Help needed [ACMP Xfrmr swap]

RightOnMusic

RightOnMusic

asshat
hey there everyone. I searched and came up empty so that is why i am posting a new thread.

I have an original st. ives vt22671 (l31267) that i'd like to swap into my acmp73. i've never attempted anything like this before. has anyone done this and if so, can anyone walk me through it? i'm pretty decent with a soldering iron and take direction VERY well. i'm confident that i'm capable of doing this, i just want to do the best job i can and would benefit from the experience of the experienced. any help?
 
It's fairly simple--find the 24V windings, connect to the power supply; find the 120V windings, connect to the mains. Polarity should not be important.

Now, here are the tricks:

- I dunno if your trafo is 120V/240V. If so, you need to wind the two primary coils in parallel, and you do need to get that polarity correct.

- The ACMP73 also has 15-0-15 windings to run the LED meters. If your trafo lacks those, you'll lose the LEDs (no great loss in my book)


So if you have the datasheet for your trafo, it should be relatively straightforward. If not, I would either wait for Steve's replacement, or buy a $25 good quality commercial 24V toroid and dump the LEDs.

It just seems to me that a real Neve trafo could serve a higher purpose than the ACMP . . . I mean what is the market value on that thing?

Edit: wait, doesn't the ACMP have a 48V winding too, for phantom? Check that out as well.
 
mshilarious said:
It's fairly simple--find the 24V windings, connect to the power supply; find the 120V windings, connect to the mains. Polarity should not be important.

Now, here are the tricks:

- I dunno if your trafo is 120V/240V. If so, you need to wind the two primary coils in parallel, and you do need to get that polarity correct.

- The ACMP73 also has 15-0-15 windings to run the LED meters. If your trafo lacks those, you'll lose the LEDs (no great loss in my book)


So if you have the datasheet for your trafo, it should be relatively straightforward. If not, I would either wait for Steve's replacement, or buy a $25 good quality commercial 24V toroid and dump the LEDs.

It just seems to me that a real Neve trafo could serve a higher purpose than the ACMP . . . I mean what is the market value on that thing?

Edit: wait, doesn't the ACMP have a 48V winding too, for phantom? Check that out as well.
Click to expand...

vt22671-1.jpg

vt22671-2.jpg

vt22671-3.jpg


i have got no data sheet. this is all i have. might i be better off just trying to make a DIY 1073 rather than trying to upgrade the acmp? and yeah i don't care about the LEDs, i care about functionality.

i'm not sure if i'm up to making a 1073 from scratch... you know what? eff that, i'm totally up to it, i'd just need some really dumbed down step by step instructions. and money.
 
RightOnMusic said:
i'm not sure if i'm up to making a 1073 from scratch... you know what? eff that, i'm totally up to it, i'd just need some really dumbed down step by step instructions. and money.
Click to expand...

You need a PCB for that, unless you are sadistic. Check the Black Market at Prodigy-Pro and see if anybody is selling them.
 
I am freaking confused about the "conversation" here.
LEDs?!!!! What the heck is going on here????? :D heh heh
these look like audio transformers.
I've found this through some quick search:
http://www.audiomaintenance.com/acatalog/Transformers_and_Inductors.html
there are pdf links there, that have info on windings. not the same transformers but I've seen somewhere that these may be are like "almost the same", sort of ;)
 

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retro1 said:
31267 is the line.
Click to expand...

poo, i'll have to find the mic one as well.... i think i've decided to make this a diy 1073 project. may take me a long time, but i'll be so proud of myself at the end of it. i also just randomly received a yellow pages lookalike from mouser (never ordered from them before...) so i think this is god's way of telling me to build something. hopefully i can find a pcb on prodigy.
 
RightOnMusic said:
poo, i'll have to find the mic one as well.... i think i've decided to make this a diy 1073 project.
Click to expand...

Think about how much you want to spend. Check the original and TNC schematics to see where things wire.

You could try the 31267 in line position and do an A/B test by making before and after recordings with a good quality file.

If you are stuck for the mic input, you can actually use the 31267 in reverse. See the JLM website.

The output transformers are cheaper. Note that the Zoebel network on the secondary will have different values for each transformer when you swap.

Roddy
 
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