Can you recommend a tube tester?

[Alsatian]

Greetings! I have need for a preamp tube tester and was wondering if anyone can recommend a good one to buy. I have heard the Maxipreamp testers are good - thoughts on this? Advice is desired. Thanks!

 

[speakerfritz]

maxi pre tester is fine. on the used front a mercury 1000 is a good tester and easy to calibrte. its a deal becuase the guts are famous brand but it gets little attention in a mercury case. last made in mid 70's so it supports a verywide portfolio of tubes. tube data is up on the net.

 

[Alsatian]

Thank you, Speakerfritz. If anyone else has advice, particularly on the maxipreamp, I'd like to hear it.

 

[v4lve lover]

if money is no problem go for an amplitex


if you want something oldskool :
Neuberger 370 375 Funke W20 avro Mk 1 through 4 CT160
Dont forget the metrix U61

If your the King of DIY build your own

 

[radiostar]

Try to find Neuberger RPM370 RPM375 ... great testers and last for centuries ...

 

[v4lve lover]

Yeah those are Beasts, but unfortunately out of many peoples price range.

Your are a user right . could you tell me if the tester requires you to adjust the plate voltage once a tube starts pulling more current ?

I'd like to know just out of curiosity.


V4lve.

 

[Alsatian]

The truth is, V4lve, I don't think so. I just need to test the tubes to see if they are good. I'm pretty new to working with tubes (very new!) but I just inherited a large number of old tubes and I think its wise to be able to test them.

 

[battradio]

An Eico 666 or 667 is a good medium of the road tube tester , i use one as back up to my hickok 539C .

 

[v4lve lover]

i would opt for a I177 tvd7/u if your in the USA it tests quite alot of the old tubes. and is not nearly as junky as some of the other stuff. its also on the cheap end of the scale and gives pretty comparable measurements

Check your tube stash if their TV tubes dont bother you wont recoup your investment . except if some ultra rare sweep tubes ofc..



v4lve

 

[ArtG]

In this day, I’d imagine that most of the tube testers in the US spend 99%+ of their time unused. I consider audio a hobby, and only a hobby. Should you just happen to be located anywhere near south central PA, you would be welcome to bring your tubes, and use my recently recalibrated TV-7 to checkout your “stash”. If it’s geographically impractical, perhaps, there are others that would extend the same offer.

 

[HollowState]

I'm going to agree with speakerfritz and battradio on the Mercury 1000 and Eico 666/667. I own them both and like them. The TV7's are way over priced for what they do and have become a cult item. Full printed manuals with data are available from "glendalemanuals" on eBay at low cost.

 

[soulmerchant]

The Eico 666 is still a bargain, but you have to be careful with the manuals - the early ones are full of errors...

The only downside to the Eico is that it tends to give different readings every time (!)

I also have an avo MKII and have taken the time to restore and fully calibrate it - but I still use a DMM to accurately set the negative grid volts. It gives accurate results if you do this.

Some testers like the avo can be used to create crude plate curves. That is the main reason I have it.

If it is just to test if tubes are OK the the Eico 666 should really be fine.

Lastly - Never buy a tester where the mains plug has been cut off.

Ian

Ian

 

[v4lve lover]

the negative grid voltage needs to be measured by a MK8 avometer ive heard..

Kind regards
v4lve

 

[Alsatian]

Thank you, All, for your guiding advice; you have given me some great ideas and suggestions. Fortunately I have time on my side and I don't have to make any rush decisions. Best wishes and (given ArtG's suggestion) if any of you are located in Minnesota US and would like to loan time, tester, or just expertise, don't hesitate to send me a private message.

 

[soulmerchant]

the negative grid voltage needs to be measured by a MK8 avometer ive heard..

Kind regards
v4lve

Funny! Any true rms AC digital voltmeter can be used if you read the Avo manual and understand how the circuit is working. If the unit is correctly calibrated, negative grid volts set to 100 will give a reading of 52.5 on your rms AC digital voltmeter...

 

[Triodethom]

The Westom 981 type 3 or the heathkit tt1 copy . Had the Weston for 15 years worked well up dated the diodes checked the osc. tube . Price has gone up from the 20 dollars I payed at a hamfest.

 

[TBL]

I ams using a Mercury 2000 tester. It uses one tube and the results are quick. It has one downside, it does not individually test either of the two sides of a dual triode such as a 12AX7. It is a true bargain coz I had mine for something like US$250 including the case and the manual, in a fully working status.