Discuss the stuff that makes your ears bleed.

Moderators: Slowy, Capt. Black

#770126
Arright. So.

New preamp valves went into my vk212 today after it chewed one of the oldies and sounded like a wet fart on toast.

Now - fuck knows how and/or why - the amp will power up (light comes on, something hums like it usually does), however, there is no sound.
No hiss, no nothing.

There is also no light from any of the valves, and no heat in any either.

I opened it up today and couldn’t find anything immediately screaming “hey I’m fried”, and all the fuses were intact.


Can anyone help based off that? :(
#770131
Mine has had same issue recently.

HT fuse would be first thing to check. Mains fuse is fine as the amp gets power, but the HT fuse is the part that protects from bad power on the tubes. Use a multimeter to test it, or just replace it and see what happens.
#770133
Sounds like a fuse, test them with a meter, they can look ok but be farked. Else it's new power tx time your heater windings fried.
#770134
Smells like I’m pulling it apart again.
Where do I find the HT fuse?
What’s this filament business, and what’s a power texas?
#770138
on the valvekings all pre amp tubes are linked so if you haven't re seated one of the tubes properly it mess with all of them (john gilmore told me that..he heavily modded one years ago and found out the hard way). My valveking was making a microphonic whistle noise but now is in exactly the same condition as yours currently, I had a mate look at it and he took out the tubes and put some other ones in but had one not quite pushed in fully and now there is no sound at all...I have checks both fuses and they look ok. So now it sits as a paper weight until I learn how to fix amps :rofl:
#770140
Bg wrote:Sounds like a fuse, test them with a meter, they can look ok but be farked. Else it's new power tx time your heater windings fried.


must do this with mine
#770141
Single coil wrote:Smells like I’m pulling it apart again.
Where do I find the HT fuse?
What’s this filament business, and what’s a power texas?


No idea where you will find it on the VK. Or if im right. Just taking wild gueeses, that are easy things to check and wont damage the amp any further.
#770145
Guna be a fun afternoon lads
#770156
Single coil wrote:Guna be a fun afternoon lads


For goodness sake... be safe!!! hahahhaha
#770160
I don't know if this will help, but...

A while ago my Marshall TSL601 Combo stopped working, produced zero sound but seemed to come on. I blamed the fact I knocked it a little harder than I'd have liked when I leaned it back against a wall to get some visibility of the controls as I tweaked and I'd just blown a valve. I did check all the fuses and all looked good, so bit the bullet and dropped it into the amp tech for new tubes.

Turns out that it wasn't the tubes but was instead another fuse mounted under/on a circuit board, this bugger didn't even look like a fuse at all - it was like some sort of transistor or something. Anyway, didn't cost me a new set of valves but did cost me an hour or tech time to fix it.

So is there a chance there's some other fuse in your amp that isn't obvious and isn't accessible from outside?
#770169
Probably. It isn’t hard to get the thing into a shitload of pieces.
Got all sorts of shit going on today so I’ll have a poke around when time permits.

Bg wrote:Don't forget you can use a nail for a fuse at a pinch.


Don’t be daft. That only works on marshalls.
#770696
BG said it earlier. If the heaters aren't glowing, the tubes won't conduct.

Its a power supply problem (of some kind), and it probably needs a good overhaul.

If its a blown fuse, that will be because some part of the power supply circuit after the fuse is drawing too much current - and merely replacing the fuse won't fix things. My guess (from this distance) is that one (or more?) of the filter caps is shorted. I'd say all the caps (including the bias supply caps) are probably overdue for replacement. There could be other problems related to the power supply. Only way to find out is pull it apart and starting metering everything. Try taking some DC voltages at the various power supply filter cap nodes. Look for cooked/exploded components.