Marshall Hot Rodding 101 (Zener Clipper Question…)

[rocker68]

Hell yeah !!!!!!!

 

[johnnyeggz]

Ripped into it tonite, no more brown sound! Thank you for the eagle eyes

Bypassed R27 with a wire

Piggybacked another 22k on R15 to get 10.8k total

R7 did measure 163v now 219v

R8 was 175v now 235v but l added a 220k right at the valve so its back to 172v

R14 was 218v is now 294v

R15 was 219v and is now 294v


All mods are:

Bypass one B+ resistor R27

.0022 uf coupler
4.7 / .68 not sure how l ended up here...over a stock 2.7 ???

I swapped the bright cap to a 4700pf

I added the depth back in, 220k with 2n2 cap

330k v1a plate

C7 to 22uf

220k across preamp

Push pull preamp pot for SAT mod clipper (10k --- 100nf --- 1meg resistor and 2) mpsa06

Headfirst 300v effects loop

And Hot Mod V2 Evo

I love how it sounds and feels, though the hot mod may be pushing it over the top even with 2 ecc81 tubes. Im not good with descriptive tone, but its definetly not brown anymore.

Ill play it for a few days and see how l like it. Of course now l have to clean up the board again...maybe...

Thanks for a great thread Johnny...seems like we are doing the same thing so hope ya dont mind me jumping into your thread. I think its becoming a super informative thread for someone wanting to mod a 2203x.

NICE!!!

 

[dtier]

Draining the filter caps through the PT secondary CT? That's a new one for me lol. Are you sure the CT wasn't merely tied to the caps' ground lug and then to chassis ground?

Like this one.

 

[johnnyeggz]

Here’s a question.

Being the boards upside down, is there any benefit to swapping some of the caps to Mallorys?

 

[FourT6and2]

Here’s a question.

Being the boards upside down, is there any benefit to swapping some of the caps to Mallorys?

Nope

 

[johnnyeggz]

All fairy dust, eh?

 

[FourT6and2]

All fairy dust, eh?

No, not fairy dust. But there's not much benefit in this situation. If you were building an amp from scratch, it could make a difference if you were going to nit pick over every component. Or if you wanted to change all polypropylene caps in an amp over to polyester or something like that. You might wind up doing more damage to the PCB and you really won't hear a huge difference either way. But if you want to do it and see what happens, sure... go for it. If you do, I would go with Vishay/ERO MKT 1813 instead of Mallory. Just gotta make sure they physically fit and have the appropriate voltage ratings for each position.

 

[johnnyeggz]

No, not fairy dust. But there's not much benefit in this situation. If you were building an amp from scratch, it could make a difference if you were going to nit pick over every component. Or if you wanted to change all polypropylene caps in an amp over to polyester or something like that. You might wind up doing more damage to the PCB and you really won't hear a huge difference either way. But if you want to do it and see what happens, sure... go for it. If you do, I would go with Vishay/ERO MKT 1813 instead of Mallory. Just gotta make sure they physically fit and have the appropriate voltage ratings for each position.

Nah.

Hahahahahaha.

I’ll put the mallorys where the mods are, and leave the rest stock, except for the treble cap, stock is one of those blue poly caps, I’ll put a silver mica, because that’s what everyone seems to put there.

 

[johnnyeggz]

I guess I did too much today and got sloppy. The irons shaft leaned against the cap.

Should I change this .1 cap or is it just the plastic coating?

I’m done for today.

 

[johnnyeggz]

But here’s where I’m leaving off.

Looks much better, I’ll finish tomorrow.

 

[shredless]

View attachment 141338

I guess I did too much today and got sloppy. The irons shaft leaned against the cap.

Should I change this .1 cap or is it just the plastic coating?

I’m done for today.

Ive done it you didnt hurt the cap but will it bug you? Mine bugs me...l have 2 like that. Functionally its fine.

Good job getting it all fixed up.

Some alcohol and a qtip will clean a surprising amount of that flux stuff around the holes. Does it protect the joints??? I dont know ...but l cleaned mine off. And was shocked at how much came off...even things that looked burnt.

 

[johnnyeggz]

Ive done it you didnt hurt the cap but will it bug you? Mine bug me...l have 2 like that. Functionally its fine.

Good job getting it all fixed up.

Some alcohol and a qtip will clean a surprising amount of that flux stuff around the holes. Does it protect the joints??? I dont know ...but l cleaned mine off. And was shocked at how much came off...even things that looked burnt.

As soon as I did that, I stopped for the night.

Tomorrow morning I got a 3 more board things to do, then I’ll wire it back in.

Honestly, this was a lotta work, I may as well just put in a turret board.

 

[shredless]

I know its alot of work...but you dont hafta disconnect all those wires. It can be done just by propping the board up...its just a bit claustraphobic that way...lol

Theres a dude on ebay that sells loaded boards...lve nearly bought one 10 times, but he builds to order and l was always impatient. His eBay name has camaro in it l think.
That would be alot of work too and youd hafta mod it. Youre almost there dude... tomorrow youll be jammin again.

 

[shredless]

Be mildy prepared for oscillations...those wires to the first tube are finicky about how they lay. If you have before pics...try and get them all laying the same way as before.

I ran my shielded wires different and one went out around the board standoff and it killed the amp. I had no gain, and the amp popped and farted just from that. Once l layed them back the same way it worked fine.

I had no idea what happened or how that could cause that. So if it acts weird, dont freak...tweak.

 

[johnnyeggz]

Look what I did where R12 used to be.
That’s where the clipper diodes or transistors will live. I took the leads from a 2 watt resistor and soldered them in, but left them high enough that I can put an alligator clip on as a heat absorber for when I wanna mess around with different values there. I made lil loops so I can just sit it in and solder.

 

[shredless]

View attachment 141343

Look what I did where R12 used to be.
That’s where the clipper diodes or transistors will live. I took the leads from a 2 watt resistor and soldered them in, but left them high enough that I can put an alligator clip on as a heat absorber for when I wanna mess around with different values there. I made lil loops so I can just sit it in and solder.

Sorta like a little turret?
Wheres r12 then? Seems smart, lm curious....

 

[johnnyeggz]

Sorta like a little turret?
Wheres r12 then? Seems smart, lm curious....

The 100k at R12 now lives on the socket where the yellow wire used to be, the ground runs under the board to the pots ground. The 10k & the .33 clipper cap lives there too,

 

[shredless]

Im so full of sh$t... When l made my mod list I dint realize my v1 cathodes were 2.7 and 4.7... this stuff confuses me... Its a wonder it still works with all the mistakes lve made

I am blonde...

But its killin it today!

 

[shredless]

The 100k at R12 now lives on the socket where the yellow wire used to be, the ground runs under the board to the pots ground. The 10k & the .33 clipper cap lives there too,

Seems like a stroke of genius

 

[johnnyeggz]

Seems like a stroke of genius

The mounting the of 100k and 10k at the socket is part of the Headfirst Hybrid Jose deal, but mounting the Zeners in sort of a raised “turret” is all me baby.

HAHAHAHA