GSSL HELP THREAD!!!

[Harpo]

Hello people,

i do have a question about some capacitors...
i dont understand the diffrence between those types, like tantal ceramic or foil / polyester?
i guess i will buy the wrong ones, so if any one can show me a photo of the dirffrent ones
or even show me a link where to buy those, please...

on the pcb they are .1, in the part list i can only find 100nf... i also cant find the right ones in online shop...
i also cant find 1pcs TANTALUM CAPACITOR 6.8µF-35V, 5pcs TANTALUM CAPACITOR 0.47µF-35V on the PCB?

thanks for any advice

For the 100nF (same as 0.1uF or 100000pF) any polyester with pin spacing 0.2" (5mm) and voltage rating of at least the connected supply voltage (>=15VDC) should do. 
The tantalum caps (these are polarized, so take care to mount these in the right direction) are located on the gssl control board.
German sources? Your local electronic shop, conrad.de, reichelt.de, buerklin.de, ....
100nF (same as 0,1uF)
Tantal 6,8/35
Tantal 0,47/35

 

[warpie]

I'm taking some measurements for my GSSL and I noticed that Frequency Response changes dramatically when changing the attack time.
However this occurs only on ratio 4 and 10. Ratio 2 seems to behave OK.

Below is the plot for Attack 0.1ms (minimum)

and that's the plot for Attack 30ms(maximum)

Is this a normal behavior??
(I'm using the Turbo mode but the same happens on the Gssl mode as well)

Also....
There is a phase difference between L and R output channels of about 200uSec (0.2ms).
Is this phase shift a serius reason for not using it as a master bus compressor?

hope I'm not asking too much...

thanks
warpie

 

[nielsk]

Got one here with ripple on the +12 rail.....tried replacing the reg, adding bypass more caps, putting a diode inline to the reg input, changing input resistors from 10 all the way up to 330 ohms.... not much improvement. Every other rail is clean as a whistle...(weird that the +15 feeding it is clean, huh?)
the unit functions normally, it has an outboard bridge w/ caps on it, good star ground, turbo board, & sidechain board. hum is getting through to the audio outputs
anyone seen this?

 

[tongenerator]

Hello people,

i do have a question about some capacitors...
i dont understand the diffrence between those types, like tantal ceramic or foil / polyester?
i guess i will buy the wrong ones, so if any one can show me a photo of the dirffrent ones
or even show me a link where to buy those, please...

on the pcb they are .1, in the part list i can only find 100nf... i also cant find the right ones in online shop...
i also cant find 1pcs TANTALUM CAPACITOR 6.8µF-35V, 5pcs TANTALUM CAPACITOR 0.47µF-35V on the PCB?

thanks for any advice

For the 100nF (same as 0.1uF or 100000pF) any polyester with pin spacing 0.2" (5mm) and voltage rating of at least the connected supply voltage (>=15VDC) should do. 
The tantalum caps (these are polarized, so take care to mount these in the right direction) are located on the gssl control board.
German sources? Your local electronic shop, conrad.de, reichelt.de, buerklin.de, ....
100nF (same as 0,1uF)
Tantal 6,8/35
Tantal 0,47/35

thanks a lot... i guess i got the right ones... i was not clear about it... that 100nf means 0,1uf on the pcb...

 

[ytsestef]

Hello everyone!
I am a newbie and this is my first post, so, please go easy one me  ;D

I want to build the ssl clone. I have done some DIY electronics before (some SID synth from midibox) and I know how to solder and stuff.
The problem is I do not know much about electronics, apart from reading a schematic, and what do the basic components do (however I am quite familiar with how compressors work). Anyway, here's my problem:

I am very confused as to what deviations from the parts jakob is suggesting are acceptable.
I live in Greece and would rather order the parts from some european store (the most decent I found is farnell), but I can't seem to find EXACTLY all the parts. Let's take for example the bridge rectifier. Jakob suggests 1A/50V minimum and Kev has chosen 1,2A/400V. Was the "minimum" referring to voltage or amperes? Then is the following 1,5A/50V one ok?

http://export.farnell.com/multicomp/am150/bridge-rectifier-1-5a-50v/dp/9381422

Of course my questions go way beyond the bridge rectifier, so maybe has someone compiled a list with such stuff? Or maybe a part list from a european store? Or should I continue asking about the other 20 components I'm not sure about?  ???

Thanks for you help, sorry about my bad english.

PS: Mods, if this is the wrong place to post this kind of question, please feel free to move it.

 

[Harpo]

I am very confused as to what deviations from the parts jakob is suggesting are acceptable.
I live in Greece and would rather order the parts from some european store (the most decent I found is farnell), but I can't seem to find EXACTLY all the parts. Let's take for example the bridge rectifier. Jakob suggests 1A/50V minimum and Kev has chosen 1,2A/400V. Was the "minimum" referring to voltage or amperes? Then is the following 1,5A/50V one ok?

http://export.farnell.com/multicomp/am150/bridge-rectifier-1-5a-50v/dp/9381422

Welcome ytsestef.

