My VH4 - not sure it is healthy - thoughts???

[Orvillain]

I've posted this on the Diezel forum too, but thought I'd post it here in case anyone had any ideas.

My VH4 doesn't really sound right. It sounds 'normal' as in, there's no weird frying bacon sounds or power tube drop outs or anything like that. But on channel 3 and 4 the overall tone is quite fuzzy, like there is too much low-end making it into the preamp distortion stages, something like that. It doesn't sound much like a lot of the Youtube demos I've heard, and I'm really wondering if there is anything wrong with the amp. But I just don't know.

I know this is a 2001 model, and I also suspect from reading stuff on here that the circuit changed slightly throughout the 2010's or something, making the amp sound more modern. Modern is not how I'd describe this amp at all.

I've tried new preamp tubes, and new poweramp tubes, no difference really. I suspect it is either some resistors out of spec, or perhaps even the caps. Here are some photos of them:

What else could cause an undefined fuzzy sound??

TBH, it might just be how the amp sounds, and it might be my Mark V is affecting my perception, but these days I'm not reaching for the VH4 at all anymore, whereas before I absolutely would!

 

[Orvillain]

You can defo see that these two are bulging a bit:

@James Freeman - any thoughts?

 

[MirrorProfiles]

bad filter caps shouldn’t really affect the sound too much but if you are getting noticeable electrical hum then it could be the caps need changing.

Tbh the caps are over 20 years old so it’s probably not a bad idea to replace and give the amp a once over. There's likely a few things that might need a freshen up.

If you can stomach the faff of sending it to Germany, I reckon having Peter Diezel check over it and/or possibly mod/update the circuit would be worth it. That way, if it is fine you can at least tinker the sound to what you want a bit more.

the overall tone is quite fuzzy, like there is too much low-end making it into the preamp distortion stages

This is how I think a lot of Diezel’s sound, although some are worse for it than others.

 

[Orvillain]

This is how I think a lot of Diezel’s sound, although some are worse for it than others.

I'm convinced mine sounds the way it does for one or two reasons - either the amp is defective in some way that I haven't been able to detect, or this is just how the early VH4's sound.

Hard to say, but today it even sounds different to this:


I'm happy with the tone in that video. Not too happy with what I'm getting from it right now though.

 

[jellodog]

@Orvillain Do you hear more ghost notes when you first turn on the amp, before it gets really warmed up?

 

[FuzzyAce]

I agree with @MirrorProfiles , it's at that age where it needs a service, including changing out those e caps. And more than likely some other components have drifted in values over time causing slight tonal changes.

 

[Eagle]

Mine is not fizzy buzzy at all . Those caps look like they are on their way out. Selecting the right V1 can have quite an effect too.

 

[EOengineer]

Given the age of the amp I’d get it in for service. I just had my 99 Dual Rectifier in for a cap job and tune up - it made a pretty significant difference. Same with my Mark III.

Basically anything from the early 2000s and older probably should see a tech at this point…especially if it’s running tubes.

 

[Shredder777]

I'm convinced mine sounds the way it does for one or two reasons - either the amp is defective in some way that I haven't been able to detect, or this is just how the early VH4's sound.

Hard to say, but today it even sounds different to this:


I'm happy with the tone in that video. Not too happy with what I'm getting from it right now though.

This doesn't sound good to me. At all.

It sounds like there is a filter that allows lower frequencies to get through with less distortion. And just fuzzy overall. If that is the Diesel sound, do not want.

 

[James Freeman]

First thing I would do if I thought something is wrong with how my real amp sounds (no other issues) is compare it to the same model in the AxeFx just to have a general sense if something is really off.
I am not familiar with the Diesel sound myself but I've read many times that it is not a tight amp.

Edit:
Bulging caps, not good, time to recap.

 

[Orvillain]

This doesn't sound good to me. At all.

I disagree.

It sounds like there is a filter that allows lower frequencies to get through with less distortion. And just fuzzy overall. If that is the Diesel sound, do not want.

What you hear in the video sounds markedly different to what the amp sounds like now.

 

[Orvillain]

@Orvillain Do you hear more ghost notes when you first turn on the amp, before it gets really warmed up?

Hmmm, not sure tbh. I will check.

 

[Shredder777]

Edit:
Bulging caps, not good, time to recap.

I've done a filter cap job before on a PCB amp. The hardest part is finding and ordering the caps. Also need to get a large resistor to discharge the caps.

Having to pay a tech is the reason most amps get to the 20 year mark and need a cap job.

 

[Shredder777]

I disagree.


What you hear in the video sounds markedly different to what the amp sounds like now.

Is that your amp several years ago and it changed?

