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NAD 1300 Recap/Restoration

I did one of these a while ago. I found some places in the signal path where I could use Wima films. I also upped the main power supply capacitors to 2200uF. Those power supply transistors do get hot, there are no vents in the top of the case which doesn't help. I did consider mounting a small heatsink on the back panel, and mounting the transistors to this.

Lee.
 
Dear all

Thank you all for sharing here, so appreciated!

I have been reading through this tread and tried keeping my head straight, as I am not trained within electronics. I can solder, I have an ESR and a multi-meter and I do understand more than zero when seeing a component on a PCB :)
I have a well-functioning 1300 and I would like to start preparing for a recap. I guess starting by making a list of capacitors to buy.

Would you help me answer some questions to get me started?

1: do I buy all capacitors listed in the service manual and replace them 1:1? I have read that it is only the electrolytic ones that need replacing (the "barrels", correct?).
a) Help me interpret the SM parts list - e.g. why are a few lines specifically listed as "Elect-C"? Or does it mean that this line and the following lines are all electrolytic capacitors? same goes for "poly", "ceramic".​
b) do I leave any capacitors marked "poly", "ceramic" untouched?​
2: are all capacitors listed in µF unless otherwise marked?
3: what capacitors do I buy (brand, type etc.) - people mention various Nichicon types etc. I want good audio quality, but I am not ready to start playing around with altering things.
4: anything about heat tolerance and % tolerance to take into account with the electrolytic capacitors?
5: a thought - can I omit entire sections if I only need phono and 1 input for digital?

What have I forgotten to think of?

My idea is to make a shareable excel sheet with values, comments and source links - may be relevant for later DIY'ers :)
- if a list exists, please share.

The SM I am leaning against is HERE
 
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I have one of these inbound now as well. I'm interested in any recent info on the project(s).
 
as @leesonic suggests beef up the power supply, replace all the electrolytic caps and you might consider replacing the IC's NJM2043 with LM4562
 
There were some concerns with power supply voltage... Has this op amp "upgrade" been confirmed to be viable?
 
Slew rate is three times as high... this should be a very good upgrade... voltages seem to overlap well enough; pinout is the same as well. Drop-in replacement.

Looks to be nine pieces on the board. The parts list has the same description broken into two lines (5&4 pieces) for some reason...
 
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Since I can't get a BoM on this preamp, has anyone used this vendor for one of his "kits"? I'm getting op amps and sockets from Mouser, and would like to get caps as well but with no BoM that is proving difficult, and I'd rather not try to build a BoM from the schematics as that often leads to errors...

www.ebay.com.au

Stereo Preamplifier NAD 1300 Repair KIT - all capacitors | eBay Australia

A good idea is to replace all the electrolytic capacitors with new ones. They also have a low ESR. You can also get the factory service manual to the NAD 1300 as an addition. I will send it in PDF format.
www.ebay.com.au
 
You would be well advised to build your own BOM, these kits, in my opinion, are not very good and expensive to boot. The service manual has more than enough information to generate the BOM. Simply replacing the caps with modern ones and replacing the IC's (use sockets) will significantly improve the performance of the preamp
 
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I don't have the preamp in my possession yet... but I'm building up a BoM at Mouser now.

I have the amps, sockets and relay in the cart; looking at Zeners now...

Thank you for the Quirk link- I'll be reading that through later tonight.

Edit- the power supply caps can be safely increased in value (not just voltage, which I do by default always) correct? Or are their capacitance key to the power supply function?
 
j!m said:
Since I can't get a BoM on this preamp, has anyone used this vendor for one of his "kits"? I'm getting op amps and sockets from Mouser, and would like to get caps as well but with no BoM that is proving difficult, and I'd rather not try to build a BoM from the schematics as that often leads to errors...

www.ebay.com.au

Stereo Preamplifier NAD 1300 Repair KIT - all capacitors | eBay Australia

A good idea is to replace all the electrolytic capacitors with new ones. They also have a low ESR. You can also get the factory service manual to the NAD 1300 as an addition. I will send it in PDF format.
www.ebay.com.au
Click to expand...

Don't take this the wrong way. But there are loads of people on this forum that come on here just looking for BOMs. If you've ever built one from scratch, you will know it can take a good couple of hours, even for a preamp. Most of us build a BOM from the parts that are in the unit, instead of the schematics. So you find yourself arching your neck, using mirrors, even some disassembly just to find out the value of a cap that's sitting under a volume control pot (not talking about the 1300 specifically here).

Then, you come to Mouser, or Digikey. You put in the cap values, hit "in stock" and cross your fingers. More and more regularly, there will be nothing exactly the same in stock. So, should you use a 160V cap where there was a 25V? Or go with a more "regular" cap compared to something "fancy" like a KL, PW, ES etc.? If you prefer Nichicon, you might have to migrate over to a Panasonic, or vice versa.

And sometimes, all the measuring of caps won't prepare you for one that doesn't quite fit. Or you might find some little part that you forgot to order. Or some big parts. I'm currently restoring a NAD 3300 amp, which is sort of like a 1300 preamp and 2400 power amp in the same chassis. I should have just sold it on as-in, because it was working when I got it. But I wanted to try and hot-rod it a little, and the 30 amp peak current output sounds nice. But I'm on my third Mouser order, so that's $24 in shipping costs (3 x $7.99) or $15 if I went SmartPost.

That said, if you need a BOM, I can send you one.
 
Well, I hear you. And I have some stuff on hand I need to sift through as well.

I built a couple Wyn Palmer preamps as well as rebuilt a Kenwood table and the Micro BL-91. So I hear you about parts list not matching. And voltage already higher than the schematic and parts list. Also had to do a few orders to get it sorted.

I’m fine with Kemet and Panasonic films usually. Then I try to keep the same brand across the board for electrolytics, but it does depend on stock often…
 
Take it with a grain of salt perhaps (depending on what suits you), but replace with films up to about 3.3-4.7uF and look for bi-polar audio types when possible until they get too large and either won't fit or become unavailable at the larger capacitances. I've started doing this on my last several recaps and have been very, very happy with the outcomes compared to earlier. The results are consistently good always without any second guessing or going back in replacing ones I don't think sound as good as other ones I have tried and used in the past that sound better. I keep as much of the UES line in-stock at all times above 10uF so I can recap most of the boards with them until 1,000uF at which point they stop. They can be prohibitively large and do not always fit everywhere needed, so keep that in mind. Another good choice is Cornell BPS, it's a new e'lytic which is bi-polar, audio rated and low ESR which is unheard of in bi-polar audio e'lytics and usually the biggest knock against using them. ESR is important, and it's also one of the specs that's not quite as important as everyone thinks it is. I look at distortion under a load as being more relevant and impactful which isn't listed in any datasheets but is always lower in bi-polar caps. Lots of good advice here from everyone, good luck with your next recap.
 
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