why a recap makes no difference
- Thread starter yotems
- Start date
steveUK
Active Member
Human beings are not pieces of test equipment. What tests the same may not sound the same, otherwise how would you explain how two different amplifiers that test the same but sound different? All these "doesn't need to be recapped" threads just serve to further cheapen the hobby and put people off paying other people fair money for their time to restore this stuff. I have personally tested known and respected brand caps that are WAY off spec, the sound performance of the equipment surely MUST have suffered because of these. If you're going to pull a cap to test it, why put the 30 year old one back? If it doesn't fail or drift out of spec today, maybe it will next week, or next year? Some of the most respected people on here do this kind of restoration work : @markthefixer, @avionic, @Hyperion, @Leestereo to name but a few. Are you tell me they are ALL wasting their time?
Lee.
You're just mis-representing the 'none total recap' brigade with a lot of the stuff you're saying there. No-one is put off having a set restored by others having a 'no full recap' view - there are lots of restorers who will work on sets and not do a full recap, and vice versa. You say you have tested caps that are way off spec.. er right.. since when was that reason to change every cap in the set? If you remove a single cap as part of a fault finding operation (not a mass swap-all) and it tests fine, then change it or put it back if you're so inclined, it'll work if the cap is good, either way is fine. And also, some of the most respected and knowledgeable people on here do NOT swap caps en masse. On that note, it isn't rocket science to figure out that the so-called "most respected" will be the ones whose methodology is in alignment with the views of the majority of people on here - whatever their view. And the ones who are changing all caps en masse are clearly not wasting their time, they're making a living out of it and giving people what they want.
well ok. but like my example...perhaps everybody should not attempt to rebuild their muscle car engine?
tools, time, experience.
you will throw a stone and hit a lot of people here with the right workbench.
and to top it off, the surgeon generals warning *is* on the back, side or bottom of the machines: no user serviceable parts inside
so you can look at this two ways, average joe gets a machine and it works - he should likely leave it alone, or if it does not work, take it to someone
OR
mr restorer gets a machine and has a phillips screwdriver imbedded where his index finger used to be....gets right to work.
if you are inside, and have a legit reason to be, and you are doing a refresh, restore, rebuild....the caps are a no brainer.
restorer-john
Addicted Member
Failed capacitors are easy to spot, locate and replace. They are either open or short.
Deteriorated or deteriorating capacitors exhibit a rise in ESR and they are just as easy to locate, quickly and without needing to remove them to test (many ESR meters will measure in-circuit). Decisions can then be sensibly made whether to replace some, none, or all the capacitors based on the number of out of spec ESR readings one gets.
Factors that all influence the scope and extent of capacitor replacement:
The age of the item.
The brand and tier of capacitors and their history of long term reliability.
The presence or absence of adhesive in and around the tinned copper wire and solder.
The placement of the vent (old caps on the bottom up against the PCB causing invisible corrosion)
Evidence of previous repairs using dubious component selection.
Inadequate components originally used.
The environment the unit has been used in- hot/dirty/damp etc.
Placement near heat producing components- heat stress etc.
Poor physical placement- damage etc.
Abnormal failure rate for a particular value where there are many the same in the unit.
Desire for a trouble free 20+ years usage.
Desire to have a unit 'freshened' up with nice new matching capacitors.
Person wanting all capacitors replaced.
Person wanting the item repaired only.
Person wanting a full restoration-cost no object.
Person wanting honest advice on what course of action is the best for their piece of gear.
The budget involved.
Lots of factors, lots of different decisions.
Deteriorated or deteriorating capacitors exhibit a rise in ESR and they are just as easy to locate, quickly and without needing to remove them to test (many ESR meters will measure in-circuit). Decisions can then be sensibly made whether to replace some, none, or all the capacitors based on the number of out of spec ESR readings one gets.
Factors that all influence the scope and extent of capacitor replacement:
The age of the item.
The brand and tier of capacitors and their history of long term reliability.
The presence or absence of adhesive in and around the tinned copper wire and solder.
The placement of the vent (old caps on the bottom up against the PCB causing invisible corrosion)
Evidence of previous repairs using dubious component selection.
Inadequate components originally used.
The environment the unit has been used in- hot/dirty/damp etc.
Placement near heat producing components- heat stress etc.
Poor physical placement- damage etc.
Abnormal failure rate for a particular value where there are many the same in the unit.
Desire for a trouble free 20+ years usage.
Desire to have a unit 'freshened' up with nice new matching capacitors.
Person wanting all capacitors replaced.
Person wanting the item repaired only.
Person wanting a full restoration-cost no object.
