Doepfer

Hi People,

I know that the topic of fuses has appeared a few times and others
have experienced similar problems but I'm not sure what to do about
this. Sorry about the long winded nature of the post but I don't want
to leave out any prudent info (including details of my own stupidity).

I have an A-100P with a 110v PSU2. I'm in Australia so I'm using a
stepdown transformer that has a 250 VA rating. The A-100P is half full
and has been operating for the last month or so without a problem. I
recently added an A-118 (Noise) and an A-131 (VCA) and had no problems. 

The other day I removed a few modules in order to fit the spring from
my  A-199 and when putting the modules back in I accidentally plugged
my A-112 in incorrectly (I plugged the cable into the bus board
without plugging it into the left hand row of pins). When I powered
the unit on the lights came on momentarily and then no power. I then
realied my error and corrected it but it seems that the fuse in my
case had also blown. I replaced this with a 500mA time lag fuse and
this worked fine. 

Since then when I power the case on the fuse blows 80% of the time and
I've just run out of 500mA fuses.  :-(   Note that 1A fuses seem to
work fine but I'm aware that these are not recommended.

I'm not sure whether this problem is being caused by :

a. A now 'damaged' A-112 (still seems to work ok).
b. A damaged PSU2.
c. Unsuitable fuses.
d. Some other factor.

Could anyone tell me whether I've likely broken anything and if there
is anything that could be causing the fuses to blow ?  

Thanks in advance

Simon

Hello Simon, even though you might have damaged one or more modules I
don't think this is the reason for the constantly blowing fuses.

Assumed by now all modules are connected correctly I suggest to try
other fuses: "630 - 700 mA time lag (slow blow)". [That info is from
Dopefer's HP -> FAQ.] Make sure they are SLOW BLOW/TIME LAG!

Hope that helps, Ingo

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

>
> Hi People,
> 
> I know that the topic of fuses has appeared a few times and others
> have experienced similar problems but I'm not sure what to do about
> this. Sorry about the long winded nature of the post but I don't want
> to leave out any prudent info (including details of my own stupidity).
> 
> I have an A-100P with a 110v PSU2. I'm in Australia so I'm using a
> stepdown transformer that has a 250 VA rating. The A-100P is half full
> and has been operating for the last month or so without a problem. I
> recently added an A-118 (Noise) and an A-131 (VCA) and had no problems. 
> 
> The other day I removed a few modules in order to fit the spring from
> my  A-199 and when putting the modules back in I accidentally plugged
> my A-112 in incorrectly (I plugged the cable into the bus board
> without plugging it into the left hand row of pins). When I powered
> the unit on the lights came on momentarily and then no power. I then
> realied my error and corrected it but it seems that the fuse in my
> case had also blown. I replaced this with a 500mA time lag fuse and
> this worked fine. 
> 
> Since then when I power the case on the fuse blows 80% of the time and
> I've just run out of 500mA fuses.  :-(   Note that 1A fuses seem to
> work fine but I'm aware that these are not recommended.
> 
> I'm not sure whether this problem is being caused by :
> 
> a. A now 'damaged' A-112 (still seems to work ok).
> b. A damaged PSU2.
> c. Unsuitable fuses.
> d. Some other factor.
> 
> Could anyone tell me whether I've likely broken anything and if there
> is anything that could be causing the fuses to blow ?  
> 
> Thanks in advance
> 
> Simon
>

I blew my modular's fuse from just changing my a148's jumper settings
and then switching it on... I thought to myself "ah, I'll just buy
another fuse and she'll be going again!"

Problem is, finding a 250v 315mA slow-blow fuse is a LOT harder to get
than I imagined... well in my town that is. No one here knows what a
slow-blow/time lag fuse is, let alone what even a modular synth is.

I found a similar kind of fuse in my Akai sampler, but it's around
1.2-1.6A. Would my modular be able to handle it (until I get the
proper fuse of course), harmlessly blow it or will it act just like
the dreaded chewing gum paper trick and turn my modular into an
expensive firework?

Thanks for your help Ingo. I hadn't noticed this info on the FAQ page.
From this info it seems I should be using a slow blow fuse in the
range 630-800mA. But is this correct.....?

