Herbert MK1 - Switchable Loop jack issue

[Giga.Blast]

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Sincerely sorry daddy Fredo. Did you take off your propeller-head hat and put on your Homulus projection crown today for the new age of impeachment (Aoi), did yah venty? Huh? … I had thought that you had already in droves realized that you've failed miserably on Diezel patrol as a private, as well documented.

All your blabber mouthing around here for years and haven't heard a peep from you talent-wise. Whatever. blah-blah-blah...

Good day Sir~

 

[Ventura]

Hi again I didn't try the cable loop test yet. I'll try it asap.
About the colouring sound, mentioned by Giga.Blast in the previous post, in my case that was caused by a dead battery using active pickups, and was solved.
The noise still present was/is a kind of going in and out of the volume paired by some random cracking popping sound.

Definitely give the loop-cable-jump a whirl, it should assist in determining where the issue derives.

Keep us posted.
Unkle Mo

 

[diezel&gas]

Basically it's as described in the manual of the Herbert, isn't it?

[3.2.3 Switch-able Loop as additional Volume Control Those of you who can live without processors in the parallel loop can use this loop for a second master volume for each channel. To do this, just loop a short 1/4” cable from the switch-able send to parallel loop return. Now you can choose a second master volume by turning the mix control past 1:00 PM to full open, and push the ‘ Loop” button to activate your second master volume. Now, with the loop activated, the mix control can act as another way to control volume.

I've done it. The cracking and shutting sound keep happening on this method too.
Especially with the mix control volume closed or near to 0.

 

[Ventura]

Basically it's as described in the manual of the Herbert, isn't it?

[3.2.3 Switch-able Loop as additional Volume Control Those of you who can live without processors in the parallel loop can use this loop for a second master volume for each channel. To do this, just loop a short 1/4” cable from the switch-able send to parallel loop return. Now you can choose a second master volume by turning the mix control past 1:00 PM to full open, and push the ‘ Loop” button to activate your second master volume. Now, with the loop activated, the mix control can act as another way to control volume.

I've done it. The cracking and shutting sound keep happening on this method too.
Especially with the mix control volume closed or near to 0.

Awesome work!! This is the cleanest way to figure out the problem - because a 1/4" guitar cable is just a straight jump from send to return.

So the crackling noise happened here too only when the Parallel loop was engaged. Excellent. So we're back to looking for 2 replacement tubes - 12AX7 - Chinese are fine, JJ are fine, whatever you have - where do you live?? EDIT: Just saw you live in Italy...do you have a supplier for tubes over there?? service@diezelamplification.com will get you in touch with Diezel HQ. But there are a number of retailers online that service Europe for vacuum tubes. PM me for any specifics.

Preamps V5 and V6 are used for loop levels send/return buffer.
Depending on how old the amp is, might be a good idea to go with a new re-tube across the board.
But if this is happening with a jumper, all things being equal, and only happens with a cable in the parallel loop and parallel loop engaged, I'd isolate the 2 tubes V5 and V6 and that's that.

Let us know how it goes - as well, let us know if you need retailers for tubes. Low noise, high gain, decent quality is what you're looking for - Chinese, Ruby, JJ, whatevs - just decent 12AX7 tubes, that don't break the bank

Unkle Mo

 

[diezel&gas]

Perfect thank you. I live in Italy, when I had the power tubes changed, I bought them from Banzai store non Europe.
The amp is from 2010 I think, I still have to check it. I've never changed preamp tubes.
It would be great to have the total specs of the tubes to get.
For instance, the Diezel page suggests to get tubes with side B specs I didn't get that much, what does that mean? Is it a parameter to focus on? A number written in the back side of the tube itself?

Thanx again.

 

[Leo Diezel]

If you are close enough to Venice I could take a look inside as well, please send me an email to leonardo@diezelamplification.com so I could give you my number as well.

As for the preamp tubes those are the default, but for diagnosis purpose anything would work:

V1: https://www.tubeampdoctor.com/7025-high ... mber=RT010
Other: https://www.tubeampdoctor.com/shuguang- ... mber=NN001

 

[Ventura]

Perfect thank you. I live in Italy, when I had the power tubes changed, I bought them from Banzai store non Europe.
The amp is from 2010 I think, I still have to check it. I've never changed preamp tubes.
It would be great to have the total specs of the tubes to get.
For instance, the Diezel page suggests to get tubes with side B specs I didn't get that much, what does that mean? Is it a parameter to focus on? A number written in the back side of the tube itself?

Thanx again.

As per Leo's message below, the amp is happy to take any high-gain, low-noise 12AX7 style tube. The Chinese/Shuguang designations of A/B/C are nothing to worry about. The most common is the Shuguang/Chinese 12AX7B, the TAD mentioned below in V1 is likely a rebranded Chinese/Russian tube with exceptional gain/low-noise/zero-microphonics.