Person wanting honest advice on what course of action is the best for their piece of gear.
The budget involved.
Lots of factors, lots of different decisions.
Oldsansui441
Super Member
Going by your later post it looks like you have a Pioneer SA-9500ii, l haven't owned one but from what others say they do have a good reputation. Maybe this amplifier just doesn't have that certain synergy with your particular speakers.
I have heard very good things about the A-717, you may have just found the perfect sounding amp for your tastes.
Being from the 80's it may be in need of a freshen up but it might also be that the Pioneer just ticks more boxes for you, hard to definitively say unless both units were brand new.
the dual mono unit i have is actually an nec aua-8000e (mcs 3865) but its got damn near an identical layout as the pioneer sa 9500 ii pictured. i used that picture because its a quality picture of the outputs which are the same as the nec i have. the nec “batwing” outputs.
if the a-910 is in need of a freshen up then the a-717 would be liable for the same age related degration. if all amps were built equally then what would be the point of high priced, boutique quality gear? if all cars do the same thing then whats the point of a bugatti veyron?
if there are speakers out there that in back to back test my a-910 will outperform my a-717, that would blow my mind
the bose 201’s might not be that great but you wouldnt know it with the pioneer driving them. the room the listening space is in is a big wooden floor bass destroying environment. im sure in a smaller room with carpet i could run it in direct and experience the same bass tremors.
the 201’s put more bass through the floor driven by the a-717 than anything ive had in that room hooked to any amount of speakers or size. i think that says something about the 201’s actual ability when driven by the right gear
Oldsansui441
Super Member
The 717 could have age related degradation also, but it depends on many factors l guess, the quality of parts used originally, the usage it has had and the environment it has been in. Sounds like you are very impressed with the 201 speakers.
im not impressed with the 201’s, im impressed the way they sound driven by the pioneer. i didnt think they were capable of sounding so good
the quality of the build design, components, and circuit boards goes to the a-910. its an intricate beast littered with high quality components. theres much more going on in the a-910, way more electrolytics, a lot of circuits for all sorts of stuff. the pioneer has way less componentry making up its density, and the circuit boards dont look as quality. the a-910 came from an easy goin environment and the a-717 seems to be in the same condition.
Ray Gianelli
Super Member
Conrad has, as usual, put it better than I could. Let me just add that the design and also ventilation will have a bearing on capacitor life.
Oldsansui441
Super Member
Oh right, it obviously brings out their best. l have also experienced this with some of my smaller speakers driven by bigger amplifiers
Maybe they are both still in fine condition electronically
.
just dave
vintage rules!
Hmmm I think a lot of people believe this and think they hear a difference.
finally, a rationalization why people buy german cars
volkswagen told me their diesel is 50 % cleaner than the competition so it must be true i saw the commericial with the white scarf exhaust test damnit they wouldnt lie in a commercial just to sell more cars
sonci
Well-Known Member
How do we know for sure that modern capacitors are better than those made in the '90?
Well technology has become better, so they should be better, last more with better specs, but if I look at a modern capacitor, it seems way cheaper than the old one. Especially if you compare a vintage audio capacitor made in Japan, with a new Panasonic built somewhere unknown..
and there are a lot of horror stories, with new capacitors failing way before 10 years.
Well technology has become better, so they should be better, last more with better specs, but if I look at a modern capacitor, it seems way cheaper than the old one. Especially if you compare a vintage audio capacitor made in Japan, with a new Panasonic built somewhere unknown..
and there are a lot of horror stories, with new capacitors failing way before 10 years.
gslikker
Super Member
No reason to think it is better or worse, when life and other specs are exactly the same indeed....
Except taking into account the continuing habit of manufacturers being on "low side"of capacitance tolerance when buying new big capacitors.
Read: less capacitance ---> more current density---> more internal heating ---> less life?
Now if having any evidence newer types are better IF specs are the same, I would be glad to read about it.
In the end, we many times compare "premium brand premium capacitors" against "standard general purpose"capacitors, excluding the low leakage ones.
Except taking into account the continuing habit of manufacturers being on "low side"of capacitance tolerance when buying new big capacitors.
Read: less capacitance ---> more current density---> more internal heating ---> less life?
Now if having any evidence newer types are better IF specs are the same, I would be glad to read about it.
In the end, we many times compare "premium brand premium capacitors" against "standard general purpose"capacitors, excluding the low leakage ones.
c.coyle
Fighting the Dunning-Kruger effect.
Now this is interesting. What is it about the look of a modern capacitor that suggests it's cheaper than a 40 year old gray Elna?
"Gosh, that's small isn't it, no wonder it's cheap - how can that puny little thing be better"?
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