Doepfer

Hi guys,

How about some sort of wave rectifier that offers half and full wave
rectification of an audio signal. It would only require one input and
four outputs – positive half, negative half, full wave positive and
full wave negative.

Apologies if this is achievable with existing modules, I'm still not
up with everything that is currently available.

Cheers,
Adam-V

With a small modification the A-174 could be used for that (signal leading
to the meter wired to an output socket) as it contains a half and full wave
rectifier according to the position of the switch.

Even the Max/Min module A-172 is working a bit like that (with one input
simply connected to GND) and could be combined with the inverter module
A-175. But the full wave rectifier is missing in the A-172.

Best wishes
Dieter Doepfer

> -----Ursprüngliche Nachricht-----
> Von: Doepfer_a100@yahoogroups.com
> [mailto:Doepfer_a100@yahoogroups.com]Im Auftrag von Adam-V
> Gesendet: Freitag, 12. Mai 2006 00:55
> An: Doepfer_a100@yahoogroups.com
> Betreff: [Doepfer_a100] Re: any more ideas for exotic future A100
> modules?
>
>
> Hi guys,
>
> How about some sort of wave rectifier that offers half and full wave
> rectification of an audio signal. It would only require one input and
> four outputs – positive half, negative half, full wave positive and
> full wave negative.
>
> Apologies if this is achievable with existing modules, I'm still not
> up with everything that is currently available.
>
> Cheers,
> Adam-V

Thanks Dieter.

I expect that was meant to be A-197 (Analog Meter) not A-174 
(Joystick)!  I see that the A-197 is marked as "running out".  Is 
there any likelihood of them selling out in the next few months? If 
so, are there likely to be any more produced once the current stocks 
run out? 

Cheers,
Adam
--- In Doepfer_a100@yahoogroups.com, "Dieter Doepfer" <hardware@...> 
wrote:
>
> With a small modification the A-174 could be used for that (signal 
leading
> to the meter wired to an output socket) as it contains a half and 
full wave
> rectifier according to the position of the switch.
> 
> Even the Max/Min module A-172 is working a bit like that (with one 
input
> simply connected to GND) and could be combined with the inverter 
module
> A-175. But the full wave rectifier is missing in the A-172.
>

Adam,

right, it's the A-197. The A-197 is running out as the sales are very poor
(only a few modules per month) and we are still selling modules from the
first series manufactured early in 2004. Consequently it does not make sense
to manufacture a new series if the modules in stock are sold out. The only
solution for such poor selling modules would be smaller series (e.g. 25 or
50 only) but this would increase the price by about 20-30% as the production
charges depend highly upon the production quantity (especially because of
the pc boards, the front panels and the assembly installations).

So I'd recommend to order an A-197 a.s.a.p. if you are interested as I
assume that they will be sold out about fall 2006. Another solution is to
find one of the customers who received a free A-197 board early this year
(sorry - we have no boards left) and to built the desired rectifier module.
Maybe some customers ordered free boards without using them really. You
could try to find them in this Yahoo group as the information concering the
free pcbs was published in this group only. Maybe Analogue Haven (USA) has
some left.

Best wishes
Dieter Doepfer

> -----Ursprüngliche Nachricht-----
> Von: Doepfer_a100@yahoogroups.com
> [mailto:Doepfer_a100@yahoogroups.com]Im Auftrag von Adam-V
> Gesendet: Sonntag, 14. Mai 2006 05:56
> An: Doepfer_a100@yahoogroups.com
> Betreff: [Doepfer_a100] Re: any more ideas for exotic future A100
> modules?
>
>
> Thanks Dieter.
>
> I expect that was meant to be A-197 (Analog Meter) not A-174
> (Joystick)!  I see that the A-197 is marked as "running out".  Is
> there any likelihood of them selling out in the next few months? If
> so, are there likely to be any more produced once the current stocks
> run out?
>
> Cheers,
> Adam
> --- In Doepfer_a100@yahoogroups.com, "Dieter Doepfer" <hardware@...>
> wrote:
> >
> > With a small modification the A-174 could be used for that (signal
> leading
> > to the meter wired to an output socket) as it contains a half and
> full wave
> > rectifier according to the position of the switch.
> >
> > Even the Max/Min module A-172 is working a bit like that (with one
> input
> > simply connected to GND) and could be combined with the inverter
> module
> > A-175. But the full wave rectifier is missing in the A-172.
> >
>
>
>
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>

Thanks Dieter,

I might have to take my chances and see what's available in late
August; I'm currently saving every cent for a trip to the UK, Europe
and Japan in July/August so I can't really afford to buy any new
modules at the moment.

If they have run out by then I guess I'll just have to go into DIY
mode and build my own rectifier module.

