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68.33.3.16
took the cover off and hmm. hell it looks like all the caps are intact in my SP-10 and none of them show any signs of aging, but the signals at the test point on the logic board, (S and T) were way off :(...about 50% out of calibration. So i adjusted them so they are right at the required setting. If nothing else it makes me feel better to know that the table is now running within its stated parameters. If you asked me it sounds a lot more relaxed and stable...almost sounds as it picked up more drive...well there is always the maintenance thingie. maybe next year i replace all the caps.
dee
;-D
True terror is to wake up one morning and discover that your high school class is running the country.
quote by Kurt Vonnegut
Follow Ups:
No matter what the caps look like, and I assume they are over 30 years old, they are out of spec.
I have a Denon DP-62L and none of my caps looked like they had any problems. No bulging, no leaking, no discoloration...nothing.
Nonetheless the speed stability bug bit me. The table needed a recapping.
I don't care who makes the electrolytic capacitor, when they are over 30 years old, they are out of spec.
Now...whether the out of spec cap causes an immediate problem is another matter but you are rolling the dice and eventually those caps will fail. Murphy is Murphy and you will end up burning up some hard to find semiconductors that are most certainly expensive to find replacements for.
And all of that was due to the fact you wanted to not replace parts that probably cost less than $1.00 each. Because they "looked OK". How wise is that?
Ed
We don't shush around here!
Life is analog...digital is just samples thereof
But was just too lazy to do it last night....I will do it when i have a little down time, for now the table is stable and sounds better.
dee
;-D
True terror is to wake up one morning and discover that your high school class is running the country.
quote by Kurt Vonnegut
The table just did something real weird. it would not stabilize its speed on 78 for a while, I turned it off and back on now it is fine...
New caps will be in it tomorrow.
dee
;=D
True terror is to wake up one morning and discover that your high school class is running the country.
quote by Kurt Vonnegut
To the best of my recollection, there are 21 or 22 lytic caps to replace, but they are very accessible, and a shortcut is to leave the "legs" of the old caps in place in the circuit board. Just clip off the old ones near the body and solder the new ones to the old legs/leads. It took no more than one long-ish evening. Then you'll feel so good about yourself.
Took me a total of about 4 hours, replaced all of them. Getting the driver board out was the most difficult step, the rest was just screwing things in and out. I desoldered each cap and replaced each one of them with the equivalent voltage and value. I did some research and bought the caps with the lowest ESR and ripple current i could find. I still ended up with most caps that are smaller in physical size than the original caps, i guess they figured out how to make them smaller. Listening to my new and improved SP-10 as we speak.
dee
;-D
True terror is to wake up one morning and discover that your high school class is running the country.
quote by Kurt Vonnegut
My D-62L started with some intermittent speed things. I started to notice a piano note wavering...stuff like that.
Again, IIRC, the DP-62L has about 40 electrolytic caps. I replaced them in about 10 hours work (over the course of two nights). It's important to observe the type of electrolytic cap being replaced. Most of them use a two to three letter designation code to let us know what type of cap it is.
I think there were about 4 non-polarized caps (this was done some years ago) and two coupling caps.
On the D-62L I initially missed the coupling caps C1 and C2. Those are "tape head" feedback to the microprocessor. I used general purpose electrolytics and coupling caps were required.
Yeah, I should have known better but the human thing invaded and I was stupid again. I pulled out the general electrolytics and put in Nichicon FG caps...fixed.
Ed
We don't shush around here!
Life is analog...digital is just samples thereof
I should have qualified my remarks by stating that I was working on an SP10 Mk2 circuit board, not a Denon. Also, so long as one observes polarity and the capacitor values (replace a 10uF with a 10uF, etc), and so long as one uses electrolytic capacitors of the same or higher voltage rating compared to the originals, everything should be OK. I don't think letter codes mean much; they are used by manufacturers to denote something about construction, usually. Of course, one also must replace nonpolar electrolytics with nonpolars. Film caps in general probably do not need to be replaced. The additional up side of doing this is that modern electrolytics are superior to those that were made 30 years ago.The term "coupling capacitor" refers only to the job that the capacitor is doing in the circuit. Any kind of capacitor can be used in a coupling application. In this case, one would want to replace like with like. So if your Denon called for a non polar or a film capacitor as a coupler, then a general purpose polar electrolytic would not be the best choice. But in fact it would work.
Edits: 11/18/14
Out of curiousity, how did you determine that the caps don't show signs of ageing? It's hard to determine when they are soldered on the board. It's a big job, but given the age of the unit, I would be inclined to swap out critical caps whilst you have the thing apart. You won't be able to determine from a visual inspection (apart from extreme cases where bulging of the pressure relief casing is seen or the cap has completely failed. You will need to determine the ESR which increases with age and confirm the capacity. The fact that your voltage references were out of spec could suggest that the caps are out of tolerance, but the control system was still able to do its job.
Regards Anthony
"Beauty is Truth, Truth Beauty.." Keats
None of them were leaking, discolored or bulging , and the table adjusted just fine. All the signals i checked were OK. So i elected no to swap them out this time. The caps are not all that stressed in this design. All of them way over specified, so it is likely that they last a lot longer than they lasted in the PSU which had caps that showed signs of aging eletrolythics one leaked and all the seals were a bit pushed out. so i replaced all those some time ago. ...It is not that difficult to get inside of the motor unit, so if i am doubtful of the results i can always just go in and take care of the caps. It takes a total of 5 screws to take out the unit and a total of 9 screws to take the bottom off. But getting all the boards out is a different story. it is a bunch of screws connectors posts, etc.....So i decided to try adjusting it first, and if that fails replace all the caps. So far it sounds fine.
dee
;-D
True terror is to wake up one morning and discover that your high school class is running the country.
quote by Kurt Vonnegut
Edits: 11/15/14
Fair enough! :)
I know what you mean about getting the board out. I'm in a similar position with one of my two Technics SL1200Mk2s. The one I bought in 1996 - the platter goes into a runaway condition because a component has failed. Since it's a pain to get at, I bought replacements for all the possible culprits (transistors). The fact that a transistor failed suggests something else around it failing.
With this in mind, I was more urging caution to avoid any other component failures in your SP10! However, glad that recalibrating your deck has improved things :)
Regards Anthony
"Beauty is Truth, Truth Beauty.." Keats
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