User Posts

Maths offers two attack-decay envelopes. It can function in more complex manners with some creative patching. You'll want some ADSR envelopes somewhere as well. ADSR envelopes come in two general flavors: linear and exponential. Some ADSR units can do both. Intelligel makes a nice two EG unit for linear. Tip Top makes the Z4000 NS EG that can do both linear and exponential... and also gives you CV input to control each stage externally. You can find basic compact LFOs, like the Batumi with Poti expander with four LFOs available. I'd also recommend an Ornaments & Crime module for functions like quantizing and a basic sequencer. Sequencers do more than just play notes if you use them correctly. Think of it as a modulation source as well.

You're a bit limited on space so you might have a time trying to reorganize the modules.

I group all my oscillators together, then all of my filters, then my VCAs. My envelope generators, LFOs, etc go together. Then my effects go together. My outputs are usually near my VCAs or effects.

I bought a couple of Muta Jovis modules. Perhaps they are just mine, but there's a voltage drop when plugging in CV. So I wouldn't use them for anything pitch related. You may also suffer a pop when using them for audio.

The DivKid mutes are based on fast acting low pass gates (vactrols). So rather than being immediately off they rapidly bring the volume down or up (like a very, very fast fade). I'd probably go with the DivKid mutes if I was purchasing it all over again. That's my $0.02.

I would start thinking about effects. A nice reverb, a nice delay, maybe something like a Rain Maker or a Monsoon (expanded version of Mutable Instruments Clouds).

As far as synth modules, an Expert Sleepers Disting Mk4 is a cheap (under $200) add and has plenty of functions. An Ornaments & Crime module would serve you well as well.

Take it slow and really get to know your new stuff. Try to squeeze as much creatively out of what you have as possible... then get a feeling of where you'd like to explore. Modules like O_C and Disting are multifunctional. If you're using a particular function a lot, you might consider a dedicated module for that purpose... for example if you're using the quantizer a lot.

Don't be afraid to make a wild, one-off purchase every now and then too... sometimes something weird shakes things up a bit.

The Wasp Filter is a particular filter and not very general. I think a dedicated multimode filter would serve you better as a first filter.

Drop the Optimix and the Wasp and put in something like an Intellijel Morgasmatron. You'll get a lot more use out of it seeing it has two multimode filters and a lot of modulation options.

Well, you'll probably want more than one sequencer. I know. That's not what you want to hear.

I generally lump sequencers into two categories: simple and complex.

Think of a simple sequencer as an 8 or 16 step sequencer that can control CV and gate (perhaps just one of the two). The Pittsburgh Modular micro 8 step sequencer, Befacos Muxlicer, Noise Engineering Mimetic Digitalis fit the bill as well as the Sequins mode of Ornaments and Crime.

A complex sequencer would be like the Eloquencer, 1010 Music Toolbox, NerdSequencer, etc. Most of them you can save your patterns in and construct entire songs.

I would go with a couple of simple sequencers first. If they have the option to be reset/synced, they'll fold nicely into a more complex set-up.

The complex sequencer is more about personal preference. With the more complex sequencers you tend to trade off real time controls for depth and the ability to recall your work.

Don't be afraid to be wrong. Order from a place that has a great return/exchange policy. A 30 day period is usually good. You don't know what's going to work for you until you've had a chance to get in depth with it.

As far as the Neutron, keep it. You'll find it more useful as your system expands. Sometimes you want to just create a sound quickly without a lot of patching. Having an all-in-one synth voice lying around can help with your inspiration rather than trying to patch the equivalent together and losing inspiration.

As far mixers.

The Blue Lantern Stereo Sir-Mix-A-Lot isn't bad. It has two stereo aux sends, two stereo returns, panning and mutes. I put one in my rack and don't mind it. It's inexpensive as far as mixers go. Happy Nerding and Roland also make decent mixers that also respond to CV for panning or panning/level depending on which brand you go with.

