VC F3DB stands for Voltage Controlled Fixed Filter Feedback Distortion Bank. The simplest description is it’s an analog 16hp six band voltage controlled fixed filter bank. But with the additions of so much gain, clipping, feedback, and self-oscillation it becomes a very flexible and unique gestural sound sculpting tool capable of; graphic equalization over 6 octaves, multi-band distortion, spectral processing, crude vocoding, multi-frequency envelope following, self-modulation, and even as an instrument on its own. With no input it can be used as a pseudo chaotic “harmonic” feedback oscillator.
The filter frequencies were specifically chosen to emphasize more ambiguous and dissonant intervals. Although the frequency bands are spread out over many octaves I purposely tried to leave out “3rds” besides a major 10th at the top frequencies to even out all the dissonance below. But the frequencies aren’t exactly equal tempered, so it’s relative. The bands roughly equate to F2, B3, F#5, C6, F7, A8.
The design is based on the Moog 914 filterbank, which it borrows the frequency bands from. But this circuit uses active filters with opamps inspired by YU Synth opposed to passive cells using inductors on the original. The 88hz is a low pass -24db/oct and 7k is a high pass -24db/oct, the rest are -12db/oct band pass filters all with a Q around 4.
The hard and soft clipping circuit on the input is fairly standard which appears in many different iterations of classic guitar pedals. But it has a lot of gain and can even boost line level signals. What makes it a bit unique is the feedback on the clipping circuit which needs to be turned on by the GFB(gain feedback) switch and the amount can be controlled by the Gain FB pot which can add some fuzz/bite to the signal depending on which clipping switch is engaged or at the extremes it will self oscillate from audio rate to LFO sort of clicking range. All the clipping stages in the module are using silicon diodes.
Consult the Signal Flow Chart to the left for a rough visual breakdown of the controls,in/outs,normalizations, and optional settings for the module.
Each band can also be muted by the top toggle switches or clipped(at the VCA) by the top slide switch which makes this design a bit different than other filter banks. As well as the overall feedback section(bottom middle) takes the sum/all bands out through a VCA(controlled by the feedback pot and FB CV) back to the input gain/clip circuit. and you can also tap into this using different sends/bands to the FB In jack to break the normalization. With this extra feedback “resonance” you can get more whistley and howly filter sounds kinda like the Serge res eq, which can also go into self oscillation.
All cv ins are expecting +5v to open the VCAs(they wont respond to negative voltage), once you get closer to +8v or so it can clip the vca regardless of the gain settings or clip switches. Output amplitude in high gain settings will exceed 10vpp and can get up to 20vpp. The envelope followers tend to stay around 0-5v out, but with clip switch active they can go up to 10v.
Since this is a high gain module there can be bleed between the bands in certain configurations and situations. Also in high gain modes with higher frequencies the 2.8k and 7k bands can bleed a little with the VCAs closed.
- Width: 16hp
- Panel Material: PCB
- Reverse Power Protected
- Current Consumption: +12v: 75mA, -12v: 75mA
- Depth: 45mm, 1.77″
- Ships with M3 black nylon screws
- Expandable: Yes
How much is my shipping?
Shipping is automatically calculated before you submit your payment information. Simply add items to your cart and proceed to the checkout page, where you'll be offered shipping options and their prices. In the UK it's normally around £4 for order values under £150, and free above that. Shipping to mainland EU is typically between £7 and £20, depending on the shipping method and the size and weight of the order.
Do you ship to my country?
Almost certainly - the site will give you an estimate of shipping costs if you add an item to the cart and then enter your country and postcode. If you have specific requirements (such as if you prefer UPS over FedEx, for example) then let us know in advance and we'll try to work something out for you.
Shipping methods
We use a combination of Parcelforce, DPD, Royal Mail and UPS for the UK, and for international orders it's either Royal Mail, UPS, DHL or FedEx depending on where you are in the world. If you have a particular preference then try to let us know BEFORE you order so we can look into it for you. Please note that there may occasionally be additional shipping charges if you live in a remote area, depending on what surcharges are applied by the shipper. We'll get in touch to discuss this with you in such cases.
Dispatch times
For UK orders, we normally dispatch the same working day if we get the order before 15:00. If you have a really urgent situation then of course drop us an email before ordering and we'll always do our absolute best to accommodate you.
For international orders, we normally dispatch the same day if we get the order before 13:00 but again, occasionally it might be the next day before we can send it out, and sometimes FedEx or UPS may come a little earlier than scheduled which would also push an order into the next day.
Shipping times
Since April 2020 the couriers we use have suspended guarantees for shipping times, so even though we're paying them for priority services - 24-48 hours for most of the world - in practice it's often an extra day on top and sometimes it can be longer.
There is absolutely nothing we can do about this unfortunately. If you are outside the UK and it's a life-or-death situation where you absolutely MUST have that passive mult for the next day then... it may be better to find a local supplier.
Saturday shipping
If you're in the UK and you order before 15:00 on a Friday then we can send something for a Saturday delivery (NB: this applies to UK mainland addresses only). The success rate with DPD is about 95% so it's worth a punt most of the time. Please note that if you select Saturday shipping on an order placed earlier in the week, we'll wait until Friday to ship it.
Pre-orders
If a product is listed as a pre-order, it means we've ordered it from the supplier but it's not physically in stock yet. The product listing will include an estimated shipping date based on the best information we have from the supplier, but do bear in mind this is subject to change and is not a guaranteed date.
If you place an order containing a mixture of in-stock and pre-order items, we'll normally hold off on shipping anything until the pre-order item(s) have arrived, rather than splitting it into multiple shipments. If you need the in-stock items sooner, we'd recommend placing separate orders. As always, please get in touch if you have questions.
