Electro Harmonix 12AY7 Mic HUM problem – $33 solution for newbies

Have you got an EH 12AY7 Mic pre with hum problems?

Well, I did and this is how you can nail that annoying noise:

1) buy a short XLR to TRS (“stereo” for us, newbies) Jack cable (it should have a XLR female and a TRS male jack) – around $3. If you find the TS (“mono”) DON NOT buy that one, is useless;

2) buy a Behringer HD 400 hum destroyer (do not pay attention to the fact that is Beh*, is just a box with two transformers and some resistors/caps in it, you will smash your head against the wall how good it sounds) – around $29.

You have saved one buck for the road 🙂

Now, connect your microphone to your valve preamp, connect the wall wart to the preamp and then stick it into the wall (if you are doing it the other way, you may see nice sparks when the power plug touches the preamp case, which is nice though 😛 ).
Connect your short cable to the XLR valve microphone preamp output and the jack to the “INPUT 1”. It is important to use the “INPUT 1” port, since this is the only one that provides grounding for the case (clever design, to avoid any ground loops, btw).

Now connect another balanced/unbalanced jack cable to your computer interface, mixer or your guitar combo.

Miracle, THE HUM IS GONE !

Pe scurt, daca ai brum (greu) in Electro-Harmonix 12AY7, e simplu.

Il duci la specialist sa il “tuneze”, sa il “regleze” si sa te scuteasca de banuti.

Dupa ce te-ai linistit cu asta, cumperi matale un cablu scurt XLR (mama) – jack TRS (tata) (am zis TRS, nu TS, adica “stereo” NU “mono”, altfel e munca in zadar, iar “las ca poate merge si asa” e valabil in alta parte, nu aici)  si un Behringer HD400 hum destroyer. Ciocu’ mic, e el Bergenbier, da’ chinezu’ mai greseste cateodata si face si lucruri bune.

Acuma legi matale microfonul la preamp, legi iesirea de XLR la cablul proaspat achizitionat (sa nu aud ca ai luat ceva mai ieftin de Cordial, ca’ iar avem treaba cu brumul si nu e bine).

Jackul il legi in “INPUT1” (am spus 1, nu 2) la HD400. Din “OUTPUT1” pleci fie cu cablu TRS catre interfata ta sau catre mixer, fie cu cablu TS catre combo-ul tau de chitara, fie catre boxa activa, fie catre cam ce vrei tu, ca’ nu mai conteaza.

Ai sa mai auzi un pic de hum, si daca ai urechi, si un pic de hiss, dar asta e ideea, desteptule, de aia ai vrut preamp pe tub, vintage !

Daca tie ti se pare ca asta e brum, sa vezi cum e cand folosesti redresare cu tub (EH 12AY7 foloseste semiconductori).

E, ai vazut ca se poate si cu bani putini?

Eeee, cu sunetul asta, nu e cum crede lumea…