Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Dumbmonkey on October 02, 2025, 06:48:26 am

Title: Should I get a tube tester?
Post by: Dumbmonkey on October 02, 2025, 06:48:26 am
Hi,
I found someone in a nearby town with a Hickok 725 tube tester for sale.  What does anyone think about this?  She says it was well cared for, but hasn't been used in years.  Should I consider purchasing this, or a tester like it?  She's asking $200. 
Title: Re: Should I get a tube tester?
Post by: shooter on October 02, 2025, 07:44:32 am
what's your end-game?  bench tech? just the cool-factor?  do you have a scope, since that will come in way more often fixing broke stuff.
most "bad" tubes can be found by swapping, catastrophic fails will be quite obvious.


does the tester come with all the 'ol tubes laying around the tester bench?  score a pile of audio PA tubes, makes the cost more effective.
Title: Re: Should I get a tube tester?
Post by: tubeswell on October 02, 2025, 03:40:51 pm
That tester probably needs a re-cap. $200 you say? She's trying to mine gold out of it.
Title: Re: Should I get a tube tester?
Post by: HotBluePlates on October 02, 2025, 06:02:18 pm
I found someone in a nearby town with a Hickok 725 tube tester for sale.  ...  She's asking $200.

I think you mean "Hickok 752."

If I'm correct, those should easily sell for $400-600.  I would personally buy it sight-unseen (if it is a "752").
Title: Re: Should I get a tube tester?
Post by: tubeswell on October 02, 2025, 07:06:42 pm
Lol this auction says 725a but the book says 752

https://ebay.us/m/jEZbsZ (https://ebay.us/m/jEZbsZ)


Title: Re: Should I get a tube tester?
Post by: Dumbmonkey on October 02, 2025, 07:53:34 pm
Hi and thanks for the replies everyone,
I stand corrected, it is a 752.  I'm not sure if I would really get much actual use out of it, but I thought it might be good to have just in case.  Now I'm having 2nd thoughts, and think it might be overkill for any work that I actually do. 
Thanks again!
Title: Re: Should I get a tube tester?
Post by: kagliostro on October 03, 2025, 12:34:16 am
Don't think about

Get It

Franco
Title: Re: Should I get a tube tester?
Post by: triode on October 03, 2025, 05:15:47 am
I stand corrected, it is a 752.  I'm not sure if I would really get much actual use out of it, but I thought it might be good to have just in case.  Now I'm having 2nd thoughts, and think it might be overkill for any work that I actually do. 

That is completely different. I'll buy it. :)

The 725a is an early model that you do not want. The 752 is a serious tube tester. I have one with a broken selector switch so when I use it I have to be _really_ careful with it.

Honestly, do you have a huge stash of tubes and check them? Matching on a 752 is not _really_ accurate, you would want a maxi-matcher or in-circuit tests for that. After about, I am not sure, 30+ years of fixing amps, I find that my tube tester is something I use on amps in-frequently, but on my large stash of tubes very frequently. I can not advise you to get it or not, but for those of us who use a tester, a 752 is a very nice unit.
Title: Re: Should I get a tube tester?
Post by: Merlin on October 03, 2025, 06:07:40 am
Do you already own an oscilloscope and signal generator? If not, that two hundred bucks would be better spent on those instead! That's opportunity cost ;)
Title: Re: Should I get a tube tester?
Post by: Dumbmonkey on October 03, 2025, 08:03:00 am
Hi,
Now I'm tempted...
I did by one of those $40 oscilloscope/signal generators on Amazon, but I'd really like to know how to use it better for amp diagnostics.  (I got it mostly for the signal generator). 
Any recommendations for an oscilloscope that would be more user friendly, and maybe some info on how to use it with tube amps.  I know there are tons of youtube videos, but if someone has one they like and recommend for newcomers like me, that would be great!
Title: Re: Should I get a tube tester?
Post by: Merlin on October 04, 2025, 05:36:00 am
 
Any recommendations for an oscilloscope that would be more user friendly,
Any bench osciloscope is worth having. Where I live the best value for money seems to be offered by Rigol, like the DS1102, but there may be other bargains where you live. Heck, even the cheap Chinese OEM ones have become 'not that bad' in the last few years.