The Vesperado Mod thread for the JCM2000 TSL-100: VERSIO DJENTER

[mickeydg5]

You have less than 24 hours to listen to it before it "expires".

Record_2023_01_18_080331.441

Listen to this track for free on Whyp.

whyp.it

Recorded with Senn e609 Ch. 1 / Audix i5 Ch. 2 > Mogami Gold XLR > MOTU M2 > USB C OTG > Samsung S5e w/ Android 10 rooted w/ Magisk > USB Audio Recorder Pro > 24bit/192lHz WAV: no post processing.

2008 USA PRS SC-250 w/ Wilkinson Overwound Bridge > strait into Crunch channel, Tone Shift On, Deep Off, "Hot Rod Plexi Mode" (1.33u C12, R18/30 1M1/320k, C16 2n2, Peakers OFF) > 1960A w/ stock Celestion G12 75T UK...and I need to finish this amp!

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[Vesperado]

Parts have arrived.. Off to make the final touches...

 

[Vesperado]

For those who have undertaken my mod, cutting the traces on the Clean PCB, they need not fret for they need to be cut for the corrective action detailed in the revised instructions. So if they are cut, congratulations, you have already one step out of the way. Disclaimer: If your amp is not fitted with an Issue20 Main PCB, you will need one to perform the mod.

Tied up a few loose ends in the preamp and Clean channel; there was a fluke in the design which had hitherto escaped mine eyes. The grid leak resistor for stage three would decrease in value anytime the Clean channel was not in use, i.e. when OD1/2 were being employed. Hence, almost all low freqq. were filtered out for the drives resulting in a "thin" and "weak" tone. And when I had relocated the Clean channel's signal inject, the inverse occurred for that channel on the backside of V2. After some considerable scrupling, I noticed that the Mainboard Relay (Issue20) was a DPDT Steady State with one of its switches unoccupied, thus I had determined to ditch the FET drain and opt for the switch instead. With the undertaking, I came to terms with the disadvantage of having relocated the Clean channel inject--again, limitations of the TSL preamp--that disadvantage being that there would be no resolve to assign an 1M1 grid leak to the Clean on the backside of V2, atleast without employing some auxillary board fitted with additional relays which would need to tie in with the rest of the DC rail, and not overload it. At any rate, and in a sense, I retrograded the Clean channel's inject to the front side of V2, but employing RL1c--its logical nomenclature--to switch in the signal, and it does so just fine. Hence, I was able to correct (once again) the maldesign of those notorious (at this point) Marshall "engineers" (so-called) all the while removing some cross-talk between the channels and, furthermore, keeping my V2 grid leak switching scheme intact. Take that, Marshall.

Adjusted some freqq. for the XLR circuit. The sound guy can further tailor the tone if needbe.

Noticed some RFI over the FX Loop, took some corrective measures there. Found TL072A preferable in tone over the OPA2134A. Lowered the signal out a hair to keep from overloading the inputs on my digital delays.

Tone wise, the "Clean" gets break-up tone (once again). Not my personal fav, but meh. There is a plus side to the fix, that is the Mid Boost has become "that much" more useable. Ofcourse, Peaker III now interferes, a tad, with the tone, but it's not unpleasant in anyway, it just boosts some mids. You can turn off the Peaker and select your value of choice for C12: this controls the resonance. Either grid leak combo suits the channel now.

(Superceded.)

 

[Vesperado]

Final revision to the final revision. Stage 3 Plate Bypass bleeds CL trebles, thus Main C24 has been retrofitted with ~20n. Channel is now useable; not great by any means...

(Superceded.)

 

[Vesperado]

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I found that a few additional picofarads of capacitance removes some of the unwanted compression over the 2n2 OD coupler value. 22p worth did it.

I mirrored the value of the Lead Gain Shape's lowpass upon the Crunch. Sounds much better now.

Discovered another untapped pull and throw, located on the Lead board, and then implemented it to regain my Super Glass cleans. I then revoiced that channel to suit my humbucker guitars better. It clips a little when pushed, unlike factory, but is now usable with all four selections for C12, which is the only cap that interacts with that channel now for I was successful in bypassing previous limitations. Sounds absolutely superb for clean work. I provided some diagrams to show how it ought to be wired.

Clean FX Mix has been rectified. Before it had too much Return signal in the mix.

