pyjaman

4:1 input transformer for 1176 ?
« on: November 19, 2010, 10:37:22 AM »
Hi,
I'm planing to build a 1176 clone based on jakob's or Mnats rev J version with transformer input. I have this 4:1 stepdown Jensen transformer laying around I'd like to use for it, just in front of the 10k pot.
My concern is: what would be the consequences of such a high step-down ?
- the comp will have an overall 6db less gain (compared to a 2:1 setup), but it has already a lot of it, no?
- the main thing is the behaviour of the input fet: it will change his treshold, and I could have trouble to drive the comp hard enough .
Do you think I will miss these 6db of max input ?
Do you usually drive your 1176 with very hot signals, with the pot or input pad fully open or do you think I could just drive it with hot signal and live with it ?

...Or should I go back to school and learn English...
Laurent.
« Last Edit: November 19, 2010, 10:39:19 AM by pyjaman »


Kingston

Re: 4:1 input transformer for 1176 ?
« Reply #1 on: November 19, 2010, 10:55:58 AM »
Do you think I will miss these 6db of max input ?

You might.

I was experimenting with a 2:1 input transformer and found out even that one did not leave me enough input gain (from modern DAW levels). I settled for 1:1 input.

Of course the extra 6-12dB of gain is most of the time a "complete sound destruction abuse" setting, but that's exactly what you want from 1176 sometimes.

If you know you will only ever do something like 5-10dB compression then a 4:1 input might be ok. But that to me is not using a 1176 to its full potential. Save your 4:1 transformer for something better.

3nity

Re: 4:1 input transformer for 1176 ?
« Reply #2 on: November 19, 2010, 05:10:42 PM »
Yes if you use the 4:1 you might need a buffer circuit bo bring back the 6dB loss.
If you dont let me know what model is and if you want to let it go.
Thanks.
Life is a path, death the destination.

creal

Re: 4:1 input transformer for 1176 ?
« Reply #3 on: November 19, 2010, 10:33:09 PM »
Hi 3nity

Yes if you use the 4:1 you might need a buffer circuit bo bring back the 6dB loss.
If you dont let me know what model is and if you want to let it go.
Thanks.

If you have the gyraf PCB juste rewire the xfrm, i just finish to rewie mine and it good.
http://www.groupdiy.com/index.php?topic=1261
Rewiring G1176 output transformer for more gain - Chef's instructions on how to rewire the output transformer for more gain.

For the Mnats, i not sure but i remember to have read it already reversed, just do it  ;)

creal

3nity

Re: 4:1 input transformer for 1176 ?
« Reply #4 on: November 19, 2010, 11:13:48 PM »
Excuse moi mais je ne comprends un mot de ce que tu as voulu dire.
Je parle francais si tu peux le traduire au francais.
Merci.
Life is a path, death the destination.

creal

Re: 4:1 input transformer for 1176 ?
« Reply #5 on: November 20, 2010, 07:35:21 AM »
Et bien, si tu as une version gyraf du PCB, je te conseil de faire la modification suivante.

http://www.groupdiy.com/index.php?topic=1261
J ai fais cette modification sur mon clone Gyraf , cela fonctionne tres bien. J ai maintenant le meme gain que mon 1176 UREI

Si c est un PCB Mnats le transfo est deja monte dans cette configuration donc rien a faire.
Bon WE
Creal

« Last Edit: November 20, 2010, 07:40:33 AM by creal »

3nity

Re: 4:1 input transformer for 1176 ?
« Reply #6 on: November 20, 2010, 09:38:36 AM »
Je suis d'accord avec vous mais ca je ne suis pas sur que ca soit la meilleure solution.
Avec la perte de 6dB, on perd seulment des dB?
Salut.
Life is a path, death the destination.

lotus

Re: 4:1 input transformer for 1176 ?
« Reply #7 on: November 20, 2010, 01:52:48 PM »
calis,tabernac ca parle francais ici :D

creal

Re: 4:1 input transformer for 1176 ?
« Reply #8 on: November 20, 2010, 06:32:30 PM »
Je suis d'accord avec vous mais ca je ne suis pas sur que ca soit la meilleure solution.
Avec la perte de 6dB, on perd seulment des dB?
Salut.

pour la perte de niveau, avec cette modification, j'ai quasiment la meme chose que sur mon vrais 1176 Urei.
La seul chose qui change, c'est la 'couleur' du son, le son est un peu plus clair avec le Lundahl.

Mais pour moi c'est tres bien, comme cela je peu choisir en fonction du resultat voulu.
Si tu as deja un transfo, teste cette mods avant l'achat du clone chez hairball

la repro pour la revision Gyraf
http://hairballaudio.com/shop/product_info.php?cPath=24&products_id=47

3nity

Re: 4:1 input transformer for 1176 ?
« Reply #9 on: November 20, 2010, 08:12:04 PM »
Lol..i dont really like french but helas i gotta speak everyday.
 ;D ;D

just kidding.
Life is a path, death the destination.


 

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