The Vesperado Mod thread for the JCM2000 TSL-100

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Cool! The resolution when watching on my phone is not so good will try when I come home. Really appreciate you sharing.

Have a question. Iam currently working on the FX have changed a lot of things like jacks and and still having problems. I did the atomium mods for unity gain. The remaining problem is signal fluctuations in the fx signal in the A loop and some strange popping sounds hard to discribe like strange distortion/compression. The B loop is working. Also chasing some hum that I suspect to be related to the fx loop.

Having problems reading the schematic do you thing IC2 and 3 on the od board might be the problem? Tried to look for intermittent contact but everything seems to be fine so looking in to IC:s and optos and stuff like that? Any other idea’s?
 

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Cool! The resolution when watching on my phone is not so good will try when I come home. Really appreciate you sharing.

Have a question. Iam currently working on the FX have changed a lot of things like jacks and and still having problems. I did the atomium mods for unity gain. The remaining problem is signal fluctuations in the fx signal in the A loop and some strange popping sounds hard to discribe like strange distortion/compression. The B loop is working. Also chasing some hum that I suspect to be related to the fx loop.

Having problems reading the schematic do you thing IC2 and 3 on the od board might be the problem? Tried to look for intermittent contact but everything seems to be fine so looking in to IC:s and optos and stuff like that? Any other idea’s?
Happy to help :)

Sounds like a bad IC. I did socket mine a while back so if for some weird reason it went I would simply replace it with another. Try that and see if it helps. Also, double checking the entire FX circuit, Rear and Lead PCB, would be constructive to narrowing down problems. You have a dmm, so your half way there. Amazon sells capacitance meters dirt cheap. Aluminum caps leak over time, and why tantalum is preferred on that premise alone (plus it doesn't alter the tone much in comparison).

The only other thing I can think of of the top of my head is: stick to batteries/battery pack for powering up your pedals, both before the amp and in the loop, that will isolate hum from being injected into your signal.

Let me know if you find anything during or after your troubleshooting and I will see what I can do.
 

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(Superceded.)

Last minute corrections are hereby annotated: Reverb C6/12 removed, Lead IC4 changed, and Rear R39/41 adjusted. It is now published in the original file size, so depending on your ISP/browser it may take a minute to download.

Enjoy!
 
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Looking at your schematic revisions now and have some questions.
1. The changing of the inject point and removal of MB C24 regarding the clean channel. Is this possible without changing the switching circuit?
2. When you write remove I guess you mean remove and brake that part of the circuit?
3. When removing MB C9 the changes in C17/18 how much higher than your recommended values would you advice going if I like the tone/brightness?
4.I am changing MB C8,15,23,28,29 to sozos 500V(stock values) and C6-7 and C27to Vishay1813 630V 0.022 any thoughts? is there any of these positions that are more sensitive when it comes to voltage ratings? Other caps to upgrade on MB?
5. Looking at the clean/crunch/clean boards, any caps you would advise changing to MKT1813 or Sozos? Have already put the micas across vol.pot crunch/OD (atomium mods).
6.Regaring the improved filtering MB C1-4. Ive already did a full recap. Do you still think these caps should be changes to 4700u 16V? I have som hum issues? I have moded the heaters supply so that all preamp heaters comes of BR1 not just v1-2 and the bridge elevated of the board and 8A. Here is a link to the mod: https://valvetubeguitaramps.com/marshall-jcm2000-dsl-hum-solution/

Your newest post of the schematic was better resolution that your first! Really appreciate your work. I was about to give up on this amp before I found your thread . Now the amps working and the bias is stable just some final fixes: FX Loop, new reverb tank and some upgrades! This amp is really brutal! Running it with a weber 100w greenback H clone (Legacy 12) in a iso box and a weber mass 200 to take it down a bit. Now I am loving this amp. Have a 1966 super reverb that gathering dust right now. Hats of for all the work you did and all your posts!
 

