Cleveland Music Co. Hothouse DIY Digital Signal Processing Pedal Kit Build Guide (Stereo Version)

Note

THIS IS THE BUILD DOC FOR THE STEREO VERSION OF THE HOTHOUSE. If you bought the mono version, the build guide can be found here. If you're not sure what you have, look at the largest PCB in the kit to confirm: the stereo version will read "Stereo" along the right edge of the face.

The Cleveland Music Co. Hothouse DIY Digital Signal Processing Pedal Kit

Tip

IF YOU PURCHASED AN ASSEMBLED HOTHOUSE, YOU CAN SKIP TO INSTALLING THE DAISY SEED IN AN ASSEMBLED HOTHOUSE, but it's still recommended that you read (or at least skim) through the guide so you understand what has already been done to this point. The pictures of the inside of the pedal are helpful in any case.

PLEASE READ THIS ENTIRE DOCUMENT BEFORE YOU BEGIN! This can’t be stressed enough. Seriously. Once you’ve seen all the pictures and you’ve read all the steps, you’ll be far better able to visualize what you’re trying to accomplish as you go along. And, most importantly, you’ll be far less likely to make frustrating mistakes.

This is a living document. Please check back regularly for updates. For suggestions, corrections, etc., please email info@clevelandmusicco.com.

Overview

The Cleveland Music Co. Hothouse is a compact pedal kit for the Electrosmith Daisy Seed DSP. You can use the Hothouse to easily get your Daisy Seed DSP projects off the breadboard and onto your pedalboard, and / or you can simply compile and flash any of the code in the companion GitHub repo to your Hothouse.

What you’ll need:

• An Electrosmith Daisy Seed (65MB RAM recommended!)
• Some experience with soldering and basic electronics DIY
• A soldering iron and solder
• Flush cut soft wire cutters (these are great)
• A small flat-blade screwdriver
• A Phillips head screwdriver
• Small needle nose pliers
• 8mm, 10mm, and 14mm deep sockets with wrench or spinner handle (try these)
• Third hand / helping hand tool (optional)
• Blue painter’s tape (optional)

Review the kit contents

Ensure you have all of the components pictured above:

• 1 – enclosure with backplate and screws
• 1 – Audio and DC I/O PCB
• 1 – Hothouse Main PCB
• 1 – Switching and LED PCB
• 1 – 2” 6-pin ribbon cable
• 1 – 1” 6-pin ribbon cable
• 2 – 20pin 2.54mm pitch female headers
• 2 – red 3mm LEDs
• 1 – DC power jack
• 2 – Neutrik audio jacks with mounting nuts
• 6 – B10K potentiometers with mounting nuts and washers
• 6 – knobs
• 3 – pot covers
• 3 – ON-OFF-ON toggle switches with mounting nuts and washers
• 2 – momentary foot switches with mounting nuts and washers

Occasionally, some of the solder pins on the potentiometers get slightly bent during shipping. This is completely normal and you can gently bend the pins back into position without any issue.

Order of operations

As of this writing, we have not done a video of the build process ... but wait ...

Important

Floyd Steinberg has! This is an awesome video presenting how he built, programmed, and uses the Hothouse.

Caution

The Hothouse in the thumbnail and video above is the legacy mono version! It has an extra ribbon cable compared to the version you will be building in this guide. Just remember that your stereo pedal WILL NOT have a long ribbon cable that "flies" over the Daisy Seed like the one above, nor will it have two cables connecting the Main PCB to the Switching & LED daughterboard. The stereo Hothouse only has two ribbon cables in total, and is generally easier to build. Apologies for any confusion!

As great as the above video is, there are a few things that differ from the build guide that follows: namely, Floyd assembles the MONO VERSION in the video. You are about to build the STEREO VERSION. So, watch the video, skim the guide, compare the two, and then engage your thinking gland. Just know that following the steps below in the presented order will help you avoid some frustrating pitfalls. So, even if you’re an experienced solder jockey, don’t go all MacGyver; do the following and in the order listed!

