sontec 1 RU build thread

[Siegfried Meier]

Awesome, you rock thanks!

 

[atticmike]

I'd appreciated a lot if anybody around here would post either their digi or mouser bom

 

[sedit1]

Hi guys!

I decided to go with the rotary switch route, but I have few newbish qustions regarding the rotary switches
So i'm kind of new with all the rotary switch thing and I havent recieved the pcb's yet so can you help me? 

-For the freq range how are you supposed to wire the rotary, the pot is dual rev log and the pcb has 6 holes.
and should the rotary then be 2 pole rotary? I'm using harpos xls

-Low shelf, what kind of switch do you need to have the normal rotary+the shelf switch

-Gain switch for 0 position do you just tie -1/+1 resistor legs together to the center lug?

Thanks!

 

[atticmike]

Does also anybody have a rough figure on how much they spent on the passive parts / components to be soldered onto the boards?

Without the expenses of either enclosure, frontplate, xlr connectors, cables and such?

And again, a simple buying list, of all the to be soldered components onto the pcbs, would help people's rather rare occasion of build undertakings and therefore their targetet parts procurement tremendously.

 

[Aleguitarpro]

Does also anybody have a rough figure on how much they spent on the passive parts / components to be soldered onto the boards?

Without the expenses of either enclosure, frontplate, xlr connectors, cables and such?

And again, a simple buying list, of all the to be soldered components onto the pcbs, would help people's rather rare occasion of build undertakings and therefore their targetet parts procurement tremendously.

Hi.
For the passive components+toroidal power transformer I've spent about 200 euro (mouser+musikding.de).
I can't say it with precision, because I've bought a lot of passive components in that order, but it's not more than 200 euro, only for sontec.
Only for the alpha pots, the cost is about 135 euro.
For the case, I've spent 75 euro on diy-racked.
The you have to buy knobs with 6,3 mm and 3,2 mm axis (CTS pots).


Now, I've a problem with my power transformer: after a short test to see if everything was good, I've switch off my Sontec.
The day after, I've switch on it and it broke my fuse.
I've repeat the test, isolating the problem (I've made a test without the summing+filter boards) and then, without the psu: always the same...
I've broken 6 fuse...
I isolate the transformer and I think that it has lose the isolation in the primary.
It's possible? This is the first time I find this problem!
I don't know if it is a problem of THIS particular transformer or if I change it, I'll burn another transformer!
The secondary seems to be ok... How can I test it?
I think the problem is in the primary, because also with the secondary disconnected it burn the fuse.
The transformer is this one:
http://it.mouser.com/Search/ProductDetail.aspx?qs=wkKrz7WmEgNNyd%2Fvat7D2Q%3D%3D
I've used a 150 mA fuse with it, according to the specific of sontec...

Thanks.
A.

 

[wolfgang]

I think your fuse is set to low since this is a 50VA transformer.
50/230 is about 220mA. i would go with 250mA to 315mA for inrush current.

I hope my calculation is right!

regards,
Wolfgang

 

[Aleguitarpro]

I think your fuse is set to low since this is a 50VA transformer.
50/230 is about 220mA. i would go with 250mA to 315mA for inrush current.

I hope my calculation is right!

regards,
Wolfgang

Oh, sh*t!
You're right...
50/220= 0.227 mA (fuse)
But I don't remerber if I've to oversize the primary fuse respect to the amperage...
150% it's ok?
es.

50VA/220=0.22 x 150% = 0.33 mA

It's ok?

It's possible that I've damaged the circuit, too, or I've "just" burn the transformer?

 

[atticmike]

Does also anybody have a rough figure on how much they spent on the passive parts / components to be soldered onto the boards?

Without the expenses of either enclosure, frontplate, xlr connectors, cables and such?

And again, a simple buying list, of all the to be soldered components onto the pcbs, would help people's rather rare occasion of build undertakings and therefore their targetet parts procurement tremendously.

Hi.
For the passive components+toroidal power transformer I've spent about 200 euro (mouser+musikding.de).
I can't say it with precision, because I've bought a lot of passive components in that order, but it's not more than 200 euro, only for sontec.
Only for the alpha pots, the cost is about 135 euro.
For the case, I've spent 75 euro on diy-racked.
The you have to buy knobs with 6,3 mm and 3,2 mm axis (CTS pots).


Now, I've a problem with my power transformer: after a short test to see if everything was good, I've switch off my Sontec.
The day after, I've switch on it and it broke my fuse.
I've repeat the test, isolating the problem (I've made a test without the summing+filter boards) and then, without the psu: always the same...
I've broken 6 fuse...
I isolate the transformer and I think that it has lose the isolation in the primary.
It's possible? This is the first time I find this problem!
I don't know if it is a problem of THIS particular transformer or if I change it, I'll burn another transformer!
The secondary seems to be ok... How can I test it?
I think the problem is in the primary, because also with the secondary disconnected it burn the fuse.
The transformer is this one:
http://it.mouser.com/Search/ProductDetail.aspx?qs=wkKrz7WmEgNNyd%2Fvat7D2Q%3D%3D
I've used a 150 mA fuse with it, according to the specific of sontec...