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Looking at your schematic revisions now and have some questions.
1. The changing of the inject point and removal of MB C24 regarding the clean channel. Is this possible without changing the switching circuit?
2. When you write remove I guess you mean remove and brake that part of the circuit?
3. When removing MB C9 the changes in C17/18 how much higher than your recommended values would you advice going if I like the tone/brightness?
4.I am changing MB C8,15,23,28,29 to sozos 500V(stock values) and C6-7 and C27to Vishay1813 630V 0.022 any thoughts? is there any of these positions that are more sensitive when it comes to voltage ratings? Other caps to upgrade on MB?
5. Looking at the clean/crunch/clean boards, any caps you would advise changing to MKT1813 or Sozos? Have already put the micas across vol.pot crunch/OD (atomium mods).
6.Regaring the improved filtering MB C1-4. Ive already did a full recap. Do you still think these caps should be changes to 4700u 16V? I have som hum issues? I have moded the heaters supply so that all preamp heaters comes of BR1 not just v1-2 and the bridge elevated of the board and 8A. Here is a link to the mod: https://valvetubeguitaramps.com/marshall-jcm2000-dsl-hum-solution/

Your newest post of the schematic was better resolution that your first! Really appreciate your work. I was about to give up on this amp before I found your thread . Now the amps working and the bias is stable just some final fixes: FX Loop, new reverb tank and some upgrades! This amp is really brutal! Running it with a weber 100w greenback H clone (Legacy 12) in a iso box and a weber mass 200 to take it down a bit. Now I am loving this amp. Have a 1966 super reverb that gathering dust right now. Hats of for all the work you did and all your posts!
1) Relocating the inject and removing C24 does not affect channel switching in any way. It corrects the maldesign of the circuit by cascading each stage positive - negative - positive - negative for each channel, whereas before they left it a mess by forcing 5-stages upon the clean, and for what purpose who knows. Four stages is ample for cleans, as additional stages do nothing but adduce rumble to the lows and muddy up what would otherwise be clear and clean.
2) Yes. "Remove" means simply "get rid of it".
3) Follow my values as close as possible. You can build a 680p with an 120p, etc. to get close to 796p. 1500p with an 100p makes 1.6n, etc. Going higher in value will have the effect of layering blankets over your speakers. Conversely, you could get away with 740p and 1n5 depending on whether you play at low volume only, etc. But if you crank it (like me, although I don't use an attenuator) then no lower than what I have published. That amp gets plenty bright, even if you did layer some extra blankets over it, but I have auditioned these bleeds for months and they are the best I can offer.
4) I believe I recommeded Nichicon QXK, and still do, however you should be okay with those manufacturers. Every cap which I recommend replacing is annotated on the drawing. 500V might work, but should you blow a fuse, or a tube fails, or what have you, they might not tolerate the spike very well, all depends. It is best to meet or exceed the ratings.
5) I know Matt bleeds his channels that way; that is his tone. I have found a solution which suits my tastes better, and a solution which retains the integrity of my tone. You are welcome to give each method a try to see what suits you best. Capacitor composition has zero impact on bleeding freqq. to ground. What matters is what lies in the signal path. Vishays are good, MCaps, WIMA MPS--2, etc. will all adduce to improved signal integrity over the stock film caps. Multi-Layer Ceramic argueably better than disk, etc.
6) Yes, especially if you have all of your preamp filaments wired together. You might consider beefing up your bridge recto to say a BR108 or higher, and if you can fit them, perhaps 5600u 10V/16V. Take measurements to find good suitable replacements. Anything 105 degrees or higher is your pick.

I have auditioned every modification numerous times over to ensure a good reception with the public. Everything works--and like a dream--but unlike a dream my amp is become a reality. The days of Marshall proper are gone, and were the Guv'nor still around I would send him my amp for an answer on his approbation. Whether or not the Japanese caps would fancy him is another story. At any rate, I have been enjoying my amp since Saturday. 44 base tones--I've been busy alright, lol. My mind is still dealing with the jet-lag of realized accomplishment: I'm astonished with disbelief, yet I did it and its done.