If you are close enough to Venice I could take a look inside as well, please send me an email to leonardo@diezelamplification.com so I could give you my number as well.

As for the preamp tubes those are the default, but for diagnosis purpose anything would work:

V1: https://www.tubeampdoctor.com/7025-high ... mber=RT010
Other: https://www.tubeampdoctor.com/shuguang- ... mber=NN001

Leo is nearby to you?? Try going with some new preamp tubes across the board (phase inverter is important, a lot of people use a SovtekLPS in that socket, but to each their own) as the amp could use some new pres after almost 10 years. If problem still exists, meet up with Leo.

Thanks for popping on Leo
Unkle Mo

 

[diezel&gas]

If you are close enough to Venice I could take a look inside as well, please send me an email to leonardo@diezelamplification.com so I could give you my number as well.

As for the preamp tubes those are the default, but for diagnosis purpose anything would work:

V1: https://www.tubeampdoctor.com/7025-high ... mber=RT010
Other: https://www.tubeampdoctor.com/shuguang- ... mber=NN001

Hi Leonardo, unfortunatelly i'm very far from Venice. I contacted the company so to ask for a preamp set, apparently they provide complete sets ( power and preamp tubes), i'd only need a pream set in case.
So now i may consider getting 2 12ax7(b) tubes for V5 and V6 or a complete set ( preamp only).

Do you seel them? Which is your shop page ? I cannot find it

Thanx!

 

[Leo Diezel]

If you are close enough to Venice I could take a look inside as well, please send me an email to leonardo@diezelamplification.com so I could give you my number as well.

As for the preamp tubes those are the default, but for diagnosis purpose anything would work:

V1: https://www.tubeampdoctor.com/7025-high ... mber=RT010
Other: https://www.tubeampdoctor.com/shuguang- ... mber=NN001

Hi Leonardo, unfortunatelly i'm very far from Venice. I contacted the company so to ask for a preamp set, apparently they provide complete sets ( power and preamp tubes), i'd only need a pream set in case.
So now i may consider getting 2 12ax7(b) tubes for V5 and V6 or a complete set ( preamp only).

Do you seel them? Which is your shop page ? I cannot find it

Thanx!

Ciao,
Puoi acquistarle regolarmente anche dal sito (tubeampdoctor), semplicemente mettendo la quantità neccessaria (1 per V1 e 5 per le altre) nel carrello per poi procedere all'acquisto!

Possiamo venderle anche noi, puoi mandare una mail a me (leonardo@diezelamplification.com) e Peter (service@diezelamplification.com) con il tuo indirizzo completo e numero di telefono e ti possiamo mandare un offerta.

Grazie!

EDIT
Ho appena realizzato che hai già mandato una mail, probabilmente la risposta di Peter è finita in posta indesiderata!

 

[diezel&gas]

Hi everyone! I've just replaced a whole set of preamp tubes. Everything ok on the 3 channels, let's make the fx loop test...... same crakckling / discontinuous /shutting off sound...
i really don't know....


edit: here's 2videos of the sound. Im not touching anyting, kust stumming open strings till the noise/crackling/shutting/decreasing sound would happen. The noise come activating the loop.

https://www.youtube.com/watch?v=_luMw1NIvZk
https://youtu.be/h_xFeOpqZzk

 

[diezel&gas]

Hi, another possible cause i suspect is the amp Switchable Loop jack. In fact if i gently rotate or touch the cable plugged into of that jack, the contact reacts/suffers the moving, depending the movement, the sounds shuts off or keep coming as normal. This with different working cables of course.
Is there a way to have a better contact of this particular head/amp jack? I already tried with electric contact cleaner as suggested.

 

[diezel&gas]

Hello, it is most likely a Switchable Loop jack fault. The electric contact cleaner alone didn't solve the issue. Then i confirm turning the jack cable in its place the sound come and go.

It's something more like a mechanical connection problem of the inside of the jack, for example the internal contact too loose that might cause its contact with the tip of the jack uneven, or in the worst case, something starting going wrong on the solderings on the PCM.

The very very strange fact is that even if nothing is attached to any of the Fx send + return, one time i engage the Loop via Midi or by hand, the noise comes. Also with a direct connection as suggested in the previous messages.

So it may be something else from the jack.

What type of jack is the Herbert equipped with? I have to start finding it, just in case it needs to be replaced.

Thanx!

 

[diezel&gas]

Hi again everyone.
The problem is still present, another thing I've noticed is when the amp is like 1 hour or less On, sometimes it works fine.
Very strange.
It's something on the Switchable Loop jack itself or the circuitry involved on that section, (I suppose).

 

[diezel&gas]

Hi there! Is it possible to detect the jack failure without physically disconnecting it from the board? I mean making readings with a digital tester/multimeter.
Thanx in advance