GroupDIY

General Discussions => Brewery => Topic started by: mikeyB on July 15, 2008, 07:34:14 PM

Title: RTFM - I wish I had!!
Post by: mikeyB on July 15, 2008, 07:34:14 PM
Well - what a knob-head!
Been scratching my head for a good few hours wondering where all the bass has gone from the inputs of DOAC.
For years I've used a mackie 1604VLZ with BALANCED AUX sends with pretty low output Z.
On my test bench I got a little 1202 - yes 1202 NOT VLZ.
Yes I assumed the Aux sends are balanced and low output Z - WRONG - a quick flip to the balanced low Z main outs gave my bass back :roll:
Ah well - too tired to finish tidying it up tonight :mad: but now I know the problem :grin: pics of finished DAOC soon but couple of  :sam: tonight :wink:
Title: RTFM - I wish I had!!
Post by: clintrubber on July 16, 2008, 07:28:50 AM
:roll:

Bass back = bass back, but while the sends of the 'original' (the MS1202) are indeed unbalanced they're still what I'd call low-Z-ish: R_source is 300 Ohms.

See:
http://www.twin-x.com/groupdiy/albums/userpics/Mackie_MS1202.zip

There you can see that the main-outs are indeed balanced but have double that 300: total R_source is 600!


What's your load, 600 ?
Title: RTFM - I wish I had!!
Post by: mikeyB on July 16, 2008, 09:17:30 AM
I'll double check my wiring - can't see how its making a circuit - i'm sure the jack ring has no contact in the aux send. With a 10k/10k edcor bass rolled off below 200hz-ish - with sowter 3575 about 300hz. Tried a 600/600 oep and it was bye-bye signal. It seems to behave like an ariel!!
transformer input wired directly across xlr pin 2&3 to jack tip and ring.

remove tx from input and joined wires - aux output is then referenced to 0v by secondary being directly connected to ground - full bass

Just happy to have sorted it :thumb: