r/tubeamps

I see vali 3 can run at 100v and comes with "6N3P" tube and can work with "6N3P, 2C51, 5670, or 396A"

buf also seems to run at 100v and comes with "6N1P" tube and can work with "6922, 6BZ7, 6DJ8".

So what I am seeing comparing the manuals is that they are very similar devices except for an extra $50 the vali 3 comes with volume control and a headphone out and they take completely different kinds of tubes.

Which one of these would be better in a signal chain that goes

turntable phono line -> schiit skoll f -> [buf or vali 3] -> powered monitor speakers

Thanks all

My pals blackstar 6L6 has no volume. If both gain and master at cranked it makes sound but super weak and sounds gated, I’ve changed the power tube to a JJ 6L6GC as well as the 12ax7 but still nothing.
Any ideas what else I need to check?

Hi everyone, my Peavey Valveking II just had a weird failure right after I flipped the power switch. I hadn't even started playing yet.

One of the preamp tubes (12AX7) suddenly started glowing extremely bright, like a lightbulb. While it was glowing, the amp was making a very faint, quiet scratchy noise (like frying bacon or a dirty jack).

There is now zero guitar signal and the Volume/Gain knobs don't respond at all. The faint scratchy noise continued until I shut it off. Before this, I had some microphonic ringing on specific notes (F/C), but the amp was working.

The tube getter is still silver (no air leak). Does the "lightbulb" glow and the silent signal mean a plate resistor or internal fuse is gone? Is it worth just swapping the tube, or is that faint noise a sign of deeper PCB damage?

I recently purchased a 1st gen YBA200 from GC. I bought it online from a GC in California and had it shipped to my local GC. So I tested it out and it didn’t seem as powerful as I thought it would. After a few weeks I plugged it in at my house and it was horribly distorted and weak. Figured maybe it had weak tubes.

Anyway, I opened it up to take a look at it. I found resistor R64 and R66 were blown out. So the outer tubes weren’t working properly.

So my question is, is this a symptom of the autobias circuit failing? Or is it caused by something else?

I know that the gen 2 switched to a fixed bias system. How hard is it to switch to a fixed bias system? Or is there a way to upgrade the autobias circuit to make it more reliable? What is the issue that makes the autobias circuit garbage?

Before anyone says it, I’m well aware that the capacitors can hold deadly voltage. All precautions will be taken while working on it. I have a background in industrial electrical maintenance.

ETA: The power tubes were switched to Ruby KT88’s. From what I gathered the originals were Sovtek 6550’s. If the previous owner didn’t use a matched quad, would that cause those resistors to blow?