3210 Chop Job?

[fitz288]

If I found a good deal on a 3210, but wanted it to fit in a smaller (3310) head shell size box, is there room to cut the chassis?
I'm not sure of the exact size of the 3310, but I'd actually like this to be the same size as a DSL20HR.
The chassis width I'm going for would be 18".
Is there room to relocate the transformer, and what ever that other thing is?
(heat sink for the MOSFETs?)
I don't see a problem with relocating the power cord jack, and I can get the chassis end with the mounting flange remounted on the cut down chassis.
But would the other stuff fit?

 

[thetragichero]

yeah i definitely wouldn't do this

 

[fitz288]

yeah i definitely wouldn't do this

So you are verifying that the components can not be relocated?
Is there some sort of a dimensional interference, a wiring impossibility, or is your reply more of a moral objection?

 

[Matthews Guitars]

No, no, no. Don't even think about chopping the chassis. That's the most classless, low rent, ignorant hick redneck thing you could possibly do to a somewhat collectible amp.

Either enjoy it as it is or sell it to someone who won't butcher it and get something more to your liking instead.

At a fair price I'll buy it off you right now just to keep it away from your hacksaw!

 

[fitz288]

No, no, no. Don't even think about chopping the chassis. That's the most classless, low rent, ignorant hick redneck thing you could possibly do to a somewhat collectible amp.

Either enjoy it as it is or sell it to someone who won't butcher it and get something more to your liking instead.

At a fair price I'll buy it off you right now just to keep it away from your hacksaw!

OK, it's a moral objection thing.
There's one for sale on CL near me.
Feel free to save it from classless, low rent, ignorant hick rednecks.

Thanks for completely ignoring my question.

 

[Wildeman]

I can measure my 3310 later if you want.

 

[fitz288]

I can measure my 3310 later if you want.

Thanks!
I'm not sure if the 3310 has the exact same components.
A pic with the rear cover off might show some differences.
Some measurements of a 3210 might also be useful.
Technical feedback would be appreciated.

Probably not worth the effort to rearrange a 3210 to fit a small box, but if it's not impossible, I don't really see the changes as some sort of blasphemous carnage of priceless Marshall heritage.
I might be able to pull off a decent head shell re-build.

I've seen worse...

 

[RLW59]

Not just a moral objection.

Eyeballing it, the power transformer won't fit.

If the drawings are off enough that the transformer would barely fit, you'd have to cut off part of the heatsink, part of the PCB, and extend the hole all the way to the sidewall of the chassis (which would severely weaken the chassis).

Cutting the heatsink would reduce heat dissipation. Plus you'd be putting a major heat source right next to another major heat source. So that output transistor wouldn't be able to dissipate its internally generated heat, plus be absorbing more heat from the transformer.

Moving the transformer closer to the signal path is likely to induce hum and buzz into the signal.

The power socket connections look like they may foul the transformer leads so you'll have to deal with that in some way.
----------------------
The second sketch may be showing an intention to move the heatsink and transistors. That would be better than cutting the heatsink, but the transformer would still be pumping extra heat into the heatsink (and through the sink into the transistor). And the other transistor will be right above those flying wires, again risking heat and noise issues.

The part of the PCB you'd need to cut away appears to have nothing on it, so it's possible. But those boards aren't particularly robust so there's some risk of collateral damage while cutting it.

The weakened sidewall could be reinforced with a gusset when the chassis sections are welded together.

But even if you overcome those issues, you won't know if it'll create unacceptable hum and buzz until after you've chopped up the chassis.

The power switch leads will foul a populated section of the PCB. You'll probably need to move the power switch to the rear panel.
-----------------
With more accurate dimensions and sketches, it might maybe be physically possible. But the thermal management and noise risks are unknowns until after you chop the chassis.

If the chances of success were high, I might have some moral qualms about chopping up a little piece of posterity. But just practically, there are a lot of obstacles to overcome with a high possibility of unacceptable results.

 

[fitz288]

Not just a moral objection.

Eyeballing it, the power transformer won't fit.

If the drawings are off enough that the transformer would barely fit, you'd have to cut off part of the heatsink, part of the PCB, and extend the hole all the way to the sidewall of the chassis (which would severely weaken the chassis).

