble. It is not , but it is a good reference book but the real action and learning can only come from learning on the job and with experience. It like another set books by another self publishing Guru which I will not mention, but I had to clean the mess some of his designs have left behind.

K.I.S.S. is and always will be best from me. Learn from real humans doing the job not some academic who thinks he understands all.


Thing like these sites:-

http://www.satsleuth.com/Schematics.aspx?Category=Misc

http://sound.westhost.com/projects.htm

There are many many more.

I'd say that "The Art of Electronics" is the best general book on electronics I've come across in a lifetime of electronics. Bible? as close as it gets for solid state as is "The Radiotron Designers handbook" for valves. Yes experience counts for much more still but by it's nature only comes with erm... experience! (and lots of time). Manufacturer's application notes are one of the best sources of real meaty solid info but do assume a basic knowledge of electronics is already present.

[pbroido]

Ok so you guys have only proved what I probably already knew .... no shortcut from A to Z so I may as well enjoy the journey.

Thanks for the references and web links - ill start with links and have decided to chicken out and step gently into this. So rather than buy a Tisbury (easy way out) or scour the net for basic passive parts, I have found a DIY passive an "enthusiast" has put together with a single input and output. I am buying it for £40 and ill pull it apart and add a switch and a second input. This will be project 1. Lets see if I catch the bug.

Soldering iron at the ready, I guess I better buy a multimeter and some plasters. Anyone able to recommend a site for switches, rca inputs, some decent wire

P.S. My wife just walked past me and thinks Im nuts.
P.P.S. Project 2 will probably be Linear PSU's or should I stay away from electricity for a while? :)

[sq225917]

Colin, I take it you're referring to Doug Self... It would help if you are specific rather than essentially bad mouthing anyone who ever published a circuit book.


One might not like his approach, all measurement and no listening. But if one genuinely wants high fidelity there's little to add to his Oeuvre.

[Colin Wonfor]

I learnt from the Radio Designer's Handbook by Langford-Smith (4th Ed 1953!) which I still use as a reference today and for loudspeakers, I started off with Gilbert Briggs book, the Loudspeaker and the later 2nd Edition. It may be over half a century old but the basics are all there. There's more modern publications such as The Art of Electronics and many other textbooks (take your pick, most introductory ones will teach you the basics) plus loads of websites (a few mentioned above). As Col mentions, they need to be supplemented by experience in order to learn more fully.

Hi Paul, I got a hell of lot of good techy books over the years from the "Million Barn Book Store" near Bath and a few from a lovely shop in Lyme Regis.
Another good source is www.archive.org (www.archive.org)a free site.

[Colin Wonfor]

After 45 years of faffing about I have just bought Morgan Jones's "Valve Amplifiers". And now I have a headache! Although I have made stuff for years, my technical knowledge is inadequate, but my brain seems to have fossilised. And my memory is definitely going!
Learning as you go is all very well, but there comes a point when some theory is necessary. Unfortunately.

Oh so so true, thank god for calculators I lost my slide rule year ago.
And Window XL is a great help, or Mathcad.

[Colin Wonfor]

Wrong Simon, Doug is not who a refer to, so please get facts before you lay a label on me please.:)

But maybe you just did oh dear.:doh:

And to bad mouthing anybody that published would mean me, my Dad and lots of my friends and my daughter so again no facts whoops.:lol:

[sq225917]

That's why I was asking for clarification Colin. It seemed an odd call...

[Reffc]

Forgot to add, to play around with circuit simulations, I can recommend LT Spice as well. I use LT spice IV and it is powerful enough to "build" any amplifier circuit that you are to mention for simulation purposes. It would be the second step after learning the basics of what is required for a specific circuit and how each type of component works, and where to use them.

[anthonyTD]

Quite agree.
Most of the stuff i have designed over the years, using various software simulation, like Spice etc, has saved me a lot of headache, components, and time, but you still need a basic understanding of components, and their function in a circuit.
Forgot to add, to play around with circuit simulations, I can recommend LT Spice as well. I use LT spice IV and it is powerful enough to "build" any amplifier circuit that you are to mention for simulation purposes. It would be the second step after learning the basics of what is required for a specific circuit and how each type of component works, and where to use them.

[pbroido]

Hi Guys - need a little help.

So decided to take your advice and jump straight in. I had the opportunity to buy for not much what looked like someone else's DIY project which was a stepped attenuator in a aluminium case single input / output. There was some issue with the grounding so I took out the attenuator which seems to be made nicely and bought RCA connectors some wire, solder, a switch, cheap multimeter and spent yesterday wiring it up,

Attached my wiring diagram - done on powerpoint (this is my first attempt - so no cheap shots). Does this look correct?

http://s3.postimg.org/lrn6v1ssz/Passive_Pre_wiring_diagram.png

I wired it up yesterday (only burnt myself twice) and I have tested the resistance between the Right input and Right output = 10 kΩ same for left, and the switch works (switching signal from one input and the other.

I'm a little confused on how to test the attenuator. I found the following wiring diagram from hificollective (it looks like the attenuator was from them and I bought my bits and pieces from them too - nice service)

http://s18.postimg.org/jsanfvdrt/wiring_diagram_for_stepped_attenuator.png

So it looks like testing resistance between in and out will just give you the resistance of IPR (in the diagram) in my case 10kΩ - so all good?

How do I test the various points along the attenuator?

I'm off to pick up a set of old powered speakers from a mate to test my monstrosity as Im scared to blow up my hifi :)

Can anyone comment on the diagram and on the attenuator testing?

Thanks
Petert

[pbroido]

I guess this threads gone dead. Just to feedback the whole thing worked fantastically.
Absolutely loving the passive pre, it just seems to have sharpened everything up. I think I have been bitten by the DIY bug. Need a next project.

Peter

[Colin Wonfor]

No not dead it all the Xmas shopping we have to do,

But this site is good fun and well enjoyed by many give it a go, Marco is there any way we can dump mini books on the system like a library ?

http://sound.westhost.com/projects.htm

[pbroido]

Thanks Colin.
I am just loving listening to my passive pre. Despite my rather amateur soldering it sounds just wonderful and there is something about having cobbled it together yourself that makes listening a little sweeter.

I have several components that may benefit from low noise PSUs (Caiman DAC Mk2 (12v), Angle Audio Phono stage (12v) and Squeeze (9v)) I'm considering building these if I can find the components at a decent price and not kill myself in the process.
I have some info on PSU design and get the gist of transformers, rectifiers, smoothhing etc (well in theory anyway).

If anyone has some direction on nice simple design and cost effective components that would help. - I think Ill start a new thread on this.

[Colin Wonfor]

Somewhere in my past drawings I have a PSU that use voltage doubling technique, now this may sound strange, but the ripple frequency is also doubled this means smaller caps or less ripple, give it a spin.