The SoundForce uChorus is 4HP compact version of the classic Juno style BDD chorus. It is using the Xvive MN3009 and the same audio path as the original circuit. It can do the classic Juno I, II and I+II modes. I+II modes are available from both the Juno 6 and Juno 60, each in mono (as the original) or stereo, giving you 4 I+II options. This module is a stripped down version of the bigger Chorus 6 module which includes CV control.
Some tech-talk:
A chorus effect is created by mixing a dry signal with a delayed signal. The delay time is modulated by an LFO to create more movement. To create some stereo width, the left and right modulation are 180 degrees out of phase. Exactly like the chorus in the Juno 6/60/106, the delay is made with MN3009 BBD chips. Also as in the original design, filters are added both before and after the BBD chips in an attempt to hide some of the artefacts of this very crude IC.
To get the audio “moving” through the chain of MOSFETs in the BBDs, driver signals are needed. This used to be done with the MN3101 BBD driver chip. Unlike the MN3009, there is no clone available of this ancient IC and this was a chance to add some modernity to the design. The drivers were replaced by a modern STM32 micro-controller along some extra ICs to convert the 3.3V logic to the negative voltage needed by the MN3009.
In order to recreate a genuine Juno-type modulation, the BDD driver signals of my Juno-106 were sampled over a few periods. Using the timer peripherals of the STM32, a replica of the BBD driver signals can be sent out to the MN3009’s. Although the driver signals only follow a very basic triangle LFO shape and could have been generated using direct synthesis in the firmware, this method gives an exact copy of the original driver signals including all the potential imperfections.
Implementing a digital programmable chip also allows a digital-style interface with tactile switches and LEDs as in the original Juno interface. The last used mode is saved and loaded when the module powers on.
Price and availability:
It’s available from end of June 2023 at ±199 euros incl VAT (164 euros outside of Europe) on the SoundForce webshop and at my dealers. US customers can order directly from Perfect Circuit Audio.
Features:
The SoundForce uChorus 6 features 3 simple tactile switches on the front panel. Press OFF, I or II to switch between the standard modes. Press both I and II to enter the I+II mode. While holding down I and II, press the OFF button to cycle through the 4 I+II options:
– Juno 60 mono – 1hz – 8% depth
– Juno 60 stereo – 1hz – 8% depth
– Juno 6 mono – 8hz – 25% depth
– Juno 6 stereo – 8hz – 25% depth
Stereo inputs:
The uChorus 6 can be used with either mono or stereo input signals. When the right channel is unconnected, the left channel is sent to the right jack so it can be used with mono signals. When using both inputs, each input signal is going through its own BBD delay line.
Input levels:
Both Eurorack and Line level signals can be used as input for the uChorus. A small slide switch between the 2 PCBs can switch between Euro and Line. In Euro levels, the input signal is attenuated to an healthy level that is well below the BBD distortion point. Some headroom is also needed as the chorus is a sum of the input signal and the modulated delayed signals. For that reason, when the chorus is turned off the output attenuation is about 50% of the input level. When the chorus is on, the resulting output amplitude is similar to the input level. Line levels are also accepted by the module when the switch is on Line. Please note that Line levels input will be amplified to the Eurorack levels range at the output of the module. So the output levels are Eurorack in both Euro or Line input ranges.
Specifications:
– 4HP
– Depth: 38mm (including power connector)
– Power: +12V 46mA, -12V 20mA
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 15:30 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
The SoundForce uChorus is 4HP compact version of the classic Juno style BDD chorus. It is using the Xvive MN3009 and the same audio path as the original circuit. It can do the classic Juno I, II and I+II modes. I+II modes are available from both the Juno 6 and Juno 60, each in mono (as the original) or stereo, giving you 4 I+II options. This module is a stripped down version of the bigger Chorus 6 module which includes CV control.
Some tech-talk:
A chorus effect is created by mixing a dry signal with a delayed signal. The delay time is modulated by an LFO to create more movement. To create some stereo width, the left and right modulation are 180 degrees out of phase. Exactly like the chorus in the Juno 6/60/106, the delay is made with MN3009 BBD chips. Also as in the original design, filters are added both before and after the BBD chips in an attempt to hide some of the artefacts of this very crude IC.
To get the audio “moving” through the chain of MOSFETs in the BBDs, driver signals are needed. This used to be done with the MN3101 BBD driver chip. Unlike the MN3009, there is no clone available of this ancient IC and this was a chance to add some modernity to the design. The drivers were replaced by a modern STM32 micro-controller along some extra ICs to convert the 3.3V logic to the negative voltage needed by the MN3009.
In order to recreate a genuine Juno-type modulation, the BDD driver signals of my Juno-106 were sampled over a few periods. Using the timer peripherals of the STM32, a replica of the BBD driver signals can be sent out to the MN3009’s. Although the driver signals only follow a very basic triangle LFO shape and could have been generated using direct synthesis in the firmware, this method gives an exact copy of the original driver signals including all the potential imperfections.
Implementing a digital programmable chip also allows a digital-style interface with tactile switches and LEDs as in the original Juno interface. The last used mode is saved and loaded when the module powers on.
Price and availability:
It’s available from end of June 2023 at ±199 euros incl VAT (164 euros outside of Europe) on the SoundForce webshop and at my dealers. US customers can order directly from Perfect Circuit Audio.
Features:
The SoundForce uChorus 6 features 3 simple tactile switches on the front panel. Press OFF, I or II to switch between the standard modes. Press both I and II to enter the I+II mode. While holding down I and II, press the OFF button to cycle through the 4 I+II options:
– Juno 60 mono – 1hz – 8% depth
– Juno 60 stereo – 1hz – 8% depth
– Juno 6 mono – 8hz – 25% depth
– Juno 6 stereo – 8hz – 25% depth
Stereo inputs:
The uChorus 6 can be used with either mono or stereo input signals. When the right channel is unconnected, the left channel is sent to the right jack so it can be used with mono signals. When using both inputs, each input signal is going through its own BBD delay line.
Input levels:
Both Eurorack and Line level signals can be used as input for the uChorus. A small slide switch between the 2 PCBs can switch between Euro and Line. In Euro levels, the input signal is attenuated to an healthy level that is well below the BBD distortion point. Some headroom is also needed as the chorus is a sum of the input signal and the modulated delayed signals. For that reason, when the chorus is turned off the output attenuation is about 50% of the input level. When the chorus is on, the resulting output amplitude is similar to the input level. Line levels are also accepted by the module when the switch is on Line. Please note that Line levels input will be amplified to the Eurorack levels range at the output of the module. So the output levels are Eurorack in both Euro or Line input ranges.
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 15:30 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.
