Best Replacement Tube For My PreSonus Studio Channel

[Jathon Delsy]

I need a Class A 12AX7 vacuum-tube.
I don't want to spend too much. Is there that much difference between the tubes?
Any recommendations, thanks.

[James Perrett]

If you are in London (as it says at the bottom of your post) then you need an ECC83 valve. Tubes are for Americans.

[Hugh Robjohns]

Class A relates to the way the valve is employed in the circuit, and has nothing to do with the valve itself.

As James says, 12AX7 is the American model code. The European code number is ECC83, but retailers all recognise both codes as exact equivalents.

Some retailers have new old stock (nos) of valves made in the 1960s. They typically have names like Mullard, Brimar, or General Electric (GE).

Modern valves mostly come from China or Russia, with names like Groove Tubes, JJ Electronic, Sovtek, electro harmonic etc.

They all have the same tech specs so should all perform identically... but some are built to higher standards than others, which is typically reflected in the price.

Here's a guide to models and prices:

https://www.watfordvalves.com/products.asp?search=ecc83

[resistorman]

Why are you replacing it? Preamp tubes last a long time. Unless, of course, you drop it

[Jathon Delsy]

Why are you replacing it? Preamp tubes last a long time. Unless, of course, you drop it

Good question. I've had the unit for only three years, and it's been in my home studio, not moved, for all that time, used about three times a week for my live streaming. Recently I noticed an intermittant crackling coming from the unit, and by a rigorous process of elimination ascertained that this noise was coming from the valve. This was confirmed by turning the send to the valve down, which completely eliminated the noise, and turning it back up, when the noise returned.
I talked to the company, and expressed my disappointment that the unit should fail after such a short time and with such light usage, but they insisted that valves are not covered by the warrenty as they are considered a consummable part, like guitar strings or drumsticks.
So now I'm looking for a replacement.

[resistorman]

Well, it might not be the valve, it's not the only thing in the circuit. I would start by pulling it out, cleaning the pins and re-seating it. I use foam swabs and deoxit, but just working it in and out might breakup corrosion. Also any connectors. Starting with cleaning physical connectors often yields good results.

[Drew Stephenson]

What Resistorman said ^^^. Three years in a mic pre-amp is not long at all for a valve to last but plenty of time for a bit of corrosion to occur. Give it a bit of TLC first.