Technics SU-8011 Receiver - Looking to recap it

[Vinster]

Hi Guys.

I just got this receiver for $30. the function switch was buggered up but I think I have that sorted out. (Testing shortly)

I've read that recapping this unit does it justice and I'm wondering which caps I should be looking at using for the replacements. There is a local electronics store around the corner but the stuff that's there is cheap Chinese stuff... in a pinch it works. But I don't really want to go that route on this restoration.

This amp was assembled in 1979.

I'm not looking to use the best of the best considering on what I paid and overall what this is worth ($75-$100). But I am out of touch on what brands are the cheap, average and what the high end units are.

Here is a link to the specs if you are wondering; http://www.hifiengine.com/manual_lib.../su-8011.shtml

Looking forward to your recommendations.

Vin

EDIT: I've tabulated a caps list.

Value - Voltage - Quantity
6800uf - 42v - 2
220uf - 50v - 1
47uf - 35v - 2
100uf - 50v - 1
100uf - 35v - 2
220uf - 35v - 1
220uf - 25v - 1
47uf - 6.3v - 6
3.3uf - 50v - 2
100uf - 6.3v - 2
47uf - 50v - 2
3.3uf - 50v - 2

24 in total.

[rhomanski]

Re: Technics SU-8011 Receiver - Looking to recp it

As a general rule of thumb for vintage gear, use low impedance for most, low leakage for sky blue or yellow or orange. I use Nichicon from Mouser. They have the best assortment, very few times am I forced to substitute. The KL series is low leakage or low noise, the PW series is low impedance. For bi-polar, I use EP series because they are 105 degree. With the KL series you can usually find them in 10% tolerance instead of 20%. The good news is capacitors have improved so much over the years a general purpose is just about as quiet as a low noise from back then and half as big.

[keeney123]

Re: Technics SU-8011 Receiver - Looking to recp it

Amazingly clean and in order you should have fun.

[Vinster]

Re: Technics SU-8011 Receiver - Looking to recp it

As a general rule of thumb for vintage gear, use low impedance for most, low leakage for sky blue or yellow or orange. I use Nichicon from Mouser. They have the best assortment, very few times am I forced to substitute. The KL series is low leakage or low noise, the PW series is low impedance. For bi-polar, I use EP series because they are 105 degree. With the KL series you can usually find them in 10% tolerance instead of 20%. The good news is capacitors have improved so much over the years a general purpose is just about as quiet as a low noise from back then and half as big.

I don't see a KL series on their website, just KZ, KT and KA. Do you have a link?

This is what I see their offering is. http://ca.mouser.com/new/nichicon/Nichicon-Audio-Caps/

Vin

[Vinster]

Re: Technics SU-8011 Receiver - Looking to recp it

Amazingly clean and in order you should have fun.

Thanks, this will my first of a few amp's to re-cap. this one being the easiest. I am looking forward to it.

Vin

[rhomanski]

Re: Technics SU-8011 Receiver - Looking to recap it

Here you go, http://ca.mouser.com/Nichicon/Passiv...z0zlbmZ1z0yp6m . They are under regular capacitors not audio grade. I have some very expensive equipment and I can assure you audio grade capacitors are pretty much a scam. In the audio path what matters is leakage which causes hiss. Another thing to look at if you have a nice amp is the transistors and diodes. Semiconductors are much quieter than they were in the seventies. If you find a 726 transistor or a 1313, replace it on principle as well as any with the black plague, you know black legs, that's corrosion and an invitation to shorts between legs up at the plastic under the transistor.

[Vinster]

Re: Technics SU-8011 Receiver - Looking to recap it

here are a few questions, I know the voltage on a cap is what it's rated for. But in an audio circuit. bumping up to the next available voltage cause any changes to the circuit?

1)
One cap thats in there is a 47uf @ 6.3v, on mouser they only start at 10v. I know that electrically isn't an issue. but again, what about an audio circuit?

2)
and any recommendations on power caps?

Vin

[stj]

Re: Technics SU-8011 Receiver - Looking to recap it

the power caps are 10mm pin-pitch snap-in type.
rubycon has a good range of those - but they co$t.

the 47uf will be fine at 10v or 16v / 35v (if it's cheaper)

[rhomanski]

Re: Technics SU-8011 Receiver - Looking to recap it

Bumping it up to 10v will make no difference. Just keep an eye out for bi-polars. I usually make a drawing of each board showing each component and polarity in reference to each other so I don't make a mistake. Get a cheap meter with Hfe if you change transistors because sometimes you'll get some with the same number but the legs will be swapped. Instead of ECB the new ones will be EBC. It can get more confusing if your substituting transistors.

For the large power filters I have always used Panasonic T HA series but they recently started discontinuing the ones I used.

This will work I think. Measure the originals and see if it's too big around. http://ca.mouser.com/ProductDetail/N...qbmxvr0mMJ4%3d .I'll tell you one thing, if you lose that double transistor in picture 4 you'll have a time finding a replacement. I bought the last Pioneer had a few years ago I got a few more from little diode but that was the last as far as I could find. A sub can be made but it's more trouble.

[rhomanski]

Re: Technics SU-8011 Receiver - Looking to recap it

Sorry STJ, posted at the same time. Didn't mean to step on your toes.

[Vinster]

Re: Technics SU-8011 Receiver - Looking to recap it

I didn't realize that they were snap-in type. I was thinking of getting these

http://ca.mouser.com/ProductDetail/N...aX95u8F7QVc%3d

but the ones you recommend has a lower leakage current and 3x the life.

it's worth the extra buck.

Vin