Midas XL3 Iref

[boogui]

Hello,
I'm currently working on a project to use old XL3 preamp/EQ (XL301 board) and fit them in a rack. I have a question regarding the I ref signal. Is it an input or output, what is the purpose of it ?
As i will use a custom power supply, do i need to connect it somewhere ?

Thanks for any explanations.

have a good day

Seb

 

[sortedaudio]

Iref supplies Q3, Q4 & Q5 which are constant current sources for the LEDs on the channel. Connect a 1k 2W resistor between Iref on pin 2 and V- on pin 5, and all will be good.

 

[boogui]

Thanks a lot for the answer. Have a good day

 

[solvatorsounds]

Hello,
I'm currently working on a project to use old XL3 preamp/EQ (XL301 board) and fit them in a rack. I have a question regarding the I ref signal. Is it an input or output, what is the purpose of it ?
As i will use a custom power supply, do i need to connect it somewhere ?

Thanks for any explanations.

have a good day

Seb

Hello,
same to me. I wanna use a XL301 Channelstrip with a custom power supply. Do you have any suggestions for the PSU? I‘m a little bit confused about the 0VA Connections, what are they for? Did you bring your Channelstrip to a good working state?
Thanks a lot for your help!!

sev

 

[boogui]

Hi, if you want to power the board directly , you have to use a symetrical power supply with -17.5v, 0v and +17.5v. I made it from a kit with a good toroidal transformer. I had to make my own 48v power supply as well. It's working like in the 90's
I made four of those.

Seb