VHT Special 6 Heater Fuse

[big_teee]

The VHT Special 6, and Special 6 Ultra is a Single ended Amp that comes with a 6V6 Power Tube.
VHT advertises that the amp can be ran with other Power Tubes.
It has a built in Eyelet, or Turret type Component Board.
They say you can try 6L6 EL34s and Others.
The problem is the Heater Circuit has an internal Fuse that several have complained about blowing if you go to a larger tube like the EL34.
VHT Says to change out the 4 Amp with a 6 Amp Slow Blow heater fuse.
It appears this Fuse is soldered to the Circuit Board.
For an Amp Supposedly Designed to Mod, the Soldered Internal Heater Fuse Seems like a terrible way to go about things.
So now you have Un-Qualified Guitar Players needing to get in the amp and solder a new fuse to the board.
Any Ideas on this, and have Others ran across this problem.
Like I said earlier Guys are buying this amp with the intent to try different tubes.
Thanks,
Terry

[Jazz P Bass]

"There are no user servicable components in this amplifier".

[big_teee]

"There are no user servicable components in this amplifier".

That's a pretty Broad Statement.
If you blow the Heater Fuse, Someone is going to have to service it!!!
It's a pretty P*ss Poor Design if you have to take it to a tech for a blown fuse!
I guess Service Techs Love that Though.
B_T

[Mandopicker]

IMO...

Changing to the higher fuse to accomodate the EL-34 and other high current draw tube just shows that the transformer is being stressed quite a bit more under the load than was spec'd. I'd consider changing the PT if I was intending to run the amp with anything more than the 6V6 (maybe the 6L6 too). Regardless, the change of tube would be more tonal than for a gain in wattage.

[big_teee]

IMO...

Changing to the higher fuse to accomodate the EL-34 and other high current draw tube just shows that the transformer is being stressed quite a bit more under the load than was spec'd. I'd consider changing the PT if I was intending to run the amp with anything more than the 6V6 (maybe the 6L6 too). Regardless, the change of tube would be more tonal than for a gain in wattage.

Don't have a Clue what Transformer is in the Amp.
Here's what I find Strange!
The Primary AC is fed with a 1 Amp Fuse in the IEC Plug.
VHT Has said to Keep from blowing the 4 Amp internal Heater fuse to change it out with a 6 Amp Slow Blow.
VHT Says that is safe to run the bigger higher current Drawing Tubes.
I hang out on anothr Forum & Everyone Loves this Amp but has been blowing the Fuse when they Experiment with the bigger Tubes.
That's why I posted this to see anyone else was Hearing much of this?
It also has a Internal .5 Amp HT B+ Fuse, but No problems blowing it.
Thanks,
Terry

[kleuck]

I would not advise anyway to use something larger than a 6L6 all the time without replacing the PT
.Running a 6L6 with a correct bias and load leads to a 20 volts drop in HT, and the PT becomes pretty hot.
Realize that EL34 heaters requires more than 3 times the 6V6's current, that's not trivial (1.5 vs 0.450)
PT is a 275 volts.

[Enzo]

Fuses that come with wires attached are called "pigtail" fuses. Two simple solder connections and it is replaced. No clips to get loose, no place for someone to stick aluminum foil. One could mount a fuse clip in there, I suppose. I stock many sizes of pigtail fuse in my shop.

[big_teee]

Fuses that come with wires attached are called "pigtail" fuses. Two simple solder connections and it is replaced. No clips to get loose, no place for someone to stick aluminum foil. One could mount a fuse clip in there, I suppose. I stock many sizes of pigtail fuse in my shop.

Have you had any dealing with Modders with this little amp.
I looked over the VHT site, and they don't say which tubes they endorse for the single Ended Special 6, and Ultra.
Where do you get the Pigtail fuses?
T

[Jazz P Bass]

EBay.
Search "pigtail fuse"
pigtail fuses | eBay

[Enzo]

Pigtails should be available at any electronics parts outlet like Mouser.

I have hundreds of them in the small 20mm size in 2, 2.5, and 3A sizes we used to use in "black box" SMPS in arcade games. SInce we no longer repair those, I mainly use them now as plain fuses. When I need a 2a fuse, I snip off the wires and snap them into the clips. At the time they cost no more than plain fuses. But when I encounter wired in fuses, boy I got the things.