Ostrawa is a fully stereo four-channel voltage-controlled mixer featuring a stereo mixing bus, one stereo auxiliary send per channel (switchable between pre and post-VCA) with stereo returns, clickless muting, individual level meters, and a super-clean and DC-coupled signal path designed with high-quality VCA and opamp chips.
We have carefully crafted Ostrawa’s voltage control response to achieve what we believe to be the optimal user experience found in a Eurorack mixer. The design features an elaborate control circuit that combines the internal voltages generated by the panel potentiometers with external CV over volume and stereo balance.
The result is a natural attenuator response that constrains VCA gain to a usable range while minimizing distortion. Ostrawa, a sister module to Xaoc Devices Praga, features similar response characteristics and layout of controls with some functional differences due to its stereo inputs and limited panel space. Multiple Ostrawa and Praga units may be chained for a custom configurable mixing system.
Features
- Full stereo architecture
- Natural volume response
- Channel level indicators
- Stereo auxiliary send and stereo returns
- Clickless channel muting
- Expandable by chaining more units and optional expander modules
Expandability
Multiple Ostrawa and Praga units may be chained to provide a cascaded sub-mix setup.
A dedicated Bohumin expander adds a second full stereo AUX bus with voltage control over the amount of the effect on each channel of Ostrawa. Bohumin also features manual attenuators for stereo returns of both AUX buses, as well as four gate inputs for automated clickless muting of each stereo input channel.
Ustka is a simple passive expander module that offers direct access to four pairs of stereo signals before they are combined into the mixed signal at the output of Ostrawa. Ustka’s main application is interfacing with external multichannel devices like computer audio interfaces and hardware multitrack recorders.
- Width: 20HP
- Power: 180 mA +12V / 150 mA -12V / 0 mA 5V
How much is my shipping?
Shipping costs are calculated automatically at checkout. Simply add items to your cart and proceed to the checkout page, where you'll see the available shipping options and their prices. VAT at the applicable rate for your country will also be displayed at checkout.
European Union orders:
- Standard shipping is free on orders over €100. Express shipping is available on orders over €100, and free on orders over €400.
Poland orders:
- Standard shipping is free on orders over 250 PLN. Express shipping is free on orders over 500 PLN.
What about local taxes?
By default prices on the site include sales tax at 20%. The precise sales tax rate for your country will be calculated at checkout.
Do you ship to my country?
We ship to all EU member states from our warehouse in Warsaw, Poland. Add an item to your cart and enter your country and postcode to see the available shipping options and prices for your location. If you have any questions about shipping to your country, drop us an email at info@signalsounds.eu and we'll be happy to help.
Shipping methods
All EU orders are shipped via UPS. We offer two service levels:
- UPS Standard – our default shipping option. Delivery times vary by country (see estimated delivery times below).
- UPS Express Saver – next business day delivery to most EU destinations.
Each product page shows the estimated delivery time for your location, so you'll always know what to expect before you order.
Estimated delivery times (Standard shipping)
The times below are estimates in working days from dispatch, based on UPS Standard service. Express Saver delivers by the next business day to most destinations.
| Country | Estimated delivery (working days) |
|---|---|
| Austria | 2–3 |
| Belgium | 2 |
| Bulgaria | 4–5 |
| Croatia | 2–4 |
| Cyprus | 10 |
| Czechia | 2–3 |
| Denmark | 3 |
| Estonia | 2–3 |
| Finland | 3–5 |
| France | 2–4 |
| Germany | 2 |
| Greece | 5–7 |
| Hungary | 2–3 |
| Ireland | 4–6 |
| Italy | 3–5 |
| Latvia | 2–3 |
| Lithuania | 1–2 |
| Luxembourg | 2 |
| Malta | 5–7 |
| Netherlands | 2 |
| Poland | 1–2 |
| Portugal | 4–5 |
| Romania | 3–4 |
| Slovakia | 2–3 |
| Slovenia | 2–3 |
| Spain | 4 |
| Sweden | 3–5 |
These times are estimates and are not guaranteed. Delivery may occasionally take a little longer due to customs processing, local conditions, or carrier delays.
Dispatch times
Orders placed before 15:00 CET (Central European Time) on a working day are normally dispatched the same day. Orders placed after 15:00 CET, or on weekends and public holidays, will be dispatched on the next working day.
If you have an urgent order, please email us at info@signalsounds.eu before placing your order and we'll do our best to accommodate you.
