New to this! Please help!

[hughes123]

Hi everyone, <p>

I'm new to DIY hi-fi, and I'm wondering if you could help. I want to build my own solid-state stereo integrated amplifier...but I'm not quite sure where to start. <p>

I'm only 15 years old, but I'm quite experienced in the vast world of hi-fi (naivity?)! I have an Arcam FMJ A32 (not sure if you get them in the states), Wharfedale EVO2 30 speakers (same) and an Arcam CD73T cd player (same again) oh, and a Project Debut III turntable (er...same). <p>

The reason I wanted to start designing/building my own amp was I successfully fixed my old JVC A-X400 amplifier (1985) and JVC A-X5 (lovely amp from '79-'81). <p>

Please advise me where to start...budget is anything upto £500 (I guess that's just under $1000!) Thanks!

[c2cthomas]

Originally posted by hughes123
Hi everyone, <p>
I'm new to DIY hi-fi, and I'm wondering if you could help. I want to build my own solid-state stereo integrated amplifier...but I'm not quite sure where to start. <p>
Please advise me where to start...budget is anything upto £500 (I guess that's just under $1000!) Thanks!

G'day hughes123 - and WELCOME to diyAudio! You might have better luck looking around here for a separate pre-amp and amplifier. Such a system will offer a great deal of flexibility and upgrade paths compared to an integrated design - thus the reason that most of us prefer to go that route. BTW (By-The-Way) there are a great number of postings and threads on both preamplifiers and amplifiers available here with just about anything that will fit any budget and skill level.

You mentioned that you have fixed some gear so you are well on your way to getting a bit of exposure to a scratch build. Do you have a good set of tools and a soldering iron or station? What test equipment do you have access to? Those things will determine what level of build you might seek out. How much do you know about electronics? Please understand that I ask these questions in a helpful manner as I and others are more than willing to help out a nubie such as yourself - we just need to know where to start. After all ---- we all started out once upon a time (in my case a looooong time ago). My usual advice to those new to the hobby is to run for the nearest exit and get out while you still can!!! It appears that it may be to late for you tho - I think ya got da bug!!


For the budget you have you will want to take a bit of time and do your research - you should be able to put together a very good kit with that amount of cash.

[AndrewT]

go and read Self, Leach and Pass.
look at the threads on chipamps and Leach and Quasi and JLH.
buy some cheap test & assembly gear to get you started. expand later.

[hughes123]

Ok, thanks Thomas and Andrew! Perhaps it is best I go down the pre-power route...then I could always build the preamp first and run that into my Arcam (using it as a poweramp) or build a power-amp and use the Arcam as a pre.

Regarding the tools I have available, my dad and grandad are into building their own electronic stuff (made many amps, speakers, computers, tvs over the years etc) so soldering iron and the rest are in the garage! Although we don't have an oscilloscope (hope that's how you spell it) but I guess I could get one off ebay!

Anymore advice is very much appreciated!

[c2cthomas]

Well huges - if I may call you that (perhaps there is something you prefer) it sounds as if you have a great resource at hand in you dad and granddad (I'm most likely about his age) as it seems that they have been at this "electronics" hobby (occupation for some) for quite awhile. I'm sure that they are a bit of an inspiration to you as - well here you are poking around seeking knowledge - eh? You have received a bit of advice from the esteemed Mr. AndrewT - follow it - and anything else that he might be so kind as to contribute. If my old friend Nelson should show up be prepared to expand your level of knowledge seeking to the "Zen" level - as I have yet to meet anyone who understands electronics theory (pertaining to audio electronics) better that he.

To the business at hand: O'scopes (short for oscilloscope) - my favorite tool for active circuits. Tektronix is my preferred manufacture and you can get a used one cheap. A two channel 20 or 40 MHz scope is all you will need for audio. Audio Signal Generator - very nice to have - HP and GenRad make the nice ones. Multi-meter - I have a Digital Multi-meter (DMM) as well as an analog one. The analog is nice to use when setting the trim pots used to bias transistor amplifiers. I like to be able to see the needle swing when I'm in there messing about "tweaking" on things. I prefer to use the meters that have a mirror on the scale behind the meter needle. The reasoning for that is to look at the needle in such a way that you cannot see it's reflection in the mirror. You are then "dead on" in front of the meter and the reading will be accurate - unlike a reading taken when your head is not in the proper position. Lastly - learn how to solder well http://www.epemag.wimborne.co.uk/solderfaq.htm#howto
Good soldering skills will save you a great deal of time - bad ones will cost you dearly. A good site for learning a bit about electronics is http://www.bcae1.com/

So there you are - now give it a go - and good luck!

[hughes123]

Thankyou very much! I will inform you when I get a bit closer to starting (I'm halfway through the design stage at the mo and the schemetics are a little boring!) but thanks for your advice and I'll hopefully get back to you in a couple of days!

Cheers!

[roger antelope]

hey there
try and get a used copy of this book
http://www.amazon.co.uk/Troubleshoot.../dp/0750694998

also visit decibel dungeon
http://myweb.tiscali.co.uk/nuukspot/decdun/

links to suppliers
Farnell,
http://uk.farnell.com/jsp/home/homepage.jsp
Rapid (same as maplins but cheaper, got Alps blues for @ £8)
http://www.rapidonline.com/
RS
http://uk.rs-online.com/web/

For a good intro build see peter daniels gainclone
http://audiosector.com/
and Nicks at Decibel Dungeon
and whatever you do, do not follow the links...
good luck and welcome

[c2cthomas]

Hughes - so you are off designing things already - well you did say that at the beginning and I must admit that I missed it. Looks as if the information I gave you might be a bit below your level of expertise and not really required (well - there will be other times). Andrew and Roger seem to have provided you with some good advice on the technical side of things so I'll advance things to a bit of a higher level than designing - it's the level of conception - the conceiving of ideas - and a chance to see how some of the best brains in audio envision things. When you have some time to spare venture over to John Curl's Blowtorch preamplifier . It is a mental "jam session" about audio design - with some very good players sitting in.

[Leolabs]

Start with this:

http://sound.westhost.com

[gain]

yeah your right we don't get that stuff in the US because it exceeds our maximum quality standards for consumer electronics. in order for a piece of equipment to make the cut here, it first has to be manufactured in sweat shops in 3rd world countries, banged around during shipping at least a few dozen times, and then tested to make sure it will indeed turn into an incendiary device if sine wave tested at full power into an 8 ohm dummy load for more than thirty seconds. then, and only then, will it be allowed into the retail market here in the states

anyways, the G. Randy Slone book is pretty decent as well. there are whole chapters dedicated to input stage design, VA stage design, OPS design, PS design ... even a candid discussion on subjectivism in audio which debunked many long standing myths in the audio field.

there is lots of advanced stuff in there but its mostly written so anyone can understand it even if they don't have a PhD in EE. there's no real heavy duty maths to wade through either, as most if not all of the concepts are described in plain english.

but if you buy only one book on electronics in your whole life, make it "The Art of Electronics" by Horwitz and Hill (mentioned above).

peace