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Doepfer A-171-4 Quad VC Slew Eurorack Module

Doepfer

£104.00
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Doepfer A-171-4 Quad VC Slew Eurorack Module main image
Doepfer A-171-4 Quad VC Slew Eurorack Module main image

Out of stock

Shipping info

Manufacturer's description

Module A-171-4 is a fourfold voltage controlled slew limiter. Its intended purpose is polyphonic portamento but can be used also for other applications where several slew limiters are required.

The common slew time can be adjusted manually and in addition controlled by an external control voltage. The module uses light-sensitive resistors (LDR). Therefore the slew times are not exactly the same for all units due to the tolerances of the LDRs and the LEDs, which are used to illuminate the LDRs.

Inputs and outputs of the slew limiters are buffered to avoid voltage drops. This is especially important for polyphonic portamento applications. Each output can drive several VCOs without the need of exernal buffers.

In addition the slew limiter inputs and outputs are available at internal pin headers for internal pre-wiring of polyphonic patches. As the switching contacts of the sockets are used for the internal pre-patching the internal patch can be overridden by using the sockets at the front panel.

The module has these controls and in/outputs available:

  • Control Man. : manual control of the slew limiter value (base value)
  • Control CV: attenuator for the signal applied to the CV socket
  • Socket CV: control voltage input 
  • Sockets In 1...4: slew limiter inputs
  • Sockets Out 1...4: slew limiter outputs
  • LED: visual control of the slew limiter value (dark = long time, bright = short time)

Technical notes

  • Each light-sensitive resistor (LDR) forms together with an associated capacitor a simple standard RC network (Resistor/Capacitor network). Input and output of each network are buffered.
  • The slew time range is about 5 ms ... 10 s (1:2000). Due to the tolerances of the LDRs and the LEDs the slew times vary a bit for each unit. By changing the capacitor values this range can be altered: by lowering the capacitor values the slew limiters can be used as 6dB low pass filters. Increasing the capacitor values result in longer slew times.
  • The 4 photo resistors and LEDs are assembled within an small lighproof box. In addition the pc boards are made of lighproof black material to avoid interfering light from other modules or the bus board.
  • On the module pc boards two pin headers with 4 pins each are available. These are planned for the internal pre-patching of polyphonic modules:
    • In 1...4: The pins of this pin header are connected to the switching contacts of the sockets In 1...4. Hereby an internal four-wire connection to the CV outputs of the polyphonic midi-CV-interface A-190-5 can be made. As long as the sockets In 1...4 are not used the internal connection to the A-190-5 is established.
    • Out 1...4: The pins of this pin header are connected to the outputs Out 1...4. Hereby an internal four-wire connection to the CV inputs of the polyphonic VCO A-111-4 can be realized. If more than one VCO has to be controlled by one output we offer so-called micro multiples.
  • Width: 4HP
  • Depth: 45mm
  • Current: +12V 40mA / -12V 40mA

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

Manufacturer's description

Module A-171-4 is a fourfold voltage controlled slew limiter. Its intended purpose is polyphonic portamento but can be used also for other applications where several slew limiters are required.

The common slew time can be adjusted manually and in addition controlled by an external control voltage. The module uses light-sensitive resistors (LDR). Therefore the slew times are not exactly the same for all units due to the tolerances of the LDRs and the LEDs, which are used to illuminate the LDRs.

Inputs and outputs of the slew limiters are buffered to avoid voltage drops. This is especially important for polyphonic portamento applications. Each output can drive several VCOs without the need of exernal buffers.

In addition the slew limiter inputs and outputs are available at internal pin headers for internal pre-wiring of polyphonic patches. As the switching contacts of the sockets are used for the internal pre-patching the internal patch can be overridden by using the sockets at the front panel.

The module has these controls and in/outputs available:

  • Control Man. : manual control of the slew limiter value (base value)
  • Control CV: attenuator for the signal applied to the CV socket
  • Socket CV: control voltage input 
  • Sockets In 1...4: slew limiter inputs
  • Sockets Out 1...4: slew limiter outputs
  • LED: visual control of the slew limiter value (dark = long time, bright = short time)

Technical notes

  • Each light-sensitive resistor (LDR) forms together with an associated capacitor a simple standard RC network (Resistor/Capacitor network). Input and output of each network are buffered.
  • The slew time range is about 5 ms ... 10 s (1:2000). Due to the tolerances of the LDRs and the LEDs the slew times vary a bit for each unit. By changing the capacitor values this range can be altered: by lowering the capacitor values the slew limiters can be used as 6dB low pass filters. Increasing the capacitor values result in longer slew times.
  • The 4 photo resistors and LEDs are assembled within an small lighproof box. In addition the pc boards are made of lighproof black material to avoid interfering light from other modules or the bus board.
  • On the module pc boards two pin headers with 4 pins each are available. These are planned for the internal pre-patching of polyphonic modules:
    • In 1...4: The pins of this pin header are connected to the switching contacts of the sockets In 1...4. Hereby an internal four-wire connection to the CV outputs of the polyphonic midi-CV-interface A-190-5 can be made. As long as the sockets In 1...4 are not used the internal connection to the A-190-5 is established.
    • Out 1...4: The pins of this pin header are connected to the outputs Out 1...4. Hereby an internal four-wire connection to the CV inputs of the polyphonic VCO A-111-4 can be realized. If more than one VCO has to be controlled by one output we offer so-called micro multiples.

Technical Specs

  • Width: 4HP
  • Depth: 45mm
  • Current: +12V 40mA / -12V 40mA

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.

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