ssl external sidechain

[Steffen]

[quote author="Greg"]Thanks Steffen. Let me make sure I have this implementation correct. I take the TO SIDECHAIN points to the FROM INPUT BUFFERS of your filter, then the TO CONTROL AMP goes to a 47K resistor to pin 1. What about the 100p and 15K from pin 1 to ground. Does that stay, or go?[/quote]


exactly! :grin:

everything else (100p, 15k.....) is the same....

steff

 

[digichild]

[quote author="gyraf"]An approach for a (mono) sidechain insert could be:

Take the two "to sidechain" signals, and add them together with two 4K7 resistors.

This becomes your insert send.

Connect the two 47K's at the input of the sidechain together.

This becomes your insert return.

Use a tip/ring stereo jack socket. Send to ring and return to tip. Normalize ring to tip. This way you can also use the insert as an input (for ducking etc.), and if no jack is inserted it will just act as a normal clone.

Result: Insert point output impedance ~2K5, input impedance ~25K.

This should be good enough for most purposes.

Unless I missed something - I havent really slept enough the latest couple of days..

Jakob E.[/quote]

i only want to use the sidechain for triggering the ssl-i don`t need a return-apart from this i don`t understand at all where i have to connect from the jack to the switch and then to the board :roll:

 

[daArry]

Hey,

I just vero'ed this sidechain circuit, but added a DRV/INA134 combo for balanced send/receive. I left out the 100R sc send resistor and just went straight to the DRV - this coo? likewise with the INA, I just went straight to switch posistion6 and skipped the 47u cap and 47K res to ground...

For powering these 3 IC's I just fed of the main +/-15V supplies - will the extra pull be okay for the vregs? Seems okay...so far :thumb:

Cheers

 

[digichild]

[quote author="gyraf"]An approach for a (mono) sidechain insert could be:

Take the two "to sidechain" signals, and add them together with two 4K7 resistors.

This becomes your insert send.

Connect the two 47K's at the input of the sidechain together.

This becomes your insert return.

Use a tip/ring stereo jack socket. Send to ring and return to tip. Normalize ring to tip. This way you can also use the insert as an input (for ducking etc.), and if no jack is inserted it will just act as a normal clone.

Result: Insert point output impedance ~2K5, input impedance ~25K.

This should be good enough for most purposes.

Unless I missed something - I havent really slept enough the latest couple of days..

Jakob E.[/quote]

excuse my ignorance,but what are the two "to sidechain" signals?
are they located leftside from the distortiontrimmer when i look on the board?

if it is like this,do i have to cut before left or right side of the resistors?

 

[radiance]

Before attempting the side-chain mod you should have a thorough look at the schematic and also a thorough look at the pcb.
On the schematic you can see clearly where the "to sidechain" signals are which is after the 22u/35v cap and before the 15k resistor. They lead to the two 47k resistors (which are before the side-chain VCA).
Those two 47k resistors are easy to spot on the pcb. They are on the left top corner off the left VCA. Then folow the pcb trace back till you reach the 22u/35v cap and voila, that's the to side-chain connection..

 

[digichild]

[quote author="radiance"]Before attempting the side-chain mod you should have a thorough look at the schematic and also a thorough look at the pcb.
On the schematic you can see clearly where the "to sidechain" signals are which is after the 22u/35v cap and before the 15k resistor. They lead to the two 47k resistors (which are before the side-chain VCA).
Those two 47k resistors are easy to spot on the pcb. They are on the left top corner off the left VCA. Then folow the pcb trace back till you reach the 22u/35v cap and voila, that's the to side-chain connection..[/quote]

thanks for your help-now everything works great-sidechan function is a killa!

now i am wondering about the voltage regualtor(7812) i used for the relais-it gets more then 70 degree hot-do i need to cool it?

 

[radiance]

Well, if it's getting hot, cool it.
Also, in case you did not know, you should not use the 12v from the ssl power supply.
Instead, use a separate power supply (you can use the same power transformer though).

 

[digichild]

[quote author="radiance"]Well, if it's getting hot, cool it.
Also, in case you did not know, you should not use the 12v from the ssl power supply.
Instead, use a separate power supply (you can use the same power transformer though).[/quote]

of course i use seperate powersupply :wink:

but also the regualtors on the ssl board get hot-but not so hot...well i think i check the datasheet...

 

[matthias]

do you still use the small 78L12 ??

simply change it to a bigger 7812 in to220 size

and you shouldn't have a problem with heat anymore...
and don't forget the protection diode for the relais

 

[digichild]

[quote author="matthias"]do you still use the small 78L12 ??

simply change it to a bigger 7812 in to220 size

and you shouldn't have a problem with heat anymore...
and don't forget the protection diode for the relais[/quote]

i am using a Ta 7812 (from reichelt : µA 7812)not a 78L12...
and also the protection diodes...

i gets quite hot-but the datasheet tells up till 75 degree its ok...

 

[matthias]

there must be something wrong... is the output voltage correct??

mat

 

[digichild]

[quote author="matthias"]there must be something wrong... is the output voltage correct??

mat[/quote]

yes correct...

the regualtor from the relais is driving 2 small relais (2xum) and the lamps from the apem switches...
the lamps are paralell to the coil of the relais-so when the button gets pushed the relais gets powered and the lamp burns...
the contacts from the relais are used for bypass mode and sidechain on/off...

 

[mike_relay]

I've been looking at the following high pass filter that Steffen has posted:

I was fooling with the idea of modifying it so that the filter can be used with an external sidechain as well. Instead of the 6 position switch I would use a five position one, and just have another switch to flip between internal/external sidechain. Would I have to change the "SC return" part of the circuit?

Here is my edited schem:

Thanks,
Mike

 

[mike_relay]

bump... (sorry, I'm itchin' to finish this thing)

 

[gyraf]

..should work.. try it..

 

[wiggins productions]

hello my first post. I ordered a few boards and was curious if the internal filter schematic worked out for you? I'm having a hard time reading a few values. Would you be so kind to type them out?
Thanks in advance.

 

[gyraf]

Hi Wig,

Welcome to GroupDIY..!

Here's my guesses at unreadables:

SC send series resistor: 100 Ohms

SC return and "to control amp" capacitors: 47uF/35V electrolytic

opamp: TL072 (or whatever you have..)

Jakob E.

 

[Steffen]

[quote author="gyraf"]Hi Wig,

Welcome to GroupDIY..!

Here's my guesses at unreadables:

SC send series resistor: 100 Ohms

SC return and "to control amp" capacitors: 47uF/35V electrolytic

opamp: TL072 (or whatever you have..)

Jakob E.[/quote]

yepp, thats right. I originally used NE5532N for the opamp but any (audio) opamp should work fine...

steff

 

[Greg]

hey Steffen:

I want to double check some resistor values on your schematic?

20K from input buffers?
10K feedback opamp 1?
72K opamp 2 inverting input? It looks like 12K but the 1/(RC) values only work out for 72K?
5.1K feeback opamp 2?

Thanks.

 

[Steffen]

[quote author="Greg"]hey Steffen:

I want to double check some resistor values on your schematic?


72K opamp 2 inverting input? It looks like 12K but the 1/(RC) values only work out for 72K?


Thanks.[/quote]

it´s 12k.

f= 1/(2*PI*R*C) :wink: