So something is definitely wrong with my brand new VH4.

[MesaSean]

Ok so hear me out, as this may sound weird.

I bought a brand new Diezel VH4 new sealed from Check Levin's Washington Music Center about 9 weeks ago. It was brand new for sure.... sealed in the box and everything.

I brought this weird issue up I am about to try to describe up once or twice in certain threads, but I am not sure what the heck is going on.

So I'll have my VH4 all dialed in to liking. I mostly play my own written (medium gain metal) music and Metallica but with a little less gain on channel 3 as I like to try to get my hands to push strings/pickups to the amp more than just cranking up the gain on channel 3. Also I like my clean channel as clean as possible.... or as clean as a VH4 can get. IMO the VH4 does not really have the crystal clean I enjoyed in an old Herbet I had years ago or my last amp a Mesa Mark V.

So every so often this really weird thing happens....but then it goes away....then comes back again a week or so later.

Out of no where....I start playing and everything sounds different. (it does not happen mid playing.... usually)

I start off on channel 3 but it has WAY more gain (and like a "sizzle" to it than normal) than what I have always had it dialed to. Also the EQ knobs sound all out of wack, yet they have not been touched. BUT the real sign something is up is when I switch to channel 1. Channel 1, which I have dialed in to be as clean as possible, now has non stop break up. And trust me, I am not imagining it and it's not the guitars or pedals etc. (I unplugged all the pedals and went straight into the amp with various clean neck pickups like I normally play with)

The clean channel has a constant break up...and volume loss (or so it feels like) The clean channel sounds lower, a bit weaker and with breakup or slight distortion. Which is obviously what I don't want. The break up drives me nuts and I just shut the amp down and stop playing.

Then like a day or so later, I'll go back to playing and the issue is gone. Then comes back again like a week or two later.

Any advice? Could it be a blown pre amp or power tube? I pulled the back plate off. Since doing that, what should I be looking for? All the tubes look lit up, but I have no experience with failed power tubes etc.

Thanks so much in advance.

 

[Daniel.S]

Ok so hear me out, as this may sound weird.

I bought a brand new Diezel VH4 new sealed from Check Levin's Washington Music Center about 9 weeks ago. It was brand new for sure.... sealed in the box and everything.

I brought this weird issue up I am about to try to describe up once or twice in certain threads, but I am not sure what the heck is going on.

So I'll have my VH4 all dialed in to liking. I mostly play my own written (medium gain metal) music and Metallica but with a little less gain on channel 3 as I like to try to get my hands to push strings/pickups to the amp more than just cranking up the gain on channel 3. Also I like my clean channel as clean as possible.... or as clean as a VH4 can get. IMO the VH4 does not really have the crystal clean I enjoyed in an old Herbet I had years ago or my last amp a Mesa Mark V.

So every so often this really weird thing happens....but then it goes away....then comes back again a week or so later.

Out of no where....I start playing and everything sounds different. (it does not happen mid playing.... usually)

I start off on channel 3 but it has WAY more gain (and like a "sizzle" to it than normal) than what I have always had it dialed to. Also the EQ knobs sound all out of wack, yet they have not been touched. BUT the real sign something is up is when I switch to channel 1. Channel 1, which I have dialed in to be as clean as possible, now has non stop break up. And trust me, I am not imagining it and it's not the guitars or pedals etc. (I unplugged all the pedals and went straight into the amp with various clean neck pickups like I normally play with)

The clean channel has a constant break up...and volume loss (or so it feels like) The clean channel sounds lower, a bit weaker and with breakup or slight distortion. Which is obviously what I don't want. The break up drives me nuts and I just shut the amp down and stop playing.

Then like a day or so later, I'll go back to playing and the issue is gone. Then comes back again like a week or two later.

Any advice? Could it be a blown pre amp or power tube? I pulled the back plate off. Since doing that, what should I be looking for? All the tubes look lit up, but I have no experience with failed power tubes etc.

Thanks so much in advance.

The preamp tubes could need reseating. These are safe to touch (when they're not on, or have just been on). Failing that, it could be the power tubes that need reseating. Best off trying that first.

 

[MesaSean]

Thanks. So you mean just take them out and put them back in?

 

[Leo Diezel]

Yes, depending on storage and shipping humidity/condition it may happen, so one of the pin may not do good contact!

 

[MesaSean]

Yes, depending on storage and shipping humidity/condition it may happen, so one of the pin may not do good contact!

Thanks Leo! Since I have the back off, I'll go through them all when the amp is off... take them out and replace them back in where they were and see if it cures this issue.

 

[Evil Z06]

If you have a chance when you have the back off snap some pictures of the inside I love to see the inside of the tank

 

[MesaSean]

If you have a chance when you have the back off snap some pictures of the inside I love to see the inside of the tank

Will do!

 

[Ventura]

Yep - rear panel off, and preamp sleeves removed - pics would be great.

If this was a new purchase, it'll be under warranty no issues at all if it's anything other than tube re-seating.

