Test & Measurement Equipment for DIY Designers

[dgardner]

Can anyone share what some of the most popular choices are for test and measurement equipment for high performance amplifier design work?

Beyond your basic precision Meters, Scope, Bench Power Supply, etc., what tools are really required to design and evaluate the worlds best designs?

How far can one go with free downloadable software like Right Mark Audio Analyzer and high-end Professional Audio Workstation sounds card? So far, RMAA and an M-Audio Delta 66 has been pretty helpful to me. What does it take to get to the next level?

Budget is hundreds to thousands, but not tens of thousands...

[sam9]

There is Audio-Tester (www.audiotester.de)

after that is Spectra Plus with a Lynx L22 card. A pretty big ticket item but a tiny fraction of the cost of an AP system.

Both of these have the issue that you need to feed the signal back in to the soundcard. For that you need to build your own voltage divider and isolation buffer. The idea of feeding amplifier output in to an expensive but unprotected soundcard should make one pause and reflect before jumping right end.

One way to avoid that is to use an external module such as Picotech's 16 bit unit or the Velleman unit.

[destroyer X]

Auto range functions, average measurements and hold functions are wonderfull.

You can pick audio direct from the first pick up amplifier transistor.... some milivolts of audio frequency are enougth to read.

Wonderfull Multimeter.

regards,

Carlos

[pinkmouse]

I like a proper signal generator for sines and square waves, as the software ones can be a bit noisy.

[tschrama]

I use:

-HP 204D sine / square generator, THD 0.1%

-HP400GL rms AC-voltmeter, measures down to 10uV rms

-DIY 1KHz pure sine generator, THD < 0.0005% (NE5534 wienbridge)

-DIY Distortion Analyzer (www.sound.au.com Project 52 & 59, NE5532), measures THD down to 0.0005%

20MHz osciloscope (about 500$), 2 channel, build in sine-generator

PC with soundcard for spectrographic analysis

I also used to have a scientific grade , calibrated, National Instruments 200samples/sec 16bit DAQ card controlled with Labview software, which was excelent for audio testings.. one day it died on me...


PS
allmost forgot... goldwave audio software, nero CD burning software and a CDplayer for a cheap and simple pure sine generator

[mauropenasa]

Hi all,
A good low cost generator @ band 1hz-100khz and low audio band thd= 0.002% is the Black Star LDO100 ( I use it with an ADC216 Picotech as FFT analizer ).
The quality of the recent PCaudio card ( and of the new software ) allows to get very accurate measures, but is fundamental an analogical interface in degree to isolate the loop GNDS and to adapt the input/output signal levels. the programs indicated by sam9 are interesting and they prepare of all the tools of analysis. In particular, the generators of signals are able to reproduce nonelementary forms a lot of difficulties to produce ( with low THD) with standards generators. If some were in degree to signal a good interface circuit for PC card to high performances ( and with isolation of GND ) I am very thankful...

Ciao

Mauro

[mastertech]

The best audio generator
The best analogue scope
and my pascal analogue simulator

cheers

[mauropenasa]

Thanks mastertech, your contribution to this thread is very important...

Ciao

Mauro

[jackinnj]

Originally posted by tschrama

I also used to have a scientific grade , calibrated, National Instruments 200samples/sec 16bit DAQ card controlled with Labview software, which was excelent for audio testings.. one day it died on me...

the NATI cards show up on EBay very frequently -- I have one which was purchased for about 1/4 the cost of new.

in addition to all the above "honorable mentions" you should consider getting a decent power supply with which to test out your projects. it can be as simple as a Lambda or Acopian "opamp" supply with +/- 15V, or a more versatile tracking supply.

also -- Textronix TM500 and TM5000 test equipment bays are really excellent -- I use one with a PS5010 programmable power supply , a couple of auto-ranging DMM's, pulse generator and an SG505 signal generator. there is a guy in Canada selling vector-style circuit cards for the TM500 series so you could build your own IMD or THD analyzer, tone burst generator etc. I am very enthusiastic about the TM500's because they are inexpensive and very high quality.

[EDUM]

What about the new Terratec Phase-X-24 (Firewire 24bit 192kHz) with Rigthmark Audio Analyzer? For about 350 Euro's it should give great value for money.
Only disadvantage is that this Phase-X-24 has been promised for a long time already....

Ward