Research polyphony on a modular synth. It's a lot more complex to do it right than you'd think. Typically, you'll use multiple VCOs stacked into a single voice. If you're looking at using three single voices in a polyphonic way, you'll need three VCOs, three VCAs, three filters, some sort of system for assigning new notes to an available oscillator. You'll have to tune each set of VCO + filter exactly the same.

I think you'll find a modular solution to be pretty inefficient versus a DCO polysynth that just works out of the box.

The 1010 Music Toolbox is also capable of recording CV (even audio). It has two audio/CV inputs that can be used in mono or dual mono. It can play back up to eight channels of CV or audio. You can also SAVE and LOAD your CV from microSD cards saved as .wav files.

The price on the Toolbox is $600US. The Flame is $400US. You'll get more mileage out of the Toolbox as it's a full sequencer with LFOs, gates, pitch, etc.

I would check out both modules before making a decision. I own the Toolbox and have used it in such a manner.

The majority of your build seems to be Doepfer modules. They are fine. But you can have a lot more functionality from other manufacturers. But I do get your point of keeping things simple (i.e. - one knob one function). You can achieve this with other modules as well.

Pair this system down to as basic of a system as you can to create your first iteration. Then use it. Get to know the modules you're starting with and don't be afraid to modify your end-goal. Using the synthesizer and gaining experience WILL change your outlook and your priorities as you find your "voice", no pun intended.

I will second Lugia's Expert Sleeper recommendation. If you're going to tie your Eurorack to a DAW or other MIDI devices, the FH2 and its expansions will serve you better than what you've put together.

Bottom line is don't go all-in at once. It will be very expensive and you'll probably regret your decision.

Mutable instruments Clouds is the most popular module for granular effects. Mutable allows for clone builds of a lot of their modules. There are micro versions (smaller footprint) versions of Clouds. At this time, my favorite is "Monsoon". Monsoon is relatively smaller, less expensive ($250US) and allows for independent modulation of attributes that can't be simultaneously modulated.

There are other sampling/granular modules out there as well. But in a Eurorack system, the oscillator/voice is just the beginning.
In all honesty, you'd be better off spending your money on a copy of Ableton Live augmented with the Max4Live device "Granulator II." If you have an existing modular system, adding a granular/sampling module isn't so much of a stretch. But starting a brand new system around granular synthesis is going to be a very expensive one-trick pony.

The OP is building a simple monophonic synthesizer. Honestly, you'd be happier buying a TB303 clone or a Neutron. They are much more sophisticated than the OP build and a lot cheaper.

An oscillator, a filter, a couple of EGs and VCAs... there's no need to get into modular for that. Where modular shines IS the modulation. Pick-out and design your modulation FIRST then worry about oscillators and filters. You'll have a much better time even with the most basic of oscillators with some great modulation, than you will have with the most complex of oscillators that only have two EGs and an LFO to play with.

The most overlooked functionality are EFFECTS. Most synth patches sound pretty dull and dry without effects. But they seem to be an afterthought when people are first putting their kit together. Do NOT skimp on the effects. They are 1/2 of your sound.

Don't be afraid to be wrong. You'll make a lot of them. You'll have lots of modules you buy today that you'll regret (not deeply) later. Keep them around until you know you'll never touch them again. You'll also find the modules you curse today might be that special dash of seasoning later on.

Are you sure that my starting set doesn’t work???
If yes, I think you need more experiments to do...
Fortunately music is an area where creativity always has the upper hand on the cold technique.
-- wmw2019

Let's see... MIDI to CV converter... a VCA... a mixer, and a noise generator. Wow... what an awesome set-up. Tell me more about what inspiring and creative patches you've come up with. I can't wait to hear. What other advice do you have for me? So knowledgeable... you should create your own tutorials. If you get a filter, you might be able to create your own hi-hat. That's awesome.

I'm done with you, troll.

Detroit Modular is my go-to place. I've never had issues ordering from them. I've had a couple of self-created issues, but they sorted me out and I was shipped the right gear. They ship same-day or next day, generally.

Perfect Circuit is very active on Youtube. However they are super-slow to ship. But sometimes they have fantastic sales for holidays.