Filter caps probably won't change the tone of the amp. They make the power section clean and noise free. If its sounding bad, most likely an old or failing power tube and needing a bias.

To test if filter caps are bad, plug a guitar directly into the return and turn up the volume if you are getting alot of buzzing its time for filter caps.

If another component is failing somewhere else in the circuit, I got nothin. It might be possible to do a visible inspection of all the smaller caps and replace any dubious looking ones.

 

[Orvillain]

Is that your amp several years ago and it changed?

Yeah exactly! That's my amp, my playing, my channel, etc. etc.

Filter caps probably won't change the tone of the amp. They make the power section clean and noise free. If its sounding bad, most likely an old or failing power tube and needing a bias.

What I've read is that filter caps that are leaking or otherwise on the way out can cause flubby bass and lack of tightness due to power supply instability.

To test if filter caps are bad, plug a guitar directly into the return and turn up the volume if you are getting alot of buzzing its time for filter caps.

If another component is failing somewhere else in the circuit, I got nothin. It might be possible to do a visible inspection of all the smaller caps and replace any dubious looking ones.

Maybe worth getting my tech to run over it with a multimeter maybe.

 

[Shredder777]

Yeah exactly! That's my amp, my playing, my channel, etc. etc.

What I've read is that filter caps that are leaking or otherwise on the way out can cause flubby bass and lack of tightness due to power supply instability.


Maybe worth getting my tech to run over it with a multimeter maybe.

Filter caps are easy to do yourself and all the caps should be < $100. If the amp is that old and you see them bulging, you should do them anyway. Techs will charge ~300 for the job.

Then also check tube age and bias. If after all that it is still a problem take it to your amp guy.

 

[GreatGreen]

@Orvillain

I've played a few VH4's and every one of them sounds exactly like you're describing in the OP, and it's specifically the reason I've always been pretty vocal about disliking them.

I have never, ever heard a tight, defined sounding VH4. Every one of them sounds muddy and wooly to me. They all sound like not only is there too much low end being allowed through the preamp, but there's also something going on where they sound like way too many highs are cut out way too early in the preamp as well, like everything above 1k is shunted straight to ground right after the input or something, so you can't even use boosts or EQ's into the front end to gain back that definition even if you wanted it like you can with other muddy amps, because unlike other muddy amps all those highs are lopped away internally either way.

From there, the distortion will add back harmonic content into the upper frequencies and give you plenty of sizzle if you want, but it feels like fake high end to me, like there is zero fundamental signal in the treble frequencies of the guitar itself getting through, just sizzly upper harmonics generated from the low mids and lows being distorted in the preamp.

You probably don't want to hear this, but I don't think there's anything wrong with your amp. Your description matches every other properly functioning VH4 I've played. Your amp sounds exactly like it was designed to sound. Judging by the specific nature of your complaints in the OP, I think you'll be happier in the long run to sell the amp to somebody who really likes VH4's and start looking for something else.

Last thing I'll add is that there is a reason literally every popular guitarist you know about who uses VH4's pairs them with other amps, which I think kind of speaks for itself.

 

[Eagle]

This is representative of mine

 

[Eagle]

@Orvillain

I've played a few VH4's and every one of them sounds exactly like you're describing in the OP, and it's specifically the reason I've always been pretty vocal about disliking them.

I have never, ever heard a tight, defined sounding VH4. Every one of them sounds muddy and wooly to me. They all sound like not only is there too much low end being allowed through the preamp, but there's also something going on where they sound like way too many highs are cut out way too early in the preamp as well, like everything above 1k is shunted straight to ground right after the input or something, so you can't even use boosts or EQ's into the front end to gain back that definition even if you wanted it like you can with other muddy amps, because unlike other muddy amps all those highs are lopped away internally either way.

From there, the distortion will add back harmonic content into the upper frequencies and give you plenty of sizzle if you want, but it feels like fake high end to me, like there is zero fundamental signal in the treble frequencies of the guitar itself getting through, just sizzly upper harmonics generated from the low mids and lows being distorted in the preamp.

You probably don't want to hear this, but I don't think there's anything wrong with your amp. Your description matches every other properly functioning VH4 I've played. Your amp sounds exactly like it was designed to sound. Judging by the specific nature of your complaints in the OP, I think you'll be happier in the long run to sell the amp to somebody who really likes VH4's and start looking for something else.

Last thing I'll add is that there is a reason literally every popular guitarist you know about who uses VH4's pairs them with other amps, which I think kind of speaks for itself.

Couldn’t disagree more.

 

[MirrorProfiles]

This is representative of mine

tbf, he's using a boost pedal specifically because the amp gets farty without it.

I generally agree with @GreatGreen 's assessment above - I keep trying to love the VH4 sound and it just sounds soft/fuzzy/limp to me