40 year old electrolytic capacitors designated LL

62vauxhall

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#1
LL meaning low loss or low leakage I believe? Can a modern general purpose be sufficient to replace an LL electrolytic from the mid 1970's?

The chore at hand is not mine, it's an aquiantance's. An Akai GX-630D open reel deck with a playback problem that has (soon to be had) a raft of 2SC458 transistors which I am in the process of replacing. While I was at it, I thought it would be an opportune time to replace the electrolytic capacitors on the record and playback boards. A few are desgnated LL. I have on hand all the values necessary in appropriate voltages but think they would be considered "general purpose".

Can a 40 year old low loss/low leakage capacitor be replaced by a modern general purpose one? I'd like to use what I already have rather than make an online purchase of just a few capacitors.

At sometime I read that newly made electrolytics can at least meet specs of old "hi-grade" ones.

Photo shows filth inside. As mentioned, it's not mine.

IMG_4788.JPG
 

Gepetto

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#3
LL meaning low loss or low leakage I believe? Can a modern general purpose be sufficient to replace an LL electrolytic from the mid 1970's?

The chore at hand is not mine, it's an aquiantance's. An Akai GX-630D open reel deck with a playback problem that has (soon to be had) a raft of 2SC458 transistors which I am in the process of replacing. While I was at it, I thought it would be an opportune time to replace the electrolytic capacitors on the record and playback boards. A few are desgnated LL. I have on hand all the values necessary in appropriate voltages but think they would be considered "general purpose".

Can a 40 year old low loss/low leakage capacitor be replaced by a modern general purpose one? I'd like to use what I already have rather than make an online purchase of just a few capacitors.

At sometime I read that newly made electrolytics can at least meet specs of old "hi-grade" ones.

Photo shows filth inside. As mentioned, it's not mine.

View attachment 50817
It depends, are these caps used in a timing circuit or other high impedance circuit? Schematic matters...
 

grapplesaw

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#7
Hi Gary
I might go with a bipolar cap there. Correct me if I am wrong but this looks to be a headphone circuit
 

62vauxhall

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#8
Hi Gary
I might go with a bipolar cap there. Correct me if I am wrong but this looks to be a headphone circuit
Thanks Glen. It's actually the playback amplifer board. There are some yellow caps on the record amplifier board as well but will not begin on that until this PB board is out of the way.

I've only got a very few BP caps on hand and nothing of that value.
 

mr_rye89

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#9
I partially recapped and re transistorized my Akai GX6somethingsomething some years ago and just recapped with audio grade electrolytics rated at a higher voltage and didn’t have issues.

These 70s Akais are not service man friendly......
 

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#10
General-purpose grade and long-life grade capacitors Aluminum electrolytic capacitors are generally divided into two basic reliability categories: capacitors for high-reliability applications and capacitors for general-purpose applications. This differentiation has also been adopted in the relevant IEC standards. In IEC publications aluminum electrolytic capacitors for high-reliability applications are identified as "Long-Life Grade" capacitors. The abbreviation LL is stamped on the capacitors. In addition to the over-anodization as described in chapter 1, further measures are taken to enhance the reliability. Generally, the materials used for aluminum electrolytic capacitors must meet strict purity requirements, and those used for producing LL grade capacitors must be specially selected. The design effort required for such capacitors affects both the case size and the price
 

Skywavebe

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#11
I have used 105*C caps from Mouser to put into these decks and have not had any adverse effects. How many more years do you think these decks will be used for from now 10- 20, 50? Do you think most of us will be using cassette decks in 2071? One must be realistic.
 

George S.

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#12
What's the remaining life expectancy of a 10 or 20 year old cassette tape? Back in the day some of mine died early deaths from being eaten by the old automobile cassette players.
Do they even make cassette tapes anymore? Hope so, as there seems to still be interest there.
They say even CDs and DVDs have limited life as they degrade and aren't eternal. Damn those cosmic rays, they say those can flip bits and corrupt electronic storage.
 

Skywavebe

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#13
It is often though that the tape will give out but really the machines with no heads and no motors will suffer more and sooner. Tape can last as long as machines can as long as the machines are working correctly- you put a $7.00 tape in a boom box that is never cleaned and what do you think is going to happen? Cassette decks in cars are right behind that- I don't know how many I clean the pinch rollers on that were totally brown with oxide and eventually that become sticky and will pull the thin tape out of the cartridge to eat it. The pull out deck for cars were the best as they could be worked on at the bench without taking a car apart. Archive CD as with Gold will last longer but then no one uses them. Again how many CD players will be able to play discs as there are a lot needing parts that were very cheaply made. Spindle motor that fail and the brushes fall off- what did they think this deck was going to do with this motor? Find a motor and put it in and the deck is up and running again. The only problem is the disc height position which needs to be put right or the focus will have trouble.
 

Skywavebe

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#14
I say put better grade of caps in the unit and it will insure the longevity of the deck electronics wise. Mechanically that still has to be dealt with. I train my guys to get rid of any caps that are less than 16V as these are known for failure all the time in large deck not in walkmans but I am through working on them. Don't use Nagravon Chinese caps as you will find out why down the road.
 

CE5 Guy

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#15
I say put better grade of caps in the unit and it will insure the longevity of the deck electronics wise. Mechanically that still has to be dealt with. I train my guys to get rid of any caps that are less than 16V as these are known for failure all the time in large deck not in walkmans but I am through working on them. Don't use Nagravon Chinese caps as you will find out why down the road.

well, if you will not fix them why do you not return them to their owners even if they offer to pay all expenses?

You do not have the right to keep them...just saying.
 

jbeckva

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#16
well, if you will not fix them why do you not return them to their owners even if they offer to pay all expenses?

You do not have the right to keep them...just saying.
You're treading very thin water, CE5 guy... 2 posts, and both of them snipes at Sam, with no other real contributions to this forum. Let's course correct now, please.
 

laatsch55

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#17
well, if you will not fix them why do you not return them to their owners even if they offer to pay all expenses?

You do not have the right to keep them...just saying.

Our PM system works perfectly well for this kind of communication. Hammering on Sam in open forum will not change anyone's opinion of him here...you're wasting your breath CE5
 
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