Product Overview
VC F3DB stands for Voltage Controlled Fixed Filter Feedback Distortion Bank. The simplest description is it’s an analog 16hp six band voltage controlled fixed filter bank. But with the additions of so much gain, clipping, feedback, and self-oscillation it becomes a very flexible and unique gestural sound sculpting tool capable of; graphic equalization over 6 octaves, multi-band distortion, spectral processing, crude vocoding, multi-frequency envelope following, self-modulation, and even as an instrument on its own. With no input it can be used as a pseudo chaotic “harmonic” feedback oscillator.
The filter frequencies were specifically chosen to emphasize more ambiguous and dissonant intervals. Although the frequency bands are spread out over many octaves I purposely tried to leave out “3rds” besides a major 10th at the top frequencies to even out all the dissonance below. But the frequencies aren’t exactly equal tempered, so it’s relative. The bands roughly equate to F2, B3, F#5, C6, F7, A8.
The design is based on the Moog 914 filterbank, which it borrows the frequency bands from. But this circuit uses active filters with opamps inspired by YU Synth opposed to passive cells using inductors on the original. The 88hz is a low pass -24db/oct and 7k is a high pass -24db/oct, the rest are -12db/oct band pass filters all with a Q around 4.
The hard and soft clipping circuit on the input is fairly standard which appears in many different iterations of classic guitar pedals. But it has a lot of gain and can even boost line level signals. What makes it a bit unique is the feedback on the clipping circuit which needs to be turned on by the GFB(gain feedback) switch and the amount can be controlled by the Gain FB pot which can add some fuzz/bite to the signal depending on which clipping switch is engaged or at the extremes it will self oscillate from audio rate to LFO sort of clicking range. All the clipping stages in the module are using silicon diodes.
Consult the Signal Flow Chart to the left for a rough visual breakdown of the controls,in/outs,normalizations, and optional settings for the module.
Each band can also be muted by the top toggle switches or clipped(at the VCA) by the top slide switch which makes this design a bit different than other filter banks. As well as the overall feedback section(bottom middle) takes the sum/all bands out through a VCA(controlled by the feedback pot and FB CV) back to the input gain/clip circuit. and you can also tap into this using different sends/bands to the FB In jack to break the normalization. With this extra feedback “resonance” you can get more whistley and howly filter sounds kinda like the Serge res eq, which can also go into self oscillation.
All cv ins are expecting +5v to open the VCAs(they wont respond to negative voltage), once you get closer to +8v or so it can clip the vca regardless of the gain settings or clip switches. Output amplitude in high gain settings will exceed 10vpp and can get up to 20vpp. The envelope followers tend to stay around 0-5v out, but with clip switch active they can go up to 10v.
Since this is a high gain module there can be bleed between the bands in certain configurations and situations. Also in high gain modes with higher frequencies the 2.8k and 7k bands can bleed a little with the VCAs closed.
Technical Specs
Shipping Details
How much is my shipping?
Shipping is automatically calculated before you submit your payment information. Simply add items to your cart and proceed to the checkout page, where you'll be offered shipping options and their prices. In the UK it's normally around £4 for order values under £150, and free above that. Shipping to mainland EU is typically between £7 and £20, depending on the shipping method and the size and weight of the order.
Do you ship to my country?
Almost certainly - the site will give you an estimate of shipping costs if you add an item to the cart and then enter your country and postcode. If you have specific requirements (such as if you prefer UPS over FedEx, for example) then let us know in advance and we'll try to work something out for you.
Shipping methods
We use a combination of Parcelforce, DPD, Royal Mail and UPS for the UK, and for international orders it's either Royal Mail, UPS, DHL or FedEx depending on where you are in the world. If you have a particular preference then try to let us know BEFORE you order so we can look into it for you. Please note that there may occasionally be additional shipping charges if you live in a remote area, depending on what surcharges are applied by the shipper. We'll get in touch to discuss this with you in such cases.
Dispatch times
For UK orders, we normally dispatch the same working day if we get the order before 15:00. If you have a really urgent situation then of course drop us an email before ordering and we'll always do our absolute best to accommodate you.
For international orders, we normally dispatch the same day if we get the order before 13:00 but again, occasionally it might be the next day before we can send it out, and sometimes FedEx or UPS may come a little earlier than scheduled which would also push an order into the next day.
Shipping times
Since April 2020 the couriers we use have suspended guarantees for shipping times, so even though we're paying them for priority services - 24-48 hours for most of the world - in practice it's often an extra day on top and sometimes it can be longer.
There is absolutely nothing we can do about this unfortunately. If you are outside the UK and it's a life-or-death situation where you absolutely MUST have that passive mult for the next day then... it may be better to find a local supplier.
Saturday shipping
If you're in the UK and you order before 15:00 on a Friday then we can send something for a Saturday delivery (NB: this applies to UK mainland addresses only). The success rate with DPD is about 95% so it's worth a punt most of the time. Please note that if you select Saturday shipping on an order placed earlier in the week, we'll wait until Friday to ship it.
Pre-orders
If a product is listed as a pre-order, it means we've ordered it from the supplier but it's not physically in stock yet. The product listing will include an estimated shipping date based on the best information we have from the supplier, but do bear in mind this is subject to change and is not a guaranteed date.
If you place an order containing a mixture of in-stock and pre-order items, we'll normally hold off on shipping anything until the pre-order item(s) have arrived, rather than splitting it into multiple shipments. If you need the in-stock items sooner, we'd recommend placing separate orders. As always, please get in touch if you have questions.
