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PostPosted: Tue Apr 25, 2017 5:40 am 
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Location: the ssauga, ON, CA
and all capacitors replaced? What ever happened to "if it aint broke dont fix it"? And where is the expiry dates on the output transistors and capacitors? Im sorry but its a cash grab total replacing critical original output transistors in lets say a marantz sansui pioneer etc unless they are blown. Before when took things for repair they fixed just the bad trans capacitor and resistor now when you take it in to everyone they want to overhaul the whole thing. Its really unneccessary.


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PostPosted: Tue Apr 25, 2017 6:06 am 
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Location: Kanata, ON, CA
++1


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PostPosted: Tue Apr 25, 2017 6:18 am 
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Location: Milton, ON, CA
I would say just electrolytic capacitors and maybe some resistors.


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PostPosted: Tue Apr 25, 2017 6:19 am 
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Location: Toronto, ON, CA
I bought an older receiver recently that needs some repair. The lights don't work and the speaker relay is malfunctioning. Bay Bloor Radio was unable to fix it (free estimate) because their policy is "no mods, only original parts" as their repair model. I can respect that. I've had several items repaired at BBR over the years and have had excellent results. This is a 40+ year old item.

I was then able to get a hold of a semi-retired repairman who has worked on my model. I mentioned what needed to be done and he said "sounds very repairable".

Then I asked ... "While your under the hood can you maybe replace the caps etc". He was firm about NOT replacing anything that is not malfunctioning, even when I offered to spend the money on it. His take is like the poster above, "If it ain't broken leave it alone". I asked... "Well... what about dried up caps etc?". Still said no. If he sees anything unusual he will replace but other than that .... don't mess with it.

I'm hoping to get the unit to him soon. I guess I'll see what shakes down.


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PostPosted: Tue Apr 25, 2017 7:07 am 
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Robbie California wrote:
I bought an older receiver recently that needs some repair. The lights don't work and the speaker relay is malfunctioning. Bay Bloor Radio was unable to fix it (free estimate) because their policy is "no mods, only original parts" as their repair model. I can respect that. I've had several items repaired at BBR over the years and have had excellent results. This is a 40+ year old item.

I was then able to get a hold of a semi-retired repairman who has worked on my model. I mentioned what needed to be done and he said "sounds very repairable".

Then I asked ... "While your under the hood can you maybe replace the caps etc". He was firm about NOT replacing anything that is not malfunctioning, even when I offered to spend the money on it. His take is like the poster above, "If it ain't broken leave it alone". I asked... "Well... what about dried up caps etc?". Still said no. If he sees anything unusual he will replace but other than that .... don't mess with it.

I'm hoping to get the unit to him soon. I guess I'll see what shakes down.


i dont have much respect for bay bloor radio anymore all they care about is pushing their modern junk and abandoned the vintage audio guy. They forgot who got them there in the first place back in 60s-80s. Its a shame..
your older tech seems like an honest technician i respect that..may i ask how i can get in touch with him?


Last edited by FRAUDBUSTER on Tue Apr 25, 2017 7:16 am, edited 1 time in total.

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PostPosted: Tue Apr 25, 2017 7:11 am 
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Location: Toronto, ON, CA
Transistors replaced?
Never heard of that before. Can you even get exact replacements for old transistors?
Only power supply caps and out of spec resistors should be replacement. If the transistors are shot the item is pretty much toast.


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PostPosted: Tue Apr 25, 2017 7:19 am 
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MENDEL24 wrote:
Transistors replaced?
Never heard of that before. Can you even get exact replacements for old transistors?
Only power supply caps and out of spec resistors should be replacement. If the transistors are shot the item is pretty much toast.


"Output Transistors"


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PostPosted: Tue Apr 25, 2017 7:35 am 
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Location: toronto, ON, CA
Leaky Transistors?


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PostPosted: Tue Apr 25, 2017 7:37 am 
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FRAUDBUSTER wrote:
MENDEL24 wrote:
Transistors replaced?
Never heard of that before. Can you even get exact replacements for old transistors?
Only power supply caps and out of spec resistors should be replacement. If the transistors are shot the item is pretty much toast.


"Output Transistors"


I'll see how the repair goes first. If things work out I'll give you his name. I had to talk him into doing my repair as he is retired and I only got his name from someone.

What exactly is the item you want repaired. I could mention it to him .... see if he would be interested.


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PostPosted: Tue Apr 25, 2017 7:50 am 
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Location: the ssauga, ON, CA
Robbie California wrote:
FRAUDBUSTER wrote:
MENDEL24 wrote:
Transistors replaced?
Never heard of that before. Can you even get exact replacements for old transistors?
Only power supply caps and out of spec resistors should be replacement. If the transistors are shot the item is pretty much toast.


"Output Transistors"


I'll see how the repair goes first. If things work out I'll give you his name. I had to talk him into doing my repair as he is retired and I only got his name from someone.