Overall, the amp sounds more Marshall classic, or proper if you will, than previously. Tackling the treble bleeds was no easy feat, and there may still be some room for improvement; that I'll leave to the owners out there to address. I think, nay, I am convinced this is the best specimen of a rectified TSL-100 anyone can attain. And not only that: its free!

 

[Vesperado]

Made two small adjustments: (1) removed the harsh highs of the Crunch channel, and, (2) improved the range of the global NFB.

(Superceded.)

I have discovered that the same values can be fitted to both drive channels without a fuss, that is, they maintain their own character irregardless. With the same values fitted, the Crunch produces a scooped-mids and a bright top, whereas the Lead exhibits a pushed low-mids and a smoothened top--both distinct yet rich in their voicings. I was formerly misled to believe that the Lead ought to be more aggressive in nature over the Crunch, but that is not the case. Both render aggressive tones as well as smooth ones. They complement one another very well.

The amp enjoys being pushed with boost in front, it handles it exceedingly well. I find that rolling the guitar's tone back to half way gives it that mid-push dynomite which will knock your socks off. That fat sizzle and bitting crunch makes a Marshall stand out against the competition, this amp does a fine job in representing what a true Marshall can do.

 

[Vesperado]

One more go for tomorrow: going to smoothen out the HT rail to see if that will remove some of the "harshness". The 1959 and 2203 had an aggregate of 100uF for filtering. Looks like Marshall emulated that filter aggregate for their TSL-100, but methinks make it twain congregate. Then, reverting to 1k8 cathode biasing values to get some 'juicier' clipping seeing how I got a little time on my hands.

 

[Vesperado]

The amp now sounds and feels like a REAL DEAL Plexi having addressed the HT filtering and the cathode biasing. I cannot recommend this enough for those having trouble getting their amps to sound like a Marshall. Totally worth the effort.

Retweaked the reverb input attenuation value to remove some clipping.

I kick myself, for I thought I had got as close as I could! At any rate, looking back in hindsight the progression which I took has been a blessing in disguise, for had I took another path I would have overlooked some necessities.

Allow me to explain:

I found the need to rebalance the HT drop down voltages with a neutral cathode bias (before I could realize this, I had to make the clipping symmetric). This rebalance was prompted by unknowingly (and dangerously) running the line at above 150 VAC, for upon troubleshooting and taking measurements during one of the phases of random progression, V4 had a triode quite 'hot' due to the original design. Upon a few corrections I then experienced the 'honkiness' or 'bark' of the tone disappear--a happy coincidence. I also remodeled the Preamp Treble Bleed while these configurations were preset, as the amp then exhibited a 'crude' behavior, along with some Tone Stack values tweeked prior to that. There was still some harshness in the upper freqq with the cathodes biased with 1500 ohm resistor values. So when I went to pull them to replace them with my preferred 1k8 values, I then noticed that I had some extra 450V aluminum cans in my bin. So I thought, why not improve the HT line filter with the retrograde? And with that, I have finally arrived at an amp worthy to be called a 'Marshall". It sizzles the bacon, rings like a bell, roars like a lion, rumbles out the cab, crunches in your face, and is even that much more dynamic in feel and expression in the hand than ever. In short, the steps taken in random progression happened to be most beneficial to arrive at near perfection, from unfavorable conditions hashed out to advance to the next step proactively and with much success. Ahh, what a joy indeed

Final Revision for the Vesperado Mod:

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[Vesperado]

#69:

(Superceded.)

Readjusted Main C12 & 13 values against the changes from yesterday. C12 should not exceed ~2u if tightness is your aim. The values which I have landed on serve exceedingly well for various styles in standard down to open C tunings with Deeps engaged (Matt's Europa mod Deeps).

R18 is now 1M1 / 2M selectable as 2M2 yielded too much low mid conjestion.

C13 truly benefits from a switch. Methinks .58u is a good all-rounder. .52u gets that classic, pronounced mid-squeeze ala 80s LA tone, .79u for going strait in on Normal mode: Angus tone. Funny thing is, a few nanofarads capacitance short of .577u will somewhat escape the Deep circuit, making it sound compressed with ghosting/random bottom end. But once the signal is tapered below ~153 Hz, the Deep's circuit can then deliver that 'classic stadium SPL-level stack bottom-end tone' because it has sufficient band-width to process. I may at some later date install a switch for C13, as I have plenty space for it. Doing so will augment my tonal bases well beyond the 500 mark.