If I had another TSL in my possession I would mirror it to clone this one here at my side. I'd keep the Accutronics tank, it has a beautiful drippy wet tone, and to have two in stereo would be absolute audio bliss...

Glad I could help :)
 

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Having auditioned the amp with the new 10 Henry choke for a few days now, one value has been changed for Peaker III: 2n7 > 2n5. The new value removes the dab of high-lows which were peaking over the 470k resistor. With those freqq. now attenuated the extension of the remaining lows are no longer drowned out. This means that the Deep is useable with both OD coupler values, Basses dimed. I had OPA2134A fitted for Deep duty, but find that the TL072ACP blends much better making it impossible to perceive that an opamp boosts resonance.

So here is the new schema:

Peakers I: 470p Amber; 985p Red
Peakers II: 1720p / OFF / 2150p
Peakers III: 2150p / OFF / 2500p
NB: Relocating Clean inject keeps Peaker III from affecting Green channel. Also, it removes over-saturation of low freqq.

Tone wise, all combinations between Deeps, Tone-Shifts, OD couplers, and Peakers II/III are useable. Not only so, but I can use stomps to push the amp over every setting, if desired. Then again, there is no need when employing Pp.II+III as there is ample boost to dispense with stomps.

It is apparent that I miscalculated the number of base tones my amp can boast, it's actually in the ballpark of 76.

I will see if I can upload an audio clip soon showcasing every preset...
 
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Hey! Looking through your mods and can't find the voltage ratings for the peaker II & III in your notes and what type of cap do you use?
 

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630V MLCC. TDK or Murata are good.

Wouldn't advise going bigger than 2n5 in either. If you need more bottom over the Red try a .82u for Stage 2 cathode bypass. If you still want more, try a 5n or 5n6 OD coupler.
 

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Revised a few things:

(Superceded.)

My current config, notwithstanding the Deep controls, enumerate to 110 tonal bases for experimentation and/or enjoyment. Becoming the more acquainted with the improved amp I have observed a few things worthy of mention:

- Normal modes prefer the stock TSL 2n2 coupler value for the drives
- Stage 2 cathode bypass for OD2 sounds best at .76u with the 1.5k cathode resistor, irrespective of OD coupler value
- the amp will let you know if you have bad pickups installed in your axe
- chorus before dirt, always
- Main R42 is unnecessary seeing that the Reverb mix control fills out that duty. Use copper to link it. Had to remove many unnecessary components it seems...
- 5n1 OD coupler value gets boogie tone with Peaker II at 2n2 and Peaker III at 2n5. Forget even touching that Deep switch! So its off to acquiring a DPDT on-on-on switch for a 3-way coupler selector for me amp.
- I say again, big bottom can be had with a 5n1 OD coupler! Do it!
 
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Switch would be a [...]DP6T[1B1M1...].

So I am revisiting the preamp in a few places in effort to make the Normal modes more useable/accessible seeing how I've been heavily focused on the Tone Shift mode, more than anything. I'm chasing that 2000s tone in my head, and probably why I've somewhat forsaken the Normal modes, lol. That 5n1 OD coupler in Tone Shift mode with cascading peakers has been oh so fun, nonetheless. Not to mention the fact how we Americans prefer big bottom over bright 'n' tight...speaking about amps here!

So I'm going to revisit Main R18/30 and C18, and review C12. Mine intimations are these: gang (or not gang) C12 cap size to corresponding OD coupler size. This should bring the Normal mode back to that classic tone. R18 might revert to the Issue 20 value, but might require an adjustment at R30; 2M2/470k > 1M/1M possibly. I feel as though stage 3 is working hard and stage 4 is not, so it should even out the work-load; this could effect the ratio of P.II/III cascading balance. More on that to follow. And C18 might do better on the OD boards right into the Tone Stacks so as to afford more harmonic content into preamp stages 3-6. That should assist the Normal modes in regaining some strength.

