marinair transformers

hi
i recently aquired a couple of marinair output transformers
they have L.O.1173/1 and T.1684 on them
i bought them as spares for a neve melbourn i recently sold.

does anybody here know the pin out for them?
they've got 5 pins.

what's the most common use for this transformer?
im going to build some 1272 style pre's soon, are they the right ones for that?

thankyou very much

LO1173's are not the ones you need for 1272's. You need LO1166's or the Sowter or Carnhill equivalents. These are gapped designs, which is necessary for this circuit.

JC

hi
thanks for letting me know guys.
are there any standard applications for these that anyone knows of.
when i saw the data sheet(thanks for that) nothing springs to mind that requires 60:600. that i can think of, i did hear somewhere that using one of them backwards or half of one backwards as an input was close to a 1166.
that was someone showing overshoot graphs of replacement input transformers for 1272 circuits it think, tho it was a while ago i saw it
am i on the right track?


thanks

The overshoto txf stuff was at Joer Malones site.
www.jlmaudio.com

Have you seen this?
http://www.groupdiy.com/index.php?topic=139718&highlight=lo1173#139718

hi
thanks for letting me know guys.
are there any standard applications for these that anyone knows of.

Click to expand...

An API 312 mic pre, with a 2520 opamp should drive it well.

thankyou for your replies
that geoff tanner bit was great
im sure i'll use em soon
in the meantime i'll get on and make sure theyre working,

ref the api312 use, if this marinair one is an 8db rise
what do my 2503's give in terms of gain?

do people round here build their own neve op amps
like the ones i had in my melbourn, they were discreet on daughterboards so did'nt look that fiddly to make.

would it be a sensible undertaking to load a spare 312 card
with carnhill input/marinair output/neve op amp on a daughterboard ?
any thoughts or am i being ridiculous trying to combine the designs just to save me time, or should i just go straight to building 1272's from scratch once i finish all my 312's ?


once again thanks for your info and ideas.

Build your 312's, and then tackle a 1272.

No, the Neve 'op amp' (I'm guessing you mean either a BA438 or BA440 amp block) won't fit an api 312-type card. The pinout is different, and the 312 uses an opamp that runs on bi-polar (+/-) voltage rails, while the Neve uses +24v only. Apples and oranges.

I personally like both apples and oranges, and have many of both myself razz, so finish the one type and then tackle the other. The api is definitely the simpler of the two (assuming you have an opamp already that you plan to use).

Both are quite worthy of your time and effort, and both are pretty well documented around here, so you will find the 'search' function at the top of the page quite handy. :wink:

JC

hi
thanks for clearing that one up,
i think i'll do some neve half way through my api
as u know rascal that's what those 20 pots are for,
the first batch is just racking up 312/325's
then a dozen or so stuffing new cards
so it should'nt take too long

does anyone round here sell 1272 pcb's/kits? or 1073/1290
ive looked at jlm,
as i said earlier i just sold my melbourn so i'd like to try some class a instead
see if they really are that much bigger?

thanks again

Greg does a hot rod kit (mix with a BA283 and away you go)
Fabio (Bauman) does 1272 and BA283s
Got to say Joe as well..
Don't seventh circle do a kit as well?
Also etch your own from circuits provided here (eg BA283, 1290)
Lots of info in the Neve Meta