NAD 1155 / 2200 Upgrades

OK here we go. The op-amp IC301

Mouser carries several AD823's. Is below the one to get?

And, I want a machined DIP8 socket that will do nicely. Below is an idea for the DIP8 socket, too, if you could take a peek.

I don't ever plan on trying any op-amps other than the planned AD823 substitution in this unit (but you never know someone else could inherit it and want to put something else in there).

AD823ANZ
110-93-308-41-605000
 
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Answering my own question here. AD823ANZ (from among Mouser's AD823-offerings), IS indeed the one to get (all the other of Mouser's AD823's are "SMD/SMT" = surface mount, i.e. not through-hole).
 
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Your welcome Spencer. Everybody posts the one style of dip socket. I can't afford that. And those type can really grab the legs of the IC's, making it harder to change the IC. The one I posted has been used where I work for years. I work for a small electronics firm producing temp controllers, temp sensors, custom electronics for customers.
 
Update: 1155 mostly done. Sounds fantastic. Definition and bass are much better now. Love the phono section. Getting ready to do the 2200. Thanks.
I did mine in stages also. I finished up with the tone section, that really pulled everything together and balanced it out. I am still amazed at the impact of changing out a few components made it into a completely different preamp.
 
I did mine in stages also.
I do no more than say half-a-dozen components, then power her up.

Poop one out there jay bo -- see where we is. (WWII mortar crew lingo? -- an older guy I used to work with -- retired preacher -- liked to say that.)

Otherwise potentially get oneself in a mess if you get too far down the pike before you find out that something took a wrong turn somewhere way back along the way.
 
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Could someone take a look at the following background and question and give me your thoughts?

Background: Pilot said, "... replaced the Class G switching diodes (S6K20) with Schottky power diodes (MBR10100). These mods got rid of a huge switching glitch when the amp went into high power mode. Now it transitions smoothly."

D329-332. These would be the commutating diodes eh. Term from pages 111-114 Bob Cordell's book for your reference Class G Operation.

Question: I have some MBR10100G's. Put 'em in?



Links leading to datasheets 'n 'at.
https://www.datasheets360.com/part/detail/s6k20/-3142856685134297292/
http://www.weisd.com/test/GenericParts_WEISD_view.php?editid1=S6K20
https://www.mouser.com/ProductDetail/ON-Semiconductor/MBR10100G?qs=3JMERSakebrmlzTWRmdCeA==
 
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Thought people might like to see a picture of one of the main boards after done. The new trimmers are so helpful. Love the test points they put on the two main boards for you on these model 2200s. What a nice touch. Look an inch behind the right-hand trimmer (blue rectangle) -- the little clear plastic rectangular base with two posts sticking up out of it. Nice.

NAD 2200 After.jpg
 
Couple more porn shots for the deviants. You know who you are.

Aforementioned DIP socket and new IC. I really like this socket. I used it in the NAD2200, too. Thanks again NAD80.
NAD 1155 After 2.jpg

Equalizer
NAD 1155 After.jpg

Power Supply (hand printed fuse ID label is 'factory')
NAD 1155 After 3.jpg

Headphone
NAD 1155 After 4.jpg

It's all on one board
NAD 1155 After 5.jpg
 
It's early to say but I have these set up now with a NAD 4155 tuner and a pair of Infinity CS 3006. After only a first few hours of listening -- sounds wonderful. Tremendously improved. Thanks everyone for your help on this project. I am most grateful to you.
 
The power amp proved to have a bad relay. Replaced relays. Back in business.

Now I'm playing these guys through some Mission 770's. Crazy good sounding.

Parts and visuals below.

Notes:
- cover on wire ribbon clip easily unlatches and swings up so you can free; and,
- replacement relays are sealed units.

SRKU-1CT-SL-24VDC (source these through "Newark element 14" -- requires enlarge slightly two through holes in your PCB)
R413 470 Ohm 2W change to 240 Ohm 2W 660-MOS2CT52R241J
NAD 2200 Relay 1.jpg NAD 2200 Relay 2.jpg
NAD 2200 Relay 3.jpg NAD 2200 Relay 4.jpg
 
Thanks for word on the 737R's. Wondered on those. Also wondered on recap. Like these 770's very much. Still new to me. The dust caps were both mooshed and a faded shade of red. I replaced with new, black. Don't know if will recap. A Limey expat fellow AK'er recommended the 770's... Best he's heard for accuracy. He is a little biased though, you understan. You no. Dem Limey's.
 
Check the caps on those 770s. Mine were right on the other side of the speaker connector. DSC02131.JPG Found both caps were high in value, but the ESR of the caps limited the signal to the tweeters. Replaced them and the tweeters sounded better. Replaced them with film caps from Parts Express. Used Dayton 1% films on sale. Matched exact value for replacement. I'll bet it was leesonic who recommended the 770s. Great guy that one.
 
OK. Will do. Thank you. I'm sure crossover on the 770 model is located right on the other side on of the panel, too. Panel on the 770 is located on the underside in the base of the cabinet. Not the best design. To fit into low stands specific to the model that permitted the wires to come straight down from under there. Clean look on the back.
 
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Was told on the 737R the front can be removed by removing the plastic pieces that hold the grille on. Then taking out the screws in those holes that holds the front to the rest of the speaker. Trying to do this by memory. Can't find the web page I found this information on.
 
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