The limitations with the TSL in the preamp are obvious. There are three channels sharing (4) valves. Any change to a stage outside of 2/3 (following the relocation of CL inject) will be a global one. We cannot simply bleed for drives off the cathode-follower, as some might venture, else our Clean will suffer heavily. The large value at C18 sounds good to me at SPL in Tone Shift mode, but in Normal it makes for a desiratim. The only place I can find for it is before a Tone Stack, as all tone stacks are independent of one another on this amp. I trust the brighter ones are tracking my reasoning by now. But, and again, only will experimentation offer up a solution.

The last thing on my mind is the switching schema for implementing C12 value select. It seems logical to gang it to C16 value select, but then again, there would be more combinations putting C12 on its own SPDT. Yet, likely impractical, I mean, would we really set it to sound awkward? At any rate, I should be able to squeez another two switches underneath the Clean board, or atleast drill new holes to position a larger switch should I elect for a ganged 3-way selector of sorts (a 3P6T?).

It can get rather hairy squeezing the maximum potential out of a single head that's already crammed with options. Perhaps TSL owners would find it best to pick out a route for their modifications? At the moment, I've fallen into the modern American big bottom camp. If you're a classic bright 'n' tight chap, or Van Hallen head, you might venture for the Marshall purest, i.e. JMP + JCM800, camp. I bring all this up because there is no way to cramm every tonal option under the sun into this amp--there is simply not enough space. There are cathode resistor values at play, each particular to their corresponding tones, and an endless list to be amassed for every other place in the circuit to accomodate said particulars. Yet, I am doing what I can to offer owners out there something useable, something tangible, something practical (notwithstanding I have removed a few options from the drawings as they were quite impractical). So this should suffice to fill in the chasm touching the Normal modes. The inconvenience of flipping a toggle or two in the back in order to employ one mode or the other is the main caveat. So be it.

And let me remind owners that all auditions are done through a stock Marshall cabinet at volume. I do not run a (colored) Send/XLR Out into an (colored buffer) IR patch into a (colored buffer) DAW into a (color buffered)...etc. etc. through a set of studio monitors made out of Neo magnets and Polypro drivers, amplified through Class A/B opamp circuitry at low SPL sitting two feet away. No. The values which I arrive at are the values which suit a Marshall cabinet and my standing about the room, at various volumes and various settings/configurations. I use various pedals and guitars, to boot. Did they even do that much back in the late nineties at Marshall? Who knows. But that is what I have done to get to where I am currently at.

I will report my findings soon. Wish me luck.
 

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Todays observations concerning R18 (as I wait for parts to arrive tomorrow) are as follows:

1M: Good for classic tones and Normal modes. Overall delivers a bright crunch. Mids are chewy and sizzly.
2M2: Boogie-esque punch and pushed low-mids, delivers chest pounding palm-mutes. Great for heavy rock/metal. Overall delivers a fat bottom.

Resolve? Throwing it on a switch. I like them both.
 
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Looking at your rear board revisions: C29-15,16,18 what values do you recommend?
Mainboard C30 when using two 22uf tantalums can I get away with 50V rated?
 
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Looking at your rear board revisions: C29-15,16,18 what values do you recommend?
Mainboard C30 when using two 22uf tantalums can I get away with 50V rated?
50V is fine. You might even do better with 105 degree types. The idea is to prolong longevity. That way you don't have to replace as often, as parts wear down over time. I read the rail a while back at 47-48V, so transient spikes do not wear too bad at 100V. Wall power fluctuates, too, so a high flux would exceed 50V easy.

The TSL is over-engineered in places, and overlooked in others.

As for filtering caps, whatever fits the board really. Same principle as your filament supply. Probably not necessary, though. I'm just being thorough in treating upon everything ;)
 

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Phase One for the rewire is currently underway. I am evaluating C12 values for the Normal modes and the Clean. More on that to follow.