Cheers,
Adam-V
--- In Doepfer_a100@yahoogroups.com, "Dieter Doepfer" <hardware@...>
wrote:
>
> Adam,
> 
> right, it's the A-197. The A-197 is running out as the sales are
very poor
> (only a few modules per month) and we are still selling modules from the
> first series manufactured early in 2004. Consequently it does not
make sense
> to manufacture a new series if the modules in stock are sold out.
The only
> solution for such poor selling modules would be smaller series (e.g.
25 or
> 50 only) but this would increase the price by about 20-30% as the
production
> charges depend highly upon the production quantity (especially
because of
> the pc boards, the front panels and the assembly installations).
> 
> So I'd recommend to order an A-197 a.s.a.p. if you are interested as I
> assume that they will be sold out about fall 2006. Another solution
is to
> find one of the customers who received a free A-197 board early this
year
> (sorry - we have no boards left) and to built the desired rectifier
module.
> Maybe some customers ordered free boards without using them really. You
> could try to find them in this Yahoo group as the information
concering the
> free pcbs was published in this group only. Maybe Analogue Haven
(USA) has

> some left.
> 
> Best wishes
> Dieter Doepfer
>

So, if I plug same source inverted and non-inverted into A-172, I get 
positive and negative full wave rectifier then? Would this work 
precisely with audio signals too?

A newbie question: How do I connect to GND?

Best regards
Jari Jokinen 

--- In Doepfer_a100@yahoogroups.com, "Dieter Doepfer" <hardware@...> 
wrote:
> Even the Max/Min module A-172 is working a bit like that (with one 
input
> simply connected to GND) and could be combined with the inverter 
module
> A-175. But the full wave rectifier is missing in the A-172.
> 
> Best wishes
> Dieter Doepfer
> 
> > -----Ursprüngliche Nachricht-----
> > Von: Doepfer_a100@yahoogroups.com
> > [mailto:Doepfer_a100@yahoogroups.com]Im Auftrag von Adam-V
> > Gesendet: Freitag, 12. Mai 2006 00:55
> > An: Doepfer_a100@yahoogroups.com
> > Betreff: [Doepfer_a100] Re: any more ideas for exotic future A100
> > modules?
> >
> >
> > Hi guys,
> >
> > How about some sort of wave rectifier that offers half and full 
wave
> > rectification of an audio signal. It would only require one input 
and
> > four outputs – positive half, negative half, full wave positive 
and
> > full wave negative.
> >
> > Apologies if this is achievable with existing modules, I'm still 
not

> > up with everything that is currently available.
> >
> > Cheers,
> > Adam-V

> So, if I plug same source inverted and non-inverted into A-172, I get
> positive and negative full wave rectifier then?

Yes.

> Would this work precisely with audio signals too?

It will work even with audio signals but there are diodes in the A-172 that
cause a small offset voltage (the so-called forward voltage of each diode).
If you replace all diodes by Schottky types the offset will be a bit smaller
but not zero.

If you need a precision rectifier: there is one in the envelope follower
circuit of the A-119 (no diode offset). If you remove the capacitor (C6)
that is used to smooth the envelope output you obtain a precision fullwave
rectifier. If you add a switch that turns C6 on/off you could switch between
envelope and rectifier.

> A newbie question: How do I connect to GND?

The simplest methode: plug a cable "half" into an unused socket. This will
connect the tip of the cable to GND.

Best wishes
Dieter Doepfer

> So, if I plug same source inverted and non-inverted into A-172, I get
> positive and negative full wave rectifier then? Would this work
> precisely with audio signals too?

While I tried to find our how this works and sounds I recorded a small audio
example that shows how the A-172 can be used for audio applications as a
dynamically controllable rectifier. Pay attention that no filters or VCAs
are used for the example. An mp3 link and a short description of the patch
can be found on the A-172 info page http://www.doepfer.de/A172.htm

Best wishes
Dieter Doepfer

I'm currently just finishing development of my own wave rectifier
module that offers Positive Half, Positive Full, Negative Half and
Negative Full wave rectification along with an offset control
(Internal and CV) to make for some really funky assymetrical rectified
signals. I'm at work at the moment but I'll post some oscillocope
screen shots from my prototype over the weekend.

I'm still trying to decide whether or not to go to the trouble of
manufacturing a small batch of these to offer up for sale or just slap
one or two together for my own use and offer the design up for other
DIYers to build themselves.

Cheers
Adam-V
--- In Doepfer_a100@yahoogroups.com, "jalmari3" <jari.jokinen@...> wrote:

>
> So, if I plug same source inverted and non-inverted into A-172, I get 
> positive and negative full wave rectifier then? Would this work 
> precisely with audio signals too?
> 
> A newbie question: How do I connect to GND?
> 
> Best regards
> Jari Jokinen

> I'm currently just finishing development of my own wave rectifier
> module that offers Positive Half, Positive Full, Negative Half and
> Negative Full wave rectification along with an offset control
> (Internal and CV) to make for some really funky assymetrical rectified
> signals.

Have you ever tried the A-136 Distortion / Waveshaper ?