Keep us posted.

 

[Daniel.S]

Sorry for the late reply, but yes reseat the tubes. Pull them straight up with a tiny tiny amount of wiggle just to get them free.

 

[MesaSean]

Sorry for the late reply, but yes reseat the tubes. Pull them straight up with a tiny tiny amount of wiggle just to get them free.

Thanks! It's on my to do list tomorrow as I was swamped. I did a quick check again today to see if it went away in between work and the issue was still there.

I'll take pictures and post them and also re seat all the pre amp tubes and power tubes.

Thanks again!

 

[MesaSean]

Ok so I re seated the power and pre amp tubes.

I'll test shortly when my neighbor downstairs leaves but one thing I noticed (see pictures)....is that the last two pre amp tubes, even when fully seated have some wiggle room if you wanted to move i. ( you can see I can move it backward and forward while fully seated. The others I cannot) Is that normal?

i'll fire it up today when my neighbor downstairs leaves. Sucks having neighbors lol

 

[Ventura]

GAWD I love the look of a minty new Diezel interior!! AND I love TAD7025S preamps. Just....ya, drool worthy.

Well, good luck - you can try swapping the looser preamps out for a different pair up the line, so long as they're all the same. Often the little pins on the bottom just get spread or whatnot and makes it so they feel loose or jiggly. They should feel very FIRM and STURDY once seated in the socket. Some wiggle room is normal but it shouldn't be excessive.

Have you had many tube amps before??
Just wondering. If the problem persists - best to throw an iPhone on it (or whatever smartphone) and get some footage of the problem as it's happening and send it to Diezel.

Best,
Mo

 

[MesaSean]

GAWD I love the look of a minty new Diezel interior!! AND I love TAD7025S preamps. Just....ya, drool worthy.

Well, good luck - you can try swapping the looser preamps out for a different pair up the line, so long as they're all the same. Often the little pins on the bottom just get spread or whatnot and makes it so they feel loose or jiggly. They should feel very FIRM and STURDY once seated in the socket. Some wiggle room is normal but it shouldn't be excessive.

Have you had many tube amps before??
Just wondering. If the problem persists - best to throw an iPhone on it (or whatever smartphone) and get some footage of the problem as it's happening and send it to Diezel.

Best,
Mo

Yeah I have been using tube amps since the 90's. Marshall JCM's, then Dual Recto's, Rectoverb, ENGL's, Diezel VH4 (2006), Herbert (old one) Mesa Mark V etc. I used to change the tubes in the Mark V. The pre amp tubes I mean... and those fit in with no wiggle at all. Hence why I thought there might be something up with that fact that I can move the last two pre amp tubes back and forward a little bit.

Hoping my annoying neighbor leaves. I'll make a video when he leaves as to what the problem is tone wise

 

[Ventura]

GAWD I love the look of a minty new Diezel interior!! AND I love TAD7025S preamps. Just....ya, drool worthy.

Well, good luck - you can try swapping the looser preamps out for a different pair up the line, so long as they're all the same. Often the little pins on the bottom just get spread or whatnot and makes it so they feel loose or jiggly. They should feel very FIRM and STURDY once seated in the socket. Some wiggle room is normal but it shouldn't be excessive.

Have you had many tube amps before??
Just wondering. If the problem persists - best to throw an iPhone on it (or whatever smartphone) and get some footage of the problem as it's happening and send it to Diezel.

Best,
Mo

Yeah I have been using tube amps since the 90's. Marshall JCM's, then Dual Recto's, Rectoverb, ENGL's, Diezel VH4 (2006), Herbert (old one) Mesa Mark V etc. I used to change the tubes in the Mark V. The pre amp tubes I mean... and those fit in with no wiggle at all. Hence why I thought there might be something up with that fact that I can move the last two pre amp tubes back and forward a little bit.

Hoping my annoying neighbor leaves. I'll make a video when he leaves as to what the problem is tone wise

Ya man....if the problem persists - get some video footage of it.

I just had to ask about tube amps because we all "know" that feeling of a SNUG preamp tube once properly seated. You know that feeling too. So your fingers should be able to guide you - maybe inspect the preamp tubes that seem loose - make sure the glass bottom isn't cracked or deteriorated at all, have a look top down to the socket to make sure the internal socket rings are all uniform and present.

And after this?? Like I said - if it's a problem, you're in awesome hands with Diezel HQ.

 

[MesaSean]

GAWD I love the look of a minty new Diezel interior!! AND I love TAD7025S preamps. Just....ya, drool worthy.

Well, good luck - you can try swapping the looser preamps out for a different pair up the line, so long as they're all the same. Often the little pins on the bottom just get spread or whatnot and makes it so they feel loose or jiggly. They should feel very FIRM and STURDY once seated in the socket. Some wiggle room is normal but it shouldn't be excessive.

Have you had many tube amps before??
Just wondering. If the problem persists - best to throw an iPhone on it (or whatever smartphone) and get some footage of the problem as it's happening and send it to Diezel.

