Amp Swap - NAD 3203

[fitz]

Well, I decided to swap out my 3210 for a 3203.
I'm keeping the custom green tolex & faded grill head shell I re-did, and selling the 3210 in the shell the 3203 came in.
Here's a couple pics from the Reverb listing.

So, the amp showed up today and I hooked it up after work for a trial run.

Pulled both the chassis and got the old head cleaned up.

If you noticed the little SPST switch, it's a cut switch to a lifted leg of C13.
Only works on the clean channel and seems to be a treble cut.

EH tubes - EL34's & a 7025 PI

Here's a side-by-side after the swap.

And the 3203 in the green pyramid with the G215 & the 210 GB/VT-jr. cabs.

Listing pic for the 3210 in the 3203 shell - I'll post a FS thread in the classifieds with a Reverb link.

If anyone is interested, I have some black and green tolex, a few different grill cloths, and I may be talked ($$$) into a facelift...

SOLD - 3210

Selling my 3210. Swapped out the chassis with a newly acquired 3203. Listing at $499 + $49 shipping. Negotiable. https://Reverb(dot)com/item/58598529-marshall-model-3210-lead-100-mosfet-head-1989

www.marshallforum.com

 

[Leonard Neemoil]

Awesome!

Enjoy. HNAD.

 

[junk notes]

oh, hocus-pocus, a swaparama! HNADSwap!

 

[Neptical]

That 3210 will eat that 3203 for breakfast,lunch and dinner. AmiRite?

Why let it gooo @fitz288 ??

I say keep BOTH. It will miss you and it will come back to you...some day. Haha.

 

[fitz]

That 3210 will eat that 3203 for breakfast,lunch and dinner. AmiRite?

Why let it gooo @fitz288 ??

I say keep BOTH. It will miss you and it will come back to you...some day. Haha.

Yes, killer amp, but hard to get the volume past 2 in my 10' x 10' office / 3rd bedroom.
100w is just kinda ridiculous for me.
It was more of an impulse buy during the tube shortage.
I love cranking my 20's, and the 30w fits a little better in my amp mix.

 

[Mitchell Pearrow]

@fitz288
Why you no keep the 3210 ??
Okay I just read your post ..

Cheers

 

[Mitchell Pearrow]

@fitz288
You posted as I was typing..
So I edited my post !!

 

[Neptical]

Yes, killer amp, but hard to get the volume past 2 in my 10' x 10' office / 3rd bedroom.
100w is just kinda ridiculous for me.
It was more of an impulse buy during the tube shortage.
I love cranking my 20's, and the 30w fits a little better in my amp mix.

BOOST CHANNEL! ...with an SD-1!!
ABSOLUTELY superb at low volume.
Without the foot switch, a touch of clean blend for secret sauce.

 

[fitz]

BOOST CHANNEL! ...with an SD-1!!
ABSOLUTELY superb at low volume.
Without the foot switch, a touch of clean blend for secret sauce.

Call me crazy, and I can understand that no one would believe this, but that little amp on the top of that pile is one of my favorites.
The G215 through the pair of 210's - master dimed, gain 1 noon, gain 2 dimed, hit it with a TS on clean boost- rippin' killer Marshall growl.
Absolutely stunning...

 

[Neptical]

@fitz288 Oh, I truly believe you man! You found THAT tone that just does it for you! It's absolutely exciting!

Once I got my first Origin 50 (h) and plugged in to my Soldano V30 4x12 ( boosted with SD-1, RAT, Tumnus), I was like...get.the.fudge...out!
I'm standing there looking at all my Boogies that I had been using for many years and telling myself..' this is the tone, man' .

I won't take away ANYTHING from my JCM 900SLX, JCM 2000 DSL50, DSL100, 3210s or 3315 whatsoever, but a boosted Origin with it's TILT does something NO Marshall I own does. It's truly the one Marshall that replicates the glassiness of my Fender combos. I'm used to the Bassman-ish spank ( which I love) but Marshall completely nailed it with the Origins.

 

[Leonard Neemoil]

Never liked mesa, Marshall ftw!

 

[fitz]

Rolled some tubes today.
The only spare EL34's I have are 2 pairs of CVC (Chelmer Valve Co) that came in my 6101.
Also tried one of my Marshall (JJ) red label ECC83 in the PI.
Wow - warmer, richer tone on both clean and boost.
The E-H tubes are all going to the bottom of the spares pile.

 

[PelliX]

If you noticed the little SPST switch, it's a cut switch to a lifted leg of C13.
Only works on the clean channel and seems to be a treble cut.