Sweetwater is fine. But they don't stock a lot of modules.

SynthroTek makes "Cheeks Of Steel" It's really inexpensive. The downside is it only comes as a kit. If you're not handy with an iron and test meters then you'll probably want to pass. But it's around $60US.

Lugia is probably/definitely the most knowledgeable person in these forums. Don't characterize what he said as "aggressive." It wasn't.

You have a collection of modules that makes absolutely no sense on their own. You haven't put the time in studying how analog synths work. You don't just buy a bunch of cool looking stuff and expect to get anywhere. But hey, it's your money and you can waste it however you see fit. You came here looking for answers. He gave them to you for free. Don't squeal because he was curt and to the point.

Now here's my advice. Buy something like a Behringer Neutron. It's $300US. It will teach you everything you need to know about BASIC modular architecture as well as a dedicated line-level out (plus synth level). It has MIDI DIN in as well as USB MIDI. You'll also be able to make use of most of the modules you've already obtained (assuming you have them in a case).

You need a LOT more knowledge before putting together a modular synth that will work for you. Dig in Youtube for tutorials and you may want to download VCV Rack. It's a simulated modular synth environment that is great to learn in.

Respect the knowledge people take the time to share with you. I'm sure you'll have more questions later on and Lugia hitting the reply button rather than skipping it because you got all whiny the last time isn't where you want to be.

Maybe the design has changed. But I see 7U worth of rack. Are you placing this in an Intellijel case? If so, go for the 104HP. It has main outs and MIDI built in... but you won't be needing an Intellijel MIDI 1U module with the Expert Sleepers FH2.

You can ditch the 1U pedal send/return as it needs another module to function. I don't see it in your rack.

You can replace the Intellijel MIDI module with an Intellijel headphone jack.

Ditch the Mutable Instruments stuff and replace them with micro versions of each. You'll appreciate the savings in rack space more than you realize.

Erica offers their modules in a pre-configured rack for 3700Euros called the "Techno System". Perhaps they will make you a deal on a system minus the modules you already have?

Here's my take. The MiniBrute 2 is capable of sending and receiving Eurorack clock pulses. I would expand it based around that functionality. I would consider three modules initially: Expert Sleepers Disting mk4, Ornaments & Crime, and Temps Utile.

All of the modules are multifunctional. This will give you a wide palette of options to augment your brute with. As you learn these three modules, you'll get a better taste for what direction you want to go with your expansion. O&C and TU are available in micro 8HP formats. That will go a long way in a cramped case. You're looking at less than $700US for the lot if you shop around.

There are tons of videos on these modules on Youtube if you choose to go that way.

The ErbeVerb is tasty. You will always want a good reverb. If you have the budget get that too.

Once you feel you've mastered these modules, you'll be in good shape to decide what's next. If you find yourself using a specific feature of one module over and over... you might want to find a dedicated version. For example the Disting and the O&C have quantizers. If you're always using a quantizer then it might be prudent to get a stand-alone module.

The FH1 can serve as an expander to the FH2. The FH2 also has dedicated expansion modules for gates/triggers and CV. If you're integrating with a DAW, that would be the way to go.

A logic module or two might be nice. Joranalogue's Compare Two might be considerable.

The Z4000 is good. I would also recommend a couple of linear envelope generators like the Intellijel Dual ADSR. Stages is good to have but after VCAs, you can never have enough envelope generators.

This is going to be one expensive case. Is this an end-goal or are you going to buy all of it in one go?

Ornaments & Crime micro would be a great replacement and you get a lot more options for your sequencing (dual 16 step sequencing). When NOT using it as a sequencer, you can use it as a quantizer for example. It's 8HP if I recall correctly.

