Reusing a DI transformer

I am planning on building a couple of Jfet Instrument pres inside of old DI boxes. Can I reuse the transformer inside of the DI boxes to wire a balanced out? They should be 1:1 correct.

They are usually something between 5:1 and 10:1.

Samuel

:? Well I guess that won't work then. Is there anyway I can check?

Hey Jeroddumas, actually it´s nothing wrong to keep the Di-Tx-
if it´´s a good one. You have to look at ratio and how much gainloss
you get.. The improvement to get an active load instead of the former,
is that most equipment normally sound "opener" with an A instead of P.
The thing is that you can get about 1Mohm or more as load, in compare
with a passive one thats around 50-100 kohm, depending of what kind
of input device that you got( Mic amp).
My experience with normal active lineboxes/phantompowered is that you normally get more level then you need. The issue is to pad it without
loading it to much. If you got a good DiTx be happy and put a Fet design
in front of it. If you search around in the forum you get several ones.

If you look it the other way. In normal phantom (+48V) you can drive
an op/discreet at max 7mA. If you let it run as a unity gain amp you
get with an active bass or synth normally 1-3V rms, more then 0dBu
If you put that signal into your fine DIYéd mic amp that can gain from 10-70 dB..well you need pad´s.
Cheers Bo

Cheers Bo

As far as I can figure it is a 5:1 transfo. I got this by measuring resistance on the primary and on the secondary. Got 5:1 ratio. I am going to try and use this as input for hamptone mic pre by wiring it backwards. :twisted: :twisted: May end up with a very colorful pre. Any thought on this?

resistance ration is often not even close to impedance ratio or turns ratio...

Definately true! You can only hope the primary and secondary wirings are the same wire material when looking at ohm resistance...

Oh well I will try it anyways, is there any other way to check it?

If these were small Monacor/Millenium/t.bone.....DIs, (all Monacor transformers, already been discussed), or something similar, i think this can be done.
If you are after a small colorful pre (that lacks some bass...), this is probably better suited than a jensen/lundahl...
I would just try out and go for it instead of measure this out.
:thumb:
Probably you got your first pre running faster than measuring out a transformer properly (...but sure this could be done, look transformer-meta)

Kind regards and happy DIY :thumb:

Martin

It's a transformer from a rapco DI. Just gonna experiment with it. Maybe just use it on an active DI out?

Experience is the best teacher. Go for it!

HTH!
Charlie