• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

recap for W70s-- need advice!

rogerfederer

rogerfederer

determined amateur
Subscriber
hi,

i just brought in some W70s and am hoping to restore them. pretty rough looking but i think they were sanded down and then never refinished. so the cabs may end up looking OK.

i checked the 4uF cap in each with my Peak ESR meter. it said both were leaky and gave ESR readings of 2.4 ohms and 2.2 ohms.

i read some old threads that suggest the W70s have paper in oil caps. the caps i found have shiny metal covers. there is a picture of one of the caps in this album:

http://albums.phanfare.com/isolated/1Kugmthg/1/6223684

are these a variant of paper in oil or what are they? what should i replace them with? i found some russian PIO caps on the auction site; are those any good?

many thanks!
 
Register to hide this ad
I think I have two 4uf Russian PIOs in a box at home.
I am at work. Drop me a PM and when I get home I will see if I can find them.
Robbin
I will give them to you. I just have to locate them.

I used them for my Altec Santana IIs...I think you may have much better results since
the Wharfedales are a much much better speaker.
 
rogerfederer said:
hi,

i just brought in some W70s and am hoping to restore them. pretty rough looking but i think they were sanded down and then never refinished. so the cabs may end up looking OK.

i checked the 4uF cap in each with my Peak ESR meter. it said both were leaky and gave ESR readings of 2.4 ohms and 2.2 ohms.

i read some old threads that suggest the W70s have paper in oil caps. the caps i found have shiny metal covers. there is a picture of one of the caps in this album:

http://albums.phanfare.com/isolated/1Kugmthg/1/6223684

are these a variant of paper in oil or what are they? what should i replace them with? i found some russian PIO caps on the auction site; are those any good?

many thanks!
Click to expand...

They look like standard electrolytic caps of the period to me, not paper-in-oil. If you need to replace them, I suggest standard non-polarity (NP) electrolytic caps of the same value, which you can get just about anywhere, from Parts-Express to Allied Electronics. I favor whatever's cheapest and that's what I used in my W70D Mark II speakers. Some prefer to spend more money. That's up to you, but I try not pay more than a dollar for a capacitor.
 
Just a word of caution on the lytics. Be sure to get audio grade caps. Bennic make them. They have a reduced D.F. compared to 'run-of-the-mill' electronics supplier caps. If not Bennics, try to find ones that are <=5% D.F.

D.F. = dissipation factor :-)
 
Wigwam Jones said:
They look like standard electrolytic caps of the period to me, not paper-in-oil. If you need to replace them, I suggest standard non-polarity (NP) electrolytic caps of the same value, which you can get just about anywhere, from Parts-Express to Allied Electronics. I favor whatever's cheapest and that's what I used in my W70D Mark II speakers. Some prefer to spend more money. That's up to you, but I try not pay more than a dollar for a capacitor.
Click to expand...

I gotta argee with Wiggy on this one.
Those caps do look small to be paper in oil. The paper in oil caps in my W60's are 10X that size.
I'm sure GT will be by soon :)
 
I would go with electrolytic non-polar caps. It'll be a cheap and easy replacement. Even if there were PIO caps in there, I'd still replace with electrolytic because paper in oil caps have an inherently high ESR.
 
OK, that is helpful.

i'll take some better pics of the caps and maybe we can rule out that they are PIO. i want to replace them with the same type of cap to keep the sound as intended.
 
Yeah, I guess those could be paper-in-oil. I'm sorry, I'm no help here. I'll let someone who is an expert reply further. Sorry I just can't tell.
 
Sorry, guys... Was eating dinner and checking out the inside of one of my W90 woofer-enclosures (Got the panel open :) I'll be posting pictures shortly).

"Where's Waldo?"......... Too-funny... :D

Nice score, dude. Those look like W70B's (or at least that's what I'm gonna' call 'em for now... These friggin' W** models, man... They make me so-crazy sometimes). The caps have the pio look, but what some people said about the size makes sense, so they must be VERY-early electrolytics (I'm guessing they started using those when they started using ceramic-magnet woofers, but it could just be a coincidence).

You're gonna' dig those, I'm telling you right now. Nice grab. they must be EARLY W70B's because they have the same-style enclosure as the early ones with that funky crooked opening in front of the mid-woofer (I thought that was a sure-fire way to identify the first-generation W70's, but I guess I was wrong on that).
 
Hey GT!

Icenine is sending me some Russian pios so will see how they sound. Talk about karma!

On the back they just say w70. Cabs are pretty plain as are the grills. Supposed to be the paper cone drivers throughout.

Bass was a bit boomy at 1st. Got a bit better as I ran them for a while.

Luckily my wife hasn't seen them yet. Not sure how I'll explain them...
 
rogerfederer said:
Hey GT!

Icenine is sending me some Russian pios so will see how they sound. Talk about karma!

On the back they just say w70. Cabs are pretty plain as are the grills. Supposed to be the paper cone drivers throughout.

Bass was a bit boomy at 1st. Got a bit better as I ran them for a while.

Luckily my wife hasn't seen them yet. Not sure how I'll explain them...
Click to expand...

Wait 'til you get good caps in them and play those for a while. They won't be. The upper-bass should be smooth and effortless when those are working properly.

(You said the existing caps were a bit out of spec, right?)

By the way, be sure to thank Icenine many times for those PIO's. He's doing you a big solid there.

AK'er Brian has a pair of early w70's, and he puts them right on the same level as his Bozak B-302a's, and after hearing both the W60's and W90's from the same era as his, I can see why.

Are the grills removable on yours? I assume not, judging by the pics.
 
You must log in or register to reply here.
Back
Top Bottom