A-110-4 is a so-called Thru Zero Quadrature VCO. The term "quadrature" means in this connection that the oscillator outputs sine and cosine waveforms simultaneously. The term "Thru-Zero" means that even "negative" frequencies are generated. But this a bit a misleading term as negative frequencies do not really exist. "Negative" means in this connection simply that the sine/cosine waves will stop when the linear control voltage reaches 0V and continue with the opposite direction as the linear control voltage becomes negative and vice versa.
The module has two control sections: linear and a exponential. The exponential section consists of the XTune control, the 1V/Oct input and the XFM input with the corresponding attenuator XFM. The exponential control voltage is the sum of these three voltages. The linear section consists of the LFrq control and the LFM input with the corresponding attenuator LFM. The linear control voltage is the sum of these two voltages. A dual color LED is used to display the polarity of the linear control voltage (red = positive, yellow = negative). The pitch of the sine/cosine outputs is determined by the control voltages of both sections. The linear section is used to control the pitch in a linear manner. When the LFrq control (LFrq means Linear Frequency Control) is fully CW the module works like a normal Quadrature VCO (e.g. like the A-143-9) and the LED lights red (red = positive). The pitch is then controlled by the exponential section with the manual Tune control XTune and the exponential frequency control inputs 1V/Oct and XFM. 1V/Oct is used to control the pitch by a 1V/Oct CV source (e.g. sequencer or Midi/USB-to-CV interface). XFM is used to apply an exponential frequency modulation with adjustable depth (e.g. from an LFO or another VCO). As the LFrq control is turned counterclockwise starting from the fully CW position the frequency is lowered in a linear manner until the sine/cosine waves (nearly) stops at the center position of LFrq (provided that no LFM signal is present). As the LFrq control is moved from the center towards the CCW position the wave starts again but into reverse direction and the LED turns yellow. When the fully CCW position of LFrq is reached the module works again like a normal Quadrature VCO. But much more exciting is the usage of the LFM input to modify the linear control voltage by an external control voltage (typically another sine VCO like a second A-110-4 - but even normal VCOs can be used). Linear modulation by another oscillator using the thru zero feature generates audio spectra than cannot be obtained from an oscillator without the thru zero function. The reason is that a "normal" VCO will simply stop as the linear control voltage becomes zero or negative. But a thru zero VCO will start again with "negative" frequencies as the the linear control voltage becomes negative.
The main advantage of the A-110-4 compared to other Thru Zero VCOs is that the design uses a sine/cosine core. The sine/cosine waves are not derived from other waveforms (e.g. sawtooth or triangle) by means of waveshaping. Rather the sine and cosine waves are the core of the VCO which results in very pure waves with a minimum of distortion and overtones.
The output level is about 10Vpp (please refer to the note at the bottom for the output level of older versions).
Important note: Please remove the bus jumper (JP3 "BUS CV") if no CV transmitter is installed on the same bus (e.g. a Midi/USB-to-CV interface A-190-x or a bus access module A-185-x). The A-110-4 applies a small voltage with high impedance (100k) to the CV line of the bus when the bus CV jumper is installed. This may affect other modules that pick-up CV from the bus (e.g. other VCOs). As soon as a CV transmitter is installed on the same bus the high impedance voltage of the A-110-4 is overwritten and no problem occurs !
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, 'next working day' shipping is free if the order value is over £150, and £5 otherwise. We can also ship on a 'next working day before 12pm' service, which costs £6 for orders over £150 and £7.50 for orders under £150.
Shipping to mainland EU typically costs 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 DPD, Royal Mail and Parcelforce for the UK, and for international orders it's either DHL, FedEx, UPS, Royal Mail or Parcelforce 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 aim to dispatch the same working day if we get the order before 16:00. 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 the couriers may come to collect a little earlier than scheduled which would also push an order into the next day.
Saturday/Sunday shipping
If you're in the UK and you order before 16:00 on a Friday then we can send something for a Saturday or Sunday delivery with DPD. This is FREE for order values over £350, £5 for order values between £75 and £250, and £7 for order values under £75. (NB: this applies to UK mainland addresses only). Please note that any orders placed after 16:00 on a Friday will ship on the Monday.
International 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.