....while I was searching for 800mA fuses (anything other than 500mA
or 1A is very hard to find in Australia), I noticed that that fuses
are rated for voltage. As I'm in Australia the fuses I'm finding are
rated at 240VAC. Given that I'm using a step down transformer for my
110v PSU2, should I be using an 800mA fuse thats rated at 110VAC ? 
Could the fact that i'm using 500mA 240VAC fuses in a 110V PSU2  be
causing me my problem ?  Sorry for my ignorance on all this :-(


--- In Doepfer_a100@yahoogroups.com, "ilanode" <techmeier@...> wrote:
>
> Hello Simon, even though you might have damaged one or more modules I
> don't think this is the reason for the constantly blowing fuses.
> 
> Assumed by now all modules are connected correctly I suggest to try
> other fuses: "630 - 700 mA time lag (slow blow)". [That info is from
> Dopefer's HP -> FAQ.] Make sure they are SLOW BLOW/TIME LAG!
> 
> Hope that helps, Ingo
> 
> --- In Doepfer_a100@yahoogroups.com, "beakanddune" <beakanddune@>
> wrote:
> >
> > Hi People,
> > 
> > I know that the topic of fuses has appeared a few times and others
> > have experienced similar problems but I'm not sure what to do about
> > this. Sorry about the long winded nature of the post but I don't want
> > to leave out any prudent info (including details of my own stupidity).
> > 
> > I have an A-100P with a 110v PSU2. I'm in Australia so I'm using a
> > stepdown transformer that has a 250 VA rating. The A-100P is half full
> > and has been operating for the last month or so without a problem. I
> > recently added an A-118 (Noise) and an A-131 (VCA) and had no
problems. 

> > 
> > The other day I removed a few modules in order to fit the spring from
> > my  A-199 and when putting the modules back in I accidentally plugged
> > my A-112 in incorrectly (I plugged the cable into the bus board
> > without plugging it into the left hand row of pins). When I powered
> > the unit on the lights came on momentarily and then no power. I then
> > realied my error and corrected it but it seems that the fuse in my
> > case had also blown. I replaced this with a 500mA time lag fuse and
> > this worked fine. 
> > 
> > Since then when I power the case on the fuse blows 80% of the time and
> > I've just run out of 500mA fuses.  :-(   Note that 1A fuses seem to
> > work fine but I'm aware that these are not recommended.
> > 
> > I'm not sure whether this problem is being caused by :
> > 
> > a. A now 'damaged' A-112 (still seems to work ok).
> > b. A damaged PSU2.
> > c. Unsuitable fuses.
> > d. Some other factor.
> > 
> > Could anyone tell me whether I've likely broken anything and if there
> > is anything that could be causing the fuses to blow ?  
> > 
> > Thanks in advance
> > 
> > Simon
> >
>

Hello Simon, we're entering territory where we risk to get lost in the
Doepferian outback... I could be *wrong* however I'd choose the
correct fuse for the device in question: the PSU2. Since you will not
fuse the mains supply and the transformer likely got his own fuse this
makes sense to me. Regards, Ingo