Best,
Mo

Yeah I have been using tube amps since the 90's. Marshall JCM's, then Dual Recto's, Rectoverb, ENGL's, Diezel VH4 (2006), Herbert (old one) Mesa Mark V etc. I used to change the tubes in the Mark V. The pre amp tubes I mean... and those fit in with no wiggle at all. Hence why I thought there might be something up with that fact that I can move the last two pre amp tubes back and forward a little bit.

Hoping my annoying neighbor leaves. I'll make a video when he leaves as to what the problem is tone wise

Ya man....if the problem persists - get some video footage of it.

I just had to ask about tube amps because we all "know" that feeling of a SNUG preamp tube once properly seated. You know that feeling too. So your fingers should be able to guide you - maybe inspect the preamp tubes that seem loose - make sure the glass bottom isn't cracked or deteriorated at all, have a look top down to the socket to make sure the internal socket rings are all uniform and present.

And after this?? Like I said - if it's a problem, you're in awesome hands with Diezel HQ.

Thanks man. Yeah I hope it fixes it.

If it is more than that.... how do I get the amp sent in for repair? Do I just contact the dealer I bought it from? It would suck big time as I would have to ship it then and be out and amp for a while ugh. I am hoping there is an authorized Diezel repair place near me (if they exist). I am based in the Queens, NYC, Long Island area.

 

[MesaSean]

Ok just checked and the VH4 sounds terrible....something is wrong.

Uploading an unlisted video now.

 

[MesaSean]

Ok here is the video. Playing through my Diezel rear loaded 4X12 (Also I made sure my Shure mic recording this was set low....the break up and clipping is NOT from my camera.... it's from the amp for sure)

Any advice? Peter, Leo etc.... am I sending this back for repair or does it sound like a tube issue? (Fuse issue maybe?)

 

[MesaSean]

Ok here is the video. Playing through my Diezel rear loaded 4X12 (Also I made sure my Shure mic recording this was set low....the break up and clipping is NOT from my camera.... it's from the amp for sure)

Any advice? Peter, Leo etc.... am I sending this back for repair or does it sound like a tube issue? (Fuse issue maybe?)

UPDATE! Good news and bad news.

I got it back to working normal and sound GREAT! BUT things are about to get weirder or....it just means I need a few new pre amp tubes (I hope)

So when looking at the back of the head... the 2-3 pre amps tube all the way to the right seem to fit...well... weird. Like they kind of don't want to go in all the way...or the do but 1 or two of them stick up taller than the others. It is hard to explain.

With that being said...I reseated them all but I noticed something weird with the far right tubes. When I jiggled those, it fixed the issue....BUT then my channel insert for channel One goes very very low or TOTALLY out. Like you'll hear the tone all start to go to shit, or the volume drop and then it comes back on, goes back down etc. It will work for like a half hour....then channel 1 goes out if the channel insert is activated... I jiggle the 2-3 far right pre amp tubes and it comes back on fine.

So my guess right now, is I just have a couple of bad tubes or dying tubes. I am assuming those are not covered by warranty and tubes are not expensive anyway.

I plan to swap out all the pre amp tubes with new ones just to be safe. Can anyone link me the set to buy? Meaning the right brand, bias, tone etc. that belongs with a stock VH4?

(I have no idea how to bias amps...but I am guessing biasing only refers to when you change out the power tubes?)

Thanks everyone for your help!

 

[Philhouse]

G'day Sean,
Stupid question: I know you said it's not the guitars earlier, but could it be a case of the EMG battery dying in the Explorer and possibly causing issues?
I'm presuming you've tried other guitars with passives and the problem is still consistantly there?
You've used a different cable straight in also?. Just trying to eliminate a shitty cable from the fault. Perhaps moving in and out of the amp to your listening spot when you wiggle the tubes and then back as such could be a shitty cable joint making contact and being intermittent
Just trying to help fault find and eliminate all possible avenues for your thread.

 

[MesaSean]

G'day Sean,
Stupid question: I know you said it's not the guitars earlier, but could it be a case of the EMG battery dying in the Explorer and possibly causing issues?
I'm presuming you've tried other guitars with passives and the problem is still consistantly there?
You've used a different cable straight in also?. Just trying to eliminate a shitty cable from the fault. Perhaps moving in and out of the amp to your listening spot when you wiggle the tubes and then back as such could be a shitty cable joint making contact and being intermittent
Just trying to help fault find and eliminate all possible avenues for your thread.

Not a stupid question at all! I tried multiple guitars including a custom shop Les Paul with passives and still had the same issue.

Tried different cables and still the same. In fact this one is a brand new cable as wel..

BUT as I mentioned before, when I wiggle or reseat the last two tubes to the right (looking at the back of the head) it seems to fix it when the problem comes back.

Anyone have a link to what exact tubes I can buy as a set and just pop right in? I just want to be safe and change them all out and see what happens and if it goes away permanently.

Thanks again everyone. Let me know your thoughts.