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

 

[solvatorsounds]

Thanks a lot for answering, this helps a lot! Your racked versions look really great, even the input metering is built in (must have been tricky to cut the PCB right and to bring back the metering).
One more question: could you tell me how many mA for the 17,5v-line would be enough for one channel?

Thanks again for any further explanations!!

sev

 

[boogui]

hello, i'm using a 50VA transformer for two channels.

 

[solvatorsounds]

Thanks again. Have a good evening!