In-Circuit Capacitor Tester
Moderators: pompeiisneaks, Colossal
In-Circuit Capacitor Tester
Call me lazy but i think it would be well worth the money to have an accurate capacitor tester (actual voltages) that didn't require me to remove the cap in order to perform the test. I've been doing some research and i might have found 2 worthey options. The first being the Sencore LC-103 it's a portable/bench unit that analyzes caps in circuit, it can also form caps which is pretty awesome if you have vintage multi cans. Its litle brother the Sencore LC-102 seems to do everything the 103 does minus the in-circuit testing. The next option is the CapAnalyzer 88A series II by EDS, it claims to be the one that everyone wants to be but it's small size worries me that it might not have a strong enough voltage. As well as the readout is in LED color not actual value. If any one cares to chime in.. good, bad or better ideas, at the moment i'm seriously considering trying the ten day trial period for the Sencore LC-103 and if it's really as great as the literature talks it up to be, it might be worth the $2500. It's the illness of perfection that keeps me up at night and searching for better ways to do things.
My Daughter Build Stone Henge
Re: In-Circuit Capacitor Tester
For $2500 I could:
1) Buy a lifetime supply of caps.
2) All the quality goodies I'd need to build somewhere between 2 and 6 amps, depending on #3 and #4.
3) Another decent used guitar of some sort.
4) Therapy to get over the perfectionist tendencies and learn how to count sheep -- IMO, a better investment than the cap tester.
1) Buy a lifetime supply of caps.
2) All the quality goodies I'd need to build somewhere between 2 and 6 amps, depending on #3 and #4.
3) Another decent used guitar of some sort.
4) Therapy to get over the perfectionist tendencies and learn how to count sheep -- IMO, a better investment than the cap tester.
Re: In-Circuit Capacitor Tester
I agree, to a pointPhil_S wrote:For $2500 I could:
1) Buy a lifetime supply of caps.
2) All the quality goodies I'd need to build somewhere between 2 and 6 amps, depending on #3 and #4.
3) Another decent used guitar of some sort.
4) Therapy to get over the perfectionist tendencies and learn how to count sheep -- IMO, a better investment than the cap tester.
If I were super anal about my builds, and I am, and I had a huge budget to buy test equipment, I'd be looking at a similar unit. Unfortunately my equipment budget is spent for the year, so it'll wait.
I don't think that $2500 would be me a lifetime supply of caps though
Eardrums!!! We don't need no stinkin' eardrums!
Re: In-Circuit Capacitor Tester
It's not going to prevent me from buying other items of restocking my tech goodies it's in addition to what I alread have. $2500 in caps might last me a year 18 months tops (depending on values and brands) if you take the shock of the $$$ out of it what do you think of the units how they perform/do the job? Really I'm far more intersted in being able to do it right and in a reasonable amount of time, far more then how much it costs. I can't take my $ w/ me but hopefully some guy will play something I touched and be inspired and write a song that lives on. I've been given a chance to equip my bench (within reason) and want to do it right the first time with equipment that will last and perform for at least 5 years if not 20 with love and care. As for guitars and amps I've collect my shair now i need to keep them all running.
My Daughter Build Stone Henge
Re: In-Circuit Capacitor Tester
Well, now we've got some context, which is very helpful. You see, I build one or two amps a year. Probably just one this year, if any.
You, on the other hand, do lots and lots of building if $2500 is a year's supply of caps. At that volume, yes, you are not building for yourself and the tester might just be the thing to have...or not...
What's wrong with just testing them before you install them? Really, in the bad old days, caps were in tolerance at +20%/-50% (or have it got it backwards -- it makes the point). Some highly desirable amps were built with crappy caps.
You, on the other hand, do lots and lots of building if $2500 is a year's supply of caps. At that volume, yes, you are not building for yourself and the tester might just be the thing to have...or not...
What's wrong with just testing them before you install them? Really, in the bad old days, caps were in tolerance at +20%/-50% (or have it got it backwards -- it makes the point). Some highly desirable amps were built with crappy caps.
cap testers
I have been doing tube electronics since 1958 (man I’m getting old) and there was a time when I believed that having an “in circuit cap tester” was the answer to all my problems.
What I believe now is that the best thing you can do is like they tell guitar players – “go wood shed”. In this context I mean get your hands dirty and work on/repair broken tube electronics. Learn your theory - get solid chops as they say. I can guarantee you without a doubt that if your theory is weak that an in circuit cap tester will drive you crazy and have you doing more soldering/re-soldering than just lifting one end of a cap that you suspect is problem based on solid knowledge.
Guitar amps have simple circuits and good trouble shooting technique will take you farther faster than owning a bunch of high price test gear and minimum knowledge.
Having said all the above I do think a high quality cap tester is a good thing to have for a builder. They are indispensable for matching caps and verifying the condition of NOS parts for vintage rebuilds, checking leakage and what I find most useful is the ability to measure ESR. I have found Electrolytic caps ESR varies wildly. I always go through my filter caps and select for low ESR when assembling a new build. I use the questionable ones for repairs on equipment were it won’t be an issue. I have an older Sencore and I would no trade or sell it. I totally rely on it for blue printing/matching and NOS part evaluation.
As an aside I have a buddy that does commercial/industrial electronic repair and works on a lot of digital machine control systems. He says that there are a couple of in circuit testers that work well on high density pcb and surface mount boards. I believe this is because of standardized design parameter/implementations for bypass, filter and noise suppression caps in theses circuits that permits the design of a tester that doesn’t have to address an infinite number of conditions. He has also told me that he found them not to be as accurate/reliable on discrete component/analog pcbs.
