[jim]

Ever since I've had my MG Head I've noticed a few pops and clicks here and there, which I just assumed to be normal. However, today I've experienced two really loud pops that actually hurt! Is this normal? I don't want this amp to blow out my headphones and/or eardrums or something... What causes this phenomenon?

Also, what's the best way to get rid of the hum?

thanks guys

 

[RGA]

You should not get any hum from this little unit...if you are then your cabling needs to be tightened or your tubes might need tightening.

I have had a few pops but this is due to my dirty discs(for shame) and power spikes...I'm using the stock JJ Tesla pre tube and Sovtek Power tubes.

MY unit is dead quiet at full volume.

 

[jim]

Hmmmm. What exactly do you mean by my tubes need tightening? And which cables? I guess the pops could come from powerspikes, so maybe I'll try connecting it to my computer's UPS and see if that helps. Not exactly a line conditioner, but it''s supposed to get rid of power spikes.

And btw, the hum is not from my computer because it hums when the computer is off as well.

 

[Dusty Chalk]

I've had this same problem on my Jolida integrated amp -- what it ended up meaning was that my power tubes were going. Time to roll them. The reason I think it's the power tubes and not the others is because the pops are loud.

What he means by "tightening them up" is to take them out of their sockets, and gently bend the pins so that they form a better contact with the socket -- if the problem is just a loose tube, then this will extend their life. (Loose contacts shorten the tube's life.) But if it's already getting worse, then it's probably already too late.

 

[chych]

Wow, dead quiet at full volume? I get quite a bit of hiss at 11 o'clock... where it starts... good thing my sourec is 7V so I can't listen any higher than 9 o'clock without blowing my ears out...

 

[jim]

Thanks for the info. I had no idea that a loose contact on the tube pins could shorten it's life like that. I've only used the unit for 250ish hours total so far, and the previous owner said he used it for 10. It's possible he used it more than 10, but probably not that much more. How long do these tubes usually last?

Hopefully my tubes aren't going out already, but I guess if they are, it's never too soon to start my tube rolling journey.

How do you guys feel about buying tubes from ebay?

I'm still unsure where the hum is coming from...I can't really hear it on my grados and akgs, but with the etys I can even hear it pretty clearly when the volume is at the 7 o'clock position (all the way down)! I notice that when the power cord of the amp gets close to the interconnects it gets louder. I wonder if I upgraded the power cord, interconnects, and added balanced power it would completely disappear? Not that I can afford to do such a thing at the moment.. I'm going to upgrade my interconnects soon anyway, so hopefully that'll help a little with the hum.

 

[RGA]

Chych:

To test for hum and hiss - simply connect the cd player to the MG Head...do not push play...turn the volume to full volume...if you don't hear a hiss or a hum then you have successfully tested the amp.

with music playing you will undoubtedly get various degrees of distortion because now the unit is driving a load...but the hum and hiss, if any, present should be from the source recording...or the amp running out of steem...the latter won't occur at 11 O'clock unless you have very heavy bass recordings and difficult to drive headphones like the HD600.

You can determine hum and hiss in your stereo's amp in the same way...With my very efficient Wharfedales there is a low hum and hiss at 0 volume...and much much more at full volume. Whatever this noise tends to be it has always been worse with Solid State equipment.

 

[chych]

Not really RGA, thats not the proper way... That seems to cancel some effect out and balance the input or something... Sure, I get no hum or hiss at full volume using that method, but it doesn't count...! Try doing that with nothing plugged to the MG Head, crazy amounts of hiss!

Except more that, I don't get ANY hiss/hum at all with my Apheared 47 at any volume with the cdp in and creating a load

 

[Joseph Lau]

You should Short the input to test Hum. It is no meaning to test it with open input. All amplifiers has higher noise when no Input connected.

Pop : it may be problem on tube sockets contact. Yes ! Try to tighten it. This problem may be cause by shipping when tube Plug in the sockets. It will bend the Pins and harmful on sockets. We have simulair model sell to Japan but don't have such problem. What difference is it ? It only packing tube seperate when shipping due to it have no tube cover. I consider to pack the tube seperately when shipping. I hope it can solve these problem.

 

[jim]

Thanks Joseph! After reading DustyChalk's post I tightened the pins and it seems that the pops have subsided a bit. I've still gotten a pop or two, but it's no where near as loud as it was before. I'll keep tinkering with it and see if it goes away completely.