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Question about replacement caps.....


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Here's the setup:  I have a pair of Technics R&B Series SB7's that I bought new from a closeout shelf about 1983. Over the years I'm sure the caps have drifted and things just aren't as sharp as they used to be. Thanks to Jimjimbo, I'll be able to take the SB7's out of service and on the bench.

 

So, I'm looking around on the net. I can match the Farad values but not the voltage. The ones I'm looking for are listed as 100V but the ones I'm finding on line are 250V.  Is that going to make much difference?

 

These old war-horses won't be used for any critical listening but I know they could sound better.

 

Thx!!

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5 minutes ago, Thaddeus Smith said:

What's going on in Indy?

 

We're breaking into HQ having a party for a few hundred friend's. LOL!!!

 

Just teasin'.  Jim's coming down for a day or so and his hotel is right next to HQ. I'm buying one of the pairs of Heresy's he has for sale and it's a good mid point between where we both live. Gonna save me about four hours of driving.

 

 

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Hang on here boys.....Definitely not an Indy novice.  Lived and built houses there, met my wife there, and, shockingly still live in the same state after a rather circuitous route.......Lived in Indy/Fishers probably more than any one place in a long freakin time......I'm thinking Shapiro's deli.....Gigantic corned beef or pastrami on their rye......unless you all have a (doubtful)....better suggestion?, I get down to Indy probably just 2 or three times a year anymore,  or whenever it's a good opportunity to meet a forum member.....I think Indy is a great town, amazing growth and cultural progress in the last 20 years....(can we say thank you! Colts.....)  Yes, a successful football team drove an enormous amount of revenue and enthusiasm into Indianapolis, and in a very important way helped the city  

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Another question for y'all:

 

I'd like to put Sonicaps in this project but I didn't see the values I need on Bob's site. Where is a good source of:

4.7 uF 100V  Film Radial

12 uF  75V  Film Radial

.47 uF 100V  Film Radial

10 uF 50V  Electrolytic

15 uF 100V  Electrolytic

2.2 uF 100V  Film Radial

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On ‎5‎/‎19‎/‎2017 at 7:38 PM, Mighty Favog said:

but I know they could sound better.

 

No so sure.  Film caps like Polypropylene or Polyester (i.e. Mylar) don't drift or otherwise degrade unless abused.  The electrolytic capacitor life is limited by time operating at maximum ripple current rating and its frequency.  That creates heat and that's what dries out the electrolyte paste in the cap.  In filter applications like power supplies this is an issue but in loudspeaker no.  There's no downside to changing the electrolytics with higher voltage ratings the biggest risk being damage to the PC board.   Lead spacing might be different.

 

Vintage Technics is top tier hardware.

 

 

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So if I could get away with only changing out the electrolytic I could still come out ahead? That could save me about $60, I guess.

 

I can't say I didn't crank these things when they were my only pair. At first it was with a Technics SA411 receiver (45wpc) and then with a Carver MX150 Receiver (150wpc). And most of the time I was also running an additional pair of Technics SB3 bookshelf speakers simultaneously.

 

When the Carver finally died, I opened it up and could plainly see burnt residue around some parts. I also had a powered sub (Yamaha SW-2) that also had some burnt parts on its board beyond recognition.

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1 hour ago, UH1dg337 said:

If you want to user sonicaps have you looked HERE  sonic craft has all of those values.

Smack me in the head.....I found that site before and only saw a half dozen numbers......didn't know the list scrolled down! DOH!

 

So, yes, thanks, they do list all the values. Now the bill would come to over $200 for the pair. That's probably more than I want to go. Just doing the electrolytic would be $96 for the pair. I could do them all in Daytons  for that much.

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On 5/19/2017 at 7:52 PM, Mighty Favog said:

 

We're breaking into HQ having a party for a few hundred friend's. LOL!!!

 

Just teasin'.  Jim's coming down for a day or so and his hotel is right next to HQ. I'm buying one of the pairs of Heresy's he has for sale and it's a good mid point between where we both live. Gonna save me about four hours of driving.

 

 

I drove 8 hours round trip to near Houston Friday in order to sell some gear. Driving 9 hours round trip to Little Rock on Wednesday to pick up new gear. :D

 

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