--- In Doepfer_a100@yahoogroups.com, "beakanddune" <beakanddune@...>
wrote:
>
> Thanks for your help Ingo. I hadn't noticed this info on the FAQ page.
> From this info it seems I should be using a slow blow fuse in the
> range 630-800mA. But is this correct.....?
> 
> ....while I was searching for 800mA fuses (anything other than 500mA
> or 1A is very hard to find in Australia), I noticed that that fuses
> are rated for voltage. As I'm in Australia the fuses I'm finding are
> rated at 240VAC. Given that I'm using a step down transformer for my
> 110v PSU2, should I be using an 800mA fuse thats rated at 110VAC ? 
> Could the fact that i'm using 500mA 240VAC fuses in a 110V PSU2  be
> causing me my problem ?  Sorry for my ignorance on all this :-(
> 
> 
> --- In Doepfer_a100@yahoogroups.com, "ilanode" <techmeier@> wrote:
> >
> > Hello Simon, even though you might have damaged one or more modules I
> > don't think this is the reason for the constantly blowing fuses.
> > 
> > Assumed by now all modules are connected correctly I suggest to try
> > other fuses: "630 - 700 mA time lag (slow blow)". [That info is from
> > Dopefer's HP -> FAQ.] Make sure they are SLOW BLOW/TIME LAG!
> > 
> > Hope that helps, Ingo
> > 
> > --- In Doepfer_a100@yahoogroups.com, "beakanddune" <beakanddune@>
> > wrote:
> > >
> > > Hi People,
> > > 
> > > I know that the topic of fuses has appeared a few times and others
> > > have experienced similar problems but I'm not sure what to do about
> > > this. Sorry about the long winded nature of the post but I don't
want
> > > to leave out any prudent info (including details of my own
stupidity).
> > > 
> > > I have an A-100P with a 110v PSU2. I'm in Australia so I'm using a
> > > stepdown transformer that has a 250 VA rating. The A-100P is
half full
> > > and has been operating for the last month or so without a problem. I
> > > recently added an A-118 (Noise) and an A-131 (VCA) and had no
> problems. 
> > > 
> > > The other day I removed a few modules in order to fit the spring
from
> > > my  A-199 and when putting the modules back in I accidentally
plugged
> > > my A-112 in incorrectly (I plugged the cable into the bus board
> > > without plugging it into the left hand row of pins). When I powered
> > > the unit on the lights came on momentarily and then no power. I then
> > > realied my error and corrected it but it seems that the fuse in my
> > > case had also blown. I replaced this with a 500mA time lag fuse and
> > > this worked fine. 
> > > 
> > > Since then when I power the case on the fuse blows 80% of the
time and
> > > I've just run out of 500mA fuses.  :-(   Note that 1A fuses seem to
> > > work fine but I'm aware that these are not recommended.
> > > 
> > > I'm not sure whether this problem is being caused by :
> > > 
> > > a. A now 'damaged' A-112 (still seems to work ok).
> > > b. A damaged PSU2.
> > > c. Unsuitable fuses.
> > > d. Some other factor.
> > > 
> > > Could anyone tell me whether I've likely broken anything and if
there

> > > is anything that could be causing the fuses to blow ?  
> > > 
> > > Thanks in advance
> > > 
> > > Simon
> > >
> >
>

Hi Simon,

You will need to use the fuse rating that is specified for the 110V 
PSU2 not the 240V PSU2 since you are using a step down transformer 
and the unit is actually operating on 110V. You can safely use a  
slightly higher value than that which is specified but I wouldn't go 
too high. I doubt that you will find 110V rated fuses anywhere in 
Australia though and I don't know that you can substitute the 240V 
rated fuses for the 110V ones. Perhaps Dieter can offer further 
advice here otherwise you might try looking at some of the overseas 
electronics suppliers like digikey to have the 110V rated ones  
shipped to you.

Cheers,
Adam-V


--- In Doepfer_a100@yahoogroups.com, "ilanode" <techmeier@...> wrote:
>
> Hello Simon, we're entering territory where we risk to get lost in 
the
> Doepferian outback... I could be *wrong* however I'd choose the
> correct fuse for the device in question: the PSU2. Since you will 
not
> fuse the mains supply and the transformer likely got his own fuse 
this
> makes sense to me. Regards, Ingo
> 
> 
> --- In Doepfer_a100@yahoogroups.com, "beakanddune" <beakanddune@>
> wrote:
> >
> > Thanks for your help Ingo. I hadn't noticed this info on the FAQ 
page.
> > From this info it seems I should be using a slow blow fuse in the
> > range 630-800mA. But is this correct.....?
> > 
> > ....while I was searching for 800mA fuses (anything other than 
500mA
> > or 1A is very hard to find in Australia), I noticed that that 
fuses
> > are rated for voltage. As I'm in Australia the fuses I'm finding 
are
> > rated at 240VAC. Given that I'm using a step down transformer for 
my
> > 110v PSU2, should I be using an 800mA fuse thats rated at 
110VAC ? 
> > Could the fact that i'm using 500mA 240VAC fuses in a 110V PSU2  
be
> > causing me my problem ?  Sorry for my ignorance on all this :-(
> > 
> > 
> > --- In Doepfer_a100@yahoogroups.com, "ilanode" <techmeier@> wrote:
> > >
> > > Hello Simon, even though you might have damaged one or more 
modules I
> > > don't think this is the reason for the constantly blowing fuses.
> > > 
> > > Assumed by now all modules are connected correctly I suggest to 
try
> > > other fuses: "630 - 700 mA time lag (slow blow)". [That info is 
from
> > > Dopefer's HP -> FAQ.] Make sure they are SLOW BLOW/TIME LAG!
> > > 
> > > Hope that helps, Ingo
> > > 
> > > --- In Doepfer_a100@yahoogroups.com, "beakanddune" 
<beakanddune@>
> > > wrote:
> > > >
> > > > Hi People,
> > > > 
> > > > I know that the topic of fuses has appeared a few times and 
others
> > > > have experienced similar problems but I'm not sure what to do 
about
> > > > this. Sorry about the long winded nature of the post but I 
don't
> want
> > > > to leave out any prudent info (including details of my own
> stupidity).
> > > > 
> > > > I have an A-100P with a 110v PSU2. I'm in Australia so I'm 
using a
> > > > stepdown transformer that has a 250 VA rating. The A-100P is
> half full
> > > > and has been operating for the last month or so without a 
problem. I
> > > > recently added an A-118 (Noise) and an A-131 (VCA) and had no
> > problems. 
> > > > 
> > > > The other day I removed a few modules in order to fit the 
spring
> from
> > > > my  A-199 and when putting the modules back in I accidentally
> plugged
> > > > my A-112 in incorrectly (I plugged the cable into the bus 
board
> > > > without plugging it into the left hand row of pins). When I 
powered
> > > > the unit on the lights came on momentarily and then no power. 
I then
> > > > realied my error and corrected it but it seems that the fuse 
in my
> > > > case had also blown. I replaced this with a 500mA time lag 
fuse and
> > > > this worked fine. 
> > > > 
> > > > Since then when I power the case on the fuse blows 80% of the
> time and
> > > > I've just run out of 500mA fuses.  :-(   Note that 1A fuses 
seem to
> > > > work fine but I'm aware that these are not recommended.
> > > > 
> > > > I'm not sure whether this problem is being caused by :
> > > > 
> > > > a. A now 'damaged' A-112 (still seems to work ok).
> > > > b. A damaged PSU2.
> > > > c. Unsuitable fuses.
> > > > d. Some other factor.
> > > > 
> > > > Could anyone tell me whether I've likely broken anything and 
if

