First posts a question on a Multimeter (which one).

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Hi to everybody at DIY audio, this is my first post.

Just a quicky, I'm sure this has been covered many times before but..

I'd like to do a bit of beginner DIY audio. My knowledge is a bit limited but I'd like to get the books and do a bit of study to get back up to speed on electronics.

As a project I'd like to build a power amp and based on my limited knowledge so far I presume some form of kit is going to be a realistic option.

Now birthdays coming up and I'll need some equipment and the families offered to try and sort me out with a multimeter which is nice.

They've asked "which features are useful" so I'd like to know what's going to be useful for a good unit features wise, what brands might be worth considering (I know fluke are good but anybody else?) and perhaps are there any particular recommended models.

I'm based in the UK.

Also I see little basic handheld digital scopes, any use or a waste of time?

I'm aware of 'buy cheap, buy twice..' so I'm keen to get something good.

For instance, is a capacitance measurer a useful thing? 'true rms' any good or not? Etc etc.

Sorry if this has been done to death already many times and thanks for any replies.

Cheers!🙂
 
Though lots of people will swear you need an expensive Fluke or similar, what can actually be more useful for amp building is one half decent one with true RMS measurement, and a couple of el cheepo £5 jobbies as well - quite often in amp building it's useful to be able to measure two or three things at the same time, such as offset voltage, bias and input current. As for the H/H 'scopes, I haven't used one, but others have commented that the limitations outweigh the benefits.
 
Thanks, pinkmouse.

Dads phoned up.. Talking about a fluke 287 meter.

Clearly this is a very high spec multi meter (with a price tag that would mean I could simply buy my amp but that's not the point..)

Anyway for a good reliable accurate meter is that:

A) yes great everything you'd ever need
B) not a great choice for audio use; pick another
C) yes great but lots of stuff you really don't need get a cheaper fluke if that's what you want.

Thanks for the tip that one good meter and several basic ones are handy, thank you.
 
I´d vote for C. you won´t need the logic stuff unless you have other amitions than amps & speakers. I have managed well with an ordinary digital multimeter, and 2 cheepo meters. I use the cheepos for monitoring voltage B+ and Bias, and the good one for current measurements. A voltage rating of 600v Cat2 is sufficient. For testing I would recomend a good computer sound card and one of the free or cheap scope, sound generator, FFt etc. applications, or a used lab scope plus tone generator. If you want to do it like the old guys, you could get a VTVM (vacum tube volt meter) It can do stuff your Fluke cant. Tales From The Tone Lounge; The Incomplete Idiot's Guide To VTVM'S!
 
Harbor Freight has a good cheap meter, then radioShack...Check out the pawn shops as they often have good deals on Fluke meters. you will need several meters as you progress...freq generators/counters...oscilliscopes the list goes on.

E
 
You can go out and buy any cheap VOM right now. As others have said, you will find having a few inexpensive meters around very handy.

After that, you can take the luxury of time to choose a higher quality one. Sometimes doing some DIY and learning of any limitations you come across will tell you what you need in a meter. For example, not everyone needs to be able to measure capacitance, but some people do. That would be an added cost feature not found on most examples.

Fluke is one excellent brand to look at.
 
Get a meter that has true RMS AC voltage measurement. It should support up to 600~1000 V both AC and DC. In addition, a low voltage (mV) range can be useful. Similarly, a DC low-current range can be useful. Must have: AC volt, DC volt, AC current, DC current, resistance, diode/conductivity check. In this modern day and age, I wouldn't buy a new meter without autorange.

A Fluke 73 or 75 would be just fine. Any of the 80-series Flukes would be very, very nice. As would anything beyond that.

I find that my trusty 20+ year-old Fluke 73 gets the job done 99.999 % of the time. If I want higher accuracy, I'll use my HP 34401A 6-digit benchtop multimeters.

I'm not impressed with the handheld scopes. I have an old Fluke 92 that someone threw at me. It eats batteries like there's no tomorrow and the user interface leaves something to be desired. Likewise, I have yet to see a PC-based oscilloscope I liked. Even the ungodly expensive PXI scopes from National Instruments are really not that good (horrible sensitivity, only two ranges, etc.)

~Tom
 
I re-read your first post Eolins, since you want to read and learn it might be a good idea to get a power supply or two. The transformers are usually the most expensive parts of an amplifier build, so having a power supplys to cover filament, bias and B+ supply + a multitap outputtransformer opens up for all kinds of learning by doing.
 
If I tell you the truth, cheap DMMs are good enough for most of jobs. But working with FLUKE is mind blowing for electronic enthusiasts like me and You can count on the measurement you get.
So unless you have very tight budget, why dont you go for a fluke?

TRUE-RMS - Of course you must have this or you won't get accurate readings for your stuff.

Temperature - I really don't think you should waste your DMM for measuring temperature. You can easily build an accurate thermometer using a micro controller. Always build things by yourself. It is fun and you learn 100 of practical and theoretical things during those projects.

Capacitance - There are many dedicated cap meters like Blue ESR meter. But I rarely use my Cap meter for measuring caps. So DMM is ok for that job.

And one valuable addition for your bench. An Oscilloscope. Buy a cheap o-scope and play with it. You might break it 😀 but You will learn things too.
 
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