sontec 1 RU build thread

[Nobieesd]

Regarding the PCB's pricing: I am more than happy to sell them lower,
but, to bring the price down, I have to order MOQ of 100 PCB's.
In case of 3-4 stereo pcb sets sold monthly, impossible.
You can organize group buy for say 20 stereo sets, the price will be 40% lower.

ok, it was just because at diy-recording-equip. it's written it should cost 90$ and at the market it was 130
however, i have bought your pcb some days ago over the diy-rec.-market

already i have found nearly all parts wich i need for the hole eq... just the pot's and the case make a problem... (for the case it will need 3 more customer from diy-racked... and i cant find the alphastats or any other pot with 5K
the amusing part:
it seems, the pot's of alphastat are manufactured in germany but nobody sell them here
is there maybe someone out of germany who know i can buy them ?
cheers, Nobieesd

 

[cstella]

You can buy them from PS Potentiometer in Germany

http://www.alphastat.de/

 

[kante1603]

You can buy them from PS Potentiometer in Germany

http://www.alphastat.de/

Exactly-although they´re a bit slow sometimes (in my case they were...but it worked with being patient).
Translation:
Genau-aber manchmal sind die ein bischen dröge....so war´s jedenfalls bei mir (funktioniert aber...Geduld).

Udo.

 

[Nobieesd]

oh thx, i will write to them...
now i have read the half thread ... and it seems all my questions are answered


*YeY*
and it beginns...

 

[Paultec]

Igor,

Did you get anywhere with  the mastering version pcbs?

Regards

Paul

 

[cstella]

Igor,

Did you get anywhere with  the mastering version pcbs?

Regards

Paul

A bit of of turn but It's happening here:

http://www.groupdiy.com/index.php?topic=47454.0

 

[Paultec]

Ah, cool...!

Thanks cstella...

 

[gda]

Hi to all! I would like to ask how do I connect the eq to an unbalanced piece of gear. I suppose, I should solder new wires...should I solder two of the three XLR pins to a mono jack and leave the one left unconnected or should I connect two of the three XLR pins together?

 

[cstella]

Hi to all! I would like to ask how do I connect the eq to an unbalanced piece of gear. I suppose, I should solder new wires...should I solder two of the three XLR pins to a mono jack and leave the one left unconnected or should I connect two of the three XLR pins together?

Typically you would tie  pin1 (ground) and 3 (-) together to ground and use  pin 2 as your signal to connect unbalanced.

 

[gda]

Today I first powered up my Sontec....the RPS2 and RPS3 (22Ohm) resistors of the in/out board of one of the channels burned. I found that I had put upright the OPA2604 (the middle IC as we see it). Bear in mind that I used 604s and 2604s. I put it correctly, I changed the resistors, powered it up and everything seemed ok.... and I have problem again. When I check the XLR out of the board between pin 1 and pin 2 I found that I have 1.5Volts, while on the other channel I have 0 Volts. Please help..what is the correct one? From the power supply board in both channels I have 24Volts coming out..so that board seems ok...

 

[sonicwarrior]

For 55k can i use 20k and 35k in series?

I'm currently trying to source that, too, but 22k and 33k in series makes more sense to me as these are E12 standard values while 35k is almost as hard to get as 55k.

using LME49860 here because quite frankly OPA2604's suck.

I thought the LME49860 are SMD only but Mouser has a DIP version in stock that is even cheaper than the OPA2604 so I'll give them a try.

Did you use them in the AD706 position, too, and used a +/- 22 V PSU with Rx = 3.48K?

 

[dagoose]

I was thinking of replacing/trying the OPA's with LME49860 but Since i have forsell 993 DOA's in the output if they run on 22v or do they really need 24v?
I tried searching the foreselltech site but Fred doesn't sell the DOA's anymore and all info seems to be gone as well.