For reference, here’s a picture of an assembled Hothouse. As you go through the build, refer back to this image if you’re unsure of what the end product is supposed to look like. In particular, note which side of the PCBs the components go on, and which side gets soldered. It is extremely tricky to de-solder components with more than 2 solder pins, and this build is comprised of almost entirely such components.

Gut shot of a finished Hothouse pedal

Assemble the main PCB

Hothouse Main PCB

1. Solder the 20 pin female headers (x2)

Note

A helping hand tool might be useful for this step.

There are 2 long lines of 20 staggered pads running left-to-right on the top half of the PCB. You will be soldering 1 header into each line. The headers should be assembled so the solder joints are on the back of the PCB (the side that reads #HEYJELLYBEAN) and the black plastic bits are on the top side with all the components (refer to the pictures).

Using the minimum amount of solder required, solder 1 pin on each header and ensure the positioning of the header is correct. Adjust and reflow the solder if necessary. Now, rinse and repeat 38 more times 😉 DO NOT USE MORE SOLDER THAN NEEDED!

Headers install perpendicular to the PCB face ... NO LEANING!

Important

Your Daisy Seed will eventually plug into these headers, so take care to ensure they are parallel and perpendicular to the PCB face as in the above image of an assembled PCB. This is CRITICAL for proper alignment of the USB port with the cutout in the enclosure.

Tip

Some builders have reported that putting the headers on the pins of their Daisy Seed before soldering them to the PCB makes it easy to keep the headers perpendicular. With this approach, the Daisy Seed is used as a makeshift jig.

Now, trim the leads of the header pins on the back of the PCB. You don't need to trim them flush to the board, but remove any portion of the pin rising out of each solder bead. This is important for getting a level PCB later, which ultimately helps align the Daisy Seed USB port with the enclosure cutout.

2. Solder the shorter 6-pin ribbon cable

It might seem strange doing this so soon, but it must be done before soldering in the potentiometers. Otherwise, you won't have access to solder this cable in after the pots are in place. This will be more clear a few steps from now.

Flip the main PCB over to the side that reads #HEYJELLYBEAN. Remove the pre-scored insulation from one end of the 1" ribbon cable. From underneath the PCB, insert the wires through the 6 holes at the top of the PCB (just above POT 2) and use the ribbon cable as a kickstand as seen below. The orientation of the red stripe is not important.

Use the ribbon cable like a kickstand

Use a small bead of solder on each of the bare wires. Reminder: the solder goes on the side that reads #HEYJELLYBEAN. Ultimately, this short cable will connect to the I/O & Power daughterboard as seen in this image of a fully-assembled pedal.

The short ribbon cable in a fully-assembled Hothouse

3. Mask the enclosure with blue painter’s tape (optional but worth it)

Why blue painter’s tape? Because it is lower tack than the white stuff. The latter can leave behind gunk you don’t want to deal with.

Since the hole layout on the enclosure is symmetrical (making it identical on the front and back), it serves as a handy jig for holding the switches and potentiometers while soldering. Simply mask the face of the pedal to protect it from scratches, splattering flux, etc.

Cover the face of the enclosure with blue painter’s tape making the overlapping seams as thin as possible. Then use an X-Acto knife to cut an “X” into the tape over each hole (except the LED holes). Take care not to cut into the powder coat of the enclosure.

The enclosure masked off and ready to be used as a jig

4. Solder the potentiometers (x6) and toggle switches (x3)

Caution

In the following sections, it is stated many times that it is CRITICAL for the PCB to be soldered level to the pots, switches, and enclosure face. This can't be stressed enough. If the PCB is not level, you may have difficulty aligning the Daisy Seed's USB port with the enclosure cutout later.

So, follow these steps, take your time and be extra meticulous. It will pay off later with a USB port that is perfectly centered in the cutout as in the picture below.

A perfectly-centered USB port. So satisfying.

Prepare the potentiometers by removing the washers and nuts from each pot and set them aside for now. Use a pair of needle nose pliers to snap the small locating tabs off each pot. (Leaving these tabs in place would stop the pots from sitting flush against the enclosure.)

Place the 3 clear plastic pot covers on 3 of the 10K pots. There is a slight cutout in the lip of each pot cover; this cutout should be oriented toward the solder pins so the pot cover slides down as far as possible over the pot body. The covers keep the pots from shorting on the back of the PCB.