There's several mixers that have cue abilities: the Pittsburgh Lifeforms System Interface, the TEX MIX system from Tesseract, ADDAC's 807 system, and so on...basically, anything that has an AUX send will allow you to do a cue mix, but you might need an extra headphone amp module for use with those. Ladik's M-053 can also be used to split a cue mix out of a mono or stereo bussed signal with an additional headphone amp.
-- Lugia

Not to nit-pick you, but an aux send isn't always cue friendly. The aux send has to be tapped pre-fader/pre-mute to serve as a cue. On most Mackie boards, there's a switch that makes one or two aux sends pre-fader/pre-mute for example. If I remember correctly, you can also monitor the mute bus... anything that is muted can be selected for monitoring.

The Mimetic will give you CV voltages and even a gate out. But, it's not the easiest device to program in a live situation. If you save and store your patterns, then you'll be okay as you can load them on-the-fly.

If you plan on setting up your patterns live, you might want something that has traditional analog faders or pots.

I would also suggest at least one dedicated quantizer. The Disting can do it. But I would definitely NOT recommend the Disting in a live set-up unless you can set it up before your set begins.

Also, Lugia once recommended to a Eurorack mixer with cue mix abilities. Perhaps he'd be kind enough to tell you about it as I don't remember the name... But you might be better off mixing on a traditional mixer that has pre-fader cues as you'll be mixing Eurorack with your line-level hardware synths... and finally, MUTES. DivKid just released a vactrol controlled set of four mutes built to avoid audible pops when switching them in or out. You can use the mutes on a traditional mixer for audio. But if you're trying to mute CV, then I'd definitely look into the DivKid mute module.

The entire FORUMS.

When sorting by the latest post, the results aren't so. I'm expecting to see the thread with the newest post at the top, followed by the second newest, third, etc. It seems almost random. Is it being sorted by the latest VIEWED rather than posted? It should be fixed right away as new forum messages and replies are getting buried by older posts.

Getting your hands on free gear is awesome. But you're going to need to add a lot more things to make them useful. My first thought is that you should get a better understanding of how basic modular modules work. There's a free eurorack simulator known as VCV rack. There's a virtual version of Clouds and Braids in it. You will also find a lot of other modules like VCAs, envelope generators, etc.

Learn how to build a basic set-up in VCV first. It costs nothing so you can make as many mistakes as you like and experiment recklessly. Get a good understanding of how it works and you'll find that making decisions on which pieces of kit to add to be a lot less daunting.

What Lugia said.

The Z8000 sequencer is huge and the outputs are unquantized. Perhaps look into an Ornaments & Crime 8HP multi-function module. The price is about $250US and you get two 16-note sequencers that won't require a quantizer. It also has a dual quantizer function in it as well. If you pair that with an Expert Sleepers Disting Mk4, you get a lot of functionality in a little space. Some functions overlap, which can be an advantage. You can always add the Z8000 to a larger version of this system and your O_C and Disting will find other uses... they won't become redundant.

Look into the 1010 Music Bitbox if you're going to have on-board percussion. It's 26HP if I remember correctly and $600US. But you won't need all of those sample-playback percussion modules and won't need any additional modules to mix them. It also has easy loading alternate firmwares (free!) as a synth engine or an FX box. You can also record and loop any audio signals from inside your modular (it doesn't record DC). This will let you record the output of the RainMaker if you have some sort of awesome ambiance going and want to buy-back some of your modules that went into making it.

A clock source or divider is also a must (IMHO) for starting a system. Pamela's New Workout or a Temps Utile would work out well.

Also, the Rainmaker and Erica DSP have stereo outputs. You'll want some sort of mixer to take your mono signals and stereo signals and combine them... the same for any stereo samples.

And last, the Batumi has an expander called the Poti. It's 3HP. It will give you a lot more functionality out of the Batumi in terms of waveforms and sync/reset. You HAVE to have it IMHO.

The case in your post isn't set up as a 7Ux104 case. Maybe your set-up has changed and the text portion of this message is outdated?

Once you've had your system for a little while, you might want to explore additional filter types including low pass gates. If that's not your thing, you can try additional modulation sources. The Worng Vector Space looks tasty as well as the Xaoc Zadar quad envelope generator.

