Installing input transformers

I ordered my Lundahls (Thanks Kevin) to install in the mic pre..My bonehead question for the day...are the color coded wires the same for diifferent kinds of xformers? I don't have a schematic..it would be great news if I can just clip out the old ones and solder the new ones right in, color for color...


Ray

Generally yes, but there's always those sometimes that a company decides to use their own conventions.

Ray,

The Lundahl transformers don't have leads, they have pins to solder wires to, so the color system won't help you.

:grin:

sorry ... shouldn't laugh
yes they are PCB mount


Can Kevin supply me with Lundahl trafos all the way down-under in Australia at a sensible price ??


Or would that be cause friction within the LL dealership. Per was almost going to cut me in the loop, then thought better of it I think... and he wasn't the only one. The move from RO has set me back on a few fronts.
never mind
it's all good

Can't you get them from Control Audio in Sydney for a sensible price?

Move from RO?

:shock:

:roll:

mmm ... perhaps I should have done that in a PM.
err
...

...

single cricket chirp...

...

...

perhaps I'll pick this up at another time and in a another place.
thanks anyway Kevin.
:thumb:

well then I am in a bit of trouble ..When I get them I will post/beg here for more info...I can't wait to hear em' tho...

Ray

Well Kev, alot of us little guys that don't mean much still love you! :green:

Kevin, did you get my email re the lundalhs?

Joel :guinness:

[quote author="Mbira"]Well Kev, alot of us little guys that don't mean much still love you! :green:

Kevin, did you get my email re the lundalhs?

Joel :guinness:[/quote]

I did. The LL5402s will be in from Sweden on the 7th.

WOW...got my lundahls from Kevin today..what a fast turn around...you are pure class my man..I am now atempting the install, without a schematic...looking at the board and trying to trace the inputs....wish me luck..the color scheme on the old transformers was yellow, red, black, white..
it appears pin 3 (xlr) is wired to the black wire and 2 i am still tracing...1 of course is just ground...well, I am off to gig..if I don't get too "happy" (good gig, free scotch!) I will do some work later....

Ray

Okay, I am stymied..after studying the board it is impossible for me to figure this out...I left the leads from the stock transformer soldered in place on the pcb with intention of attaching them to the lundahl's pins..I have a good idea how the lundalh needs to be wired (pin 2 xlr to 1 and 4 on trafo in parallel, pin 3 (which I am having trouble tracing) xlr to 1 and 3 on the trafo..it is the other side that has me totally stumped..one pcb lead appears to be attached to the ground which leaves the positive ?...what would be the effect of incorrectly wiring this in ? can I kill these beautiful lundahls? or would it simply not function or function poorly? I have a tester and tried testing the other channels trafo that is still connected to determine the ins and outs...only more confusion...HELP

Ray

What piece is this that you are trying to replace the transformer in?

An old bellari rp220 pre that I got on the CHEAP...has a cool "dirty" sound..I replaced the opamps, tubes and some of the caps and it is much improved...I took out one of the input tranny's to see if I could find a manufacturer (and decipher the leads) but it is totally blank inside and out...

Does the block diagram at http://www.rolls.com/data/rp220man.pdf page 3 help at all? It indicates that the secondary of the input transformer goes to the polarity reversal switch.

which is what puzzled me..I don't have a polarity reverse switch on mine..input pad, phantom power..no phase..I did some testing with the meter
(thanks Rattafred) and I think I can tackle this tommorow...I glued some mounting brackets on the 1530's and I want to let the epoxy set before I install them..i also strapped it for 1:7..I should be able to take it for a test spin tommorow..I left the stock trafo in channel 2 (For the time being) so I can a/b the results, make sure the phase is correct etc...Said it before and I will say it again..Kev, you are a class act..as are the rest of you guys...

Ray

Hi,
Old thread, but how did it turn out? Was it an improvement? Did you take note of the correct way to install the Lundahl?

..this was 19 years ago (!)