Cutting the heatsink would reduce heat dissipation. Plus you'd be putting a major heat source right next to another major heat source. So that output transistor wouldn't be able to dissipate its internally generated heat, plus be absorbing more heat from the transformer.

Moving the transformer closer to the signal path is likely to induce hum and buzz into the signal.

The power socket connections look like they may foul the transformer leads so you'll have to deal with that in some way.
----------------------
The second sketch may be showing an intention to move the heatsink and transistors. That would be better than cutting the heatsink, but the transformer would still be pumping extra heat into the heatsink (and through the sink into the transistor). And the other transistor will be right above those flying wires, again risking heat and noise issues.

The part of the PCB you'd need to cut away appears to have nothing on it, so it's possible. But those boards aren't particularly robust so there's some risk of collateral damage while cutting it.

The weakened sidewall could be reinforced with a gusset when the chassis sections are welded together.

But even if you overcome those issues, you won't know if it'll create unacceptable hum and buzz until after you've chopped up the chassis.

The power switch leads will foul a populated section of the PCB. You'll probably need to move the power switch to the rear panel.
-----------------
With more accurate dimensions and sketches, it might maybe be physically possible. But the thermal management and noise risks are unknowns until after you chop the chassis.

If the chances of success were high, I might have some moral qualms about chopping up a little piece of posterity. But just practically, there are a lot of obstacles to overcome with a high possibility of unacceptable results.

Thank you for the reply.
Definitely the issues that I was interested in learning about.
Cutting the PCB would be out of the question - not going there if the components don't fit.
I'm just talking about moving the transformer, heat sink, power jack & chassis side wall.
(I have access to a full sheet metal shop with expert welders that would do the chassis mods for me at no cost)
I wonder how they made it all fit and work on the 3310?

 

[Rokinroller]

Sorry , but NO ! I dont care if whatever fits or not . I would never even think of doing such a thing ! You can do what you want , but I certainly would not . Chopping a perfectly good amp is .... well ..... NOT a thing I appreciate .

 

[fitz288]

Wow.
Didn't intend to start a philosophical discussion.
Never mind, you can all go back to discussing woke slaps, gas prices, political unrest and global supply chain issues.
Sorry I brought up an amp mod topic in the workbench.

 

[Matthews Guitars]

I'd make a new chassis and transfer the guts to the new chassis before I'd chop the chassis.

That amp as it stands is somewhat collectible now. If you don't F it to death it'll only become more collectible and gain value in the future.

But cut it, and it'll forever be stuck in trash tier status.

All because you want it in a different cabinet? Seriously??

I'd suggest that you look for a smaller amp in the same series. Like a 30 watt master lead combo, or a Lead 20. They'll sound the same,
if hooked up to the same speakers. And they're smaller and may fit in your preferred cabinet without cutting anything.

A Lead 20's chassis width is 17 and 1/2 inches.

This may be the workbench but we're almost all Marshall enthusiasts here. We appreciate vintage Marshalls for what they are,
and most of us don't have a high opinion of hacking up a Marshall chassis just to make it fit in a different cabinet.

Circuit mods to make an amp sound better are one thing. Taking a sawzall to a chassis because you want it smaller is quite another.
You won't find much support for that notion. Not here.

 

[fitz288]

I'd make a new chassis and transfer the guts to the new chassis before I'd chop the chassis.

That amp as it stands is somewhat collectible now. If you don't F it to death it'll only become more collectible and gain value in the future.

But cut it, and it'll forever be stuck in trash tier status.

All because you want it in a different cabinet? Seriously??

I'd suggest that you look for a smaller amp in the same series. Like a 30 watt master lead combo, or a Lead 20. They'll sound the same,
if hooked up to the same speakers. And they're smaller and may fit in your preferred cabinet without cutting anything.

A Lead 20's chassis width is 17 and 1/2 inches.

This may be the workbench but we're almost all Marshall enthusiasts here. We appreciate vintage Marshalls for what they are,
and most of us don't have a high opinion of hacking up a Marshall chassis just to make it fit in a different cabinet.

