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Old 28th July 2009, 11:59 PM   #101
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Makes me want to take mine out and drive it around the block.

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Old 30th July 2009, 09:27 PM   #102
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here a schematic, that I have make 10 years ago for troubleshooting/faultfinding. There are higher resolution than the online versions. Sound quality is very good after replace all electrolytic capacitors - especially by MC-cartridges with low input resistance - mainly through the common base circuit of the MC head amp at front end.
For the new capacitor devices I recommend only 63V versions, because than there are lower ESR in most cases, in some cases even by half of capacitance value.
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Old 19th May 2011, 12:04 AM   #103
elac310 is offline elac310  France
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Default changing or not also the tantalum caps

Have just bought an SL10; it is noisy (hiss and hum) and I assume it needs recaping.
With reference to the schematic in post 98, is it worth changing also the tantalums (and not just the larger electrolytics?).

Manufacturers argue that tantalums do not age and I'm ready to keep them since they probably participate (some of them at least) in the sonic signature of this preamp. But I'd prefer doing what needs to be done in one go.

Thanks for advice.

Chris
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Old 19th May 2011, 01:07 AM   #104
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Oh yes, do replace them. I believe that there are a few .15uf tants in the the SL-10 that are replaced nicely with a WIMA #MKP2F031501K00JSSD .15uf 250v Polypropylene Film Cap.
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Old 19th May 2011, 03:11 AM   #105
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Quote:
Originally Posted by Forrestc View Post
Oh yes, do replace them. I believe that there are a few .15uf tants in the the SL-10 that are replaced nicely with a WIMA #MKP2F031501K00JSSD .15uf 250v Polypropylene Film Cap.
................. which are out of stock until mid August.

I've re-capped 2 SL-10s and have always left the tantalums alone, as they have never given me a problem. One of these SL-10s acts as my phono stage and it is on 24/7 and is dead silent. My friend uses the other SL-10 in his office system so it is on 8 to 10 / 5 and is also silent.

It is probably a good idea to replace them, but you could live with them until the above mentioned caps are available. The electrolytics definitely will make a difference. A better power supply improves things too.
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Old 19th May 2011, 10:11 PM   #106
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You're right Bill, replacing those old electrolytics are a must, where as replacing the tantalums are not going to make as big of an impact to the sound.

I changed out the factory installed electrolytics to BlackGates a few years back and have never been more pleased with the results.

Another upgrade that really improved the sound of SL-10 was replacement of the nice original Alps pot with a cheap 20k SMD step-attenuator bought off of eBay for $10 USD from a Hong Kong seller. I would have used something nicer, but the space between the PCB and the front panel is very small, and this was the only step attenuator that I found that would fit. I figured that for $10 I would give it a try. I could alway go back to the original Alps. To my surprise, the improvement was almost as great as the BlackGate upgrade. On the other hand, I have no idea how long this cheap step-attenuator will last.

Also, I doubt that Chris will be buying from Mouser since it appears that he lives in France. My guess it that there is a better supply of WIMA products from European distributors than in the USA.
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Last edited by Forrestc; 19th May 2011 at 10:15 PM.
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Old 19th May 2011, 10:34 PM   #107
elac310 is offline elac310  France
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Thank you Bill and Forrest for sharing your experience.
Maybe, I'l proceed step by step after all, and start with the 'lytics.
I believe you recommend those Wimas because of the short lead spacing. Another possibility is to use axial caps (even KP ones) but soldered vertically. Shouldn't take much space either.

I'll keep anyway an eye on Mouser, which is accessible also in / from France, idem for Farnell, Radiospares, Digikey etc.

I look forward to getting this preamp silent since I can't afford much noise on my 4 way high sensitivity speakers.

BTW: does one of you have a pdf of the user or service manual? As indicated earlier, the schematic is available but I usually like to have a manual of the good pieces of equipment that I own.

Best.

Chris.
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Old 20th May 2011, 12:34 AM   #108
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I'm pretty sure I have an owner's manual. If I can locate it I will take it to work tomorrow and scan it to a PDF for you. I beleive I have a sales brochure too.

