Studer 169 EQ in API 500 format

Thanks.

I've been having a look at Net Eq schematic, and I preffer to use a section of another eq rather than a circuit I just found on the web.

So, should I drop the gain in the line receiver using this design? I will use a DPDT switch for bypassing it.

Time to read about filters. ..

dirtyhanfri said:

So, should I drop the gain in the line receiver using this design? I will use a DPDT switch for bypassing it.

Click to expand...

No. Gain in line receiver can stay at 0.5 (-6dB) if you want to have the HPF (whatever this design might refer to) bypassable, else the 169EQ circuit wouldn't be unity gain with level pots centered.

Harpo said:

(whatever this design might refer to)

Click to expand...

I was refering to BP Net EQ HPF section

Thanks, I will build it in a perf board and try to calculate values for the rotary switch

hello im building 3 of them right now...


i have left over some caps from another project and would like to use them in these EQs

the caps are 8n2 with 630V rating so they are a bit big for a 500 modul but my freq will be switchable i think i can mount them...

is a 630V cap a good choice for a HF section? the wimas are @63v or 100v... does this volt rating matter?

electrisizer said:

hello im building 3 of them right now...


i have left over some caps from another project and would like to use them in these EQs

the caps are 8n2 with 630V rating so they are a bit big for a 500 modul but my freq will be switchable i think i can mount them...

is a 630V cap a good choice for a HF section? the wimas are @63v or 100v... does this volt rating matter?

Click to expand...

No,it's just big.Capacitance does.
Funny detail:Will start building three of them soon,same as you,hahaha.....
Christmas time I'd say.

Best,

Udo.

@kante  ;D lunchbox slutz we are!
thanks for answer...

what config are you going to build?

mine have 5534, trafo in, 3x freq switch for HF, 2x freq switch for LF...

if interested im posting my FP later this day

heres my FP...
its not produced yet. i hope it will fit

https://app.box.com/s/u9f4borkfr1ffg5kyz2h

electrisizer said:

heres my FP...
its not produced yet. i hope it will fit

https://app.box.com/s/u9f4borkfr1ffg5kyz2h

Click to expand...

Hi,

looking nice so far,but why not make the low swich do three frequencies?I think a low one as in the 20+ Hz area could be very useful.At least I´ll start there (the original value) and have it on single IC-sockets temporarily for easy exchange.
Despite of that I´ll have the transformers too,same as you,got them cheap and new from evil b**,a pair for 29,95-Euros,cool!
Will start with NE5534s too and listen,maybe later do some trials with doas,got some sockets on the way from Volker right now.
Think I´ll start with them around christmas or so ("die stille Zeit")

Keep us posted!

Best,

Udo.

kante1603 said:

electrisizer said:

heres my FP...
its not produced yet. i hope it will fit

https://app.box.com/s/u9f4borkfr1ffg5kyz2h

Click to expand...

Hi,

looking nice so far,but why not make the low swich do three frequencies?I think a low one as in the 20+ Hz area could be very useful.At least I´ll start there (the original value) and have it on single IC-sockets temporarily for easy exchange.

Click to expand...

got the trafos cheap too... btw neutrik was used in studer 169 too. no need to look for vintage trafos. neutrik = studer with anothe sticker...

i choose the frequencies from my mixing expirience... 60hz is the lowest freq i ever used. some eqs here have lower freqs too - i tried often but returned to 60hz for lowest - even in deep bass hiphop tracks - AND its my favorite freq on my console too (i want to replace the console with the bunch of 500 boxes sometimes).

its kind of special that the default freq is so low for a broadcast mixer. perhaps it is used in combination with the low cut switch of an original 169 channel? i have a racked predecessor (studer 189) channel strip here and the fixed lows are @ 80hz

really dont know whats going on here...

i finished my 1st unit and my 511 rack burned the +/- 16v fuses...

i begin checking the board and every(!) card pin connector does have a connection to every other card pin connector  is this a faulty batch of boards?

YES it is a bad batch of boards - but ive found the problem... with solution 

the copper pins connect to each other. the boards are not cutted the right way.

i cut the copper connection with a knife. perhaps one can do this with a rasp? its important to make a clean cut. look at the picure (circuits sign the cut)

Wow!

Thanks for sharing!

Haven't completed mine yet but it's worth to take a closer look.

Best,

Udo.

O.k.,have my three boards checked,two of them have full continuity over all pins!
The third one doesn't,it is looking more yellowish and has a better silkscreen than the others.
A big thanks to you electrisizer,I might have run into huge trouble!
It is really hard to see,so best to check them people.
Will try the "rasp"- method soon and report back here.

Best,

Udo.

Edit:CONFIRMED!A small rasp does the trick.

electrisizer mailed me to inform me about this problem.

I am SO sorry about this.

In standard production, the boards are probe tested for shorts and opens. Since testing happens while the boards are still in their production panels, and routing is done afterwards, this problem was not caught. (The connectors are shorted for chemical gold plating).

The last batch of boards is sold out, and I will have a new batch back this week (We still send the boards out of house for gold plating). I'll make sure to check up on this on the new batch, and once again - really sorry about this problem.

Gustav

Yea I had the same problem about 20 threads ago! Thanks for solving the problem. I will also try the rasp method. Been racking my brain about these boards.

Bonsaimaster

Eureka! The rasp worked! Two boards are now singing the the case! I thought I was crazy trying to figure out what was wrong!! Thanks so much for the help. A month of head scratching for a 5 sec fix!!! Ugh. Well here is my assessment. Build one with transformer and 2520's and one without. The non-transformer version is harsher and the trans one is smoother. I actually like the non-transformer version better. Much more to work with.

Bonsaimaster

Very cool that you got them working and that you like them. Cheers!
Harsh? Really? I built a pair and gotta say I've never found them to be harsh in any way.

I guess harsh would mean aggressive compared to the transformer version.

Mine are done too,here a pic.
Thanks to audiox for this great eq,Frank for the panels,Gustav for the pcbs and last but not least our member electrisizer for his excellent hint!

Cheers,

Udo.

Edit:Forgot to mention that these eqs are really great sounding.Mine are non-doa but with ntl1 transformers.Although they look so simple they do an excellent job when it comes to sweetening.
I went with the original frequencies for low and high shelf after tests with other values.Absolutely no need for me to make them switchable,so around 20Hz and 19,xxx Khz it is.The low band drops in soft like butter,the high band creates a nice air band.Since the mid bandwidth is pretty wide lowering the 1 to 2k area and giving a slight boost on high and low gives you a nice hifi-style loudness curve if you're after that.
These guys aren't surgeons.....they are musicians.
Highly recommended!

Hey all,

Been a while since I built my 169s, but haven't been able to post a pic as they were missing a switch cap until now. Anyway, now I can finally check them off the list with the switch caps + unity gain trimmers installed, so I just wanted to come back and thank everyone before I forgot! Thanks to audiox for designing them...I went with the IC + NTL1 option, and thanks to Gustav for providing the pcbs. Panels used the provided layout and fabricated by Frank.

Anyway, I tend to keep things fairly by the book and standard, so nothing interesting to see here, but for what it's worth, see the attached pic!

Cheers,

Kaz