Thanks.
A.

But still, if it shows what parts you've procured, it'd be hell of a help

 

[Aleguitarpro]

But still, if it shows what parts you've procured, it'd be hell of a help

FROM MOUSER:

- CTS pots
3 5K LIN POTSW
http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=CT2204-ND

1 5K LIN POT
http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=CT2226-ND
(you have to copy the product code in Mouser)

- power transformer
- neutrik xlr
- not common european value resistors
- 2604 OPA
- some ceramic capacitor

FROM ALPHASTAT:
- 5 50k CTPOT
2207 RD1601-20F4-30R
ALPHASTAT 63250-01610/B50K 50K LIN CENTERTAPCENTERDETENT

- 5 100K RLOG DUAL_ALPHA_2
4196 RD1602-20B4-30R
ALPHASTAT 63256-02600/C100K 100K REV-LOG

FROM MUSIKDING (a place in europe in which you could find passive components for a very good price...supposing you're from europe...)

- all resistors 0.6 W
- OPA 604
- OPA 275
- capacitors (WIMA, tantalum, etc.)
- connectors (MOLEX)
- power connector
- wirings
- led
- diodes
- heatsink
- etc.

CASE from DIY-RACKED for 75 euro.

Hope this could help you.

A.

 

[wolfgang]

Oh, sh*t!
You're right...
50/220= 0.227 mA (fuse)
But I don't remerber if I've to oversize the primary fuse respect to the amperage...
150% it's ok?
es.

50VA/220=0.22 x 150% = 0.33 mA

It's ok?

It's possible that I've damaged the circuit, too, or I've "just" burn the transformer?

I would go with 150%. so 315mA is a standard-value in that range that should work.
If something else is gone ? can happen but dont have to! I would  connect the PSU-Board only and check the DC-Voltages. Then you will see!

regards,
Wolfgang

 

[cstella]

I had a similar problem that drove me crazy! I was blowing fuses and had other strange behavior. I had a new transformer but some how the protective film had been broken and the transformer was shorting out against the chassis mount screw. I removed the transformer and covered it with electrical binding tape. No more shorts and the Sontec works great!

Maybe that helps.

Thanks, Charles

 

[atticmike]

Is it that 0207 are 0.4 resistors and 0204 equals 0.25?

 

[kante1603]

But the BIG QUESTION is: why the primary is shorted?
Why it lose the isolation?

Hi,

this often occurs when overtightening the mounting screw.I had exactly that in a different built.Also don´t mount them with the wires running from the bottom of the torroid;I know it looks better but it´s possible to break one.Mount them correctly with all the mounting parts like a rubber sheet and the metall pieces etc.
I´m sure you know that the mounting screw shouldn´t touch both the bottom and the top of the case because this will cause a magnetic short by creating one single winding-that´s a killer.

Hope to have helped,

Udo.

 

[atticmike]

From what I've understand, you employ two ics for every channel.

Which ones would you recommend? Thankfully with referring to an online source where I can get em.

Mike

Still, are the 0207 as well 1/4 0.25 watt resistors, kind of curious because they're listed separately?

 

[Leonardo_007]

maybe it will depend on your selected sources for procurement but i would definitely recommend the combination OPA 604 / 2604 as they will provide the best value for money ratio and you won't have to calculate with different values for the resistors. they are robust (even work w/o sockets) and you can get along with 24v.

 

[Leonardo_007]

just for official clarification.. the codes "0207" "0204" on resistors are size indications in mm, for instance: "0207" means the resistor is 2mm wide and 7mm long.

 

[ilfungo]

hi Igor
Any news about stepped sontec?
Thanks

 

[ptron]

hi Igor
Any news about stepped sontec?
Thanks

i think this project has moved on with the name of Uni-Q

 

[atticmike]

just for official clarification.. the codes "0207" "0204" on resistors are size indications in mm, for instance: "0207" means the resistor is 2mm wide and 7mm long.

but that'd mean I could just take regular 1/4 resistors since you can stretch em anyways by the lead?

 

[Harpo]

just for official clarification.. the codes "0207" "0204" on resistors are size indications in mm, for instance: "0207" means the resistor is 2mm wide and 7mm long.

Look up the resistors datasheet for the 0204 and 0207 types to get the difference (parts size / power rating / voltage), maybe from this manufacturer ...
http://www.yageo.com/documents/recent/Leaded-R_MF0_2011.pdf

Use ohms law to check, if it matters for a specific part in question.
(hint: with a +/-24V supply, 0.25W rated resistors with value lower than 2K3, 0.4W rated resistors with value lower than 1K4 or 0.6W rated resistors with value lower than 960R might need a 2nd look, if their power rating will be sufficient in a specific spot in this application)
For this EQ build, RPS1...5 (and R16 in a shorted output condition by maybe connected broken XLR cable) better have a higher power rating than 0.25W or 0.4W.