I'm also balancing the inject level for relocating Main R80 to the Clean board, seeing how before it was on the Mainboard and a pain to get to. More on that to follow.

Although the current Treble Bleed scheme is GOOD, I am experimenting to see if I can get a little more high-end bite and hair out of the circuit for the Normal Modes running the 2n2 coupler, etc. So it'll be dumb luck if I gain anything out of that. Avoiding the dreaded ear-fatigue as much as possible!

Managed to install a 4PDT 2203 spec option. More on that to follow.

The new rewire augments the tonal bases somewhere over 500 total with the amp.
 

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Phase One has been revealing. I'm just wrapping up some things in preparation for Phase Two. So far the "2203 4PDT" attempt has been a failure tone-wise. There are more components which would need to be toggled in order to get a legitament 2203 tone; the cheese dick method was a no-go. R31 must remain at 1k for this amp. 820R is (as I have said before) compressed in tone. 1k gets clarity for days, so I have removed 820R as an option, among other options, from my annotations altogether.

C12 heavily effects the overall tone and feel for the amp. I am discovering that it can be manipulated to match the resonance of your speaker(s). Doing so will bring that classic Plexi tone to your fingertips. It also effects how clear your bass rings over the Clean channel. I have dialed in the values which provide for "grand piano lows". Highly rewarding.

R18/30 seems to work best in two separate configurations for the two separate modes (Normal and Tone Shift). At the moment I am grappling with the volume boost inherent with the Normal modes (a Tone Stack circuit limitation). I might throw R18/30 along with R79 on the 4PDT, and dedicate that switch to be "that additional toggle" in the back. It is what it is. More on that to follow.

R80 has effectively been relocated to the Clean board. This is the only modification where a trace, two to be exact, must be cut. There is also a volume boost whenever employing the Mid Boost mode on that channel, so I will see if I can dial in a value to accomodate both modes there, but I doubt I will give it a similar treatment as I shall with the drives.

C18. C18. Good thing I have time on my hands, else I'd be content to leave it as is. I have relocated it to the drives' Tone Stack circuits' inputs. It works without coloring the tone I am happy to report. Nevertheless, they must be augmented as four additional stages have amplified their highs, and need to be bleed afresh. With them now, the Normal modes have more "air" and fingertip-on-the-string "pickup". Not sure if its even worth the adventure to be honest. 1.6n makes for that "air" to swarm the ears...ouch.

There are several places in the circuit which lend themselves a hand to ward off the importunity of those unpleasant highs.
- Plate Resistors: They are R13/22/23/32/1 in the preamp, PI excluded.
- Grid Leak Resistors: Those are R16/18/30/40.
- Impedance Attenuator Pairs: There are two in the preamp, one between Stage 2/3 and the other, Stage 4/5.
- Tone Stack circuit.

R13 is to be ruled out for several reasons, (1) it is the prima face of the signal, consider this stage the most crucial, which mirrors, or replicates if you'd like, your guitar including any effect pedal after it. (2) R22 is currently employed, and that at a value far greater than that which would be peaking R13 (100p typically). This begs the question: what's the point? (3) Headroom across the band. Why limit that?

R22's peaker, C17, is as large as I'd like it to be.

R23/32 present themselves as good candidates for the task, but R23 might as well mascarade as C18. Maybe. R32 is global, yet if it doesn't drastically alter the tone of my Super-Glass tone, that wonderful 1960s American Jensen combo amp tone, then perhaps I could shave some off here, at minimum. Let's then consider R32 a possibility, then again, why not R1?

Grid leak R18 could likewise mascarade as C18. R30/40 would be global, yet R40 would allow for more highs to pass through the Reverb circuit before their attenuation (remember, both positions are global). But like R32/R1 peaker, it would need to be made small.