Granted, you can't go wrong adding an Expert Sleepers Disting Mk4 for a sampler-pack of useful features you might want to add a dedicated module to reproduce.

The Expert Sleeper is a great sampler plate of audio and CV functionality. It's super clunky to use and requires a cheat-sheet print out or an iPhone open to the manual to adjust anything. For the sub $200US, it's worth the hassle for features you're willing to take a few minutes to set-n-forget.

For simple sequencing, have you looked at a micro Ornaments & Crime? The sequencer, Sequins, is VERY useful and offers a LOT of features for a basic sequencer. Plus you have all of the other modes available (like a dual quantizer, etc.). You're looking at $250-300 for the micro version (8HP). Some functions overlap with the Disting. But that gives you a lot more options between the two modules.

So after a lot of hand-wringing, I ordered some more Eurorack modules. I had been debating more and more over the mixer... whether to add a 1010 Music Bitbox at this point and a bunch of other modules. I settled for a Blue Lantern STEREO mixer. It has the most ins and outs and TWO aux sends and returns.

I added a switch, some mutes, an attenuverter, some nice Tiptop ADSRs, and a Joranalogue Filter 8. I took a step back and thought about where I was hitting roadblocks in patches rather than thinking about gear lust. I'm trying to get into the undiscovered aspects of my set-up more and more rather than adding new gear, but I just didn't feel like I was at a point where ideas could develop to the point that I was comfortable taking them into a DAW.

There's more modules planned and probably another 4U Intellijel rack that will become "master-control" with sequencing, interfaces and anything else that was hands on.

Where's the Grayscale Supercell? It's basically Clouds on steroids.

You can find micro versions of Plaits and Tides. That will save you some HP to add in other modules. I would get the Poti expander for the Batumi. Being able to access the additional LFO waveforms as well as sync and reset functions without pulling the module and moving jumpers is a MUST in my opinion.

I would also look at the 2HP line and think about logic modules and switches after you get the core of your system up and running and start thinking about more complex patching.

So what's going in case #2? They don't call it Eurocrack for no reason. :)

I believe the FH1 to be out of production. The FH2 will serve you better. The FH2's browser based interface can't be accessed once your DAW has taken ahold of the FH2. So it's a good idea to know how you'd like it configured before wiggling any knobs. Else you can make adjustments via the front panel... but the menuing is a little clunky on the front panel.

I take it that your DPO and BAI are going to be routed back into the Pro2? I didn't see any dedicated filters or VCAs.

I've been over this a few times... made some revisions... thought about some things. It's more than you want to spend. But your first case is always the most expensive.

Let's not go random. Let's use a sequencer. In fact, let's go with a good sequencer. The 1010 Music Toolbox is $600. Perfect Circuit will discount it to $500 once in a while during sales (Christmas etc.). There are 8 gate outputs and 8 CV outs. You can multiple sequencers running at once. You can have LFOs, random CV, notes (CV and gates)... you can even sample control voltages, record them, and then play them back in a loop (works for audio too). It'll cover a lot of modulation sources, which you'll want for evolving stuff.

Braids. Braids is a workhorse of different sounds. Having a multitude of different sounds will give you a much wider palette than a basic oscillator. Braids also has a built in internal quantizer just in case you really do want to go random... I didn't forget.

A simple multimode filter. Not thrilling... but filters can create a lot of movement in ambient sounds. It will output all three filtered outputs at once (modulating two or more with two VCAs can be tasty).
Z4000 ADSR with nice long stages available. Plus you can modulate the amount each stage.

Intellijel Quad VCA. This is the one to get. It's very versatile and can even sum outputs.
A-138s stereo mixer. Mono-ambient sounds... (yawn)
Pittsburgh Modular Lifeforms Out. If a tree falls in an oscillator and there's no one to hear it... it's also stereo and has a dedicated headphone jack... very convenient when you're tweaking and wiggling away.

There's a lot more you can do with slew limiters, other FX, more ADSRs, dedicated LFOs, etc. But to me this set-up will be fast to learn and give you a lot of possibilities and will grow with you into a larger case. I even left you 6HP of space. :)

As always, take this with a grain of salt. Research everything.

