Country hick*** Di Box
- Thread starter BYacey
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okgb
Well-known member
Hey , let's see the J45 then !
J45 what I was thinking... J48
here are a couple of pictures of the guts, I bet it is similar to the countryman with an active output(op amp) instead of the transformer.
http://www.radialeng.com/r2011/images/photos/j48-inside-hirez.jpg
http://attachments.brisound.com.au/products/images_large/2294.png?r=1255323089
sadly there are not photos of the other side of the PCB to trace it.
here are a couple of pictures of the guts, I bet it is similar to the countryman with an active output(op amp) instead of the transformer.
http://www.radialeng.com/r2011/images/photos/j48-inside-hirez.jpg
http://attachments.brisound.com.au/products/images_large/2294.png?r=1255323089
sadly there are not photos of the other side of the PCB to trace it.
BYacey
Well-known member
What some manufacturers do like KT, is put the transformer on the front end, and then have all the phantom powered active electronics after the transformer driving the balanced line. This simplifies the ground lift situation, but I don't think this configuration works as well as the Countryman design as it puts much higher demands on the quality of the transformer, and you still won't achieve the high input impedance of the fet input.
In many cases this isn't necessary, but with magnetic guitar pickups or peizo devices, it's nice to have the 10meg impedance to prevent loading of the pickup.
In many cases this isn't necessary, but with magnetic guitar pickups or peizo devices, it's nice to have the 10meg impedance to prevent loading of the pickup.
okgb
Well-known member
I have a countryman 85 that is useless with a battery , no real headroom , are they all like this ?
BYacey
Well-known member
How much headroom do you need? a fresh 9V battery will handle input signal of around 3 volts RMS.
CJ
Well-known member
running 8 AA batts in a radio shack carrier = 12 volts
BYacey
Well-known member
That would only raise the maximum input to about 4 volts, hardly enough to get excited over. There is the speaker level pad available if you want to drive it with higher signal levels, although it drags the input impedance down to about 10K.
CJ
Well-known member
there are the 1n4148 diodes that clamp small signal input currents at about 0.4 volts,
you might need a higher voltage if using stomp boxes in front of the DI.
this box also works great for bass, you get a nice compressed sound and a little bit of dirt,
you might need a higher voltage if using stomp boxes in front of the DI.
this box also works great for bass, you get a nice compressed sound and a little bit of dirt,
BYacey
Well-known member
Those diodes only conduct if the input signal exceeds 1/2 of the supply voltage. You would have to exceed 4.5V if the rail voltage is 9 volts before the diodes conduct.
CJ
Well-known member
that is correct, me bad, the diodes are biased up to 4.5,
okgb
Well-known member
enough headroom for a gtr to not distort when strummed hard , that's how much headroom I need
perhaps mine has a problem ? it's fine on phantom
perhaps mine has a problem ? it's fine on phantom
BYacey
Well-known member
Most magnetic pickup guitars I have measured develop around 100 to 500mv output, unloaded. If it has active electronics on board, there may be considerable extra gain, but most guitars also have a volume control that can be used to attenuate the output to a usable level.
okgb
Well-known member
Like I say , you just can't use mine with the battery , Phantom is fine
and if I have to turn the gtr down , I'll use use another d.i. ,where I don't
No one else has this problem ? that was my only real question .
could be time for the countryman to go though, with so many
preamps offering hi z 1/4 " inputs I've got more than enough
[ and it's not high on the " go to " list anyway . It was fun to see the schematic though , thanks
and if I have to turn the gtr down , I'll use use another d.i. ,where I don't
No one else has this problem ? that was my only real question .
could be time for the countryman to go though, with so many
preamps offering hi z 1/4 " inputs I've got more than enough
[ and it's not high on the " go to " list anyway . It was fun to see the schematic though , thanks
Hi there. Sorry to reopen this thread. I was looking to see if the Triad Magnetics transformers would work in this application? Something like this: https://www.digikey.com/product-detail/en/triad-magnetics/SP-33/237-1144-ND/242666
CJ
Well-known member
kind of small but it should work if you do not go past 5 V-rms input which is a reasonable request for a a box powered by a 9 V batt.
Is the schenmatic for the 'CountryHick' on this site or does someone have it ? - old links defunct.
Thanks.
Thanks.
scott2000
Well-known member
https://web.archive.org/web/20070828220154/http://www.diyfactory.com/projects/countryhick/countryhick.htm
Great. Thanks '2000 