That's a fair deal of wire on there, if you're picking up excess noise, you may want to shorten it. I've got a similar construction for a low-pass filter in a SS VOX amp. Also note how it's closing the circuit with that resistor - that should be a capacitor according to the board...

https://www.drtube.com/schematics/marshall/3203pre.gif

I can't quite make out what that should be, 78pF?? Maybe replace the switch with an SPDT and re-add C13 as an alternative to the resistor?

That said - if you dig it, you dig it!

 

[fitz]

That's a fair deal of wire on there, if you're picking up excess noise, you may want to shorten it. I've got a similar construction for a low-pass filter in a SS VOX amp. Also note how it's closing the circuit with that resistor - that should be a capacitor according to the board...

https://www.drtube.com/schematics/marshall/3203pre.gif

I can't quite make out what that should be, 78pF?? Maybe replace the switch with an SPDT and re-add C13 as an alternative to the resistor?

That said - if you dig it, you dig it!

I never checked the schem, and probably can't understand much of anything if I was looking at it.
I was assuming it was just a lifted leg on the stock whatever that electrimical thingamabob is, and that "on" was normal.
Definitely brighter with the switch on.
In the off position, the clean seems closer in overall tone to the boost without the gain.

If anyone can tell if C13 should be something completely different, I may want to return it to stock and leave the "off" switch as is.
I can post other pics if required.

I was thinking the same thing about the wire length, but I don't notice any sort of excess noise.

 

[PelliX]

The schematic is very hard to make out and I can't find a better one for the 3203, but maybe @Jon Snell has one in his archives, per chance?

I was assuming it was just a lifted leg on the stock whatever that electrimical thingamabob is, and that "on" was normal.

Same, then I saw that it was a resistor. You'll notice that the 'beads' are in the Cx positions, those are tiny capacitors. This should have been one of those. The 1/4W "standard" resistors are easy to spot as they have colour bands which denote their value and tolerance and are marked as Rx. There are also some ZDx's which are Zener diodes. Funny sidenote, they've marked the lugs as Lx, where L would usually indicate an inductor. ICx is pretty clear and VRx are the pots (Variable Resistor).

(EDIT: ok, it's 2019 and I've had so time to screw around with the 'Normal Channel', and replacing C13 with a 1uF cap is great to my ears. Nice gain boost, and smoother taper into distortion on the Volume control, and I still like it for a completely clean channel with or w/out the clipping diodes.)

C13 appears to be a bright cap for the normal channel and the target of a lot of mods. Putting a resistor in there might work nicer with some pedals, I could imagine. Maybe that should be 270pF by default.

 

[fitz]

The schematic is very hard to make out and I can't find a better one for the 3203, but maybe @Jon Snell has one in his archives, per chance?



Same, then I saw that it was a resistor. You'll notice that the 'beads' are in the Cx positions, those are tiny capacitors. This should have been one of those. The 1/4W "standard" resistors are easy to spot as they have colour bands which denote their value and tolerance and are marked as Rx. There are also some ZDx's which are Zener diodes. Funny sidenote, they've marked the lugs as Lx, where L would usually indicate an inductor. ICx is pretty clear and VRx are the pots (Variable Resistor).



C13 appears to be a bright cap for the normal channel and the target of a lot of mods. Putting a resistor in there might work nicer with some pedals, I could imagine. Maybe that should be 270pF by default.

Thanks for the link to the 3203 thread by @wakjob - I marked it for reference and consideration.

 

[fitz]

then I saw that it was a resistor.

My electrical knowledge gets fuzzy past wiring up a tone capacitor and some pickups.
Here's some zoomed in shots of whatever is in the C13 / switch thing I got.

 

[PelliX]

My electrical knowledge gets fuzzy past wiring up a tone capacitor and some pickups.
Here's some zoomed in shots of whatever is in the C13 / switch thing I got.
View attachment 112244View attachment 112245

Hmmm, upon closer inspection, that could be an old type of capacitor when they still used colour codes like that. If so that checks in at 470pF, the presumed value from the schematic. I think mystery solved; I need to zoom more and you simply have an on/off switch for the bright cap.

 

[fitz]

Hmmm, upon closer inspection, that could be an old type of capacitor when they still used colour codes like that. If so that checks in at 470pF, the presumed value from the schematic. I think mystery solved; I need to zoom more and you simply have an on/off switch for the bright cap.

Thanks!
If you think it's stock with an on/off switch, then I have no plans to change anything.

 

[PelliX]

I never could remember the capacitor colour codes as I used them so little, but it's the same basic concept as for resistors.

Capacitor Color Code Value Calculator - Online Finder

Tool to find the value of a capacitor. The Capacitor color code is similar to that of resistors and therefore applies partly to capacitors and provides a visual value.

www.dcode.fr

Looks like Yellow, Violet, Brown, Silver, Silver to me. Note that similar to resistors, you cannot actually calculate them backwards.