Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: mayburyds on February 29, 2016, 10:44:17 am

Title: Low volume of bright channel on 5E3
Post by: mayburyds on February 29, 2016, 10:44:17 am
Hi,


Need some help again!


5E3 was fine yesterday, today there is hardly any volume on bright channel, normal channel seems to be a bit louder but that could be my imagination.


Tried new valves in pre amp section, checked that the input jacks on bolted down tight and re-flowed solder joints for the bright channel but no joy.


Any ideas on where to look next would be welcomed!


Cheers.

Title: Re: Low volume of bright channel on 5E3
Post by: Ed_Chambley on February 29, 2016, 02:32:43 pm
Volume pot?  There are 2 and I have seen it when you have one turned up actually lower the volume on the one you are plugged into.
Title: Re: Low volume of bright channel on 5E3
Post by: mayburyds on February 29, 2016, 03:08:30 pm
Hi,


Thanks for the reply.


I understand the pots interact with each other, but if I have both volume pots on 3 I just about get sound from the bright channel and bordering on break up on the normal channel.


Cheers.
Title: Re: Low volume of bright channel on 5E3
Post by: PRR on February 29, 2016, 04:02:10 pm
> fine yesterday, today there is hardly any

Such trouble is *usually* a bad connection. Works one day, not the next.

Yes, the 5E3's interactions can also mean a large change of response from "small" change of knob settings. I assume you fiddled enough to know.

Bad tube, bad pot etc.

But on a new build which DID work, I would be looking at the joints. Sometimes they just barely work, but that is good enough, until they don't work at all.
Title: Re: Low volume of bright channel on 5E3
Post by: mayburyds on February 29, 2016, 05:01:29 pm
OK, thanks, I'll go over the joints again and double check.

Cheers.
Title: Re: Low volume of bright channel on 5E3
Post by: mayburyds on March 02, 2016, 07:38:36 am
Checked the voltage on pin 6 on v1 and it was very high. Reflowed the solder on the shared bias connection on pin 8 and that fixed the problem.

Many thanks for your help.
Title: Re: Low volume of bright channel on 5E3
Post by: Willabe on March 02, 2016, 08:46:52 am
Good job.   :icon_biggrin: