Sontec: hardware bypass, balanced THAT I/O, MS, power supply - at one PCB!

[Igor]

Nice porn! But hell, why not use horizontal layout (channel L top, channel R bottom) and use shorter cables/easier wiring?

 

[dandeurloo]

Hey guys does this Power transformer seem to be big enough for the Main boards and M/S board? 
http://www.antekinc.com/details.php?p=24

I see most guys are using 30VA or 50VA transformers.  I was gonna order some other stuff from them so I thought I might try this.  Let me know if you think it will work fine. 

 

[Igor]

Yes, this one should fit fine. Current consumption of whole EQ is less than +/- 300 ma, stuffed with DOA's and all relays on.

 

[druu]

Hey Igor, while u're here, any idea what would cause this issue;

On band MF2, 12db boost, any frequency i switch on that band over 5k seems to lower the gain incrementally as I go higher in Hz. Any idea what would cause this?

 

[dandeurloo]

Thanks Igor I will order one!

 

[Igor]

Hey Igor, while u're here, any idea what would cause this issue;

On band MF2, 12db boost, any frequency i switch on that band over 5k seems to lower the gain incrementally as I go higher in Hz. Any idea what would cause this?

Depending on how much gain drop there is here... I'd say, maybe, the filter capacitors have may high tolerance. 0.47 uf and 330 pf should be within 5% for best results.
As well, maybe, you're on high Q settings... if you can provide a soundcard plots of the issue, I will try to help)

 

[Sylvain D.]

Whoa!
Druu, that look as great!

Did you use the pcb for smd resistors on switches? Or did you use axial resistors?

And what doa at output summing is that I see?

 

[kante1603]

And what doa at output summing is that I see?

Looks pretty much like those I have around here,app992, right?

Best regards,

Udo.

 

[druu]

Yes APP992 from ppa. I didn't use zayances PCB's as I was worried they wouldn't fit, quite tight with that layout though if I do build another stepped version I think I would go that route.

 

[duantro]

I got this thing completed and it sounds sweet! I'm not getting any eq out of the side channel, when switched in mid/ side. I'll have to check my connections. Thanks for making this possible Igor. The M/S board sure makes hookup a breeze. ;D

 

[duantro]

An under the hood shot. Sorry about the crappy phone pics

 

[duantro]

How does the m/s balance trimmer need to be calibrated? Maybe this is why my (right) side  in m/s is inactive?

 

[druu]

I just pre-trimmed at 2.5k, did the trick for me.

Just to double check; your M/S switch is on-off-on?

 

[Igor]

The MS/Bypass/LR switch is on-off-on

 

[duantro]

I have the m/s switch as an off/on, that is on the pcb with the power switch. Is this not the preferred setup?

 

[druu]

M/S L/R switch should be ON-OFF-ON. OFF position is Bypass. You'll have to change that switch.

 

[duantro]

I didnt think i needed 2 bypasses, since it has the regular eq in/ bypass on each channel, in addition to the left right/ mid side switch.

 

[druu]

The EQ IN switch on each filter board is only to turn the channel on. It's not a 'bypass' and doesn't use any relays on the I/O board.

The only 'true' bypass is that switch you need to change.

 

[duantro]

Gotcha. I will switch it out. Thanks.
Edit: used this eq today and damn it sounds nice! Everything is very musical. High end is really sweet. I'm really glad to have this in my rack!

 

[ilfungo]

Sorry I have a little problem ......
Now everything works even m / S
But when I go to M / S, there is a difference of 0.2 dB between L and R
Is there a way to correct it?
I used Igor Doa What are the trimmer on them?
thanks