The Sontec thread! <ATT. BUILDERS - C22 & C23>

[mik]

Guys do you think is possible to match the two 2 ch to work in stereo with just one side to contol the unit ? like the real one.. :?:

 

[chrissugar]

Yes, you can use dual pots or stepped switches.
I opted for dual mono with stepped switches for all controls because it gives you more freedom. In a MS mastering situation maybe you want to aply a diferent equalisation to the M channel. Also there is the advantage that you can use it at recording/mixing as two independent equalisers.

chrissugar

 

[chrissugar]

Still no time to solder those tons of resistors to the ELMAs.
http://img.photobucket.com/albums/v292/chrissugar/CMS-LAB-MEQ2/DSCF6864X.jpg
http://img.photobucket.com/albums/v292/chrissugar/CMS-LAB-MEQ2/DSCF6863X.jpg
http://img.photobucket.com/albums/v292/chrissugar/CMS-LAB-MEQ2/DSCF6861X.jpg
chrissugar

 

[TomWaterman]

Holy **** Chris!!!!

Wow - that looks awesome - I like your filter board mounting idea too, really great space saving option.

Where do you guys get all of your elmas? You must either have extremely deep pockets or a really cheap source? If its the latter - would you consider a nice little export to the UK?

Great stuff - I just hope these all sound as amazing as they look.

Jaakko - any news on your box?

Cheers Tom

 

[chrissugar]

The ELMAs for the Sontec were bought last year.
Two month ago I bought 50 and this week I ordered 70 more. They are expensive. I use mostly the 24 step single waffer [good for stepped attenuators and gain pots] and the 2x11 step single waffer type [good for gain switch for the SSL9k preamp or Jensen twin type preamp or freq switch for equalisers]
Rarely I buy the 24 step three waffers switch for N_E_V_E 1073, 1290 type preamps but they are very expensive.

chrissugar

 

[Bauman]

GREAT STUFF! :shock:

Are you going to diy the boards? Discrete opamps?

cheers!
Fabio

 

[chrissugar]

My first idea was to build from the begining an upgraded version with discrete JFET opamps on all boards and OPA604 servos but after doing some research and also talking with Brad Blackwood I discovered that many people like this eq with the stock NE5534 and TL07x opamp so my decission is to use the stock opamps and only on the main board to use JFET discrete opamp.
The power supply is dual, separate regulation for each channel and also option to change voltage to 24V for OPA604 and discrete opamps for the filter boards.

chrissugar

 

[Bauman]

YEA! I what pics!!!!

 

[chrissugar]

Not bad that Canon. :thumb:
I use for more than a year the Fuji Finepix S5000 but soon upgrade to the Nikon D100. :grin:

chrissugar

 

[rafafredd]

I have a NIKON coolpix 5700 and I hate it. The focus sucks.

I really prefer my brothers sony cybershot 5.1. Simple and great!

 

[chrissugar]

Rafa, do not confuse the Coolpix Nikon with the D series. The Coolpix is a toy digicam made for amateurs that will not learn how to make quality pictures and the whole photo technique. The D is a pro machine with high quality optics and electronics. You can also do everything manualy like on a classic machine.

chrissugar

 

[kvintus]

The D70 is also very nice. I'm really happy with mine. Now I just need to finish some of my projects so I can post some pictures...

/Anders

 

[rafafredd]

[quote author="chrissugar"]Rafa, do not confuse the Coolpix Nikon with the D series. The Coolpix is a toy digicam ...

chrissugar[/quote]

Nice to know it, because it really sucks. Even compared with other TOY digicams like that sony that I have. It really really sucks.

But the D series is probably THE THING.

 

[Rob Flinn]

Questions

Amp board:

On the parts list, R80 is specified as "4K7/6K4?". Can anyone elaborate on this ?

How do you calibrate the preset pot?

Filter Board

1. What is the value for R78 ? Its not specified on the parts list.
2. How do you calibrate the preset pot?

General:

1. What are the op amps that were used in the original ?

 

[Rob Flinn]

Hello,

Help pleeease!

Someone must know the answers to the questions in my previous post.

 

[Rob Flinn]

Thankyou Jaakko,

I can now move further with this.

 

[chrissugar]

"Soldering tuning resistors in to filter board nr. 8/10, and I noticed I've been going the wrong way all the time on all previous boards. The high end of the frequency scale is at the CCW position now."

:green: :green: :green:

chrissugar

 

[zmix]

:grin:

 

[rafafredd]

Soldering tuning resistors in to filter board nr. 8/10, and I noticed I've been going the wrong way all the time on all previous boards.

:evil:

What are you doing with my babes?

 

[thedug]

I decided to ditch the discrete business at least for the time being.

I am going to use OPA604 for the amp, 5534s for the filter and TL051s for the servos

I am just curious about a couple other parts though.

1) on the original schematic there is a note by A saying "R76 short" and by E saying "R75 short". What exacly am I supposed to do?
2) FOR C26,I couldn't find a 39p poly. Will mica be ok here? If not what should I use?
3) C23 is listed on the original as .68uF but on the fabio's list is says .68uF - 1uF why would you increase this?
4) Just curiosity sake, the noise cancel adjust saying to turn R75 and R76 CCW. But aren't they 1 pot? Just thought that was wierd to say.
5) Noise cancel adjust should be for R83. What is the adjustment procedure for R70(Bias) and R39(Unity Gain)? I assume by the name that R39 is adjusted for 0 gain on IC4? Just measure volts in and volts out?

Thanks..


d./