Impedance Attenuator first leg, C18, is good. In fact, sounds great with the Tone Shifts engaged. It could be relocated to R38, but not only wouuld this be global, it would need to augment in value to produce the same effect.

Tone Stack input bleed is preferable to a pre-volume bleed to maintain signal integrity. Perform the experiment to hear for yourself.

I trust by now we can accede to why multi-channel amps are limited in what they have to offer. Some one preset/configuration will need to suffer the lateral change. The trick with which I desire to pull off is to minimize that impact.
 

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(Superceded.)

Amp breaths fire. It crushes. It claws. It roars. Could probably ditch my pedal board now.

Nothing wrong with Wilkinson Overwounds, absolutely lovely with this amp. That Duncan Custom is gone by tomorrow.

Still need to adjust levels for the drives. Its a bit hot. "1" on a 30W set-up shakes the building, no kidding.

You guys don't know what your missing out on...
 
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Well, in preparation for Phase Three, I have found, that, my B+ rail underwent an augment once I replaced my choke, from 3 to 10 henries of inductance. I stumbled upon this troubleshooting the present global volume issue, it being a bit too loud for "1" running at 30W of power. Ofcourse, I did not so much notice it until I auditioned the bypass on Main R23, when, at that time much harmonic "voltage" presented itself to me. The amp sounds like a Trainwreck, if anything. So I must resolve my HIGH VOLTAGE amp and plea with it for a minute to content itself in being a lower voltaged one. Sorry ol' chap.

V1A: 244V
V1B: 253V
V2A: 261V
V2B: 249V
V3A: 446V
V3B: 256V
V4A: 275V
V4B: 293V
V5: 525V
V8: 525V

Had I left the amp in its current state, I would have needed to replace V3 more often than not. What's dangerous, however, and worth mentioning is, the filter at the end of the rail is fitted with 450V caps. This means, had I plugged into a hot wall somewhere other than here, surely I would have lost (2) electrolytics and a valve. Not to mention the utter dissatisfaction of missing out on the opportunity to showcase me ol' chap.

So, while I recalculate my drop downs, I have a temporary solution so that I may proceed forward with Phase III of my rewire. So I will swap R61 with R62 and hopefully not miss a beat. I have to admit, though, HIGH VOLTAGES sound absolutely BOSS. Oh, and those mil-spec SOVTEKs are absolute BOSS.

In other news, I think C18 can be left in position for those sessions with the pedal board. So I will repurpose that 4PDT to toggle betwixt the twain. If there is anything to be said about one over the other, it is, that you loose much energy from the higher band when bleeding the signal itself. This produces a perceivable reduction in volume, and likely why I dilly-dallied so long on checking my plates, anyways, better late than never. :p The plate load resistor bypass method is preferrable due to the fact that it pre-forms the bandwidth with which it treats, and amplifies that band more or less evenly compared to amplifying a partially weakened signal. If that makes any sense? So because there is not a full band-pass of signal employing C18 into a stage that amplifies a larger spectrum of freqq., it fills the void with some noise, hence the hash or "air" which then becomes outputted onto the next stage, and so on, etc. etc. So high band noise compounds and ear fatigue sets in. Go figure. Fortunately, there are two stages where we can perform a proper bleed scheme in the TSL once we have relocated our Clean inject.

With the amp as it now stands, tonal bases equate to 660 total via the (6) present toggles installed. Most of the combinations are useable, and some, not so much. Some favour some guitars over others. But so far, me ol' chap seems to be the best ol' chap standing. :)
 
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Well I'm postponing Phase III. I took new measurements across the plates, this time with the autotranny:

V1A: 249 221 213
V1B: 258 228 220
V2A: 266 236 227
V2B: 253 225 216
V3A: 447 401 379
V3B: 257 235 225
V4A: 275 251 240
V4B: 294 271 257
V5: 529 474 444
V6: not used
V7: not used
V8: 528 474 444
DC rail: 22.6 21.5 18.8
V3Pin3: 270 250 262

AC at the primary was 125, 115, and 110, respectively.

