Dialing in Plexi jumpered model (50W 6Ca7)

Chewie5150

Chewie5150

Fractal Fanatic
I have a preset with bunch of different Marshalls and I always linger the longest on the Plexi 50W 6CA7. although I already have a great sounding preset I'm trying to better understand how the controls work on the jumpered version and picking up bits of info on various threads including Yeks amp guide thread series. I have no real life experience on an actual Marshall.

Looking for some discussion specifically on this model and you all like to dial it in. Here are some of the tips I've come across so far ;

1. from Yeks amp guide: "Some players of a real Plexi use patch cables to “jumper” them. This enables them to have the benefits of both channels at once. This is modeled in the “Jumpered” models. These have two Drive controls. Set them at the same position, or keep Normal Drive lower than Treble Drive."

-so with that , here's a question: how are most of you liking to set the Normal/Treble Drive in relation to eachother. I know there are no rules...whatever sounds good. but the guide gives a basic tip on keeping the normal drive lower than treble drive. This is the main aspect of this amp that I don't fully understand to be honest. I've never played an amp IRL with jumpered channels.

2. turning off bright or lowering bright cap to tame the highs though the former will also inherently lower the overall gain yes?

3. hitting the input of the amp with a boost for more gain. What boosts y;all like using with the Plexi?

4. Negative feedback. I've been playing with that parameter a lot more lately and can't decide where I like it on this model ...quite yet.

Then of course there's cabs! what are you fav cabs with the Plexi. Greenbacks are the go to it seems.
 
1. I have a superlead mk2 and generally just run norm input. Bright takes yer head off in a hurry, and i snipped the cap lol. I also dont get it to breakup levels at home - grrrrreat pedal platform. My jtm-45 has a master and I do run the jumper here. Still enjoy the normal channel and bring up treble channel for a bit more bite and compression.

2. Bright cap is only on the treble channel iirc? Not sure it would lower the gain to lose it given the voicing of the amp.

3. This is the goods right here. Real life goosin: solidgoldfx spanish castle dual fuzzface, boss sd1, maxon od808 (lawd its a ts10), ehx triangle fuzz, eqd special cranker, carl martin plexiranger plexi + dallas rangemaster combo, axiom SDD 3000 preamp circuit (love the SDD pre in axe so i got one built), tonebender mk2 coming in the mail. These feed the superlead or the jtm-45. Once we jam with a bassist it will hopefully be clear which type of fuzz works best…

Each type (muff, fuzzface, sd1/808, sdd pre) works well with plexis or jtm’s. I dont miss my 5150 because sd1 into triangle fuzz hits the same ballpark here.

In the axe I like the treble boost, klone, sdd and fuzzface options. Never was a Rat guy, owned one irl and wasnt a fan.

4. Negative feedback really nails that last 10% imo. Once i find the amp and ir, thats one of my first tweaks to get the “weight” of the sound right. Usually 5 or higher. Irl i did consider modding to run an nfb knob. One of those “didnt know til i had an axefx” things.

IR: my main presets pretty much all run @York Audio MV30 IRs in some capacity. Irl I have various greenbacks, G12T-75s and hopefully soon a quad of G12H-100. My love for my axe3 has not dissipated.

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(follow lunchtimetones on IG to hear things)
 
1. from Yeks amp guide: "Some players of a real Plexi use patch cables to “jumper” them. This enables them to have the benefits of both channels at once. This is modeled in the “Jumpered” models. These have two Drive controls. Set them at the same position, or keep Normal Drive lower than Treble Drive."

-so with that , here's a question: how are most of you liking to set the Normal/Treble Drive in relation to eachother. I know there are no rules...whatever sounds good. but the guide gives a basic tip on keeping the normal drive lower than treble drive. This is the main aspect of this amp that I don't fully understand to be honest. I've never played an amp IRL with jumpered channels.
Click to expand...
Not a pro on the model but I used my 67 50W Plexi for a lot of years jumped. Don't think of it as a ratio, turn the normal (bass) channel all the way down and dial in the treble channel the way you would with the non-jumped Marshall models. Then start turning up the bass channel and it adds a thumpy bottom end. Then just tweak the EQ a little to taste. I run mine like this (knobs probably wont map exactly to the model)
 

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I’ve been using the 100W Plexi with the tube switched to the 6CA7. My main is a single coil strat, which is plenty bright, so keep that in mind.

Bright switch off.
Normal drive around 5, treble drive 5.5-6, for a mostly clean / edge of breakup tone.
[EDIT: My actual settings are Normal 4.59, Treble 5.26. I was a bit off going by memory.]

I’ve been using a parametric EQ block to run a transparent 4dB boost. My aim was to have something closer to if I had turned up the amp vs adding a pedal. Plus Distortion and Klon sound great as pedal boosts.

It has taken me a while to learn the controls. There are many ways to adjust the treble, but they do it so differently.
Presence: I’ve been running this at 10 lately. The key thing is this is intertwined with negative feedback. Turning this up excludes highs from the negative feedback, which opens them up and keeps them from feeling choked.
Negative Feedback: think of this as mainly for the lower frequencies, since Presence will adjust the highs.
Treble Drive: This is my main tool to control both treble and gain. It adds a full range of treble and some upper mids.
Normal Drive: Adds a full swath of mids and bass. This is the only way to control the low mids.
Mids: Add/subtract upper mids.
Highs: this is the more delicate, airy highs.
Lows: this is typically the last thing I fine tune, after I’ve gotten the mids where I want them.
 
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@Budda you are the Marshall /Gibson man. I gotta play more with fuzz drives. I rarely deviate from my usuals like T808 mod/super OD/klon/ and lately the nobellium a bit. I also need to spend some more time with the JTM45. I was watching a vid Burgs did demo'ing his preset which sounded fantastic. Also , i need to spend more time with my YA cab packs. I think i have the MV30 pack . Recently bought the Marsh M20 pack.
 
@Chewie5150 I’d try more packs if I wanted to explore more tones but frankly im more set and forget haha.

Fuzz is fairly new to me and a lot of fun. I wanted one each of the real ones and succeeded, just waiting for the tonebender mk2 be completed.
 
roodboy said:
This is the other factor to consider on these amps
Click to expand...

I can hear the MVCap working in Ax3 Marshall models with MV set low as per the video but on some other models it seems to have no effect - ie: on the Legacy Models, even with MV set low, high MVCap values don't increase hi end - what other factors are at play?
 
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