Herbert MK1 - Switchable Loop jack issue

[diezel&gas]

Hi, i was playing thru the clean channel 1 of my Herbert and i noticed the amp was making a dirty colouring sound when i strummed barely hard a chord or notes... something like it was on channel 2-, a clipping sound. I tried changing both guitar and cable but the unwanted distortion kept coming.
If i play lightly it stays clean, but if i raise the power of the touch, it comes the distortion.
Power tubes are quite new as i replaced them not long ago.
Preamp tubes are stock from day one.
Might the distortion/break up come from one of the preamp tube?
Thanx

 

[Ventura]

No effects in front or in the loops?? Just direct into amp?? Amp then to single 412 cabinet or...??

Please let us know.

Unkle Mo

 

[diezel&gas]

i was initially playing with the effects On, in the parallel effect Loop - and switchable send connection.
Then i shut off the effect to test the amp alone, and played it straight, no effects, the cab is a 2x12. The unwanted distortion was still there

 

[Ventura]

So guitar + cord into amp. No effects in loops. No effects in front. Just a guitar, cable and amp.

Does the distortion oly happen on Ch.1?
Does the rest of the amp sound at all different than before?

Likely V1 preamp tube, but could also be components.

Have you tested for microphonics?? As well, have you tried a couple different guitars??

V1, Phase Inverter, or component. If only on clean channel. If effects at all on, could be tube buffer tube.

Do you have a spare 12AX7 tube?? Might be worth trying - but before you replace - try the amp on low volume, guitar and cab plugged in, rear panel of Herbert off, and just tap the preamp tubes. Bad tubes make a loud noise when tapped with a standard pencil. Always good to check. If you have a spare 12AX7 tube, with amp off, replace V1 (closest preamp tube to the guitar input jack), and try. If sound is better, you may want to replace all the bottles in your amp - do you know how old the tubes are??

Phase Inverter would effect all channels - but it is a very heavily used tube. I always change my PI tube when changing power-tubes.

Let us know.
Unkle Mo

 

[diezel&gas]

thanx for the help, i think i've solved the issue tomorrow the final test

 

[Ventura]

thanx for the help, i think i've solved the issue tomorrow the final test

Glad to be of service, and please do let us know what the solution was...even if it was user error - it's helpful to everyone experiencing similar issues and using the "Search" function.

We're a community here.

Glad your Diezel is back up and kicking sonic ass!!

Unkle Mo

 

[diezel&gas]

Sure! I still have to check again, but the result of that noise was probably simply a dead battery of the active pick ups in my guitar. Sometimes they fools me... So nothing to do with the amp.
Asaic i'll get another one to try with the same guitar.

To check properly the cause of the noise, yesterday i plugged another guitar with passive pick ups and that noise didn't show, so it must be that ( dead battery on the active pick up equipped guitar), plain and simple.

The other day, when i opened the topic i was sure the noise was present on the guitar with passive pick ups as well, just because i was playing clean, but at a little high volume and something in my room was shaking/vibrating (a shelf) that's why i was hearing bad sounds, those noises distracted me

 

[Ventura]

Well that was an EASY solution!!

Glad you figured it out, and yes, a low powered pup can definitely be problematic. Always good to have a couple guitars to check out the issue.

Keep us posted if anything changes and rock on!

 

[diezel&gas]

Hi again, i just turned off the amp....i made another quick test.. because i had a thought in my mind... This last one was made with the guitar w/passive pickups.
So, the cracking noise comes only with the effect processor ( rocktron xpression) engaged. If for instance i'm on ch1 with no effects (so the loop is off), the amp sounds fine, also on any other channel; if i engage the Xpression by the loop effects via midi pedalboard, let's say on Ch1, the noise comes randomly depending how much hard i strum a note or a chord, and it comes and go whenever it wants.
I tried swapping the connection cables between the effect processors and amp send + return but nothing have changed.
I tried to gently touch the cables while playing to see if the noise would happen or modify its presence but with no reaction.

What the problem could be now?

a) Effect processor connection cables damaged; b ) Effect processor unit alone ; c) Preamp tube, maybe V5?

Talking about the guitar with active pickups, that might be a different issue, still to be verified because with it, the bad sound came with the effect processor totally off.

 

[Ventura]

Hmmmmm.

V5 & V6 are responsible for send and return for the loop.
V1 is obviously not JUST for clean, but ALL channels go through V1.

However, if this is ONLY happening with the effects engaged, I would suggest two things:
- do you have any other FX, doesn't matter, reverb, delay, etc. that you could try IN the loop other than the Rocktron? If so, try that.
- plugged DIRECTLY into the amp, and with just a cable between the LOOP send-return in question, is there still a crackling??

Anyway - do you have some extra 12AX7 tubes kicking around??
I'd try replacing V5 & V6 if this is an effects/loop issue only after making sure (via direct cable or a different unit) that it's not the Rocktron itself.

And you can't hear this problem on Ch.2, 3 or 4 with the Rocktron engaged??

 

[diezel&gas]

Hi there, i have 2 news, a good one and a bad one. The good is i solved the guitar problem, yes, it was a dead battery causing the unwanted distortion, it was dead indeed as it was kinda exploded...one of its pole was broken too...

The bad one is that the amp fx section (or the external Fx unit) issue, still make the crackling and shutting noise. It seems it has also got worse, when the problem appears, it stays longer.... maybe its a preamp tube near its end of life.
I tried changing cables with others functioning but with no good result.
I tried the amp thru each channel and the problem with the effect On appears in any of them. So it's an issue only with the Loop On. The amp sounds fine withouit the Xpression engaged by the Loop.