1010 Music Toolbox $599
Michigan Synthworks uBraids II $250
2HP MMF $119
TipTop Z4000 NS $165
Intellijel Quad VCA $189
Doepfer A-138s $90
Pittsburgh Modular Lifeforms Out $99

What's your budget excluding the case? Clouds is a stereo module. Will you be satisfied with a mono output? Are you using the white noise generator as just as a random voltage source and/or an audio source?

Don't purchase anything. It feels like you're throwing modules into a rack and hoping that something useful takes shape.

The Mutable Instruments Clouds module is no longer available. However, you can purchase it used or better yet buy a 3rd party micro version. Look for a Michigan Synthworks uBurst or the like.

My advice would be to download VCV Rack. It's free. It also has a virtual version of Clouds. Look for some ambient tutorials on Youtube and start practicing. Once you've learned HOW to make random ambient textures in VCV then start looking at putting together a system.

This is an established rack.
The modules that I'm about ready to add are the following:
1010 Music Bitbox
Befaco Dual Attenuverter
Joranalogue Switch 4
Tiptop Audio Z4000NS
Intellijel USB Power 1U (2)

I'm mostly creating pitched sequences. But I'm wanting to branch out into some ambient textures as well. I'm not looking to produce full songs on modular. I'll probably arrange in a DAW.

A Happy Nerding PanMix will probably end up in the rack eventually. Are there any other utility type of modules I might be missing at this stage? There's more stuff on the wishlist but I wanted you to chime in. Your opinion is always respected.

What exactly are you trying to get out of your sequencer. I'm a little confused if you're looking for basic sequencing or something advanced to use along side something basic.

I'd spend a couple of days looking through manuals and watching Youtube videos around the following sequencers:
1. Eloquencer
2. 1010 Music Toolbox
3. Micro Ornaments and Crime in "Sequins" mode.
4. NerdSeq
5. Tiptop Z8000
6. Pittsburgh Modular Electronic Sequence Designer

Each of them have their strengths and weaknesses of course. You're looking around $500-700US for each except O_C ($250-300) The Pittsburgh unit is also available in a stand-alone case for $50 more; which extends the life of your rack in terms of available HP. There are plenty more solutions out there. But at the end of the day you'll do your research, hold your breath, and then hope you made the right decision as you enter your credit card info.

My opinion would be to start with something basic like the O_C then make another purchase a few months later. The O_C can serve quite a few purposes so it won't become redundant in your rack.

There is no wrong way to build a patch. Sometimes you start with the audio pathing... sometimes you start with the CV. It depends on your idea or mental sketch.

Once you have a bit of experience, you'll start coming up with interesting ideas... AWAY from your case. Maybe there's a feature you haven't explored. Maybe you have this crazy CV routing idea that might or might not work the way you've envisioned it.

Just be prepared for happy-little-accidents that take you away from your original goal. Don't be afraid to explore something accidental or unintended. That's the beauty of modular.

Why dummy patches?

I have an Intellijel Morgasmatron dual filter. Both filters can be used discretely. HOWEVER, the FM2 input of filter one is normalled to the FM2 input of filter two. If I don't want the modulation of filter one to affect filter two, I have to connect a dummy patch to the FM2 input of filter two to break the normal.

As far as limited space:
Get the Moogs out of the rack as Lugia suggested.

Here are some recommendations:
Expert Sleepers Disting Mk4. I find it clunky to use. But for the price and the space it's hard to beat. The module offers a lot of functionality. I used it as a wildcard in my patches as well as a great sampler (not musical but like a box of chocolates) of functionality. Do I need a dedicated quantizer, precision adder, etc? If I find myself using a particular function over and over, I probably should investigate buying a dedicated module for that functionality.

Ornaments and Crime/Temps Utile (micro versions): Each one is around the $250 mark. They are multi-function modules as well. Same principle as above.