I am now getting very convincing Boogie/Bogner-esque tones, even more so than before. And with that at my disposal, metal tones produce extreme textures and beyond. It dials in the mayhem.

The amp's OD channels are impeccable with the above changes made as far as I'm concerned. Owners really ought to try my values out to discover what they've been missing.

Ain't no TSL-100 like 'er on the planet--NONE. That djent

 

[Vesperado]

Tweaked a few more values to taste:

(Superceded.)

Crunch C5
Preamp switches
Main R41
Reverb R1

Might get a Short Tank to cut back on natural decay time...still sounds phenomenal. There was a miniscule amount of clipping with 96k, so I reverted to the stock value. Very clear 'verb now. R41 must be reduced to gain full range of the front-plate Reverb knob.

When adjusting OD coupler value, there is no formula other than trial and error. The best way to go about finding a suitable value is to audition the "air" and low-end "bump" of the tone. I ran out of supplies, so I was unable to audition 2.3n, which maybe a more suitable value, albeit the one I made got pretty close. The 2.222 and 2.383 nano farad caps lean towards a "tighter" tone, whereas the 5.147n gets that low-end, crushing, punch-you-in-the-gut power. 5n6 was rather "bland" and "unexciting". The new value keeps the tone tight enough for employing the Deeps with full bass. I play six'ers, ymmv. That factory 4n7 DSL spec (to include the 4u7 at the input) was JUST AWFUL!

C12 can be further tightened or loosened depending upon taste. The 1.55u aluminum can I find renders maximum support for the lows based off C16 "5.15n". Very reminiscent of an Uberschall's and Mark IV's low-end.

Peaker II can be finiky until C12/16 pair well. I think a 1960p-ish might hit it better but all that was on hand was a 1982p.

R18/30 could benefit from some more flexibility with an intermediate value, say a 1M8? The 2M seems to favor drop-mayhem tones.

If your aim is to make a more classic-vibed TSL, throw C13 on a switch to toggle in .79u for Angus tones in standard off the Red channel. If you couldn't tell by now, my amp is a Modern Monster. I can dial in classic tones, but the Normal modes hardly ever get any use from me. I find more satisfaction in bumping mids with a Boost in front of the amp to simulate "classic" tone. Good enough for my purposes.

I've abandoned to use the Clean channel. It was designed for a 4u7 at C12. Not only so, but it requires 1M at R30 (with my mod). No way to implement a switching 4u7 to bypass OD1/2, all resources have been tapped. I might gut that board and build an entirely new board with a fresh circuit, but we'll see...(its just a lil' gripe)...

Treble bleeds on drive channel Gain stage circuits are what count for overall "hair" and "bite". And on another note, Peaker I values should not dip below 500p imo. I cannot understand why guys are thorwing 390p in those places, that would yield for ear fatigue fairly quick methinks. But, to each his own.

ENJOY

 

[lesexypaul82]

Hi mate. Been reading your mod build lots. Im only learning the basics and reading what your modding and then being able to see the changes on your PDF is bloody brilliant!!
I love my TSL its a 2005 with Ver7 main board. Ive got a Ver 20 sittting and waiting. Ive only had the amp a month or so and havent givinen it any more then 5 hours of play but no issues
with it and easy to dial in.
One day i will try this mod of yours. When i understand more.

 

[Vesperado]

Added a DPDT switch for symm.-asymm. clipping, and then adjusted some values to fit those changes:

(Superceded.)

Amp now boasts above 770 tonal combinations under the hood. No kidding, and the majority sound superb.

The 2n2 OD coupler has been made even larger via a 47p in parallel with it. Goodbye unpleasent mids.

Stage 2 is not a good recipient for asymm. tweaks.

Wasn't supposed to touch the amp again, so I thought, until my curiosity came back. At any rate, I now have got: (2) OD channels, (2) Tone-Stack modes, (4) Peaker combinations, (3) Coupler selections, (2) Grid-Leak combinations, (4) Input Hi-Pass selections, (2) Clipping mode selections, (2) Deeps, a shared Presence control, a shared NFB control, etc. etc. and much time to kill.

 

[Vesperado]

VERSIO DJENTER:

(Superceded.)