 

[hop.sing]

Today I first powered up my Sontec....the RPS2 and RPS3 (22Ohm) resistors of the in/out board of one of the channels burned. I found that I had put upright the OPA2604 (the middle IC as we see it). Bear in mind that I used 604s and 2604s. I put it correctly, I changed the resistors, powered it up and everything seemed ok.... and I have problem again. When I check the XLR out of the board between pin 1 and pin 2 I found that I have 1.5Volts, while on the other channel I have 0 Volts. Please help..what is the correct one? From the power supply board in both channels I have 24Volts coming out..so that board seems ok...

The middle opa2604 is acting as a servo for both opa604 in and output opamps. That means it corrects dc offset from the audioopamps so that there is no electrolytic in and output cap necessary. Having dc on pin 2 means probably, that the servo opamp (opa2604) does not work anymore because it is fried. Change it and things should be fine again.

 

[cstella]

I've successfully used the Forssell DOA's at 15v. So 22v should be fine.

 

[gda]

Thank you hop.sing! well I changed the opa2604 and I still have the voltage...I connected the eq and passed signal through it and it works! I realized also that that opa gets really hot in contrast with all the others...can't find any bad connection...what is happening...?should I leave it? the other channel doesn't get such hot...

 

[hop.sing]

Thank you hop.sing! well I changed the opa2604 and I still have the voltage...I connected the eq and passed signal through it and it works! I realized also that that opa gets really hot in contrast with all the others...can't find any bad connection...what is happening...?should I leave it? the other channel doesn't get such hot...

Well, that opamp is not really (just a little bit) in the signal path, so the channel will still kind of work with it malfunctioning.
Getting hot could be a sign of oscillation, if you have a scope you can verify that, otherwise check all the surrounding components for values and solder joints again, I bet you will find the problem there.
But I would try to solve that problem, not leave it as it is, some gear does not like dc on its input (Think of transformers, dc between pin 2 and 3 will degrade their performance) and if it is oscillating, the audio opamps in the signalpath will probably be affected, too.

 

[gda]

Thanks again! I will check for another time the nearby components...may be I will replace them too...will see...

 

[ptron]

hello! well i just jumped in both legs first into this got 2 stereo sets.. i really need this eq in my life!! anyways ... i was looking now into pots. i seen the ones on digikey..
http://search.digikey.com/us/en/products/270X232A502B1A1/CT2204-ND/203785
http://search.digikey.com/us/en/products/270X232A502B1B1/CT2226-ND/203807?cur=USD

thing is.. i already ordering a massive list for a gssl and some parts for a 2254 on mouser and would really like to source em there..

i found some bourns pots and honeywell ones 5k lin ... i wanted to ask.. are these ok and suitable for audio purposes?
http://mx.mouser.com/ProductDetail/Bourns/PTD902-2215K-B502/?qs=sGAEpiMZZMsYXAobifOWHHsvVlmygg1PJ15czyNNTvQ%3d
http://mx.mouser.com/ProductDetail/Honeywell/585SX4Q25F502SP/?qs=sGAEpiMZZMsYXAobifOWHABmzPQ018zT6tcr500YAG4%3d

this one says AUDIO but does this mean is a Log one? or just good quality?
http://mx.mouser.com/ProductDetail/Bourns/PTD901-2015K-A502/?qs=sGAEpiMZZMsYXAobifOWHHsvVlmygg1PSRrH8DJbHc4%3d

the 5k with switch i cant find on mouser.. i sent an email to alphastat.de to ask about prices but before all that happens i wanted to know if anyone has 2 stereo sets of pots here? would be great!

anyways thanks a lot ill be coming to hassle to this thread more often

 

[zayance]

I give you a hint: Copy/Paste Manufacturer Part number from Digikey in Mouser's Search field 

 

[ptron]

http://mx.mouser.com/ProductDetail/CTS/270X232A502B1A1/?qs=GxOUx7aO6nwVwavGBMqnkg%3d%3d so 3 per channel?

http://mx.mouser.com/ProductDetail/CTS/270X232A502B1B1/?qs=GxOUx7aO6nyHwVWMNHDkQg%3d%3d 1 per channel?

thanks a lot zayance