how to reduce humming in guitar amplifier

Status
Not open for further replies.
i made a guitar amp usin tl072 as preamp and tda2050 as power it hums and buzzes annoyingly but they are reduced wenever i touch the circuit ground. plz help also, y r circuit grounds connected to chassis of the amp? do they help 2 reduce noise?
 
Are your input jacks grounded (ie shorting-type, which connects signal ground to input- we are not necessarily talking about grounded chassis here, though that is common) ?
Is the buzzing present when the guitar is not plugged in and the input is shorted?
Answer: Yes- problem is in the amp.
Answer: No- problem is noise pickup from guitar/cable.

Just a point: You will likely get more responses if you use 'normal English' rather than 'texting' abbreviations in your posts. Some 'old fogeys' -like me- find it irritating to read......

Cheers
John
 
theres no problem when the input is shorted but when the input is left floating( without connecting either to guitar and ground ) the hum is multifold .also is there any noise reduction
when the preamp is in inverting mode than in non inverting mode?
 
G'day,

winner said:
will replacing tl072 with any other better quality preamp help? chips like opa 2134 are very hard to get here. is there a readily available good quality ic available for substitute of tl072/74 ?

TL072 is a gorgeous op amp for HiFi and absolutely spectacular for guitar in my experience.

I think Test Electrix might have been on to something with "Might be radio interference". Any device pushed into saturation, transistor, opamp or tube, will hum like a son-of-a.

First thing I'd look at is grounding. I use a single point ground, even on my guitar amps.

Cheers!
 
Status
Not open for further replies.