Prepare the toggle switches by removing the washers and nuts from each switch. Now, put a locking washer back on each toggle switch, followed by a nut. By hand, tighten the nut as far as it will go. This is important for keeping the PCB level while soldering. Set the other three nuts aside for now. The tabbed finish washer can be discarded.

Tip

Someone smarter than me suggested putting the locking washers on the toggle switches first, and the guide has been updated with this tip. Doing it the other way around can lead to frustration as you remove and reinsert the switches and pots in later steps. However, THE PHOTOGRAPHS AREN'T UPDATED YET. So, "do as we say; not as we show in the photos we post" 🫣

With the masked enclosure face-up, insert the two outer toggle switches, one covered pot in the KNOB 5 hole, and two bare pots into the KNOB 1 and KNOB 3 holes of the enclosure. Place the components with the solder pins and lugs facing up and oriented toward the bottom of the enclosure as in the picture below. Also, place the 2 toggle switches so that the text on the sides of the switches face the same direction. (We like the "ON OFF ON" text on the left, so the groove on the shaft of each switch points up.)

Place the pots and switches in the enclosure. NOTE: reverse the order of the locking washers and nuts from what is in this photo!

Now carefully lower the main PCB down over the solder pins and lugs as in the following picture. The pot pins should come through the POT3, POT1, and POT5 holes (three pins each). The solder lugs should come through the SW_3 and SW_1 holes (three lugs each).

The first pots and switches ready to solder

Caution

CHECK THAT THE PCB IS LEVEL AND THE POTS AND SWITCHES ARE FLUSH AND PERPENDICULAR TO THE ENCLOSURE! If the PCB is higher on the toggle switch side of the PCB, try removing the locking washers to level it. The locking washers were used in the above picture, however, the washers may or may not be necessary on your build, depending on how much solder you used while soldering the Daisy Seed headers.

This first solder joint is important and the explanation is a little complex, so read it a few times before proceeding.

You are going to solder the lug closest to the edge of the PCB on SW_3. While you do this, you need to obsessively do three things:

1. Ensure the PCB is level and parallel to the face of the enclosure,
2. Keep the pots and switches flush and perpendicular to the enclosure face, and ...
3. Gently apply pressure to slide the PCB toward the footswitch and LED end of the enclosure without tipping the pots or switches; just use enough pressure so that the PCB is as far toward that end of the enclosure as it can be.

This sounds trickier than it is in practice, so read that last bit again until you're confident.

Now, while performing all three of these things, solder the the lug closest to the edge of the PCB on SW_3. Be prepared to feed a lot of solder! The PCB may not be flush against the base of the toggle switch lugs, and that's OK; it is far more important that the PCB is level and as far toward the footswitch end of the enclosure as possible. Refer to the below picture to see what you will eventually accomplish, but just focus on soldering this first lug for now.

A level PCB with the switches and pots flush against the enclosure (note we used the optional locking washers here)

Tip

When soldering the toggle switches, if you hold the soldering iron to a lug for more than 2-3 seconds, it’s a good idea to take a break from that switch and wait a moment or two before returning to it. We don’t want to smell melting epoxy!

After soldering the first lug on SW_3, perform the following steps while still obsessing over the PCB level and position, and keeping the switches and pots flush to the enclosure:

1. Solder the lug closest to the edge of the PCB on SW_1. Recheck for level and position and reflow the solder if needed.
2. Solder the middle pin on POT5. Recheck for level and position and reflow the solder if needed.
3. Solder the middle pins on POT3 and POT1.

At this point you have a stable base for the rest of the switch and pot soldering operations. You have soldered 5 of 27 total pins and lugs. You can proceed to place and solder the remaining pots and switches in any order you like, but go slow and continue to focus on keeping the PCB level, and the pots and switches flush to the enclosure.

5. Solder the 2” 6-pin ribbon cable

Remove the pre-scored insulation from one end of the 2” 6-pin ribbon cable. From the backside of the PCB, insert the pins of the ribbon cable through the 6 solder pads along the bottom edge of the PCB, so the wires protrude out the top of the PCB. The cable is stiff enough to act like a kickstand and hold the PCB up. Solder the 6 wires on the face of the PCB. In the picture below, you can see that the solder is on the top side of the PCB.

