About vtb9049

[diyfanatic]

Hi guys!

Small question:

On 1272 output transformer, there is a cap and a 1k5 resistor.
These are on Nevé schematics, So I guess they're part or the circuit.
Since I don't understand the goal of this I'm a bit lost.
M'y question is, I want to use this output Tx on a passive eq amp, should I use the same cap ans resistor?

 

[Slenderchap]

You would normally always fit them..... an unloaded transformer will have a spike in the frequency response at about 40-50kHz..... fitting this 10nF/1k5 zobel network will remove the spike....

However, it is not compulsory..... you may prefer the sound without it fitted.... or with different component values...

The actual results will also depend upon the nature of the attached load.... is it driving long cables or a 600R input for example...

Colin
www.audiomaintenance.com

 

[diyfanatic]

hummm thanks Colin, so that's the nobel network!!
need to do some research about it...

I ordered from you few days ago and maybe I'll place a second order for some 10k/10k for my daoc.

I'm redoing the amp output of my pultec, made with WSW siemens module that don't work as I expected.
so the tx is for the output of the Jlm dINgo with 5534 for starter and if it work well I'll buy some app99F.
http://jlmaudio.com/dINgO.htm
cables aren't too long since it's for home-studio, 3 meters maximum.

 

[wolfgang]

Are you sure that a 5534 Ic has enoough power for driving a transformer?
I dont have the specs in mind but some ic´s need a discrete darlington output-pair to get enough current for driving a transformer!

wolfgang

 

[diyfanatic]

hi wolfgang,

yeah, as you can see on the jlm website, the dINgo as the possibility to add an output tx son prob here I think?
my mistake by the way it's NE5532AP... :

http://jlmaudio.com/JLM%20dINgO%20complete%20schematic.pdf

 

[diyfanatic]

humm will wait for 99f before adding output tx.

by Joe Malone
The NE5532A provide electronic balanced out and are not recommended for driving any transformers. If you use a DOA like out 99v or Hybrid then any output transformer of 1:2 to 1:3 that can handle +24dBM out the high ratio can be used.