sontec 1 RU build thread

[horvitz]

For all guys here who want this EQ steped.
I hate the idea with cutting my logo on PCB with dremel tool
To be more accurate and let you all have nicer stepped EQ's
without cutting the PCB's with dremel.

Not so fond of cutting, myself!  But I'm curious, are you thinking of any real functional changes or just going to change the layout so that it's on multiple boards?

  Brian

 

[Igor]

But I'm curious, are you thinking of any real functional changes or just going to change the layout so that it's on multiple boards?

There will be motherboard and filter's boards....
Finally, after 95% (rough nr, anyway finishing the motherboard,
I got a crazy idea about adding MS and output level trim.....
/never counted myself normal, cough
The EQ can be build in "vertical" and "horisontal" front arrangement,
i.e. left channel at left side/right chann. at right side, or
left channel top/right channel bottom. Just...some time, it is there.

 

[horvitz]

Now, where's the fun in normal?  ;D

But, interesting stuff!  I was going to get working on your 1RU boards, but I think I'll hang out and see how this develops.  M/S is a neat idea.

 

[mrcase]

hi all!

did someone test piers app99f substitute for the JE990 in this circuit?
Am I good to go with these for my sontec?

 

[mrcase]

ok. one more...
still sourcing parts.
What kind of wimas are you guys using? Am I good to go with "normal" MKS types or should I care for polypropylenes ones?
any other good hints regarding caps to make this eq sound killer?  ;D

thank you all!
cheers
martin

 

[mrcase]

Hi all!

a question regarding the bom. are the R-EU_0207/15 resistors supposed to be carbon resistors?

cheers

 

[Pieter001]

Hello,

I want to know for sure if i wired the toroid the right way in my sontec. The color of the wires:

BLK 0v
RED 25v

ORA 0v
YEL 25v

I connected the black wire to ~1 on the pcb, the red and orange wires to ~AB and the yellow wire to ~2
Is this right? ???

Thanks

 

[zayance]

Hello,

I want to know for sure if i wired the toroid the right way in my sontec. The color of the wires:

BLK 0v
RED 25v

ORA 0v
YEL 25v

I connected the black wire to ~1 on the pcb, the red and orange wires to ~AB and the yellow wire to ~2
Is this right? ???

Thanks

Sounds good

 

[deuc224]

Im looking for the jfet 993s and they arent on the foressell site, they only havethe schematic in he schematic section. Discontinued? ???

 

[zayance]

Im looking for the jfet 993s and they arent on the foressell site, they only havethe schematic in he schematic section. Discontinued? ???

http://www.forsselltech.com/products/jfet993.html

 

[UNIVAC]

But I'm curious, are you thinking of any real functional changes or just going to change the layout so that it's on multiple boards?

There will be motherboard and filter's boards....
Finally, after 95% (rough nr, anyway finishing the motherboard,
I got a crazy idea about adding MS and output level trim.....
/never counted myself normal, cough
The EQ can be build in "vertical" and "horisontal" front arrangement,
i.e. left channel at left side/right chann. at right side, or
left channel top/right channel bottom. Just...some time, it is there.

it is a MS - DECODER

 

[Pieter001]

Powerd up my sontec today. D19 got realy hot and the transformer warms up too.
Measure little more than 20v at ~1 and ~2 from my 25v transformer. On the wires on the other side of the psu pcb i measure a realy low voltage.
There is something wrong with my psu but i cant find the thing. Could it be a bad diode? ???

Thanks

 

[zayance]

Powerd up my sontec today

It's better to test the PSU always first before connecting to the boards, so you know it's doing fine before feeding the Main boards with IC out and checking again, just saying maybe you've done this anyway, not sure tough.

D19 got realy hot and the transformer warms up too.

Transformer getting hot is a sign of a short somewhere If i'm correct, or transformer maybe underated in terms of VA?, did you install the Diodes the right way around? Any bad soldering underneath the PCB...
And of course little voltage at the other end is sign of something wrong, check everything as always, it's small mistake most of the time...
I'm not a pro but maybe this can help???  

 

[1234]

I have just finished soldering my Sontec PCB. It works perfect! thank you Igor!
Very good sounding EQ - transparent, big, but with sweet hint...the noise is quite low too. Sometimes one can forget that there it is EQ in the sound path...very natural sounding equalisation. Found it wery useful on channel.
And for information - I have tried it with old first generation Forsell DOAs from the schematics on their site (a friend has rolled them for me) on input and output on one channel and AB tested it with 604 ICs on the other channel. I consider the variant with DOAs superior sounding - better detail, more animated sound, silkier too. But do not think 604 is bad  - actualy it is very nice sounding and it is quite close in quality to DOA variant. Noise does not change significantly in both variants, probably its origin in this topology is not OP Amp dependant.

 

[electrisizer]

thats interesting to hear! when igor release the mastering version i will go with DOAs too... but im still very happy with this IC beast
perhaps the only wish thats left for me would be a more detailed control range for the low frequences... 50hz-120hz

 

[Igor]

1234: thanx for the info and enjoy!
Yes, those small 604's aren't bad sounding, hehe...
I absolutely agree about Forssell's op-amps. I used both older version and 993, and, IMHO, this is best sounding opt.

electrisizer: I finishing the new version proto PCB design, with stepped control;
here, you can expand or squeeze control range as you want, and have 23 steps in 50-120 hz

 

[electrisizer]

here, you can expand or squeeze control range as you want, and have 23 steps in 50-120 hz

oh yeah its christmas  ;D

 

[Igor]

lol

 

[gandhalf3]

Hello, I'v finished my Sontec, and he is not working well. I v'got two problemes :

1. When I turn the Gain on a band clockwise, the level of the band is decreasing, and when i turn counter clockwise is increasing. (Same probleme on each band)

2.  I'v Got MF3 on each channel don't working. strange. (In fact when I Turn the knob full CCW I'v got a boost of all the spectrum about 0,5db and CW a -0,5db on all the spectrum.)

I need your help.

Thanks  8)

 

[gandhalf3]

Hello, I'v finished my Sontec, and he is not working well. I v'got two problemes :

1. When I turn the Gain on a band clockwise, the level of the band is decreasing, and when i turn counter clockwise is increasing. (Same probleme on each band)

2.  I'v Got MF3 on each channel don't working. strange. (In fact when I Turn the knob full CCW I'v got a boost of all the spectrum about 0,5db and CW a -0,5db on all the spectrum.)

I need your help.

Thanks  8)

Please help !  :'(