Herbert bad noise on clean channel

[willy_1272]

Hi everybody,
being my first message posted here please let me briefly introduce myself.
My name is Guglielmo, 38 yrs old, I live and play in Italy (Milano). I am a fan of Tool band (like most of you i guess) and that genre of music is more or less the one i prefer to play with my band. I own a brand new Herbert since about 2 months ago.

Now the bad news about my Herbie:
- 3 weeks ago I had to replace 1 fuse probably due to an unusual electrical peak at the recording studio where I used to play.
- The second fuse was replaced last week in a different studio and different condition.
- Both times I noticed that a fuse was broken because of the blue led at the back of the head, not for a significant different in voicing or for the head gone out of work (as one could normally expect from an electric appliance).
- So I replaced the fuse again, but since then a disturbing background noise comes from the speaker when the channel 1 is selected, no matter the level of the master or the volume of the guitar. When I switch for the 2nd and 3rd channel the noise stops and the tone seems to come properly.
Is there any relation between the background noise on channel 1 and the fuses burnt and replaced?
If not, what can that noise on clean channel only be due to?
Because of the high frequency the fuses got burnt, could the electrical peak of the first episode determine the condition for the second fuse to burn in a later time?
Finally, what actually happens in the circuit when a fuse breaks? Why the head keeps working and in what condition?
I thank in advance anybody who can tell me something about this, as I could not find any other topic here concerning this specific trouble.

By the way....Herbert forever!

 

[MARK2C]

A. Condition your power.
B. Change the power tubes that correspond to the lit tube fault LED

It appears you have an intermittent short in one of your power tubes
that is nocking out the fuses.
The noise itself could be from the power tubes or a bad preamp tube.

 

[bronz79]

Hi everybody,
being my first message posted here please let me briefly introduce myself.
My name is Guglielmo, 38 yrs old, I live and play in Italy (Milano). I am a fan of Tool band (like most of you i guess) and that genre of music is more or less the one i prefer to play with my band. I own a brand new Herbert since about 2 months ago.

Now the bad news about my Herbie:
- 3 weeks ago I had to replace 1 fuse probably due to an unusual electrical peak at the recording studio where I used to play.
- The second fuse was replaced last week in a different studio and different condition.
- Both times I noticed that a fuse was broken because of the blue led at the back of the head, not for a significant different in voicing or for the head gone out of work (as one could normally expect from an electric appliance).
- So I replaced the fuse again, but since then a disturbing background noise comes from the speaker when the channel 1 is selected, no matter the level of the master or the volume of the guitar. When I switch for the 2nd and 3rd channel the noise stops and the tone seems to come properly.
Is there any relation between the background noise on channel 1 and the fuses burnt and replaced?
If not, what can that noise on clean channel only be due to?
Because of the high frequency the fuses got burnt, could the electrical peak of the first episode determine the condition for the second fuse to burn in a later time?
Finally, what actually happens in the circuit when a fuse breaks? Why the head keeps working and in what condition?
I thank in advance anybody who can tell me something about this, as I could not find any other topic here concerning this specific trouble.

By the way....Herbert forever!

Benvenuto Guglielmo!..hehehe..due Herbert sotto la madunnina!

Follow Mark2c advices:
-replace faulty power tube/tubes
-replace preamp v1 and v2 first, i can give you an hg+ and hg ruby if you need experiments.

Let me know,ciao!

 

[shadow070]

I used to have a background noice.

Like wind was blowing through the speakers. It was a preamp tube, i knever got to know which one but iff you dont want to loose to much time, do a swam of everything.

 

[willy_1272]

Thank you all again!
Concerning the background noise today I am going to replace one by one the ruby preamp tubes with some ELECTRO HARMONIX - 12AX7 EH and see what happens. Any of you experienced these tubes in your Herbert?
Further i will replace all final fuses with a set of new ones, if something still goes wrong I will then have the power tubes changed.
My main concern anyway is about the background noise, which comes from the speaker only when the clean channel is selected. In my humble opinion and knowledge if something is wrong with any of the tubes (except for the ones specifically related to the 3rd channel and FX loop) this should involve all channels and not only one. Is this right?

@Bronz79: mille grazie del benvenuto e dell'offerta di valvole! Good to know that i am not the only crazy nearby.
Come vedi ho questo dubbio sul canale pulito, e visto che sono ancora in garanzia ho bisogno di capire subito se sarà il caso di far vedere la testata direttamente dal costruttore.

 

[shadow070]

Iff im right when its a tube and it effects only one channel it should be a preamp tube, the other guys could clear more about this.

 

[Profound]

I had issues with strange noises and burnt fuses in my Einstein also.
The blue led at the rear are associated with a pair of power tubes. When one pair of tubes are out (corresponding fuse out, corresponding led on), the amp will continue to operate with the two remaining pairs.
The problem with my amp was overheated power tubes. I changed one pair of stock 6550 with EL34. Now I'm running the beast with EL34 outer and 6550 inner, and everything works just fine.