Yes I do have a big muff pedal to try if it's righ for the purpose..
Unfortunatelly i don't have any preamp tube to swap as a test.

 

[John4021]

Wondering if spraying the cable end with Deoxit contact cleaner and working it in and out of the loop jacks might quiet things down.
I know when input jacks don't get used they tend to become noisy.

If you are able to do that just remember to spray it on the cable end then insert it several times to the input loop jacks...DONT SPRAY INTO THE input jack holes.

I even spray the pins on tubes and insert then just to clean them a bit.

Give the spray a few minutes to work before turning on the amp.

 

[Ventura]

Hi there, i have 2 news, a good one and a bad one. The good is i solved the guitar problem, yes, it was a dead battery causing the unwanted distortion, it was dead indeed as it was kinda exploded...one of its pole was broken too...

The bad one is that the amp fx section (or the external Fx unit) issue, still make the crackling and shutting noise. It seems it has also got worse, when the problem appears, it stays longer.... maybe its a preamp tube near its end of life.
I tried changing cables with others functioning but with no good result.
I tried the amp thru each channel and the problem with the effect On appears in any of them. So it's an issue only with the Loop On. The amp sounds fine withouit the Xpression engaged by the Loop.

Yes I do have a big muff pedal to try if it's righ for the purpose..
Unfortunatelly i don't have any preamp tube to swap as a test.

Have you tried just using a jumper cable from send to return and engaging the loop to see if the noise is still there?? If it's not there with a jumped cable, then the FX unit has shit the bed. If the noise IS there, it's V5 + V6 tubes, likely. Or as the above post mentions, perhaps a lil DeOXIT would help...

Jumper the circuit and see if the noise is still there - that's the easiest.
Peace
Unkle Mo

 

[diezel&gas]

Hello, i didn't try a deoxid spray, I'll do next.
About the cable, you mean to plug a cable with nothing in between from send to return, the same used at the moment by the FX unit?
I ask because I don't want to make a short circuit kind of connection

I tried to plug a big muff pedal, there was no noise but neither the distortion sound from the pedal ( maybe because it's not designed to work in parallel), it acted only like a volume pedal ( if I turned the pedal volume off, the volume went to zero, if at max the sound would pass thru).

 

[Ventura]

About the cable, you mean to plug a cable with nothing in between from send to return, the same used at the moment by the FX unit?
I ask because I don't want to make a short circuit kind of connection

No short circuit will occur - just think about how many pedals out there are "true bypass" - same thing.

I tried to plug a big muff pedal, there was no noise but neither the distortion sound from the pedal ( maybe because it's not designed to work in parallel), it acted only like a volume pedal ( if I turned the pedal volume off, the volume went to zero, if at max the sound would pass thru).

Sounds to be as though the parallel loop is working fine, but your Rocktron Effects unit is dodgy. Have you tried using the Rocktron unit "in front" of the amp?? Anyway - ya, the BigMuff is hard to tell in the parallel loop - it's a preamp style stomp, not loop stomp - but by using "it" or just a plain jumper cable and manipulating the parallel loops dry/wet ratio and listening for any noise or the like, it'll indicate whether it's loop or V5/V6 related. But the fact you used a BigMuff in there, and there was no noise - my guess?? The Rocktron unit is scratchy.

 

[diezel&gas]

Hi, I had the time to test the amp fx today, I used an electric contact cleaner as suggested.
At the beginning nothing changed, then after a while using the amp and fx the problem seems to be gone. I have to make multiple test so to say the problem is 100% solved but maybe we got it

 

[Ventura]

Hi, I had the time to test the amp fx today, I used an electric contact cleaner as suggested.
At the beginning nothing changed, then after a while using the amp and fx the problem seems to be gone. I have to make multiple test so to say the problem is 100% solved but maybe we got it

Cool.

Did you ever try just a straight jumper cable with the loop initiated to ON...??

Peace
Unkle Mo

 

[Giga.Blast]

Hi, i was playing thru the clean channel 1 of my Herbert and i noticed the amp was making a dirty colouring sound when i strummed barely hard a chord or notes... something like it was on channel 2-, a clipping sound.

My 2003 Herbert original does the same thing, CH1. No worries, I look at it like painter Bob Ross, "We don't make mistakes, just happy little accidents and beat the devil out of it (brush)" and it merely adds more character to the little doer.

Ruby 12AX7CA5 high-grade+ in all 12 preamp section, just because and piece of mind. My Mk2 can't touch my original in my stereo rig. The spatial vibe is almost surreal (u4ia) in the studio. For those of you who know what I'm speaking of.

 

[Ventura]

Hi, i was playing thru the clean channel 1 of my Herbert and i noticed the amp was making a dirty colouring sound when i strummed barely hard a chord or notes... something like it was on channel 2-, a clipping sound.

My 2003 Herbert original does the same thing, CH1. No worries, I look at it like painter Bob Ross, "We don't make mistakes, just happy little accidents and beat the devil out of it (brush)" and it merely adds more character to the little doer.

Ruby 12AX7CA5 high-grade+ in all 12 preamp section, just because and piece of mind. My Mk2 can't touch my original in my stereo rig. The spatial vibe is almost surreal (u4ia) in the studio. For those of you who know what I'm speaking of.

Tread carefully, Dave. Your response offers little with respect to alleviating the situation. It's not "just coloring" of the tone, we've got some amp specific noise happening. Don't be busting out the high-and-all-mighty Herbert Mk.1 is God nonsense here - we're all entitled to our own opinions, but we're here to also help fellow members with their specific amp related questions and concerns.

Next up, "spatial vibe in the studio"??

And it's "peace" of mind, not "piece".

A nice day to you, Dave.
Unkle Mo

 

[diezel&gas]

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.