What exactly is the item you want repaired. I could mention it to him .... see if he would be interested.


get him to check over my 60s receivers


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PostPosted: Tue Apr 25, 2017 7:52 am 
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FRAUDBUSTER wrote:
and all capacitors replaced? What ever happened to "if it aint broke dont fix it"? And where is the expiry dates on the output transistors and capacitors? Im sorry but its a cash grab total replacing critical original output transistors in lets say a marantz sansui pioneer etc unless they are blown. Before when took things for repair they fixed just the bad trans capacitor and resistor now when you take it in to everyone they want to overhaul the whole thing. Its really unneccessary.


There is no need to replace output transistors if they are working, and in many cases it may be impossible to do so.

Think of it like a vintage car you can just fix what's broken or you can do a full restoration back to factory or go for the full on Resto-Mod. All of these have there advantages and disadvantages, opinions vary widely on the subject. Some people believe the designer was all knowing and picked those exact parts for a reason, others believe that the accountants picked the parts. One thing is for certain, the quality and tolerances of modern parts are much better than they were in the 70's and 80's.
As the owner of the piece you are the one that has to decide as you are the one who will be paying for it and listening to the item afterwards.

Personally (unless it has great value as an unmolested vintage piece) I believe that if you change one resistor you should change them all, as putting 1 new low noise metal film resistor on a board full of old carbon resistors just doesn't make any sense to me, same holds true for capacitors, as for transistors unless they are common available transistors (available in enough quantity to be matched) or they are defective, I leave them alone.


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PostPosted: Tue Apr 25, 2017 8:27 am 
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Location: ajax, ON, CA
i have a model 500 kenwood from 1977. over the years i found the volume to be dropping.
the gain of the output transistors was dropping, and i replaced them. it was back to normal then.

other than this there is no reason to replace them.
goog luck
rob


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PostPosted: Tue Apr 25, 2017 12:38 pm 
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Location: London, ON, CA
Output transistors can be checked for leakage and if they test fine, then there is no need to replace them.

As far as electrolytic capacitors, they do in fact have rated lifespan based on hours and operating temperature. They also have a shelf life rating. The ratings are contained in the data sheet for the cap.
There are two main reasons to re-cap a unit.

1) Preventative maintenance. There are parts in vintage units that are no longer available. Capacitors that are operating well past their lifespan risk damaging parts that are no longer available if they fail.
2) Sound quality. Old electrolytic can leak physically and electrically. They also increase in resistance. The combined effect can roll off high frequencies. What some people call the “warm vintage sound” can actually be caused by out of spec electrolytics. The unit can sound slow, too warm and muddy. Recapping can improve high frequency response. Is the unit actually working as designed when operating with functional but out of spec capacitors??

I have had the discussion regarding “if it aint broke don’t fix it” discussion with older technicians as well and I disagree. When these old guys were servicing the Pioneers, Marantzs, Sansui etc they weren’t vintage and parts were readily available. I would hate to see a Pioneer SX-1080 turn into a boat anchor because of no preventive maintenance. There are no replacement output transistors for that unit.

In my opinion, many of the old techs don’t want to re-cap because it is time consuming and hard to make a decent buck from it. I read one well known tech in the USA explain that at the end of the day when he calculates the amount of time into a unit per hour, he basically makes minimum wage. Additionally to check the health of a capacitor; you need to take it out of circuit. Again, very time consuming and little $ per hour. Some people don’t like to pay for the labour in a disposable society.

I provide my customers with options and let them make the decision. If they only want a repair then that is what I do. If re-capping doesn’t add value to a unit then I tell them. If a unit is nostalgic to them and they want it recapped I can do that. If they want it restored I can provide that service as well. For a piece that has value but money is tight, I usually recommend recapping the heat accumulation and protection areas. That means the power supply, amplifier, and protection circuitry. This can be either the protection circuit (DC coupled unit) or the output capacitors (in a cap coupled unit).


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PostPosted: Tue Apr 25, 2017 1:14 pm 
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I bought an HK630 receiver for very little because the output transistors were blown. I was fortunate to find a technician who would take it on, and he replaced the dead parts. The new transistors were not exact replacements. Such things are apparently not available for this unit, which was discontinued in 1974. However to my ears, this repaired receiver sounds better than my other, stock HK630.


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PostPosted: Tue Apr 25, 2017 1:28 pm 
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Location: Toronto, ON, CA
Quote:
The Nostalgia Co


This is the response I was hoping to see. It tells the other side of the story.

I actually can't tell you in all honesty "why" I want to fix up this old receiver other than I love the look, even though I never actually owned one, and I will be downsizing in a few years and would like just one unit with bookshelf speakers instead of floor standers and shelves of separates I have now.

When I do drop off my unit at this guy's place I want to stress I would like to get it back up to spec if possible ... even if I spend money. I guess I'll have to explain that I'll make it worth his while to put the "extra" effort into achieving said goal.

This might be going over board for this thread/post but here's what I have ... it's pretty clean inside?

I have know idea what I'm looking at but it appears that if I wanted to replace caps etc ... geez ... looks like a lot of stuff in there!


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