The Disting is 4HP, the O_C and T_U are 8HP each. So for $700 and 20HP you get a boatload of functionality for a very young rack. As you learn more and want to expand your capabilities you can grow your rack around them.

There's a precision adder in the Disting. Joranalogue also makes one that's pretty tasty.

With buffered mults, in an ideal world, you want multiple copies of EXACTLY what you've fed into it. Being able to attenuate or boost the outputs would defeat the purpose of a well made mult. Your buffered mults will serve you well when you're trying to split the same control voltages... especially those controlling the pitch of two or more oscillators. Passive mults or simply splitting (like with a stackable cable) can cause voltage drops. A drop in voltage means you're not getting the exact CV that you've put into it.

Cool! Nice set-up BTW. Also, be sure to invest in enough patch cables. You'll want some stackables as well. ALSO, Kona makes some cables with built in passive attenuators. They are handy in a pinch.

Oh, do you have any buffered mults? You may want some if you can squeeze 2HP somewhere.

I've bought Michigan Synth Works before. They are good builds and available from retailers. You can also get your micro units commissioned by private builders; but check around before you send off your money. I had a couple made from someone on Modular Grid and he did a great job and delivered as promised (actually a couple of days early).

Using an envelope inside PNW, Disting, or another module like Ornaments & Crime will definitely work. But the flip-side to that is that the envelopes are readily available for tweaking. Menu diving sucks. Envelopes tend to take a lot of back and forth depending on what you're trying to achieve (like getting that perfect pitch and decay envelope on an 808 style kick). The two envelopes in the Neutron would be okay. But it's pretty inconvenient using them and they are pretty basic. Trying using what you have at first. But keep in the back of your mind that you might want space for the dedicated envelopes. Envelopes can do more than control VCA and filter cutoffs. You'll probably want more and a few different types.

Looks good. I see three HP of empty space. If you could squeeze in a Poti (3HP) for the Batumi, that would be advantageous. You can change the waveshapes of the Batumi on the fly as well as its behavior regarding sync vs. restarting.

You may also want to check out the micro versions of Clouds and Tides. They'll save you some rack space and give you a little more HP room to play with.

As far as your MIDI to CV converter, you may want to review Expert Sleepers FH2. You'll have more outputs and save some rack space there too.

I don't see any standard envelope generators. You have the Maths and Stages. But you might want something a little more traditional as well like a Tip Top Z4000NS. Each stage of the envelope can be modulated independently as well.

Also, the Erica tube gear uses up a lot of amps when you first turn the system on. Considering that you have a full-boat of modules, CAREFULLY go over the total number of amps you're going to draw per power supply. I believe that you have two.

Get rid of the Mutamix since you have two u4xVCAs and replace it with the Happy Nerding PanMix. Now you have a stereo mixer with a headphone out built in. You can get rid of the Intellijel Headphone Out and the blank panel and pop in another Intellijel buffered mult or the Intellijel ZeroScope.

Also, you're 1HP over on your bottom row.

"Faders and mute switches"

That sounds like a job for the Roland 531 Mixer module. You get six channels with faders and pans. The pans are CV controllable. You also get mute switches, a preamp and a headphone output.
https://www.modulargrid.net/e/roland-system-500-531

Veils functions similar to the Quadratt EXCEPT you have CV control of each output volume. I wouldn't define either of these as a proper mixer, though you can use them as basic mixers or submixers. I would think about all of your outputs (drum modules, FX units, etc.) and figure out how many audio signals you might want to mix together at once. With eight "mixer" inputs (seven if you're cascading one unit into another), you're going to probably be short when it comes to a complicated patch.

Look into the Roland 531, Happy Nerding PanMix, Pittsburgh Modular Lifeforms System Interface, and Blue Lantern Stereo Sir Mix A Lot. All of them are 6 input mixers with pan capabilities on all/most channels depending on the unit. With exception to the Blue Lantern, they all have headphone outputs as well.

You probably won't need a decent mixer to begin with. The Quadratt and Veils will be enough to get you going. But as you start to flush out your case, you'll probably want one.