Skip to main content

A-170 Dual Slew Limiter

I mentioned my A-170 Dual Slew Limiter earlier in a few BFF posts, but so far i never took the time to write a separate blogpost about it. Until now that is...

The A-170 Dual Slew Limiter consists of  two separate slew limiters, also known as portamento controllers or integrators.
In electronics, the slew rate represents the maximum rate of change of a signal at any point in a circuit. Just like a Glide circuitry, it flattens or smoothes the incoming signal.

The top section of the module is the 'simplest' of the two Slew Limiters, with one joint control, which sets both rise and fall times (from approx. 0 ...10 sec).
For precision voltage control this one is recommended, but version One (before May 2009 / check your version number on the module's PCB) had a small voltage drop that was caused by the protection resistor at the A-170 output.
( check Doepfer's solutions for that HERE
A-170 modules after May 2009 don't have this voltage loss.

The second Slew Limiter has separate controls for rise and fall times, and you can set the overall range (high/low/medium) for these parameters with a three-position switch. 
Because the diodes in the lower Slew Limiter are voltage-dependant, there is a voltage off-set of around 0.5 V.  This naturally makes it unsuitable for precise 1Volt- per-octave work, but for simple voltage control this is no problem at all.

Not only is the lower Slew Generator suitable for pitch-CV's, you can alternatively use this one as a simple AR (attack/release) envelope generator (works with any gate/trigger or LFO).
Very useful if you don't have enough envelope generators and want some punchy or percussive basslines.

Also worth reading: Wikipedia Current Limiting

Popular posts from this blog

DIY Modular Case Ideas

There are many ways to house your (eurorack) modular synth, i wrote about the pre-manufactured options from Doepfer earlier, find that post HERE, but of course you can also try to build you own case.
There are many ways to make your own A-100/Eurorack case if you start out with just the basic rails and busboard, and you can make it as cheap or expensive as you can.

Check out a few ideas;
Wooden cabinets and side-panels are still very popular amongst (modular) synth enthusiasts.
These simple case standards for the pre-manufactured LC9 cases are very simple, and can be sooo useful Also check out the other great modular pictures on his site.
Matthew Goike (@Goiks) also has some nice wooden cabinets on display and for sale on his website:

...or do what Stretta did (or rather what his brother did), make a high-end wood/brushed aluminium cabinet with integrated LED-lights and some …

Doepfer A-150-8 Octal Manual/Voltage Controlled Programmable Switches Announced

Doepfer has just released some info on their new modules for NAMM 2017 (19-21 jan.) Besides some vintage editions of existing modules, the A-135ABC VC Performance mixer modules, the A-110-6Trapezoid Thru Zero Quadrature VCO and a new A-100LC1 case (economically priced small housing with 48 HP width) there was also one other interesting new module announcement:
Module A-150-8 contains eight manually/voltage controlled switches.  Each of the eight switches has a manual control button (Man.), a control voltage input (CV), a common Out / Input (O/I), and two In / Outputs (I/O1, I/O2).  The switches are bi-directional, i.e. they can work in both directions, so can connect one input to either of two outputs, or either of two inputs to one output. 
Two LEDs show which in / output is active (ie. which is connected to the common out / input).  In addition the LEDs are used for the programming of the module: For each unit the operating mode can be selected:  Toggle or Level controlled. In Toggl…

Happy New Year From PatchPierre

Hi there, it's me again... Happy New Year!

You might have noticed that I havent posted a lot in the last 2 years...
It's been a rough time for me since the sudden loss of two parents within a relatively short time-span and I really needed some time to get myself together... to set things straight, finding myself and selecting priorities... even my regular work suffered from this breakdown.

It took a while to understand it all, and to get a better grip on it, and it's sometimes still not very clear.
I think I have found a way to cope with most of it now... although the slight autism that I have (ADD-like) doesn't make it easy for, especially in crowds with lots of people I don't know...
On my journey I also (re-)discovered the beautiful woman that has always lived inside of me and that i need to accept and cherish... more on that maybe later... I'm not considering changing the name of the blog to PatchPetra.Net 😇 (...yet), but you might spot me somewhere at mod…