Circuit mods to make an amp sound better are one thing. Taking a sawzall to a chassis because you want it smaller is quite another.
You won't find much support for that notion. Not here.

I guess I'll skip the new faceplates inquiry...

 

[AtomicRob]

I'd make a new chassis and transfer the guts to the new chassis before I'd chop the chassis.

Regardless of whether you feel the amp is collectible or not, using a new chassis would probably be EASIER than modifying the existing chassis and it would end up looking cleaner. Especially if your shop can make a new chassis to whatever size you need. Just use the old chassis holes as a drill template and you're good to go. It also looks like you could slide the whole pcb over another inch or so to leave more room for the transformer if you drill up a new chassis.

 

[Gunner64]

You could make it work, but Imo it would be a major pita. Myself, who has done this kinda shit before with other amps would just keep searching for the little guy. But if the 3210 is cheap enough I'd buy it just because. Don't get mad..lol.

I think in the 3310 the pcb is pushed down towards and possibly over the power transformer, I think you'd have to go that way with it, drill new holes for the pots, ect.

 

[fitz288]

You could make it work, but Imo it would be a major pita. Myself, who has done this kinda shit before with other amps would just keep searching for the little guy. But if the 3210 is cheap enough I'd buy it just because. Don't get mad..lol.

I think in the 3310 the pcb is pushed down towards and possibly over the power transformer, I think you'd have to go that way with it, drill new holes for the pots, ect.

Thank you for the rational reply.
For Pete's sake (no offense Pete), it was just a "what if "dimensions question.

I've seen a few 3310's go for around the $400 mark in the past few months on the usual gear sites.
They were beat to $#!+, and shipping costs kinda kill any sense of getting a bargain.

There are two 3210's in my area for $300 & $325.

Doesn't seem worth the effort, and I'd hate to condemn my soul to eternal damnation...

 

[Wildeman]

Thank you for the rational reply.
For Pete's sake (no offense Pete), it was just a "what if "dimensions question.

I've seen a few 3310's go for around the $400 mark in the past few months on the usual gear sites.
They were beat to $#!+, and shipping costs kinda kill any sense of getting a bargain.

There are two 3210's in my area for $300 & $325.

Doesn't seem worth the effort, and I'd hate to condemn my soul to eternal damnation...

Dang man, i got 0 negative responses when i brought up routing my '57 Gretsch 6190 for a bridge pickup on Gretsch Talk, here they wanna kill you for desecrating a solid state Marshall

 

[Wildeman]

Chassis is 17 1/4", head box opening not including blocks for the screen cover is 17 1/2" x 8", blocks are 3/4" stock if you're gonna use a screen.
Same fuckin amp, just move the board closer to the tranny, drill a few new holes, take out your hatchet and whack a few inches of, make sure your drunk first, and your done

 

[fitz288]

Dang man, i got 0 negative responses when i brought up routing my '57 Gretsch 6190 for a bridge pickup on Gretsch Talk, here they wanna kill you for desecrating a solid state Marshall

Well I wouldn't group everyone here as "they", but I guess I've offended His Holiness, THE Amp Repair Guru.
Not sure when the 3210 achieved it's sanctimonious status as a highly collectable amp that needs to be cherished and preserved for future generations.
$300? - I've seen MG amps go for more.

Chassis is 17 1/4", head box opening not including blocks for the screen cover is 17 1/2" x 8", blocks are 3/4" stock if you're gonna use a screen.
Same fuckin amp, just move the board closer to the tranny, drill a few new holes, take out your hatchet and whack a few inches of, make sure your drunk first, and your done

View attachment 105867

And thanks for the pics - I appreciate the effort to help with my questions.
Looks like a different heat sink, but that's the general configuration I thought might work with the 3210 components.
An 18" chassis might even give slightly more wiggle room.
I'd prefer to find a good deal on a decent 3310, but I might have to get out my Sawzall just to piss someone off.
Some things you just can't put a dollar value on.

 

[Matthews Guitars]

It won't piss me off. I may laugh but I won't get angry. You can do what you want. It's your money. Buy what you want, do what you want with it. But you can be sure I'm not going to be very supportive.