EF1 Channel imbalance

[AmanGeorge]

Hey guys,

Recently, I noticed that my EF1 is occasionally and spontaneously have problems with a channel imbalance, with the right channel being about 4-5 dB lower than the left (tested with pink noise and an spl meter). Any ideas on what this could be? Could the tube be wearing out? I've only had the amp for about 5 months, so I would be surprised if it were an issue with the tube.

Would very much appreciate any advice,

Thanks in advance!

 

[Tridacnid]

Do you have a spare tube to pop in? That would be my first guess, although some people here have had trouble with the EF1 similar to this, so it may be something different.

 

[AmanGeorge]

*Sigh* sadly I don't. I'll see if I can get my hands on one this week if the problem persists, to see if that is the issue.

 

[mrarroyo]

First clean the pot using a pot cleaner (sold at electronic stores and even at Radio Shack). If it does not go solve the problem send me a PM and I can send you a tube for free.

 

[ghettocoolie]

I find that I will have this problem if my PC volume is not set at the maximum and the EF1 volume isn't set around 8 o'clock or 9 o'clock. Since you are using a PC source, I recommend that you turn the volume on your PC to the maximum and see if you get better results that way.

 

[AmanGeorge]

Now I'm getting nothing out of the right channel, but I'm hopefully going to try swapping another tube in tomorrow, though I appreciate the offer a ton mrarroyo. I'll also see if I can get my hands on a pot cleaner and with luck that'll help.

 

[AmanGeorge]

Took the lid off, blew around to clear out dust, wiped off the pins of the tube. Got my sound back in both channels, without a channel imbalance... for about 5 minutes, then it came back. Bah!

 

[soidera]

Maybe cause by heat?

 

[crossmd]

You're not alone, I had the same problem before, in that only one of my channels was getting sound(or it was just really faint in one channel) until I was told that putting my source volume at maximum was the key, did that..seemed to help, until just now that I'm only getting sound out of my right ear.

This was remedied by taking the tube in and out, until it was now in just the other ear instead. I'm thinking seriously about trying to send it back. I wouldn't want to doubt Fang's craftmanship, but this is getting at the very least, annoying, if not frustrating.

I was maybe looking to sell the EF1 this week(or atleast write a review!), having ordered a Canamp, but really.. who's going to want it if it only plays through one ear?

Some more help would be very much appreciated.

 

[plonter]

that's really a bummer guys. I wanted to get one myself, but with all the comments on the channel imbalance i started to think that maybe this is not so good idea.

 

[soidera]

i have just pulled the trigger, ef1 on the way from head direct, hope mine not have the problem

 

[plonter]

Quote:

Originally Posted by soidera /img/forum/go_quote.gif i have just pulled the trigger, ef1 on the way from head direct, hope mine not have the problem

we are all holding our fingers for you mate.

 

[AmanGeorge]

My issue has gone away after jiggling/cleaning the tube and fiddling with the connection between my headphones and amp.

As a side note, when I emailed Fang about the issue, he just told me to send the amp to an address in NY with a note that I needed a replacement and said that he would send me one with no issues - if you do have EF1 problems, Fang seems to be very responsive and reasonable.

 

[plonter]

Glad to hear that you problem solved. i am planing to get the EF1 for myself soon.

 

[crossmd]

So I went to bed, woke up this morning..fired up the rig, and everything was fine. I really wish that I could figure out what was the variable here. I'm really tempted to say that its tube was the biggest factor, but why did it take care of itself overnight? I think I'm going to end up buying a new 12AU7 just to make sure..a send in to Fang might still be in order.. Thanks for all your help guys.