Voltage rating requirement for your bridge rectifier is not related to any published BOM but to the transformer that you intend to use. From Jakob's schematic this is a 5VA 2x15V or 2x18V transformer to make this gssl work without the need of additional heatsinks for the voltage regulators.
(If a build plan for your gssl also includes additional circuits like a turbo circuit, sidechainfilter(s), optical gimmicks, cigarretlighters or whatever, this 5VA rating might need to be increased for these currents.)
Anyway, this maybe 2x15V transformer is wired with secondaries in series, giving a center tap at the junction in the middle (so a 30V center tapped transformer will also fit). This voltage is AC, but for the diodes inside your bridge rectifier the value of interest is AC peak voltage, so multiply this 30V by sqr(2), giving 42.4V pk. Your mains line voltage is not a constant and might vary by +/-10%, depending on location or mood of a generator for an open air venue, that also will show up on the transformers secondary. Adding this for a high mains scenatio by factor 1.1 for +10%, voltage will be 46.7V pk. This 2x15V or 30VCT number from catalog or transformer attached sticker is the secondary voltage under load condition and might be 20% higher unloaded. Adding this by factor 1.2 for +20%, your rectifier has to stand 56V pk for a worst case scenario, 50V for a less conservative calculation might do. A 2x18V or 36VCT transformer might need a rectifier rated for at least 67V, so next higher standard value would be 80V or 100V. Rule of thumb is, double transformers secondary voltage for your rectifiers voltage rating. A 400V part probably will cost the same.
Again current rating requirement for your bridge rectifier is not related to any published BOM but to the transformer that you intend to use.
Switching your gssl on, the empty capacitors after this bridge rectifier will nearly represent a short and draw all current, your transformer can deliver for some AC cycles. A 5VA transformer will deliver less current than a 10VA, 15VA or even a 30VA transformer that some members here used for whatever reason to build their compressor and your bridge rectifier has to stand this current. Just use the highest rating that fits the pcb. Difference in cost between a overspecced part and a close fit will be cents if any.
For the gssl rectifiers pcb footprint and maybe farnell, have a look at
1497585 for a 400V/2A part is 0.77€ in singles (same cost for a 50V, 100V, 200V or 600V type).
Your quote 9381422 for a 50V/1.5A part is only 0.42€, but has a 5 pcs min.order.
(last digits order number after the slash for farnell in Greece is probably the same as here)

 

[ytsestef]

hey, thanks a lot harpo, that was really useful. I only intend to add the turbo mod (no switch, constantly in) anyway, so I guess the one I chose isn't exactly wrong, if I got it correctly, although the one you are suggesting is safer choice. what I needed to stress is that my confusion spans over 6 or 7 components and the bridge rectifier is just a mere example.

I am unsure about (you're gonna laugh) the LED!!!
i mean, really. there are so many types and specifications. does it have to match the current and the voltage of the transformer output?

the other thing that beats me is the 1N4148 diode. during older DIY electronic projects I just went to a local store, asked for a 1N4148 and they gave me one. but in farnell's store the options are too many! am I too picky? I don't know. I can't seem to match the "80V-0.1A" jakob is suggesting. is this one good?

http://uk.farnell.com/fairchild-semiconductor/1n4148/diode-high-speed-do-35/dp/9843680

EDIT: I live in greece, so the ac power here is 50Hz I think. Do I need a 50Hz toroidal transformer? I can only find 60Hz. Does it matter??

thanks a lot for your time.
this is really helpful.

PS1: There is no farnell in greece actually there is no decent electronic parts store in greece, I'm just ordering from farnell export.
PS2: I am still uncertain. I am posting in the right thread  :-\ ?

 

[Harpo]

I am unsure about (you're gonna laugh) the LED!!!
i mean, really. there are so many types and specifications. does it have to match the current and the voltage of the transformer output?

Have a look at the schematic (in any case not the worst idea). The LED is not connected to the transformer but after rectifier and regulator, so it will see a predictibal DC voltage, +12V in this case, as it is connected between the output of a 12V regulator and 0V. The current flowing thru this LED is limited by a 1K resistor to not exceed the max. forward current If of this part. A red LED may have a If of 20mA or 30mA and a forward voltage Vf of typ. 2V. Brightness of this LED within limits is controlled by current and you probably don't want an eye blinding part on your frontpanel, so Jakob decided in his plan, a (12V - 2V)/1000 ohm = 0.01A = 10mA forward current for this LED could fit. If your plan shows a maybe blue LED, the value of this 1K resistor needs to be changed for this part, as blue LEDs come with maybe 3.5V forward voltage. Just pick a LED with colour and shape to match your plan and maybe tweak this 1K resistor to not exceed the parts limits. Ohms law will help.

the other thing that beats me is the 1N4148 diode. during older DIY electronic projects I just went to a local store, asked for a 1N4148 and they gave me one. but in farnell's store the options are too many! am I too picky? I don't know. I can't seem to match the "80V-0.1A" jakob is suggesting. is this one good?
http://uk.farnell.com/fairchild-semiconductor/1n4148/diode-high-speed-do-35/dp/9843680

Any 1N4148 diode (better don't pic a SMD part when the pcb calls for a thru hole part) will fit. These diodes are connected to op-amps that are fed from a +/-12V supply and will not see more voltage than this range.