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
A-110-4 is a so-called Thru Zero Quadrature VCO. The term "quadrature" means in this connection that the oscillator outputs sine and cosine waveforms simultaneously. The term "Thru-Zero" means that even "negative" frequencies are generated. But this a bit a misleading term as negative frequencies do not really exist. "Negative" means in this connection simply that the sine/cosine waves will stop when the linear control voltage reaches 0V and continue with the opposite direction as the linear control voltage becomes negative and vice versa.
The module has two control sections: linear and a exponential. The exponential section consists of the XTune control, the 1V/Oct input and the XFM input with the corresponding attenuator XFM. The exponential control voltage is the sum of these three voltages. The linear section consists of the LFrq control and the LFM input with the corresponding attenuator LFM. The linear control voltage is the sum of these two voltages. A dual color LED is used to display the polarity of the linear control voltage (red = positive, yellow = negative). The pitch of the sine/cosine outputs is determined by the control voltages of both sections. The linear section is used to control the pitch in a linear manner. When the LFrq control (LFrq means Linear Frequency Control) is fully CW the module works like a normal Quadrature VCO (e.g. like the A-143-9) and the LED lights red (red = positive). The pitch is then controlled by the exponential section with the manual Tune control XTune and the exponential frequency control inputs 1V/Oct and XFM. 1V/Oct is used to control the pitch by a 1V/Oct CV source (e.g. sequencer or Midi/USB-to-CV interface). XFM is used to apply an exponential frequency modulation with adjustable depth (e.g. from an LFO or another VCO). As the LFrq control is turned counterclockwise starting from the fully CW position the frequency is lowered in a linear manner until the sine/cosine waves (nearly) stops at the center position of LFrq (provided that no LFM signal is present). As the LFrq control is moved from the center towards the CCW position the wave starts again but into reverse direction and the LED turns yellow. When the fully CCW position of LFrq is reached the module works again like a normal Quadrature VCO. But much more exciting is the usage of the LFM input to modify the linear control voltage by an external control voltage (typically another sine VCO like a second A-110-4 - but even normal VCOs can be used). Linear modulation by another oscillator using the thru zero feature generates audio spectra than cannot be obtained from an oscillator without the thru zero function. The reason is that a "normal" VCO will simply stop as the linear control voltage becomes zero or negative. But a thru zero VCO will start again with "negative" frequencies as the the linear control voltage becomes negative.
The main advantage of the A-110-4 compared to other Thru Zero VCOs is that the design uses a sine/cosine core. The sine/cosine waves are not derived from other waveforms (e.g. sawtooth or triangle) by means of waveshaping. Rather the sine and cosine waves are the core of the VCO which results in very pure waves with a minimum of distortion and overtones.
The output level is about 10Vpp (please refer to the note at the bottom for the output level of older versions).
Important note: Please remove the bus jumper (JP3 "BUS CV") if no CV transmitter is installed on the same bus (e.g. a Midi/USB-to-CV interface A-190-x or a bus access module A-185-x). The A-110-4 applies a small voltage with high impedance (100k) to the CV line of the bus when the bus CV jumper is installed. This may affect other modules that pick-up CV from the bus (e.g. other VCOs). As soon as a CV transmitter is installed on the same bus the high impedance voltage of the A-110-4 is overwritten and no problem occurs !
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, 'next working day' shipping is free if the order value is over £150, and £5 otherwise. We can also ship on a 'next working day before 12pm' service, which costs £6 for orders over £150 and £7.50 for orders under £150.
Shipping to mainland EU typically costs 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 DPD, Royal Mail and Parcelforce for the UK, and for international orders it's either DHL, FedEx, UPS, Royal Mail or Parcelforce 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 aim to dispatch the same working day if we get the order before 16:00. 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 the couriers may come to collect a little earlier than scheduled which would also push an order into the next day.
Saturday/Sunday shipping
If you're in the UK and you order before 16:00 on a Friday then we can send something for a Saturday or Sunday delivery with DPD. This is FREE for order values over £350, £5 for order values between £75 and £250, and £7 for order values under £75. (NB: this applies to UK mainland addresses only). Please note that any orders placed after 16:00 on a Friday will ship on the Monday.
International 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.
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.
