Tube Change on VHX - Help with retube?

[Veritas0Aequitas]

Hey all,

I am just wondering for future reference when I get my VHX, is a tube change the same as the other amps? I know KT77s are recommended but I vastly prefer the tone of the EL34B-STR so I do a quick re-tube on it before I start dialing in tones.

Thanks!

 

[Leo Diezel]

Yes, it's just the same as other Diezel, there are 4 bias test point and two trimmers for each tube pairs.

 

[Veritas0Aequitas]

I've been trying to find someone to retube my VHX for me and I can't.

Is it possible anyone help me with this? I've retubed my VH4 but I'm not sure how to on the VHX and need to get this done before I record here soon.

 

[Leo Diezel]

Procedure is similar:

Power off the amp
Wait long enough
Remove amp from headshell
Remove old tubes
Put new tubes
Set master at 0
Locate the 2 trimmers at bottom left
Set multimeters to mV
Place the multimeter negative tip to the hole under trimmers with G label
Place the multimeter positive tip to the holes with V* label, each one corresponding to a tube
Power on the amp and wait some minutes for tubes to heat
Measure all the 4 points moving the positive tip of the multimeters to respective measure point
Slowly rotate the 2 trimmers until all the points reads about 35mV
After about 10 minutes it would settle to the right value

 

[Ventura]

Weber BiasRite is a great tool...

But, without sounding at all off-the-cuff, I'd just let the stock 77s sit pretty in that brand new head and its related tech before I'd go changing anything. But that's just me - I know EACH amp off the line from Diezel is tone-tested with the preamp & power tubes all having to exceed otherwise "standard fare" tone. Even the PI that I'm usually without even trying an amp replace with an LPS, I just let Diezels run their course outta the box first - for quite sometime - before making (if even) any decisions at that time.

VHX - here we go with the GAS pedal....