sontec 1 RU build thread

[bpucekov]

1. definitely yes, never use toroid screw for this purpose

 

[analogica]

buuuuuuuuuuuut, could you explain me why....im na ignorant, cuz the screw never touch nothing more than ground wires and the metal rack....

thanks

 

[kante1603]

buuuuuuuuuuuut, could you explain me why....im na ignorant, cuz the screw never touch nothing more than ground wires and the metal rack....

thanks

Hi analogica,

as bpucekov stated:Never do it-you might end up in magnetic short!This is also given when the screw touches the bottom and top of a metall housing because you create a one-winding coil arround the transformer-HORROR!!!

So may I suggest to move your starground somewhere else-please

Best,

Udo.

 

[analogica]

thanks everyone for your help...

  ive changed the main ground from there to another place...but the hum is still there, is not a big noise but more than on the other analog stuff i got...

where can i check??? 

  i have no clue how to solve this and how to make the unit sound equal and even...

  thanks for your patience

 

[analogica]

HELPPPP

  One channel do not reduce or dim the signal if I turn down the dbs pot,    it amplifies ...slightly different to the other channel but it doesnt reduce , or is something really really unnoticiable.

do you think thats a problem on the summing board????

  thans fellas , i need your help

 

[analogica]

Hi again guys...

  i ve tested the unit again...let see what happens now.

  1.As i said to you If i turn on the EQ on both channels with all gains on 0, the signal doesnt change, right?.

      -but If I remove PS 2 wires from the filter board and turn on the EQ switch the signal amplifies and sound so distorted on mediums i think...and if I move the pots then, nothing changes

      If I do the same on the other channel(the one which amplifies and reduce right)the signal doesnt amplify, and if i move the pots the signal changes a bit.

  As I said, one channel seems to work well, and the other doesnt reduce when I move all gains on all frequencies, and amplifies very bright to me ears.

  Dont you think thats something on the summing board????  what can i do ?????


  thanks guys , im waiting for an answer to solve this



  is so strange....

 

[briomusic]

I don't quite understand your test procedure....

wouldn't it be easier to swap the filterboards around (at the 5 pin connector) to see if the problem follows the filterboard or stays with the amp board?

 

[analogica]

i have to desolder everything then....but ill do, ill say what happens

 

[briomusic]

I know the feeling.....

now I always use molex connectors, so much easier to troubleshoot!

 

[analogica]

it works!!!!!!

  it was a bad connection on the 5 pin wires, thanks for your help.

  the pmly thing left is to get rid of that hum....

 

[analogica]

Hi,

  ive resoldered the main star ground and the hum is a bit quieter but is still there,

  I didnt notice that all pins 2 on the unit goes to ground.,.......?????, is that correct????

  Should be better to solder a ground lift on the XLR to get rid of that hum ????

    thanks

 

[analogica]

pleaseeeee, can somebody help me with the ground?????  I guess should be normal to have some noise if pin 2 goes to ground....is that correct????

what should i do?

 

[Sylvain D.]

This may be a noob question but: :

Is there any use in getting "film" caps in higher voltage than the circuit can swing i.e +- 24V=48V  (headroom maybe...) or is it useless to buy 250, 630 volts etc... caps?

Will 63V caps suffice in a filter function? (specifically in this EQ)

Sylvain

 

[benlindell]

Extra voltage is definitely not nessecary for the filter.

 

[Sylvain D.]

Is it just me, or are some of these caps really hard to find?

like the ones bellow... I have found many of these values but in the 7 mm or 7.5 mm width. Can I cheat and use these instead of 6 mm width?

CAPACITORS-POLY ETC.

1 0.15U C-10-15/6
2 0.47U C-10-15/6
8 1U C-10-15/6
1 2U2 C-10-15/6
1 1U C-10-15/6
2 2u2 C-10-15/6

1 4u7 C-10-15/6

Anyone...?


Thanks
Sylvain

 

[daggertX]

Forsell JFET 993 discontinued  :'(    now what ??? 

I am okay with using 604s but has anybody had good results with any discrete opamps?

 

[sonicwarrior]

The BOM says:

POTENTIOMETERS
3 5K LIN POTSW (CTS 270X232A502B1A1)
1 5K LIN POT (CTS 270X232A502B1B1)

But the B1A1 variant ist the one without a switch and the B1B1 is the one with a switch. Do I need 3 with or without switch?
I looked at the schematic but I didn't see any pot there with a switch.  ???

 

[zayance]

You need 1 with switch (For the LF Shape(Q)/Shelf Position), all the 3 others are without, and that for one channel.
Check first picture on page 1 for having an idea....

 

[sonicwarrior]

I checked the pictures before and now again but I still don't see a clue anyware that there should a pot with a switch.
Or is the 'shelf' the clue?

 

[zayance]

I was reffering to the picture just for confirming my statement and have a visual of it that the LF shape(Q) is the switched position that's all...
The inner picture where you see the CTS pots From up view gives you the answer also, for if you had the pic of the CTS on Digikey for ex, the switched one is different than the "normal" ones...