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 at info@signalsounds.eu if you have questions.
Product Overview
Ostrawa is a fully stereo four-channel voltage-controlled mixer featuring a stereo mixing bus, one stereo auxiliary send per channel (switchable between pre and post-VCA) with stereo returns, clickless muting, individual level meters, and a super-clean and DC-coupled signal path designed with high-quality VCA and opamp chips.
We have carefully crafted Ostrawa’s voltage control response to achieve what we believe to be the optimal user experience found in a Eurorack mixer. The design features an elaborate control circuit that combines the internal voltages generated by the panel potentiometers with external CV over volume and stereo balance.
The result is a natural attenuator response that constrains VCA gain to a usable range while minimizing distortion. Ostrawa, a sister module to Xaoc Devices Praga, features similar response characteristics and layout of controls with some functional differences due to its stereo inputs and limited panel space. Multiple Ostrawa and Praga units may be chained for a custom configurable mixing system.
Features
- Full stereo architecture
- Natural volume response
- Channel level indicators
- Stereo auxiliary send and stereo returns
- Clickless channel muting
- Expandable by chaining more units and optional expander modules
Expandability
Multiple Ostrawa and Praga units may be chained to provide a cascaded sub-mix setup.
A dedicated Bohumin expander adds a second full stereo AUX bus with voltage control over the amount of the effect on each channel of Ostrawa. Bohumin also features manual attenuators for stereo returns of both AUX buses, as well as four gate inputs for automated clickless muting of each stereo input channel.
Ustka is a simple passive expander module that offers direct access to four pairs of stereo signals before they are combined into the mixed signal at the output of Ostrawa. Ustka’s main application is interfacing with external multichannel devices like computer audio interfaces and hardware multitrack recorders.
Technical Specs
Shipping Details
How much is my shipping?
Shipping costs are calculated automatically at checkout. Simply add items to your cart and proceed to the checkout page, where you'll see the available shipping options and their prices. VAT at the applicable rate for your country will also be displayed at checkout.
European Union orders:
- Standard shipping is free on orders over €100. Express shipping is available on orders over €100, and free on orders over €400.
Poland orders:
- Standard shipping is free on orders over 250 PLN. Express shipping is free on orders over 500 PLN.
What about local taxes?
By default prices on the site include sales tax at 20%. The precise sales tax rate for your country will be calculated at checkout.
Do you ship to my country?
We ship to all EU member states from our warehouse in Warsaw, Poland. Add an item to your cart and enter your country and postcode to see the available shipping options and prices for your location. If you have any questions about shipping to your country, drop us an email at info@signalsounds.eu and we'll be happy to help.
Shipping methods
All EU orders are shipped via UPS. We offer two service levels:
- UPS Standard – our default shipping option. Delivery times vary by country (see estimated delivery times below).
- UPS Express Saver – next business day delivery to most EU destinations.
Each product page shows the estimated delivery time for your location, so you'll always know what to expect before you order.
Estimated delivery times (Standard shipping)
The times below are estimates in working days from dispatch, based on UPS Standard service. Express Saver delivers by the next business day to most destinations.
| Country | Estimated delivery (working days) |
|---|---|
| Austria | 2–3 |
| Belgium | 2 |
| Bulgaria | 4–5 |
| Croatia | 2–4 |
| Cyprus | 10 |
| Czechia | 2–3 |
| Denmark | 3 |
| Estonia | 2–3 |
| Finland | 3–5 |
| France | 2–4 |
| Germany | 2 |
| Greece | 5–7 |
| Hungary | 2–3 |
| Ireland | 4–6 |
| Italy | 3–5 |
| Latvia | 2–3 |
| Lithuania | 1–2 |
| Luxembourg | 2 |
| Malta | 5–7 |
| Netherlands | 2 |
| Poland | 1–2 |
| Portugal | 4–5 |
| Romania | 3–4 |
| Slovakia | 2–3 |
| Slovenia | 2–3 |
| Spain | 4 |
| Sweden | 3–5 |
These times are estimates and are not guaranteed. Delivery may occasionally take a little longer due to customs processing, local conditions, or carrier delays.
Dispatch times
Orders placed before 15:00 CET (Central European Time) on a working day are normally dispatched the same day. Orders placed after 15:00 CET, or on weekends and public holidays, will be dispatched on the next working day.
If you have an urgent order, please email us at info@signalsounds.eu before placing your order and we'll do our best to accommodate you.
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 at info@signalsounds.eu if you have questions.
