Conn 650 Capacitor Identification Please

[ukmusicman]

Hi everyone. I'm having a lot of trouble trying to solve a problem with the Fun-Master on my Conn 650 Type 1. I've solved several electronic faults, but this one has really got me stumped. This fault was there when I got the organ six years ago, but have not got around to tackling this one. Does anyone know what type of capacitors these pictures show. I'm thinking that if I need to replace any of these, I probably won't be able to get any original types, so I might have to buy modern ones. I know that there are different types for different jobs, but not knowing what these ones are makes it very difficult to order any new ones. I have found pictures of all of these on the Internet except the last one which I have included two images of, but no information as to what type they are. Any suggestions would be very helpful.

Also, I am under the impression that the line on some of these capacitors to the left of the info indicates the negative lead, does anyone know if this is correct? Thanks guys.

[Admin]

In order of the photos:
1. Sprague Orange Drop - Polypropylene
2. Mallory - Electrolytic. These from Mallory were junk. Replace
3. Unbranded - Electrolytic
4. Polystyrene
5. Polystyrene.

Of the above, the electrolytics are the most failure prone. I've had dozens of the Mallory type depicted fail. I'd replace them all.

You can replace the electrolytics with virtually any brand electrolytic of the same value and voltage rating. I usually use Panasonic.

You can find NOS Sprague Orange Drops online and they are now manufactured by Cornell-Dublier, CDE, but again virtually any polypropylene capacitor of same value and voltage rating will work.

Polystyrene capacitors are no longer manufactured. You can substitute a metalized film capacitor of the same value and voltage rating. Polystyrene capacitors were typically used in tuning and other circuits requiring high temperature stability. I've never seen one that has failed, but if they were exposed to excessive heat and melted, their value will have changed permanently.

Non-electrolytic capacitors are non-polarized and can be installed in either orientation. The line on these indicates the lead that is connected to the outside foil. If there's a choice, it's best to connect this end to ground, or the lower impedance side of the circuit, as it can reduce hum pickup; however, the construction of modern capacitors has changed and they may no longer have an outside foil and this marking. In that case, it makes absolutely no difference how you orient the leads.

[David Anderson]

Capacitors 4 and 5 are actually Mylar. Polystyrene caps were not made with leads attached like that, and a .33uF polystyrene capacitor would be very large.

The black electrolytic capacitor was made by Callins (EIA code 1068).

[ukmusicman]

Thanks for the quick reply. Very helpful.

[ukmusicman]

Sorry, I have another query regarding capacitor type. I have read on the Internet that the Good-All capacitors used in Conn organs are electrolytic, but I'm not sure this is correct as I was under the impression that all electrolytics were polarized. If this is not correct, what type are they. Can anyone confirm which is correct please? Picture included. Thanks.

[Admin]

That does not appear to be a polarized capacitor. First because there are no polarity markings, and second, because values below 1 uF are rarely polarized.

[David Anderson]

This type will be Mylar (polyester) film and foil. The marked end is supposed to indicate the outer foil end, but they are not polarized in the same way that electrolytic capacitors are polarized.

[toodles]

See this site: https://www.antiqueradios.com/forums....php?p=1984972

It indicates Good-All made mylar capacitors (not polarized). Most capacitor manufacturers made many different types of capacitors, not just one. The technology for capacitors is such that it makes sense to make more than just one type.

[Nutball]

It couldn't hurt to confirm the polarity markings with the type and brand you want to use. Sometimes there's an odd one like tantalum capacitors I think are marked on the positive end, which is really strange, but they are common in modern SMD circuits.

Great capacitor info by the way, maybe we could have a sticky cap info thread?

[toodles]

Unlikely that this is a tantalum capacitor--it looks too old; tantalum capacitors became popular in the mid 1970's, and a 0.68 mfd tantalum would be much smaller. The popular shapes for tantalum capacitors with lead were teardrop and bullet shaped, the rounded end indicating polarity.

[John Vanderlee]

Just an FYI, I found that tantalum DC filter caps tend to fail by shorting out. Therefore, if you ever run into a failure of what looks like the power supply, look for bad tantalums downstream first, if they are used in the circuit.

[David Anderson]

Tantalum capacitors can fail shorted or open. I've actually seen more open ones in Leslie SS amps.

According to a Kemet video, some older tantalum capacitors failed due to a compound used in their manufacture, but current production tantalums don't have that problem.

I don't run across that many tantalum capacitors, but guys who work on studio mixing consoles sometimes have to replace dozens of them in restorations.

[ukmusicman]

After some more delving and correspondence with two people, one being a seller of some very similar types, it seems that the Good-All capacitor pictured in my last post of November 6, suggests that it is a polyester type. In one of my inquiries, the reply was quote "Bad-All dump them". But my Conn 650 which is fifty-one years old and working perfectly except for the Fun-Master, has loads of these with various values and I have not had any trouble with any of them, so they can't be that bad. The only reason I was asking about testing low value capacitors, was because there was this very small one which I was not able to test in case it was faulty. However, I've replaced it with one from a fully working Conn, so that hopefully will negate the possibility of a fault in this particular one.

As the Fun-Master has a fault somewhere, I was in the process of testing everything to try and find out where the fault is. I am waiting for a capacitor leakage tester to arrive so I can test them properly. I don't see the point of throwing them all out in case one or more has a fault, only to find that the problem is still there. Also, it will give be some more experience in fault finding. Thanks for all your suggestions, much appreciated. If I find out where the fault is, I'll post an update.