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On 05/18/2017 07:15 PM, Wayne DePrince
Jr. wrote:
ahoy all,
i
have been testing out a Zoom H5 which (along w/ the H6 for that matter) is advertised
as NOT supporting passive instrument connections on the TRS
inputs. to quote the manual: "Direct input of passive guitars
and basses is not supported." thus i assumed that i would need
a DI box/effect box/etc. to record well any directly connected
passive electric guitar or bass.
however,
when i connect my electric guitar (Lace Sensors and Alumitone
pickups) and electric bass, both passive, to the TRS connections
on inputs 1 & 2 of the H5 with gain only at 5 of 10, i get a
good sound and strong signal, seemingly the same as when
they are connected to an interface (in this case a Zoom U-44) that supports Hi-Z
connections.
i
first contacted Zoom support and they replied:
"There is no issue connecting a passive guitar to the 1/4" input
on the H5.
There may only be an issue with level or noise, but if you are
satisfied with the audio quality then there is no problem."
now
while i do not yet have a good understanding of Lo vs. Hi-Z, i
have read various posts about it.
they seem to indicate that the passive guitar signal would lose
some frequencies with this kind of connection and thus this
setup is undesirable.
but again as it "sounds the same", i had some questions before
investing in a DI box or getting a different interface:
- would the fact that the pickups are Lace Sensors and
Alumintones have anything to do with the passive signal being
picked up fairly well by the non Hi-Z input?
- is there a way to check (preferably in software) if
frequencies are actually missing or if the signal quality is
indeed reduced when compared to one from a Hi-Z input?
- is it possible that the H5 has good enough
preamps/whatever that the gain on the inputs is enough to
make the passive signal OK?
so
to summarize: is this an acceptable solution for recording a
directly connected passive instrument (in this case an electric
guitar and bass) even though the H5 does not officially support
it?
thanks, w
PS: for those wondering the H5 works great w/ GNU+Linux as an
audio interface
Hi. According to the Zoom HS specs, the input impedance on Mic/Line
In is
2 Kilo Ohms or more while Inputs 1/2 are 1.8 Kilo Ohms or more.
This is terrible for a guitar pickup.
The pickup's coil and the input impedance of the device it is
plugged into
form a low-pass filter. The higher the input impedance the better.
That's why guitar inputs are always 1 Mega Ohm or more.
But it is bad for another reason as well:
Most guitar pickups have between 6 and 12 Kilo Ohms resistance.
When fed into your 1.8 Kilo Ohms input, it forms a voltage divider
which will severely lower the overall output of your pickup.
Get a DI box.
If you want the maximum possible frequency response and you
want the most out of your pickups, get an active DI box.
It may introduce a bit more noise due to the active circuit.
On the other hand, if you want convenience of no batteries
and just plug and go, get a passive DI box.
It may introduce a bit of noise due to non-linearity of the
passive transformer, and the frequency response may not
be as full or flat as an active DI box.
Mine is a Radial Engineering DI box. I am happy with it.
Even though the sound is slightly coloured by the
passive transformer, it is far better than no DI box at all.
As for measuring the differences, that's a tough one.
I was able to see clearly a difference simply by using
my oscilloscope and plucking strings.
With the guitar plugged into a 10 Kilo Ohm mixer input,
I could clearly see less high frequency content (harmonics etc.)
than with the guitar-to-scope alone. (The scope probe has
1 Mega Ohm input impedance.)
A more scientific method might involve simultaneously
recording the un-loaded pickup signal and the loaded
signal and then comparing with software.
Tim.
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