2" 6-pin ribbon cable ready to solder

Set the assembled main PCB aside and move on to the switching and LED PCB.

Assemble the switching and LED PCB

Hothouse Switching & LED PCB

1. Solder the foot switches (x2)

Remove the washers and nuts from both momentary foot switches. Put a nut back on each foot switch and tighten it until about 3-4mm remain between the nut and switch body. This measurement isn’t critical, but it helps to keep the foot switches from sticking up too high on the face of the pedal. Set the other washers and nuts aside for later.

Insert the foot switches into the corresponding FOOTSWITCH 1 and FOOTSWITCH 2 enclosure holes with the solder lugs sticking up and the switches oriented with the curved end facing out and the straight end facing in. (The back of the PCB indicates this orientation, but remember that this is the BACK of the PCB and you will be soldering on the TOP like the image below!)

Solder on this side!

Place the PCB on the 4 solder lugs with the top side of the PCB up (matching the picture above). By design, there is some available wiggle room to allow for manufacturing tolerances, but it’s best to try to solder the switches as close to one another as possible and to keep them straight. This ensures clearance between the switches and the enclosure walls later.

Be ready to feed a lot of solder as you solder each of the 4 lugs!

Important

DO NOT solder the LEDs yet!

Assemble the audio I/O and DC power PCB

Hothouse Audio I/O and DC Power PCB

1. Solder the DC jack (x1)

Note

A helping hand tool could be useful here.

Place the DC power jack on the BACK of the PCB (there is a footprint on the silkscreen) and solder the pins on the TOP. The side you should be soldering reads “Solder this side”. The jack should protrude from the edge of the PCB.

Tip

If you don't have a helping hand tool, get creative; we like to use a pair of needle nose pliers.

2. Solder the audio jacks (x2)

Insert the audio jack pins through the BACK of the PCB with the female jacks facing the same direction as the DC power jack. All three jacks should be oriented the same direction and slightly protrude from the edge of the PCB.

The audio jacks make a handy table that you can easily rest the PCB on while you solder.

Using the audio jacks as a table jig

Final assembly

1. Solder the Main PCB to the Switching & LED PCB with the ribbon cable.

There are several ways to accomplish this using the enclosure as a jig (be creative), but below is a picture of how we like to do it.

Using the enclosure as a jig while soldering the ribbon cable to the Switching & LED PCB

Remove the pre-scored insulation from the ribbon cable. Insert the 6 wires through the back of the PCB and position the assembly as in the picture. Solder the 6 wires on the top side of the Switching & LED PCB.

2. Solder the Audio I/O & DC Power PCB to the Main PCB

Again, there are several ways you can do this, but here's a picture of how we do it.

The 1" ribbon cable is stiff enough to hold the assembled PCB up

Insert the Main and Switching PCB assembly into the enclosure while gently bending the 2" ribbon cable that joins them. Remove the pre-scored insulation from the 1" ribbon cable and rest the Audio I/O & DC Power PCB on top of the 6 wires as in the picture. Now, solder the 2 outer wires, one at a time, while holding the PCB level. Once the 2 outer wires are soldered, you can solder the remaining 4 wires without needing to level the PCB.

3. Final assembly

1. Remove the painter's tape from the enclosure.
2. Insert the 2 LEDs through the provided pads on the Switching & LED PCB so that the LEDs will feed through from the back of the enclosure. The longer leg goes in the pad marked with a + (this is the anode). To hold the LEDs in place while you do final assembly, splay the legs just slightly; only enough to keep the LEDs from falling out easily.

Gently splay the LEDs like this so they don't fall out

3. Gently push the Audio I/O & DC Power PCB toward the Daisy Seed headers, keeping the audio jacks slightly pointed down toward the Main PCB (this will allow clearance for the next step).
4. Now, insert the whole assembly into the enclosure so the pots and switches all come through the face while simultaneously inserting the audio jacks through the holes on the top of the enclosure. This is easier said than done, so a little wiggling will be required. Just be patient and don't apply force.
5. Check the alignment of the Daisy Seed headers with the USB cutout. There is a little bit of tolerance that should allow you to move the Main PCB in the control holes until everything is in alignment.