It has probably all these features available. The incoming signal is divided
into 3 sections:

- positive share of the signal with adjustable clipping level and
positive/negative amplification of this component
- negative share of the signal with adjustable clipping level and
positive/negative amplification of this component
- original signal with positive/negative amplification

Precision rectifiers are used for the pos/neg shares in the A-136 (not only
simple diodes). According to the control settings of the A-136 controls all
suggested rectifier functions and anything in between are possible. I know
that the A-136 is a bit underestimated, probably because it's not very easy
to understand.
Only the offset controls are missing. For this external modules (e.g.
A-129-3 or A-138c) can be used. DIY's could add 2 or 3 potentiometers and
sockets with switching contacts for the offset functions. If someone is
interested I will email him the schematics of the A-136 (not a big secret
for an electronic technician).

Best wishes
Dieter Doepfer

I love the A-136...a great module.

>
> > I'm currently just finishing development of my own wave rectifier
> > module that offers Positive Half, Positive Full, Negative Half and
> > Negative Full wave rectification along with an offset control
> > (Internal and CV) to make for some really funky assymetrical rectified
> > signals.
> 
> Have you ever tried the A-136 Distortion / Waveshaper ?
> 
> It has probably all these features available. The incoming signal is
divided
> into 3 sections:
> 
> - positive share of the signal with adjustable clipping level and
> positive/negative amplification of this component
> - negative share of the signal with adjustable clipping level and
> positive/negative amplification of this component
> - original signal with positive/negative amplification
> 
> Precision rectifiers are used for the pos/neg shares in the A-136
(not only
> simple diodes). According to the control settings of the A-136
controls all
> suggested rectifier functions and anything in between are possible.
I know
> that the A-136 is a bit underestimated, probably because it's not
very easy
> to understand.
> Only the offset controls are missing. For this external modules (e.g.
> A-129-3 or A-138c) can be used. DIY's could add 2 or 3
potentiometers and
> sockets with switching contacts for the offset functions. If someone is
> interested I will email him the schematics of the A-136 (not a big
secret

> for an electronic technician).
> 
> Best wishes
> Dieter Doepfer
>

Unless A-136 Distortion / Waveshaper can do the trick well, as 
suggested by Mr. Doepfer, you can count me in.

Best regards
Jari jokinen

--- In Doepfer_a100@yahoogroups.com, "Adam-V" <adam-v@...> wrote:
> I'm still trying to decide whether or not to go to the trouble of
> manufacturing a small batch of these to offer up for sale

Could someone test, how accurately A-136 does the half and full wave 
rectifying at audio rate? On paper it looks capable, although some 
precision knob twisting seems to be needed...

+L and -L (level controls) should be at zero.

A (amplification control for original signal) at 5 (twelve o'clock).

+A (amplification control for positive signal component above the 
positive clipping level) at 3.5 or 6.5 depending the desired type of 
rectifying.

-A (amplification control for negative signal component below the 
negative clipping level) at 3.5 or 6.5 depending the desired type of 
rectifying.


Best regards
Jari Jokinen

As promised,  I have uploaded some oscilloscope screen shots from my
breadboarded. They are located in the Wave Rectifier folder of the
files section.  The input signal in the shots  is a 1.5kHz 10Vp-p sine
wave. The offset control in the gven examples was set such that
rectification occurs around approx +2.5V rather than 0V.

There is also a quick mock-up front panel showing what controls and
connections I propose to put on the module if and when I decide to
manufacture it. This was a cut and paste job from module images on the
doepfer website and is meant as an indicator only since it would be
very wrong for me to produce a module that looks exactly like a
doepfer one.

Dieter, I would be interested in the schematics of the A-136 merely to
check out the modifications you suggested.

Jari,I will put through my A-136  through it's paces if I get time
later this week (unless somebody else beats me to it).

Cheers,
Adam-V.

It certainly does appear that you are rectifying the crap out of those
waves!

>
> As promised,  I have uploaded some oscilloscope screen shots from my
> breadboarded. They are located in the Wave Rectifier folder of the
> files section.  The input signal in the shots  is a 1.5kHz 10Vp-p sine
> wave. The offset control in the gven examples was set such that
> rectification occurs around approx +2.5V rather than 0V.
> 
> There is also a quick mock-up front panel showing what controls and
> connections I propose to put on the module if and when I decide to
> manufacture it. This was a cut and paste job from module images on the
> doepfer website and is meant as an indicator only since it would be
> very wrong for me to produce a module that looks exactly like a
> doepfer one.
> 
> Dieter, I would be interested in the schematics of the A-136 merely to
> check out the modifications you suggested.
> 
> Jari,I will put through my A-136  through it's paces if I get time
> later this week (unless somebody else beats me to it).
> 
> Cheers,
> Adam-V.
>

I most certainly am!

--- In Doepfer_a100@yahoogroups.com, "travesty14850"
<travesty14850@...> wrote:

>
> It certainly does appear that you are rectifying the crap out of those
> waves!
>

> Dieter, I would be interested in the schematics of the A-136 merely to
> check out the modifications you suggested.
>
> Cheers,
> Adam-V.

Please contact me directly to get the schematics.

Best wishes
Dieter Doepfer