Herbert Channel 2 is very quiet -solved-

  • Thread starter Thread starter don_huberto
  • Start date Start date
don_huberto

don_huberto

New member
Hello

My 4 year old Herbert possibly has a tube issue. The second channel is very quiet in difference to channel one and channel three.

Am I right that a preamp tube has to be changed. To verify that this is a preamp issue I will exchange the preamp tubes and see if other channels get quieter. And last but not least I will have to buy one, or tow 12AX7 tubes.

Is this correct? And another question. Is it true that I have to skrew the back panel to get to the preamp tubes. Or is there a way from the front?

Or should I visit a professionalist?

BW don_huberto
 
yeah you have to pull the back off and also pull the amp out of the shell that will give you alot of room to work with
 
And no professionalist needed.

Its realy easy to change preamp tubes :thumbsup:
 
don_huberto":3rb26pnd said:
Hello
And another question. Is it true that I have to skrew the back panel to get to the preamp tubes. Or is there a way from the front?
Click to expand...
Are all tubes glowing (power and preamp) when you fire up Herbert in standby?

Before you replace any tubes, being that the amp is 4 y/o try to reseat all the tubes first before buying new tubes. That is reseating the power and preamp tubes first.

You might want to apply a contact solution to the pins on the tubes like DeoxIT to make sure the contacts are clean.

To get to the tubes, simply remove the grille on the back of Herbert then you will have full access to the power and preamp tubes.

You "do not" need to remove the amp from its shell, leave that alone.

Then remove all six power tubes and mark them so you can recall their position (when you reinstall them) to avoid re-biasing Herbert. Now you have full access to the preamp tubes up front.

Reseat all the preamp tubes and return them to their original position. Do the same with the power tubes.

If the problem persists then try a new preamp tube in V1 (all channels) then V3 (all channels.)

Hope this helps...
 
Hi

Thank you King Crimson for your detailed help. I switched preamp tube one and two. Now everything is very quiet. ... And Tube at place one which was previously on place two does not glow.

So. I know what to do... :thumbsup:

Thank you.

Regards don_huberto
 
@Peter Diezel: Thank you.

@all others: A poti had a problem and Peter solved it. Besides the fantastic gear from Diezel there is another thing that makes this company unique. The outstanding customer support.

Diezel rules :rock: :rock: :rock:
 
You must log in or register to reply here.
Back
Top