All of your questions have been answered in previous posts of this thread, so please read them. Lots to learn along the way and from other members faults.

 

[ytsestef]

thanks a lot!

I noticed that the led is placed on the 12V domain after I posted and before you answer!  :

So, I found an orange LED with If 25mA and Vf 1,9V.

http://uk.farnell.com/jsp/search/productdetail.jsp?sku=1003212&_requestid=248728

If we use the same 1k Ohm resistor, does this mean:
12-1,9/1000=10,1mA?

which is less than half the led's max. forward current (25mA).

Is this right? Does this means I can use a slightly smaller value resistor?

Just making sure.

 

[Harpo]

So, I found an orange LED with If 25mA and Vf 1,9V.
http://uk.farnell.com/jsp/search/productdetail.jsp?sku=1003212&_requestid=248728
If we use the same 1k Ohm resistor, does this mean:
12-1,9/1000=10,1mA?
which is less than half the led's max. forward current (25mA).
Is this right? Does this means I can use a slightly smaller value resistor?

Yes (ignoring missing paranthesis and units in formula), lowest resistor value is 404 ohm for 25mA. I'd try it with a 1K start value and maybe tweak to taste within parts limits afterwards if needed.
Your selected part has a brightness of 7 mcd or 10 lux and comfortable wide viewing angle of 60°. An orange LED (wavelength 600-610nm) is a bit closer to the most eye-sensitive spectral area (~560nm) than a red LED (625-645nm), so it will apear brighter compared to a red one with same mcd value and same current.

 

[ytsestef]

ok, thanks a lot!
your devotion gives me confidence!
I am almost ready to place my order.

The last thing I want to make sure (and I did try to search for that before I post)
is the Power Rating of the resistors. Is 125mW enough or should I go for 250mW??

Thanks a lot for all your help guys!  ;D ;D

 

[Harpo]

The last thing I want to make sure (and I did try to search for that before I post)
is the Power Rating of the resistors. Is 125mW enough or should I go for 250mW??

Did your search already included ohms law? (hint P=U2/R)
Did you ever work with these flimsy parts, breaking when you look at them for too long ? Maybe download the datasheet of a selected resistor and look for its outer dimensions. My eyes will fail identifying a 5 ring colour code within a 2.5-3mm part. Imagine to debug your circuit with these parts soldered in. I'd probably invest the additional 0.007€ in a +/-1% tolerance metal film 0.4W, 0.5W or 0.6W part. As always YMMV.

 

[3nity]

Guys its been a while since i built my first 2 gssls and i dont have them anymore.
So i was wondering how the meter reacts on bypass mode?

I'm building a 3rd one and using relays to bypass so what i'm thinking its to leave the compressor always on
Switching the relays to input or compressor..

If i do it that ways whats the reaction of the meter? or even if i do it just like the original whas the reaction on bypass mode!
thanks.

 

[Kingston]

with the standard bypass the meter does not move, and is set to zero ie. no current through it. It would behave the same with relay hard bypass, since you'll have no audio through the compressor, even if it's on.

 

[3nity]

thanks thats all i wanted to know!

Jorge Aristondo.

 

[tweedclassic]

for some reason i am getting a funny voltage on the input of my GSSL(turbo).
after further research i discovered some funny voltages on both the input ne5534's

voltages as followed on Ne5534's
pin 1(1 OUT)  :  12.22 vdc
pin 2(1 IN-)  :    0.0
pin 3(1 IN+)  :    0.0
pin 4(Vcc-)    :    0.0
pin 5(2 IN+)  :  -15.0  vdc
pin 6(2 IN-)  :  -0.614 vdc
pin 7(2 OUT)  :  14.75vdc
pin 8(Vcc+)    :  12.23 v

??? ??? ??? ??? ??? ??? ???
any ideas direction guidance would be greatly appreciated.

Cheers
Robert

 

[Harpo]

for the input op-amps maybe doublecheck, you put in a NE5534 for real, facing in the right direction.
Your quoted pin numbers relate to a dual op-amp, such as NE5532 and voltage readings look a little mixed up.

 

[intellijel]

I just got two Purusha cases that have the slots cutout for Farnell meters. Unfortunately the Farnell meters are really expensive to ship to Canada (it works out to be $30/meter!!) and I also already have two of the Behringer style meters.

My options are:

1. Hack the slot to fit the Behringer meters?

2. Find a cheaper source for the Farnell meters (anyone have some here????)

3. Use another similar edgewise meter that fits in its place? (any suggestions?)

 

[3nity]

Try Newark man!!!
Try newark for the meters!!!

 

[intellijel]

I tried Newark and there is an automatic $20 handling fee attached to anything they order via Farnell. So one meter is $18+$20fee+$20 shipping!!!

It only becomes economical if you order a bunch of them.