Now boasting 1,540 tonal platform combinations, the VERSIO DJENTER has arrived!!

Still need to figure out what to do with the Green Channel, whether or not I should try to implement an add-on relay, for Main C12, or ditch that thing altogether and give the Amber its own set of separate controls.

Since last, I tripled the filter values on the B+ line, which is an improvement, perhaps a miniscule one, but worthy nonetheless. It took some more "hash" off the signal.

Main C9 is no easy-to-land-on value. Ofcourse, one could dispense with it altogether, but it does offer some additional low-mid crunch. Higher values will yield more intense effect, which is, akin to a treble booster before the circuit in tone. Problem is, it will color everything before the amp, which some may or may not prefer. Neat trick for going strait-in but not so much with stomps. 66p should suit a good in-between. C12, however, is taken out of the circuit for my symmetrical clipping mode. 61p gets a hot-rodded Fender-type bottom-end, reminiscent of RHCP imo. 67p and above is pretty intense, and colors the bottom-end much. YMMV.

Recalculated the Tone Shift Treble corner freqq. They cannot be made the same, albeit the channels are similar, but they really are not. The Gain Low-pass filters need to be small enough to allow chorus/flanger shimmer through, but large enough to negate that harsh top-end from amplification downrange. The Amber wants one from the factory, so it received one. 68p serves my purposes.

Having readjusted my bleeds to suit both Normal and Tone Shift modes, a final 10p pre-PI low-pass equally suits both symm./asymm. clipping modes to boot. As I have stated before, bleeds are EVERYTHING with this particular amp.

C13 has since received a new switch, hence the two-fold increase in total combinations.

And finally, the Reverb for OD was readjusted from 7k3 to 9k1 to combat excessive decay.

ENJOY

 

[Vesperado]

Got tired of C9 pushing mids and making my palm mutes flubby, so I threw it on a DP6T, wired: symm./asymm./asymm.+C9.

Provides for even more combined configurations now. Figured I'd keep it 'cuz I get a Boogie-esque tone with it ON and C12 OFF, plus selected peakers. But, a more classic tone without it in the Normal modes.

Probably should save up for a Rectifier and a Plexi...

 

[Vesperado]

3,458.

Stay tuned...

 

[Tatzmann]

Probably should save up for a Rectifier and a Plexi...

That may do the trick, but since you like to tinker (obviously) a nice ampkit might be the best decision.

Or since its beyond original now anyways, how about gutting the damn thing and putting the transformers, tubes and chassis out of their shame, living with those messy innards?

 

[Vesperado]

10,374 combinations in the drives alone, excluding the Deeps:

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marshallforum.com

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marshallforum.com

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marshallforum.com

(Superceded.)

Changes since last:
- Improved Reverb DC rail filtering, cleaner echo!
- Reverb R13 adjusted to reduce decay time. 39k probably better.
- Green channel fitted with a treble peaker across R4.
- Green channel now has a dedicated hi-pass input cap, switched in parallel via Main TR2.
- Crunch Gain Pre-Emph. now has a treble bleed.
- Global treble bleed now permanent.
- OD Reverb signal attenuator Lead R26 slightly adjusted.
- Main C16 given 3-way switch for Red Channel's cathode bypass. Values provide for both modern and classic tones.
- Main C16 completely reworked. 2380p value is dedicated for classic tones.
- Main C17 has been removed. The negative lobe is no place for a boost in the highs.
- Peaker cascade parameters have been reassigned.
- A 3-way switch for the cap peaking Main R23 has been added.
- Main C24 is NF.
- Main R17/30 has been reworked for a more classic tone. That Plexi crunch really crunches!
- Main R3 has been fitted with a "hair" switch across it. EVH on tap!

Overall, amp breaths FIRE more so than ever now. The range of tones are plentiful and tasteful. Pretty much encompasses many old school tones and new ones, even ones never heard of before. Having reworked the preamp to better suit the Normal modes, the crunch is out of this realm. Believe you, me. Not bad for T75s, either. The Green channel is pretty much useless except for a handful of configurations. I must remind the reader that I did not design this amp. If I were to get a new amp, it would need to have a dedicated V1 for cleanish and a separate dedicated valve for the drives. It would also need to have two B+ primaries, one for the preamp and the other for the power amp section. But rater than dream on, this amp is worthy to be called a dream amp--in the drives, mind you.

