Yamaha DTXpress/DTXplorer/DTXtreme

Hi,

I decided to start a separate topic about the FD8.

I bought the FD8 to use with my DTXPress IV without much thought,
thinking they would work together just fine. As it turns out, I should
have done a little investigation first.

After a bit of experimenting, I found out that if I use an inverted
polarity TRS cable plugged in the FD8, the module interprets that as a
closed hi-hat signal. Stomping on the pedal has no effect. With a
regular stereo cable stomping on the pedal also has no effect, but the
hi-hat sound is open instead.

Does anyone have any further info about how the hi-hat control works
on the FD8 and on the DTXPress? It seems like there can't be a huge
difference between the brands, as I already got a closed sound with
the custom cable.

I know there's an adapter I can buy, but I'd rather not order
something from half way across the globe if I can put something
similar together using a couple of old resistors I have in my drawer.
Besides, DIY is fun! BTW, I'm almost finished with a couple of DIY 10"
mesh head pads. I got the idea for that when I realized I don't really
wanna pay hundreds of e's for the 8" Roland equivalents.

I don't know anything about the FD8, but I do have the Yamaha HH pedal
and know how that works.  If you have access to multimeter and measure
the resistance from the tip and ring to the sleeve then we should be
able to work out the differences.  The other option is for you to
dismantle it and trace out the circuit.

Keith.

--- In DTXpress@yahoogroups.com, "Keith" <keith@...> wrote:
>
> I don't know anything about the FD8, but I do have the Yamaha HH pedal
> and know how that works.  If you have access to multimeter and measure
> the resistance from the tip and ring to the sleeve then we should be
> able to work out the differences.  The other option is for you to
> dismantle it and trace out the circuit.
> 
> Keith.

Thanks, that would be greatly helpful. I have a multimeter, I'm going
to test the pedal some time today probably.

Alright, I got around to do some measuring. Fully depressed, the FD8
has zero resistance, and 20.8 kOhms in the up position. This is on
tip/sleeve, as I think the pedal has a mono jack anyway. I'll check
though if there's anything on the ring pathway later on.

--- In DTXpress@yahoogroups.com, "hccs_k" <hccs_k@...> wrote:
>
> Alright, I got around to do some measuring. Fully depressed, the FD8
> has zero resistance, and 20.8 kOhms in the up position. This is on
> tip/sleeve, as I think the pedal has a mono jack anyway. I'll check
> though if there's anything on the ring pathway later on.
>

OK, at least the resitance goes the right way round i.e closing it
lowers the resitance.  The Yamaha peadal has a 150k resistor in series
with the tip.  It also has 10k, 47k, 150k resistors which it
progressively shorts through a 1k to the ring.  So, what you have
found by connecting to the ring rather than the tip makes sense.  

I suggest you try adding a 1k resistor in series with the ring to the
Yamaha and connecting the Roland tip to the Yamaha ring.

I am not sure what to do with the Roland ring - it depends on what you
measure.

Keith.

Just re-reading an old post I made when someone was trying to make a
simple switch work as a hihat pedal, I suggested putting a 150k from
the ring to the tip as well - worth a try.

Keith.

> I suggest you try adding a 1k resistor in series with the ring to the
> Yamaha and connecting the Roland tip to the Yamaha ring.
> 
> I am not sure what to do with the Roland ring - it depends on what you
> measure.
> 
> Keith.

After experimenting with quite a number of different resistors, I am
now able to open and close the hi-hat. With a 5.6k resistor, it seemed
to work somewhat but I noticed it was extremely hard to get the foot
close sound. So I guessed I should try a 3.9k one - works nicely
otherwise, but I can't get the foot close sound _at all_.

Such behaviour seems quite mysterious to me. I'm not sure if the
Yamaha tip has something to do with producing the different sounds. By
the way, is the DTXPress IV supposed to have a dedicated half-open
sound for the hi-hat? So far I have only gotten open and closed.

Any ideas?

I will put the circuit of the HH65 pedal in the files section.  I have
never really been able to fully understand what the module expects
from the pedal.  For example, the diode with series 220k resistor is
virtually shorted out by the 1k resistor, so what's the point?  From
my experiments it does seem that both the ring and tip are required,
if you want to get closed, open, close and splash sounds.

I don't think your pedal helps because you cannot get a very high open
resistance.  The Yamaha pedal seems to use quite high resistors.

There may of course be a mistake in my circuit, but I don't think so,
although it is a while since I took it apart and drew the circut out.

Keith.