V3A takes a beating. If I leave it as is I will need to replace it oftener. I am on the fence about swapping R61/62 with eachother, or R63 can be increased and I can run the amp with a higher voltage at the primary. That is at this time, nevertheless, up in the air. 115 VAC does the job better than 110 tone-wise, still can't beat that 155+ VAC imo. Now I understand why Angus Young ran them the way he did!

The MAR-100C and MC10H do a fantastic job clamping down the rail. Why do I say this? Because the second pair of house sockets on my Tripp-Lite 1kW Isotranny produce 155-160 VAC from a 120 VAC line. That is where my amp has been residing for, dunno, two months? So I recommend Mercury Magnetics, JJ, and Sovtek for those looking for reliable components.

So now with a better understanding of my set-up power-wise, I can forego R39/41. I know if R61/62 trade places, V3A/B will reduce their gain a hair, and might fair well in doing so. I might try that for Phase III.

Reverb Mix gets more wet in Normal modes and less wet in Tone Shift modes due to the Tone Stack topologies. It's a compromise.

Bottom end conversely cleans up with more voltage over the B+ rail. High mids conversely reduce with more voltage " ". It's just BOSS.

I did not mention this before concerning R23, but V3B is positive lobe, that means bypassing it here is preferable than bypassing the plate load at V1B, so we can gain some advantage there in keeping our input signal at its optimum. A win-win, really.

Pedal board does just fine with C18 across R23, so no need to implement a switch there. That TS9 is BOSS. Chorus (I'm a sucker for) sparkles even better since relocating C18. It just swirls about you!

Amp is a step (or phase) away from perfection. Just need to figure out what to do with B+...I'm open for suggestions. I might make R63 5k6, and have R61/2 trade places. This should afford 120 VAC at the primary...
 
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Getting ready to enter Phase III.

I took more measurements today. I will begin with R61/62, 3k/2k7 for starters. That should knock a little more than 10V off the top for V3. Then I will do something similar for the DC rail. Aiming for 125 VAC at the primary, minimum.

C12 has been revaluated for half-step down tunning, both for 2n2 and 5n1 in C16. For 2n2, methinks 1.33u is better than 1u5, and 3u3 than 4u7 for 5n1. It is worth mentioning that the Clean is unusable altogether with 4u7 in C12, the lows are uncontrollable and wash everything out. 3u3 is a good compromise for access to the Clean channel and 5n1 OD coupler for dropped axes. The DSL values for C12/16 should be selected together when employing 4n7 for the OD coupler. I tried all configs, Deeps ON, both pickups selected, pedals ON, etc.

If there is anything to say about the tone from the configurations, they vary a bit. Between the many, there are some really good and useable tones, but there is no purpose in ganging certain values with others, for different axes/tunnings/pedals/etc. and switching between channels/tone stacks all have their effect on tone. I thought I could just gang the DSL values at C12/16 together, but then I'd be missing out on some nice combintions which employ one or the other. So, to work around that, I am going to make use of that seventh hole on the chassis (which I drilled originally for a 2203 option) for a SPDT, to toggle C12 On or Off, and use Chassis SW6 for the preset value. The values which I think are suitable are 4u7/3u3/1.33u and OFF.

I suppose if someone was not interested in the DSL values, or cared to explore big bottom type tones, then a simple SPDT with 1.33u on one side would do just fine for C12, and C16 can remain in position, stock. Also, R18/30 could be changed and left in position at 1M/1M. Then all you need is three switches: Peaker II, Peaker III, and SPL Treble Bleed (On/Off). And, if a pot is too much work, a fourth switch, say a 3-way for the NFB, at 22k/47k/100k. So for the minimalist, 4 switches will get you a really nice TSL. And if you wanted to, at some later time, upgrade, then three or four more switches would bring you up to speed--all which will tuck away underneath the Clean channel board.

For those awaiting the completion, its underway...
 


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