Enjoy!

 

[Vesperado]

Updated the Reverb circuit today:

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Changes were made at:
- Reverb R1
- Reverb R12
- Main R41

The reverb circuit needed revision after making many changes since the last. The input attenuator must be raised to make the effect more dynamic, id est: touch sensitive to picking nuances. Found a good all-rounder for all channels and styles. The tone of the effect was a little on the cold side, so I adjusted the input Z to the output opamp a tad to allow some more lows to pass through. I had discovered that making C5 any bigger than what I have there overloads the springs, so that prompted to change R12 instead. The reverb inject/mixer on the preamp max'es out at 40k. Anything under that will cause a drop in volume before the last amplifying stage. R13 can be left stock, but I find 47k colors the tone less than 56k. Bear in mind, with more amplitude entering the output opamp, 47k is a better value over 56k; keeps that 'verb clean. No point in overloading the signal, afterall, it's not a stomp box. So with the above changes we now have exceptionally defined reverb at our disposal!

 

[Vesperado]

New cleans for me Marshall:

(Superceded.)

Without completely ditching the TSL topography, I spec'd the Green channel to mimic vintage Fender tone. Still, its no pedal platform, but whatever.

And, in case anyone was curious, Reverb R1 seems to taper off at around 183k for picking dynamics.

Probably should make a video soon.

 

[Vesperado]

(Superceded.)

Spanky cleans. Even more spanky than before.

Improved the lows by removing a good chunck out of the high-bass flub. This was accomplished with a cap larger than the mid cap and fitting it between the tone pots, like Leo's circuit has. Two traces had to be cut. Also dispensed with the Treble Peaker riding the slope as it is not needed whatsoever. The value I landed on (for now) is a 68nF. 100nF was a tad 'weak' and 'unfelt' given the numerous parameters with the amp, afterall, its not a Fender. At any rate, any cap between those two values should suffice, depending on your gear and taste. Some low-mid content needs to peak through to get the T75 to push air. This entirely rests upon the call of the owner to where the bass ought to reside. I think that notorious mid-scoop is still distinctly heard, albeit the bass corner has shifted a tad to the right, ymmv. R12 can be lowered further to help pass more bass freqq. through the PI, that'll make it sound "warmer", if one really wanted to get closer to Leo's tone. It's a nice tone, no doubt. I really dig it. Other than that, the Volume pot has a profound impact upon, or correlation with, the Gain pot. So if the owner chooses to adjust R12 outside of what I have recommended, they will need to rebalance the range of sweep of the Gain via R12, and perhaps even replace the pot itself for a well-tapered one (which I had to do, and thankfully I had four on hand to select from), maybe even increase the Bass cap. This process is entirely necessary to get the most out of the Green channel, or else your tone will be hid within a narrow scope, and then your Cleans will become a "one-trick-pony". Don't say that I didn't tell you. Behold, I did most of the leg work for you. You can thank me later.

The Deep assigned to the Clean may/may not sound good depending on Main C12 value. 200n there is enough to make a difference. Truth be told, with (adhoc) 68n you will not ever need to employ the Deep, nor would you should you make R12 less than 320k.

There is the option to replace the Treble and Bass pots with B250K. I am leaving my B200K's in there for now, as I don't need to goose anything. There is ample bass and treble in this circuit. It is warm and spanky, chimes and jangles...&c. &c. If you find yourself reaching the limit of one of these to get a good tone, that will be an indicator that you will have to rebalance R12 and VR2, i.e. replace the pot for a better taper.

I am digging the 'Glass-top/Bass-boost' switch, does wonders. Chorus and Phaser stand out in a halographic sense, and swirl about you. The Green channel takes finger-picking and foxtrot strumin' exceptionally well. Man. Leo's circuit. Man was a genius. I have one of the guitars made at his Fullerton factory under his ownership, that is, before he passed.

Yes, the Green channel is a modified Fender tone stack. They gave it a Mid control, but cut some (minor) corners. Probably due to import agreements, patents, and whatnots. My mod removes a stage from it. The original circuit only had two. Here, we get four. It still gets PLENTY warm in tone. It can do some light overdrive via a stomp, but nothing further. HEY, you have TWO outstanding drive channels--whatcha fussin' about? Now you've got SPANKY CLEAN, to boot. What more could you need?