All this attention to detail was about making sure these headers align perfectly

6. Holding the Main PCB in position, turn it over and place a nut (no washer needed) on each toggle switch and hand tighten
7. Place a washer and nut on each potentiometer and hand tighten.
8. Place a washer and a nut on each foot switch and hand tighten.
9. Flip the enclosure over and carefully feed the LEDs down and through the LED holes so the bulbs poke through the face. The holes are just the right size and won’t let the LEDs fall through. Solder and trim the leads.

The LEDs ready to be pushed down through the holes

The LEDs pushed down through the holes and ready to be soldered and trimmed

4. Hardware dressing

You’re just about done!

1. Use your sockets to tighten all the nuts on the face of the enclosure.
2. Use your small flat head screwdriver to put the knobs on the potentiometers.
3. Secure the audio jacks sticking through the top holes of the enclosure with the provided nuts. There is a little bit of tolerance in this operation; use it to position the DC jack so it is roughly centered in the hole drilled for the barrel connector.
4. Insert your Daisy Seed into the headers with pin 1 in the lower left hand position (and the USB connector facing left as in the pictures).

Tip

The short ribbon cable will bend just slightly during this operation. To control the direction of the bend, use a small tool (screwdriver, needle nose pliers, etc.) to gently bow the ribbon cable away from the Daisy Seed headers.

5. Leave the enclosure backing off while you program the Daisy Seed (at least the first time!). This is because you will either be using a ST LINK V3 MINI Debugger or a USB cable to flash it. For the mini debugger you'll need access to the JTAG header on the Daisy Seed, while the USB approach requires access to the RESET and BOOT buttons. However, you can program the hardware controls on the Hothouse to take care of the reset to bootloader operation for you, if you wish.
6. Once you've got the Daisy Seed programmed as you like, put the enclosure backing on with the provided screws and a Phillips head screwdriver.

Congratulations! You’re ready to use your Hothouse.

Installing the Daisy Seed into an assembled Hothouse

If the Hothouse is already assembled and you want to replace or install the Daisy Seed, the procedure is really simple.

1. Use a Phillips head screwdriver to remove the screws from the enclosure backing and set the backing and screws aside.
2. Insert the Daisy Seed into the headers with pin 1 in the lower left hand position (as seen in the pictures in this guide).
3. Leave the enclosure backing off while you program the Daisy Seed (at least the first time!). This is because you will either be using a ST LINK V3 MINI Debugger or a USB cable to flash it. For the mini debugger you'll need access to the JTAG header on the Daisy Seed, while the USB approach requires access to the RESET and BOOT buttons. However, you can program the hardware controls on the Hothouse to take care of the reset to bootloader operation for you, if you wish.
4. Once the Daisy Seed is programmed as you like, put the enclosure backing on with the provided screws and a Phillips head screwdriver.

About power

Caution

The Hothouse requires a 9V center negative power supply! This is the industry standard for effects pedals, so using a power supply purpose-made for a BOSS-style pedal or pedal board would be fine. There is reverse-polarity protection in the Hothouse, so if you accidentally plug in a center positive supply for a short period of time, your Daisy Seed and the Hothouse itself will probably not be damaged. However, this can't be guaranteed, so please take care when selecting your power supply. It should have this symbol on it (which matches the graphic on the Hothouse enclosure):

More about power

• The Hothouse uses operational amplifiers to buffer the audio in and out of the Daisy Seed. These operational amplifiers are powered by the 9V supply. So, the Hothouse cannot produce sound without the 9V supply.
• With a USB cable plugged in but no 9V supply, you might be able to get the LEDs on the Hothouse to light up (depending on what code you have flashed on it). This is because the 5V supplied by USB is sufficient to power the Daisy Seed itself, but you will never hear sound coming from the Hothouse without a 9V supply powering the operational amplifiers.

What's next?

Now, to get some software running on your Hothouse! Head over to the 10-Minute Quick Start.