Lynch Mod for the SC JCM 800's

Robert Herndon said:
@ivan H , @Amp Mad Scientist - How tough could this really be???

I'm serious...
Click to expand...
We don't have a schematic of the origin.
It's sort of hard to tell what would work.

I have to draw the whole thing from scratch to get a schematic.
But sooner or later I will probably have a custom version for the origin. (not plug-in)
I also want to make a custom version of the newer 15 watt 12 inch Princeton which will be a 40 watt mod.

One channel amp no channel switching.

Clean Mode:
Normal channel with tone controls and no master volume.

Boost Mode:
Boost bypasses tone controls and activates master volume.
Boost activates infinite sustain.
Boost is passive with no added gain stages.

Effects Loop:
separate Send and return level controls.
Series / parallel adjustable mix / bypass effects loop control. (one knob) The effects loop operates in series or parallel.
 
steveb63 said:
Hmmm... not a permanent mod? Is reversible?

I do have an amp on the list. Very interesting.

If you don't mind me asking, any idea of the cost?

I'd sure like to try this out with my JTM45, as long as it's safe, not permanent etc.....

Interesting indeed....................
Click to expand...

You plug it into V2 of your amp. No tweaking or circuit massaging.
 
steveb63 said:
Hmmm... not a permanent mod? Is reversible?

I do have an amp on the list. Very interesting.

If you don't mind me asking, any idea of the cost?

I'd sure like to try this out with my JTM45, as long as it's safe, not permanent etc.....

Interesting indeed....................
Click to expand...
Yeah like plexi said, $300 for the Lynch and $200 for the Hotmod, though the used market has them a little cheaper on the Hot Mod V2 from time to time. Just a plug and play! Its basically just two 12AX7s running together into one slow with a few switches on the side pending on which version you buy, like bass boost or hi and low gain switches.

Apparently its very safe on any amp that its capable of working with and completely reversible if you dont like the end results.

Heres a good example of it vs the old Soldano Hot Mod from back in the 80s into an old JMP 2203
 
Pissed Plexi said:
5 watts has a place.

20 watts has more of a place.

listen even with the :poo: brass the phone added it kicks some greasy chit into playing. Makes me want to play naked. I know...weird. Isn't that what a Marshall does?
Click to expand...
Lol cant beat the Marshall crunch n punch in any size! As much as i love other amps, im like a hopeless junkie always going back for his fix with Marshalls: they just get the job done every time and in any situation.

I got a 2500 SLX currently dead on its feet that im trying to get back up and running that I would REALLY like to try one of these Hot Mods on, as I havent seen anyone else try that but i know its one of the listed amps thats capable of it working on.
 
Ok,

Got in touch with Marshall for a schematic. In the interim, I found a few interesting things:

From The Marshall Forum:

"I recently bought a Marshall Origin 5 and had high hopes it would be a screamer out of the box. Not really. So I took it apart to see what was under the hood. After tracing through the circuit I was amazed that the base circuit is almost an exact clone (even the component designators!) of the original Class 5.

Of course the Origin 5 has the additional components associated with the low power, and boost switches, so there are a dozen or so more resistors, a couple microcircuits, a couple transistors, a couple diodes, a few square/rectangular large resistors. It would be great to see a schematic of the Origin 5 to better understand what is going on. In the meantime, here's a list of values of the basic circuit, which is almost a clone to the Class 5 (I attached the original Class 5 schematic and the Lyle-suggested-free-mod Class 5 schematic):

R20-470K
C10-47pf
R19-33K

R18-1.5K
C8-10uF

R1-100K
C9-.022F

C13-.022uf
R7-220K
R9-1M
R10-39K
R28-68K (now called R101)
C14-470pf (now called C104)
C20-.047uf (now called C105)
C22-.022uf (now called C106)

C11-10uF
R2-10K

C21-.1uf
R22-2.2 M (prev 470K, probably related to the high/low and boost functions)
R23-470K
R21-6.8K
R3-100K
C2-.0022uf
R14-470K
R12-470K
R11-470K

R13-220K
C1-.001 uf
C5-.0022uF
R15-1.5K
R24-100K
R25-2.2K
R26-470K

C15-22uF
R4-10K

R27-150 ohm
C12-47uF

R5-1K
C3-10uF

Screenshot_20210311-064740_Drive.jpg

Marshall-Class-5-Mods.jpg
 

Attachments

Pissed Plexi said:
You plug it into V2 of your amp. No tweaking or circuit massaging.
Click to expand...

Almost all Marshall amps are the same at V2. However we don't know that the Origin is the same.

What you really want to know is: Origin is a Valve State Amp. (also called hybrid)
It's 1/2 solid state and half tube.
That much we probably do know....the power controlling is a Mosfet / tube phase inverter circuit.
 
Amp Mad Scientist said:
Almost all Marshall amps are the same at V2. However we don't know that the Origin is the same.

What you really want to know is: Origin is a Valve State Amp. (also called hybrid)
It's 1/2 solid state and half tube.
Click to expand...

I'm working through my contacts to see what I can find out.

From what I gather, the Lynch Mod is simply putting the Tim Caswell extra gain stage in a self-contained, external box???
 
Robert Herndon said:
I'm working through my contacts to see what I can find out.

From what I gather, the Lynch Mod is simply putting the Tim Caswell extra gain stage in a self-contained, external box???
Click to expand...
It's basically all the same circuit from Fender Bassman / Marshall 2203.
That's really what they all are.

But adding more stages also adds noise and tends to mud out when pushed...
 
You must log in or register to reply here.
Back
Top