NAD 7020 Receiver - Worth a full recap?

Straying off post, apology
Have a refurb'd KA-7100, very decent however sound stage not as wide as CA-800, though bass is more accurate
Have a refurb'd 3140, both KA-7100 and CA-800 are better
Agree on the Luxmans, have refurb'd SQ-505X and SQ-700X. Have an L-480 to do, would like to move up a bit
Big sound departure at Yamaha CA-1010/CA-2010, some would say sterile. The CA-1000 has fuller tones.
Trying to save up for a Sansui 919 or better...
 
Thanks OMGCat!

That's what I needed to hear. I'm not afraid of investing in tools. My shop is full of tools and I use most of them regularly.
I looked at used Hakko desoldering stations, but none of the inexpensive ones I found over a period of time included the gun/iron. By the time I added that, it added up pretty quickly. Maybe I was just looking at a bad time...
I finally decided to get a Hakko FR-300 (self-contained desoldering gun.) I found a USA model, new, for under $240. (The Japan models are all over "that auction site" for a little over $200, if you want to take a chance on it working on US 110V, and don't mind not having a warranty.)
I didn't need one... but it sure takes the drudgery out of desoldering. It's so quick, easy and accurate that it's kind of fun to just pop parts out.
Even if I never use it a lot, it's worth it to me in the convenience... and I can always sell it if at some point I'm not using it.
 
This thread seems to be getting trolled. The OP asked for help about recapping his 7020 receiver, and now it's getting into "this amp is better than that amp" kind of talk. A Kenwood KA-7100 sounds better than a NAD 3140? Refurbed by who? I've restored plenty of both of them, and I would not hesitate to use either of them on a daily basis. NAD were legendary in making a silk purse out of a sow's ear, certainly insofar as the caps they used. The transistors were all good-stuff : Philips, Siemens, Hitachi, Sanken, Motorola and RCA, but they never used low-leakage caps in the signal path like Kenwood, and certainly nothing as nice as Elna's. Do a little upgrading by fitting some low leakage KLs into the signal path, or even Wima films, and the game changes. How is the Kenwood's performance under low impedance loads and peak power? Stereo Review magazine tested the 3140, and found it peaked at 103, 152 and 201 watts into 8, 4 and 2 ohm loads.

I would suggest the OP contact a moderator and have the off-topic threads removed from his posting, mine included.

Lee.
 
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Nice scan, thanks for posting.

Did you order the caps yet? I would use the following :

Phono stage : 401, 402, 434, 424 - Wima MKS2 films. $15 416 - Nichicon KLs, Nichicon KWs everywhere else.
Line driver : 533,534 - Wimas, 521-524 - KLs, KWs everywhere else
Power amp : 603-606 - Wimas, 601, 602, 623, 624 - KLs, KWs everywhere else
Tuner : 218-227 - KLs, KWs everywhere else
Power supply : all 8xx and 9xx caps PWs, main caps can be uprated to 3300uF 50v, KWs or FWs.

Hope this helps,

Lee.
 
Nice scan, thanks for posting.

Did you order the caps yet? I would use the following :

Phono stage : 401, 402, 434, 424 - Wima MKS2 films. $15 416 - Nichicon KLs, Nichicon KWs everywhere else.
Line driver : 533,534 - Wimas, 521-524 - KLs, KWs everywhere else
Power amp : 603-606 - Wimas, 601, 602, 623, 624 - KLs, KWs everywhere else
Tuner : 218-227 - KLs, KWs everywhere else
Power supply : all 8xx and 9xx caps PWs, main caps can be uprated to 3300uF 50v, KWs or FWs.

Hope this helps,

Lee.

Lee,

Absolutely that helps. I haven't ordered anything yet. I was just starting to look at the PS caps in the diagram and trying to get the values from the Service Man. Strange, but the 911-914 PS caps aren't in the parts list of this Rev 2 manual - even though they appear on the diagram. This is going to be a long slow project due to life being busy. I want to put the whole list together to save on shipping. Your list is a huge huge help. I'll post updates.

BTW, this unit came with a broken Bass control. I have a replacement on hand. It's going to be a comprehensive refurb once I get going.

Thanks again.
 
Try not to go off the parts list and concentrate on the schematic. Then verify it with what's actually in your unit. I think I have an Excel spreadsheet somewhere, send me your email address and I'll send it to you. I'm not too fond of posting cap lists here. Too many people getting paid off of my hard work.

Lee.
 
using any browser, go to the home page, www.audiokarma.org, scroll down to the
fifth blue section or the blue section that is titled audio forum, scroll down again
and look for digital docs. click on that and do a search or follow the instructions
for locating what you want.
 
Hi Tim D

I was eagerly looking /reading to see how your project ended?
Old thread I know - but always keen to see the end.

Cheers
Alan
 
Just jumping in here with my first post. I've just completed a full recap and refurbish of an original 7020 - well, I think it's the second revision of the original, but still with the analogue tuner. Can say hands down, recapping an early 7020 is definitely worth it. I've also got a 3020A which I recapped a couple of months ago. Of the two, I think I prefer the 7020 sound-wise - I'd imagine it's essentially based on the original 'Series 20' 3020. It sounds 'bigger' than the 3020A - not as taut at the bottom end, and perhaps lacking in some of the very top-end sparkle, but it's just lovely to listen to. The 3020A is probably more 'accurate', but the 7020 goes to the heart of the music. Whilst recapping, I also took the opportunity of making a slight change around the power supply - there are a couple of regulator transistors and dropper resisters that run quite hot, and they're stuffed in amongst other components, so I've replaced the trannies, and changed the resistors for 2W, mounting both on the opposite side of the PCB and added clip-on heatsinks to the transistors. That way, they have plenty of air around them and they won't interfere with the other components. Maybe overkill - the original design has worked fine for 40 years after all. I also sorted the tuner dial illumination - the original incandescent bulb had long since blown, so lighting is now by a high intensity white LED - works well. Anyway, I picked up another 7020 last week on eBay, which I'll be working on next..
 
Welcome to AK and nice write up. I've got a 7020 in the queue.
Thanks. Yes, I'm staring at the second one on the bench - they're quite a daunting prospect with so many caps that need replacing.. I found myself doing little bits at a time, the daughter PCBs first. It might be a few days or weeks before I get stuck into the second one, been finding myself just listening to records through the first! And the radio tuner is pretty good, too - not quite as sensitive as Japanese kit of the same era, but sounds lovely..
 
Lee,

Found the Rev 2 service manual. I'll be uploading it for the library. The manual indicates that is is for units starting at serial number 7218469. Mine is above that number.
Hi Tim

would you be able to share the Rev 2 NAD 7020 service manual? this manual is almost non existent else where!

thanks in advance
 
From the main Forums page of AK -> Digital Docs -> Here is the database -> "Click on the link in the only post in the thread" -> Brands L-R User Manuals -> NAD -> " On Page 1" NAD 7020 Service Manual Rev_2
 
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