 

[MARK2C]

Thank you all again!
Concerning the background noise today I am going to replace one by one the ruby preamp tubes with some ELECTRO HARMONIX - 12AX7 EH and see what happens. Any of you experienced these tubes in your Herbert?
Further i will replace all final fuses with a set of new ones, if something still goes wrong I will then have the power tubes changed.
My main concern anyway is about the background noise, which comes from the speaker only when the clean channel is selected. In my humble opinion and knowledge if something is wrong with any of the tubes (except for the ones specifically related to the 3rd channel and FX loop) this should involve all channels and not only one. Is this right?

@Bronz79: mille grazie del benvenuto e dell'offerta di valvole! Good to know that i am not the only crazy nearby.
Come vedi ho questo dubbio sul canale pulito, e visto che sono ancora in garanzia ho bisogno di capire subito se sarà il caso di far vedere la testata direttamente dal costruttore.

Papa can correct me if I am wrong, but the clean channel is all in the V1B. Channel 2 works off V1A and the input from V1B and Channel 3 works off V1B and V2 A and B. This makes V1 the most important tube. If you are having a high idle hiss or signal to noise ratio issues, V1 is the best tube to replace first. When you switch to Ch.3, the noise
is most likely getting swamped by the gain and compression or possibly getting switched out of circuit. Each 12AX7 is two tubes in one bottle. If one side of the twin triode can have problems while the other side works fine. In the Herbert you have 10 triodes, but 90% of the time it's the V1.
Since you have been blowing fuses, it would also be a good idea to check the bias on all of the power tubes. Imbalance in these can cause noise or hum.

 

[willy_1272]

Thank you Mark

Update:
Opened the shell, found EL34 n.2 smoked.
Checked the preamp tubes, nothin apparently wrong. Bought anyway some spare to verify that they work properly. Result: preamp tubes are not involved.
Bought a pair of new power tubes (EL34 Electro Harmonics) and changed tubes n. 2 and 5.
Biased all the final tubes at 60 to 61 mA (by the way, anybody can tell if a higher bias would be better for the Electro harmonics pair of EL34?)
Worked a very little on the "hum" regulation.
Result: clean channel now is much more quite even not as much as it was when I unpacked the herbie, while 2nd and 3rd are now significantly more noisy than before.
What's the hypotesis now? I am beginning to be worried about this.

 

[MARK2C]

Thank you Mark

Update:
Opened the shell, found EL34 n.2 smoked.
Checked the preamp tubes, nothin apparently wrong. Bought anyway some spare to verify that they work properly. Result: preamp tubes are not involved.
Bought a pair of new power tubes (EL34 Electro Harmonics) and changed tubes n. 2 and 5.
Biased all the final tubes at 60 to 61 mA (by the way, anybody can tell if a higher bias would be better for the Electro harmonics pair of EL34?)
Worked a very little on the "hum" regulation.
Result: clean channel now is much more quite even not as much as it was when I unpacked the herbie, while 2nd and 3rd are now significantly more noisy than before.
What's the hypotesis now? I am beginning to be worried about this.

Now it's starting to sound like it's running normal.

Ch. 1 - Should be quiet. maybe some faint hiss
Ch. 2+- Some idle hiss
Ch. 3- Some idle hiss

Of course the hiss is louder when the guitar volume knob is full up.

If the hiss gets better when lowering the gain on 2 and 3, your amp should be operating normally.
The Hum Trimmer setting should be done on Channel 3 with a good amount of gain. Every one I set
seems to be between 6:00-6:30 (50 Ohm), or the arrow dead center or a notch to the left. It just regulates the
tube heaters reference to ground to prevent any background hum.

 

[Peter Diezel]

Please check preamp tube V3 and V4

 

[willy_1272]

Please check preamp tube V3 and V4

I will for sure as soon as I get new Rubies. What I can say so far is that Electro harmonics tubes in V3 and V4 make the whole sound extremely weak compared to rubies.

 

[bronz79]

Please check preamp tube V3 and V4

I will for sure as soon as I get new Rubies. What I can say so far is that Electro harmonics tubes in V3 and V4 make the whole sound extremely weak compared to rubies.

Guglielmo,
for Ruby preamp:

http://www.musicgallery.it/dettaglio.as ... bcatid=273 V1,V2
http://www.musicgallery.it/dettaglio.as ... bcatid=273 V3..>> V6

for power amp they got only BSTR
http://www.musicgallery.it/dettaglio.as ... bcatid=324

Let me know where you find BHT in Italy and when your Herbie is ok.

 

[willy_1272]

Please check preamp tube V3 and V4

I will for sure as soon as I get new Rubies. What I can say so far is that Electro harmonics tubes in V3 and V4 make the whole sound extremely weak compared to rubies.

Guglielmo,
for Ruby preamp:

http://www.musicgallery.it/dettaglio.as ... bcatid=273 V1,V2
http://www.musicgallery.it/dettaglio.as ... bcatid=273 V3..>> V6

for power amp they got only BSTR
http://www.musicgallery.it/dettaglio.as ... bcatid=324

Let me know where you find BHT in Italy and when your Herbie is ok.

Thank you for the links! I think I will go asap personally to the shop as I work 5 minutes drive from them.
About BHT seems not easy to find them in Italy.