1290 1073 Line-in - please vote w/ your preference.

hello    martn,

i have 2 existing ez1290s that i want to use on the 2 bus as line stages.  should i...


add carnhill line transformers and switch them in/out ($$$  150usd or more)  if i go this route i could leave out the gain switch and use the existing trim knob already in circuit?

use a pad prior to the mic xformer (not sure about degrading the signal)

go DI after mic xformer (lose the character of the carnhill iron?)

id be great to ge some feedback before i start cutting  

i have finished the second unit, working perfectly.
there is this problem tho...
if i power one at a time, there is no noise, no hum... sweet sounding mono unit.
when i use them both at the same time (from the same PSU) as stereo unit, there is a huge hum ???

i am using JLM ac/dc.
i have tried all sort of grounding... nothing helps.

what should i do ?


edit: both units are not boxed... all transformers are (carnhill) well away from each other. psu is well away too

EDIT II : i was using 30-0-30 toroidal transformer ( psu adjusted to 24v) i was only using 30-0 connections. when i connected the second 30V to JLM ac/dc ' s second V, all hum went away

Hey Martin,

Great deal, I'll be waiting for these pcbs.  I have a pair of each tranny here and can't wait to put them to use.

take care
Gil

madriaanse said:

C:
Both A and B are compromises. Ideally I would want to use a 3X24 PCB mount rotary, but I don't know of anyone who makes one. If there is such a beast it will be pricey I'm sure. Is there an Elma or Grayhill I need to know about?

Click to expand...

I didn't read through the thread, so maybe someone else has posted this, but you could get a 3P24T switch through Elma. I have a 4-24 that is still waiting to be wired as a balanced monitor gain controller. I don't know how many you'd need or what expensive is to you. I think mine cost about $120, so I'd suspect that one deck less would be roughly 3/4 of that. I also bought it a couple years ago, so their prices may be higher.

Thanks Bob, Elmas are great and worth every penny, but they don't make a 3X24 **PCB mounted** switch - only a 3x12. The whole point of the EZ1290 and, now the EZ1272LN   is to avoid having to deal with wiring an off-board rotary switch, running all sorts of shielded wire etc. Doing so is very time consuming and meticulous work, however the EZ1290, EZ1272LN can almost be built with your eyes closed... almost.

Best,

M.

Aha... I missed that point.

Bob, I just looked at the hybrid 312 boards in your sig; they look really, really great!! Nice work.

M.

Thanks! It was a great project and the 8 I built sound fantastic. Your 8 channel build looks great too!

Did any thing happen with this project?, would be great to add a line input to this project as we could then run signals recorded else where/ different pres through, I hear a lot of mix engineers run drums through a 1073 because they add a certain punch

Hi Martin,
when will the EZ1272LN be available?

thanks

Hi Guys, EZ1272LN's are available and sounding seriously good! email me if you're interested: martin_adriaanse {at} yahoo {dot) com.

M.

martin, any thoughts on my question above?  basically between padding vs going DI.  thoughts on impedance and tone are what im struggling with.

Hello, I would do neither and just use EZ1272LN w. 31267. Personal pref. Running the bus output at a low level from your DAW and using the 1272LN for makeup is a thing of beauty - almost as nice as doing a passive summing bus with EZ1290 makeup.

M.

i think the passive summing with the EZ1290 makeup is what im going for.  ill see if the gain on the 1290 can be set low enough to send a 2 bus mix through.
thanks