New user - VH4 questions

[Vigier Arpege]

Hi!

I've just purchased a VH4, first of all i have to say i love the sound and i could't be happier with it.
I use the amp in Norway, it's a 230V amp. I'm the second owner.

But i have a few questions(sorry if they are stupid, i'm a bit noob at this

1. Fuses:

Main fuse:

I noticed that the main fuse that is used says: T2L 250V. Is this the right fuse to be used? I read in the Owner's Manual that the main fuse for 220V operation, must be 4 A slow blow. can i use the "T2L 250V" fuse?

Tube fault fuse: (250mA slow blow)

The "tube fault fuse" that are used says: T250L250V, is this the right fuse? The manual says that "250mA slow blow" fuse has to be used.

2. Tubes:

Biasing:

The amp is equipped with 4 6L6 GC power amp tubes. There is a switch behind the tubes that says 6L6 and EL34 on each side, can i just use this switch when changing from 6L6 to EL34 tubes or do i have to rebias the amp inside?

Pre amp tubes:

When i power up the amp i see that only 6 of the 7 pre amp tubes lights up, the one that does'nt light up is the one allt the way to the right side(seen from the back of the amp) Is there a problem with this tube? This tube also differ from the other pre amp tubes, shouldn't they be the same type?

I noticed whn i run effects thru the parallel loop the effect isn't that powerful as compared to when i use the effects thru the channel inserts, could this be the case because of the faulty pre amp tube (the one that doesn't lit)?

Hope you have the time to answer my questions, and thank you for this awesome amp! I really want it to perform at it's highest potential.

Thanks!

 

[reussen]

hmmm... I am NOT able to answer all your questions...

All tubes should light up... you sure it's not lit? I don't think it would sound as good as you say with one tube not working...

Bias: yes, always check the bias when switching tubes.

Robert

 

[duesentrieb]

1. Fuses:
Main fuse:
I noticed that the main fuse that is used says: T2L 250V. Is this the right fuse to be used? I read in the Owner's Manual that the main fuse for 220V operation, must be 4 A slow blow. can i use the "T2L 250V" fuse?

2-2.5 A slow blo is ok for 230V use. T = träge = slo blo, fuses are always made (here) for 250Volts

Tube fault fuse: (250mA slow blow)

The "tube fault fuse" that are used says: T250L250V, is this the right fuse? The manual says that "250mA slow blow" fuse has to be used.

yes, probably you don't see either the mA or 0, . . . on the fuse

2. Tubes:

Biasing:

The amp is equipped with 4 6L6 GC power amp tubes. There is a switch behind the tubes that says 6L6 and EL34 on each side, can i just use this switch when changing from 6L6 to EL34 tubes or do i have to rebias the amp inside?

you need to rebias when you switch to EL34s - and you flip the switch - if your amp has a bias pot. Whats its serial number please?

Pre amp tubes:
When i power up the amp i see that only 6 of the 7 pre amp tubes lights up, the one that does'nt light up is the one allt the way to the right side(seen from the back of the amp) Is there a problem with this tube? This tube also differ from the other pre amp tubes, shouldn't they be the same type?
I noticed whn i run effects thru the parallel loop the effect isn't that powerful as compared to when i use the effects thru the channel inserts, could this be the case because of the faulty pre amp tube (the one that doesn't lit)?
Hope you have the time to answer my questions, and thank you for this awesome amp! I really want it to perform at it's highest potential.
Thanks!

Some preamp tubes glow more than others.
The loss of signal strenght in your parallel loop is caused by your fx-return volume, the send level (frontplate) and of course the settings of your fx.

If all features on your amp are working /channel inserts, serial loop, parallel loop) and no tube fault lights are on - all you need is to enjoy your amp and use the correct fx settings when running them in parallel. Try to use them serial too, probably thats better.
Which unit is hooked to the parallel loop.


Congrats and welcome to the family.

Olaf

 

[Vigier Arpege]

Thank you for your reply Olaf!

The serial number is: 020293.

So then I first re-bias and then flip the switch?
How do I actually take the chassis out of the headshell? Do I have to remove the pre amp tubes and the power tubes first?
When I'm re-biasing, I turn on the amp with no speakers connected right? I read in the manual that I should never turn on the amp with no speaker connected and that this can damage the amp...is this true?
Which current do you recommend for EL34?

The V1 preamp tube is the one that doesn't lit and it is different than the others, the 6 others are 12AX7 tubes.
Should I change the first tube to a 12AX7? Can the amp work at all if the first preamp tube is faulty? Should I change all the pre amp tubes if I change one?

I connected a digital delay-pedal (BOSS DD-3) to the parallel and it just sounds a bit "dull" and not that clear, almost like it is in the background, compared to when I connect it to the insert channel or directly in to the amp in front. Can't figure it out.

A lot of questions here , I just like to be precocious with this fine amp.

Thank you for your patience.

 

[duesentrieb]

Thank you for your reply Olaf!

The serial number is: 020293.

- made in 2002, so it can be biased

So then I first re-bias and then flip the switch?

- first switch, then set bias


How do I actually take the chassis out of the headshell? Do I have to remove the pre amp tubes and the power tubes first?

- take off the back grille, then remove the 4 screws underneath the headshell - voilà

When I'm re-biasing, I turn on the amp with no speakers connected right?

- either hook a speaker to it or make sure the master volume is set to "0" !

I read in the manual that I should never turn on the amp with no speaker connected and that this can damage the amp...is this true?

- see above: no signal (master = 0) - no damage

Which current do you recommend for EL34?

- 33mA per tube. How will you measure it? Bias Rite (or other tool) or with a DMM reading it off the OT?
Then (reading off the OT) set bias to 65mA (thats for a pair)

The V1 preamp tube is the one that doesn't lit and it is different than the others, the 6 others are 12AX7 tubes.
Should I change the first tube to a 12AX7? Can the amp work at all if the first preamp tube is faulty? Should I change all the pre amp tubes if I change one?

- the amp wouldn't work if V1 (closest to the input jack) is faulty.

I connected a digital delay-pedal (BOSS DD-3) to the parallel and it just sounds a bit "dull" and not that clear, almost like it is in the background, compared to when I connect it to the insert channel or directly in to the amp in front. Can't figure it out.

- set level on the pedal when running in parallel to 100%, adjust fx-level on the frontpanel of the amp

A lot of questions here , I just like to be precocious with this fine amp.

- you're welcome

Thank you for your patience.

 

[Vigier Arpege]

Ok, thanks!

So can i change just one pre amp tube or is it a better solution to change all 7 at the same time?

 

[duesentrieb]

Tzhe first two have the biggest influence/effect on the sound.
First = closest to the input jack - called V1 and V2.

 

[Vigier Arpege]

I've got "Mesa/Boogie 6L6 STR 440 Duet amplifier tube matched pair" power tubes,
and the following pre amp tubes:
V1: Sovtek 12AX7LPS
V2-V7: Sovtek 12AX7WB

I've heard that the Sovtek-tubes aren't that good and the are better tubes out there.
Has Diezel ever used Sovtek-tubes in their amps?

What pre amp tubes do you suggest using to boost the sound quality in the VH4?, I mainly use channel 3 for heavy riffs and channel 2 for a "semi clean" tone.

Is it a good idea to use some high-grade tubes in V1-V3?

Option 1: Maybe 12AX7AC5 HG+ in V1 and V2, and Tung-Sol 12AX7 in V3-V7? Or Tung-Sol 12AX7 in V1-V7.

Option 2: 12AX7AC5 HG+ in V1-V3, 12AX7AC5 HG in V4-V7 and change my powertubes to JJ kt77.

What's your advice on this?