My power supply is a CRC type with 60,000 uF of capacitance and uses MUR1560 diodes. (The stock supply had 20,000 uF with a small bridge rectifier.)

I used Elna Silmics in my unit. I used Panasonic FMs in the unit that my friend is using.

I think they must have used different pots throughout the product's lifespan. I have a brochure that says they used a Waters sealed conductive plastic. My units were both Nobles, not Alps. I checked the channel to channel tracking and they where within 0.1 db or less through most of the "normal" volume range, so I left them alone. I think I have the same cheap SMD attenuators that Forrestc referred to, but have been too lazy to change them out.

This is a wonderful preamp, and the phonostage in particular works well with my phono setups. I've tried many other preamps, but I keep coming back to the SL10. (I have used it exclusively for the past 2 or 3 years.) Nelson really designed a keeper in this model.

They are definitely worth updating with a few parts swaps. I hope you are able to get the noise out, because there is some fine music left in that unit.
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Old 20th May 2011, 02:52 PM   #109
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Quote:
Originally Posted by MashBill View Post
I'm pretty sure I have an owner's manual. If I can locate it I will take it to work tomorrow and scan it to a PDF for you. I beleive I have a sales brochure too.

My power supply is a CRC type with 60,000 uF of capacitance and uses MUR1560 diodes. (The stock supply had 20,000 uF with a small bridge rectifier.)

I used Elna Silmics in my unit. I used Panasonic FMs in the unit that my friend is using.

I think they must have used different pots throughout the product's lifespan. I have a brochure that says they used a Waters sealed conductive plastic. My units were both Nobles, not Alps. I checked the channel to channel tracking and they where within 0.1 db or less through most of the "normal" volume range, so I left them alone. I think I have the same cheap SMD attenuators that Forrestc referred to, but have been too lazy to change them out.

This is a wonderful preamp, and the phonostage in particular works well with my phono setups. I've tried many other preamps, but I keep coming back to the SL10. (I have used it exclusively for the past 2 or 3 years.) Nelson really designed a keeper in this model.

They are definitely worth updating with a few parts swaps. I hope you are able to get the noise out, because there is some fine music left in that unit.
Thanks again, Bill, for this most useful and interesting input. The CRC would indeed be a very seducive approach especially since the original xformer is rated for 220V (according to sticker on it) and we have here in practice 230-240V or more nowadays; so there is some margin for implementing such a set up without affecting too much the nominal voltages. The xformer is a Hammond, apparently very quiet (no vibration of the metal box at all). One probably doesn't need as much as 75V capacitors as is currently the case, and smaller caps VDCwise might give extra space for a CRC filter if I decided to follow this approach.

In fact, I presume you are referring to the front end power supply (the separately boxed one); did you make comparisons of the results with and without a CRC? the reason I'm asking is because on the preamp PCB, the PS is subsequently regulated so I'm wondering how much such a CRC configuration can add qualitatively (so far, I've always assumed that PS topologies would be either CRC OR regulated but I confess my knowledge is limited as a hobbyist).

The Elna silmics are those I too had in mind as best cost/value candidates for recapping at the moment. So your recommendation is reassuring.

Haven't IDed the volume pot yet; just saw it's a square black one (so could be a noble or an early alps). The serial number of my preamp is like 79....... (year 1979??), so would be an early version. I also have a big multi-position smd pot from Poland in stock, which I intended for a volume box (I hate saying passive pre); but it wouldn' fit sizewise and the current pot doesn't seem to scratch anyway.

All PCB tracks look like they're gold plated, and so seem to be the legs of the transistors (!) etc. The amp is worth its used market price just for the quantity of gold implemented inside if one considers the current metal market price trends (LOL).

From the little I've heard so far and neglecting the noise issues of course, the SL 10 will probably meet the (high) expectations I had when I decided to get one.

Last but not least, I'd be sincerely grateful for any documentation you can dig out. Cheers.

Chris.
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Old 1st July 2011, 05:26 PM   #110
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Default SL10 Documents

Sorry for the delay, but I finally scanned all of my SL10 documentation and posted it here:

https://docs.google.com/leaf?id=0B38...5MDMw&hl=en_US

Hope you find it useful.

Bill
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