Oh and by the way you don’t need to spend $2500. The Sencore units are on eBay all the time. If you are careful you can get a good one with no issues for less than $600 and if you do get stuck with a bad one you can still get them repaired and calibrated.
Regards
Randy
What I believe now is that the best thing you can do is like they tell guitar players – “go wood shed”. In this context I mean get your hands dirty and work on/repair broken tube electronics. Learn your theory - get solid chops as they say. I can guarantee you without a doubt that if your theory is weak that an in circuit cap tester will drive you crazy and have you doing more soldering/re-soldering than just lifting one end of a cap that you suspect is problem based on solid knowledge.
Guitar amps have simple circuits and good trouble shooting technique will take you farther faster than owning a bunch of high price test gear and minimum knowledge.
Having said all the above I do think a high quality cap tester is a good thing to have for a builder. They are indispensable for matching caps and verifying the condition of NOS parts for vintage rebuilds, checking leakage and what I find most useful is the ability to measure ESR. I have found Electrolytic caps ESR varies wildly. I always go through my filter caps and select for low ESR when assembling a new build. I use the questionable ones for repairs on equipment were it won’t be an issue. I have an older Sencore and I would no trade or sell it. I totally rely on it for blue printing/matching and NOS part evaluation.
As an aside I have a buddy that does commercial/industrial electronic repair and works on a lot of digital machine control systems. He says that there are a couple of in circuit testers that work well on high density pcb and surface mount boards. I believe this is because of standardized design parameter/implementations for bypass, filter and noise suppression caps in theses circuits that permits the design of a tester that doesn’t have to address an infinite number of conditions. He has also told me that he found them not to be as accurate/reliable on discrete component/analog pcbs.
Oh and by the way you don’t need to spend $2500. The Sencore units are on eBay all the time. If you are careful you can get a good one with no issues for less than $600 and if you do get stuck with a bad one you can still get them repaired and calibrated.
Regards
Randy
Re: In-Circuit Capacitor Tester
I agree it's not to be used as a crutch but it is a very handy tool to have. I use an RTA while i mix monitors that shows the SPL and the frequency range it's very useful for a fast attack on frequency issues and priceless for level matching between mixes but by no means can rely on it for your mix. Nothing can replace experience, self confidence and your ear, but it's a huge tool to have when your fixing a mix 75ft away. is it 1.26K or 1.6K that's wanting to run? I'm just thinking that it would be handy to have a similiar tool on my bench for capacitors plus the ability to reform caps with a good function is priceless, at least to me.
Yes they sell the LC-102 on ebay al the time but it's not an in circuit tester. Other wise yes $600 and i would be in business...
Yes they sell the LC-102 on ebay al the time but it's not an in circuit tester. Other wise yes $600 and i would be in business...
My Daughter Build Stone Henge
Re: In-Circuit Capacitor Tester
I just stumble across another cap tester called a cap wizard. This is getting very frustrating cause everyone wants you to believe they make the best so you'll purchase their product, I understand that, but they all seem to do the same function cost about the same $ and all have the same limitation and disclaimer "the only way to know if the cap is truly good is to compare the reading with a known good one" what a way with words. I have a cap tester built into my fluke 867 i just want to make sure i'm not buying the same tester in a different housing.
My Daughter Build Stone Henge
Re: In-Circuit Capacitor Tester
This just showed up today on eBay. LC-103 Resolver(in circuit) with a $850 buy it now.
http://cgi.ebay.com/SENCORE-ReZolver-LC ... .m14.l1318
http://cgi.ebay.com/SENCORE-ReZolver-LC ... .m14.l1318
Re: In-Circuit Capacitor Tester
GREAT EYE!!! I Had my finger on the buy it now button and decided i needed to read it one more time.... it's in singipor and the seller has only sold 8 items. as great as it would be to get that piece for $850 i would hate to throw away $ on a fraud post. It sucks but i'm not comfortable enough to bid. 
Again! GREAT JOB thanks for the link!
Again! GREAT JOB thanks for the link!My Daughter Build Stone Henge
Re: In-Circuit Capacitor Tester
I have an LC-75 and it rocks. Test all kinds of stuff. Inductors, Caps, Forms caps, Up to 600 V. Chased it for months on Ebay and I got one that went off at 2 p.m. Everyone musthave been at work. $300. 
Re: In-Circuit Capacitor Tester
I've looked at the LC-75 it seems pretty sweet they pop up about once a week now on ebay, and calibration is under $100 plus shipping. what have you found to be it's limitations? is it designed more for building amps then repairing them since it's not deesigned for in-circuit testing? maybe i should look into picking up a sencore LC-75 and then a cap wizard for the in-circuit testing?
My Daughter Build Stone Henge
Re: In-Circuit Capacitor Tester
is there a reason other then cost you chose the LC-75 over the 102?
My Daughter Build Stone Henge
Re: In-Circuit Capacitor Tester
OK I GOT ONE!!!
*Sencore LC-102 complete with test leads / battery / bench power supply / calibrated / manual / and shipped 2nd day for $425
*Mid West Cap Wizard with WizCapSavr to protect against stupidity $229
thank you for posting your thoughts and helping point the way!
there is a great LC-75 on ebay at the moment!
*Sencore LC-102 complete with test leads / battery / bench power supply / calibrated / manual / and shipped 2nd day for $425
*Mid West Cap Wizard with WizCapSavr to protect against stupidity $229
thank you for posting your thoughts and helping point the way!
there is a great LC-75 on ebay at the moment!
My Daughter Build Stone Henge