> there
> > > > is anything that could be causing the fuses to blow ?  
> > > > 
> > > > Thanks in advance
> > > > 
> > > > Simon
> > > >
> > >
> >
>

> Hi Simon,
>
> You will need to use the fuse rating that is specified for the 110V
> PSU2 not the 240V PSU2 since you are using a step down transformer
> and the unit is actually operating on 110V. You can safely use a
> slightly higher value than that which is specified but I wouldn't go
> too high. I doubt that you will find 110V rated fuses anywhere in
> Australia though and I don't know that you can substitute the 240V
> rated fuses for the 110V ones. Perhaps Dieter can offer further
> advice here otherwise you might try looking at some of the overseas
> electronics suppliers like digikey to have the 110V rated ones
> shipped to you.
>
> Cheers,
> Adam-V

The PSU does not "know" if the voltage comes from the normal mains or from a
step down/up transformer. The voltage that is used to run the PSU (i.e. the
voltage at the mains connector of the A-100 frame) is the crucial voltage
value.

The voltage spec of a fuse is the max. voltage for the fuse. It is not
necessary that the voltage specified on the fuse is the same as the voltage
that is used. The voltage specified on the fuse has to be the same or more
than the actual mains voltage (i.e. a 240V fuse can be used even for 110 or
115V, but a 110 V cannot be used with 230 V mains voltage).

Different responses for fuses is - as far a I know a standard - all over the
world as you need different responses for different applications. The lag
time is specified by a character normally added before of after the current
value:"F" = fast (German: flink), "M" = medium (German: mittel), "T" = time
lag (German: traege). Example: T800mA or 800mAT

I'm not in the office next week. Consequently I cannot answer question from
the group during this time.

Have a nice weekend
Dieter Doepfer

--- In Doepfer_a100@yahoogroups.com, "shleedance" <shleedance@...> wrote:
>
> I blew my modular's fuse from just changing my a148's jumper settings
> and then switching it on... I thought to myself "ah, I'll just buy
> another fuse and she'll be going again!"
> 
> Problem is, finding a 250v 315mA slow-blow fuse is a LOT harder to get
> than I imagined... well in my town that is. No one here knows what a
> slow-blow/time lag fuse is, let alone what even a modular synth is.
> 
> I found a similar kind of fuse in my Akai sampler, but it's around
> 1.2-1.6A. Would my modular be able to handle it (until I get the
> proper fuse of course), harmlessly blow it or will it act just like
> the dreaded chewing gum paper trick and turn my modular into an
> expensive firework?
>

Nevermind, I've bought a few 250mA and 500mA fuses in another town
today... everything works perfect now. :)