Looking for my first/last bench multimeter

[G0HZU]

If you can live with the basic looking fonts of the 34401A it is probably the best all rounder, but these meters are getting quite expensive to buy used. If you buy a Keithley 2000 then make sure the display is still fairly bright as they can fade over time to become very dim.

How is the 34401A different form the Keithley 2000?

I'm not quite sure what you mean by different, but in terms of using them everyday for bench use, the display fonts of the 34401A are much bigger and easier to read. So this helps make it much nicer to use. I don't think there's much between them in terms of accuracy, but other people will know more about that side of things than me. The 34401A looks and feels a bit flimsy and cheap compared to the 2000 but this improves if the rubber boot surrounds are fitted.

If the choice is for a second luxury bench meter that mainly gets used for logging and critical measurements, I would opt for the Keithley 2015THD as it offers the DSP modes and it can measure SINAD and THD and it also has a built in audio source that is quite accurate.

If it helps, I've got one of each of these meters, a Fluke 45, a Keithley 2015THD a Keithley 2000 and an Agilent 34401A although I've only had the 34401A a couple of days. I've used lots of 34401A meters at work though. For me, the Keithley 2015THD is the most versatile meter but I couldn't tolerate using it as an everyday meter on the bench. The Fluke 45 is much nicer to use in this respect.

[G0HZU]

I guess the other thing to consider is how annoying each meter can be to use.

The Fluke 45 is annoyingly slow to auto-range on resistance, it takes about 2.5 seconds to make an auto reading of a low resistance for example. The 34401A takes maybe 0.3 of a second and the Keithley 2015THD appears to be instant.

The Agilent 34401A display has an annoying  'blinking star' refresh indicator on the display and if left on DC volts (with floating test leads) the display digits will constantly change about 3 times a second along with the blinking star. This might be OK for some users but I find it distracting. The 34401A also emits a slight hum from the internal transformer.

The display digits of the Keithley change fluidly all the time when the leads are left floating so it can be distracting as well, but the fluid nature of the display isn't as annoying as the 'three updates a second' 34401A in this respect.

The display of the Fluke 45 settles fairly quickly to a static display reading and is much less distracting than the other meters. I guess this is because it has a 10M ohm input vs the ultra high input Z of the other meters?

Some people may have the opposite view, they might like the look of a meter that always looks busy even when not in use.

[tautech]

There are several things outdated bench meters can't do:

Sure, but do you need them to? 

And who hasn't needed to test an LED ? 

Point is, older instruments have design constraints that inhibit usefulness.

[alm]

There are several things outdated bench meters can't do:
https://www.eevblog.com/forum/testgear/cant-test-led-with-hp34401a/

There are several things some outdated bench meters can't do. The Keithley 2000 diode test has 3V and 10V ranges with different test currents. And only some newer meters can measure diode drops that high. So some older meters can do it, and some older meters can't. And some newer meters can do it, and some newer meters can't. What's your point again?

The main advantage I see for more modern meters is the graphical display and software which allows histograms and trend plots. Downside is worse performance (resolution, stability, accuracy, reading rate) per $, and sometimes less reliability and stability (like the Keysight meters that lose their front panel firmware). Also generally less maintainable. Does Siglent publish calibration and adjustment procedures and commands for their bench meters? I would rather buy a used HP 34401A where full schematics, service documentation and a lot of discussion about their repair is available, then a used Rigol or Siglent meter where the only option may be paying for repair if they even offer that service to someone who is not the original buyer.

I like the Keithley 2000 for its speed. It will auto-range and settle on a reading much faster than any other meter I've used. The nice thing about 6.5 digits is that if the bouncing between range when the leads are unconnected annoys you, you can just set it to the 100V range and still have plenty of resolution for most measurements. Same with the current ranges to get lower burden voltage. Or resistance ranges for a lower test current. But my main meter for repair is a Fluke handheld. The bench meters tend to get used for more static jobs where the leads are hooked up using clips like monitoring power rails. Or when I need its extra features like speed or a variable continuity threshold.

[tautech]

Does Siglent publish calibration and adjustment procedures and commands for their bench meters?

No but manuals need updating to show the User adjustment feature.
Calibration verification steps and recommended equipment is all listed in the service manual and a Defpom video takes you through the steps required to make and save adjustment/corrections:

[Wallace Gasiewicz]

I do not know what you mostly do with electronics. 
I mostly fix radios and test equipment. the TE I fix is stuff I buy cheap and I think I would like to have.Over 95 % of the time all I need is my hand held Fluke 4 digit and a BSIDE component tester.   When measuring volts ohms etc   We are not discussing SA or Scopes here.   
I have two HP 3456 units that I have fixed and they now work well.   Then I had to buy a volt source and a resistance box (good one but not Metrology grade) to make sure these things work.   
Then I had to get the volt source Calibrated. Not Cheap.     
I also have two HP LCR meters.   For more exacting measurements.  And a General Radio LCR Bridge....And MORE...   
Sometimes I get nostalgic and drag out the old analog multimeters for fun. Sometimes I need the old meters because they can measure Kilovolts, they also have the high volt leads.

All of this finally dawned on my little brain that I was "Going Down the Rabbit Hole"   
But it was too late. 

If you really need a very good bench volt ohm meter you need to include in your budget some money for periodic calibration   
Please consider the probable time cost of fixing old equipment also. This may or may not be important if it is your hobby. 
Also consider the cost of proper test leads for fancy equipment.    IMHO this is something that most people do not have, even when they have good equipment.

For most measurements I prefer a separate Multimeter and separate component tester. Just my opinion.  Also cheaper;

Please note that the people who respond here are extremely knowledgeable about their instruments and are very helpful. They typically know a lot about the modern equipment.   
Surely more than I do.

[Fried Chicken]

How about being a little less obsessive and go for a 4 1/2 digit meter?

I ended up getting a Fluke 45 and am now figuring out how to get it calibrated.

The only reason I was looking at 6.5-digit DMMs was because I saw a keithley 2001 locally for $300

[J-R]

Is the Fluke 45 autorange speed for resistance faster if you select F rate vs. M or S?

[Smokey]

How about being a little less obsessive and go for a 4 1/2 digit meter?

I ended up getting a Fluke 45...

... it begins!
Next thing you know you'll have a rack with multiple Keithleys and HPs too.... Then come the power supplies...
Welcome to the club!

[Fried Chicken]

How about being a little less obsessive and go for a 4 1/2 digit meter?

I ended up getting a Fluke 45...

... it begins!
Next thing you know you'll have a rack with multiple Keithleys and HPs too.... Then come the power supplies...
Welcome to the club!

Well...:


Not pictured is my analog o-scope (Tektronix Something with Digital Storage.... love not having to wait for a "boot time")

Also not pictured: a DE-5000 LCR meter, a cheap-o LCR meter, and a chinese function generator that's getting sold as the BK Precision is replacing it (although i think it needs service), and my Hakko FX951 soldering thing that I'm not particularly fond of, but gets the job done.

It's my nice little  bench for and and all electronics stuff that needs repairing.