NAD - 3210 (3rd Time's a Charm?)

fitz

fitz

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Picked up this 3210 today from a local CL listing as "not working" (my 3rd one).
It was listed with a 1965A cab as a half stack deal for a decent price.
Told the seller I kinda just want the amp, and someone else told him they kinda just want the cab.
He had a moment of brilliance - I got the amp for $100.

3210.1.jpg

Good shape cosmetically.
V serial #, so 1987.
Looks all original, reverb tank seems intact, and it has the back grill.

3210.7.jpg

Initial look inside revealed a blown fuse.
Pack of T3A ordered, should be here tomorrow.
Begs the question of why the fuse blew...

3210.2.jpg

Here's a full gut shot.
I can post details if anything looks odd.
Didn't see any scorch marks or exploded components.
A few strange things seemed to check out against the schematic I have.

3210.6.jpg

Hopefully the new fuse does the trick.
 
While I'm waiting on the fuse, I got started on making it match the 2556A cab.
The head will probably turn green at some point...

3210.8.jpg

Decided I was tired of the G215RCD, so I put that in the little green headshell.
Posted it on Reverb and sold it in a matter of minutes for a net gain of $95 after fees and shipping.
So far, my math is at $5 for a trade of sorts for a 3210 with a blown fuse.
If further repairs are needed, I'm ok with embarking on a learning experience.

g215.1.jpg

And the 5100 is now living in the old home-made little Class 5 clone stack (inverted).

5100.1.jpg

Hoping to have dueling stereo 100w MOSFETs downstairs in the workshop soon.
 
fitz said:
Picked up this 3210 today from a local CL listing as "not working" (my 3rd one).
It was listed with a 1965A cab as a half stack deal for a decent price.
Told the seller I kinda just want the amp, and someone else told him they kinda just want the cab.
He had a moment of brilliance - I got the amp for $100.

View attachment 102795

Good shape cosmetically.
V serial #, so 1987.
Looks all original, reverb tank seems intact, and it has the back grill.

View attachment 102798

Initial look inside revealed a blown fuse.
Pack of T3A ordered, should be here tomorrow.
Begs the question of why the fuse blew...

View attachment 102796

Here's a full gut shot.
I can post details if anything looks odd.
Didn't see any scorch marks or exploded components.
A few strange things seemed to check out against the schematic I have.

View attachment 102797

Hopefully the new fuse does the trick.
Click to expand...
If the fuse is blown it can be the output mosfet transistors that are shorted. I think I have also seen the zener diodes short out.
 
Brian Krashpad said:
Congrats! That certainly is a great price, good luck with repairs.
Click to expand...
Thanks!

I had a really nice one at one point that had op amp sockets installed and 2604 chips in the 4 main slots.
Sold it to buy a 3203 that I wound up not keeping for very long.

2nd one was also a "non-functional" buy that I got cheap.
Was just going to use the shell for a project, but I cleaned it up and it started working.
Decided to just sell it for what I had into it.

Hoping to keep this one for a while.
Planning to install the op amp sockets to try different chips.
 
Last edited:
Update:

Turns out those 4 mod-looking things are all on the Rev. 7 schematic.
Not sure if it was factory done to use up an old board, or previous owner / tech updating the circuit.

With a good deal of assistance from some guys on MF, I was able to verify most of the board components were testing to spec.
Made a light bulb limiter to run the circuit at lower voltage.
Got a new little tester gizmo and the MOSFETs, along with a few of the circuit transistors all tested fine.

m1.jpgm2.jpg

There was a voltage drop along the negative side and finding the culprit was illusive to a point.
Then while running 20vdc through the LBL, the rectifier (that tested ok on its own) gave up the ghost.

rectifier.jpg

Replacement rectifier came today and once installed; all the voltages started testing as balanced.
Put back all the stuff I had pulled for testing and fired it up.

It's now functioning as it should - for the most part.
Had to replace the normal channel volume pot and I may wind up replacing them all.

PXL_20240907_190738074.MP.jpgPXL_20240907_192114152.jpg
 
fitz said:
Update:

Turns out those 4 mod-looking things are all on the Rev. 7 schematic.
Not sure if it was factory done to use up an old board, or previous owner / tech updating the circuit.

With a good deal of assistance from some guys on MF, I was able to verify most of the board components were testing to spec.
Made a light bulb limiter to run the circuit at lower voltage.
Got a new little tester gizmo and the MOSFETs, along with a few of the circuit transistors all tested fine.

View attachment 103044View attachment 103045

There was a voltage drop along the negative side and finding the culprit was illusive to a point.
Then while running 20vdc through the LBL, the rectifier (that tested ok on its own) gave up the ghost.

View attachment 103046

Replacement rectifier came today and once installed; all the voltages started testing as balanced.
Put back all the stuff I had pulled for testing and fired it up.

It's now functioning as it should - for the most part.
Had to replace the normal channel volume pot and I may wind up replacing them all.

View attachment 103047View attachment 103049
Click to expand...
MOSFET tester , you don’t say.
IMG_0455.gif
 
Last edited:
Mitch Pearrow SJMP said:
Well how’s it sounding ??

Congratulations on your 3’rd one
Click to expand...
Thanks!
Might be too soon to tell, the 3210 is sounding kinda odd on the boost channel, but that one tone knob is suspect and may need replaced.
(kinda mid scooped honk - idk...)
Clean channel sounds great.
Was just A/B -ing the 3210 & 5100, because if you were wondering if I hooked them up in stereo...
1725746537638.png
Together they sound awesome.
 
fitz said:
Thanks!
Might be too soon to tell, the 3210 is sounding kinda odd on the boost channel, but that one tone knob is suspect and may need replaced.
(kinda mid scooped honk - idk...)
Clean channel sounds great.
Was just A/B -ing the 3210 & 5100, because if you were wondering if I hooked them up in stereo...
View attachment 103052
Together they sound awesome.
Click to expand...
I do that with mine and you are not lying, they sound great paired up with any other amp..
 
Wacky side story: I got the G215 back.

It was damaged in shipment and the kid that bought it was clueless about why it didn't work.
I packed that thing so well that I couldn't even imagine what would have happened to it.
Hard to file a damage claim with Reverb when the problem is unidentified, so I sent him a return shipping label that cost me $22.

Got it back and found the problem.
The amp somehow took a blow hard enough to rip all 4 legs out of both of the output transistors.
The board on the little amp is supported by the pots on the front and the heat sink for the transistors on the back.
It must have dropped straight down from a good height and landed flat on the box bottom - there was no sign of any kind of impact on the box.

Well, I filed a claim with reverb with pics of the damage and they refunded the buyer in full.
I got to keep the initial net of fees transaction money, but ate the return shipping.
Everything was covered by their "safe shipping" guarantee that I ALWAYS get for an additional fee.

Might be fixable, but not sure it's even worth trying.
The head shell parts (and logo) are worth more to me than $22, so I'm not upset at all with the eventual outcome.
Seller would have probably just binned it after getting his refund if I didn't ship it back.
 
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