Valve swap - how much of a difference?

[Ramirez]

Now, I'm the kind who scoffs loudly and pulls annoyed faces whenever I hear of "valve warmth" and how important valves are if you are to sound remotely like any guitarist or bassist who has ever lived, and how your guitar somehow sound like an artificial approximation of a guitar if played through anything but a hand wired valve amp, with no effect pedals withing 75 miles.

My bass amp, however, is an Orange Terror Bass. Bass is also my main instrument. I couldn't really give a damn that my Orange has valves in it, but it looks great, is portable, and I got a good deal.

Now, by the same token as the opening statement, I'm also not the sort to claim that something is inferior just because it has valves. My Orange has valves, and they seem to be actually doing something.

And so on to my question - do different types / brands of valves really make a difference in tone, or is it really just snake oil? Or is it not quite snake oil, but rather more a matter of gain differences?

The kind of people I would like to see replying would be Sensible People*. So if you're ever bought anything by Russ Andrews I might not be needing your advice. Also if you're never heard a good sounding solid state amp you might be given a stern stare from behind my screen. That ICBM fellow seems to be one of the Sensible People regarding technical stuff. I wonder if he'd like to help me.

[ICBM]

They can make a difference, both to gain (although they're not supposed to if they're the same type!) and tone, but how much depends on the amp - some amps are much more sensitive than others, and I have no idea which that Orange is. But, since you need a spare valve anyway, it wouldn't be a bad idea to buy one that's different from the stock valves and try it in both of the positions (I think it has two) and see if either of them makes a more or less noticeable difference. If it does, it may be worth spending more money on a much better quality set.

First, we need to know what valves are in it. It's likely to be some sort of generic Chinese or Russian type, but which is important since they sound quite a bit different and using one of the other main type is probably the quickest way to find out whether valve swapping is likely to be worthwhile. Have a look inside and see if the valves have any markings on them.

[Ramirez]

Thanks.

I think the Terror uses Chinese 12ax7s - I've read of people putting 12au7s in with good results, as it tames the gain a bit (something I'd quite like)

So long as it's something than can possibly make a proper difference, I'll probably try a couple of decent 12au7s in. And record comparison files, of course.

Thanks,
Aled

[ICBM]

Valve *type* - as opposed to brand - makes a very substantial difference because you are actually changing the gain and bandwidth characteristics drastically.

Two 12AU7s will make a very major difference - probably too much. Each half of the 12AU7 has only 20% of the gain of a 12AX7, and it's likely that at least two of them are in series, so the gain loss is multiplied. If one of the valves is used as a phase inverter it will make less difference there, so if you want to go down that route I would get just one to begin with and try it in each of the positions. It may also be worth getting a 12AT7 and possibly a 12AY7 as well, these all give different (but all less than a 12AX7) amounts of gain, and different tones.

[Ramirez]

Smashing. Might just try a 12AU7 in V1 then. What would a good one to buy?!

Aled

[Rocker]

The OP should use his own judgement and not be looking for the approval of MusicRadar formites for any decision he makes re: valves in his amp. He is right to ask ICBM or any of the techs about valves but the final decision is his and his alone. Don't sell yourself short my friend. If YOU think there is a difference [better or worse] then there is a difference. If not there is none. Simple, use your ears.

Believe me, this tiny gem of knowledge has cost me a small fortune to fully understand and appreciate.

[thermionic]

I did a bit of valve-swapping in my AC15 a while back, I thought the stock Chinese preamp valves must be getting a bit tired as they'd been there since 1996! So I bought three different modern production ECC83s from Karltone, took the chassis out and started swapping. I also had an E-H from a Vox Tonelab to add to the mix.

I have to admit I couldn't really tell any difference. I mainly swapped out V5 & V4 (first stage and Top Boost) and also the phase inverter - the other two drive the reverb and the tremolo so I left those in to avoid confusion. I could only conclude that mid-90s Chinese unbranded valves were pretty good, and that modern production valves (tested by the seller) are very consistent. Interestingly, one of the modern ones gave a drastically-reduced volume in the Tonelab, but sounded fine in the amp.

Swapping an ECC83 with an ECC82 is obviously a bit different, and a bass amp is different to a guitar amp, so for the sake of a little over £10 for a valve it's a good experiment to try.

[icmkarthi]

Swapping an ECC83 with an ECC82 is obviously a bit different, and a bass amp is different to a guitar amp, so for the sake of a little over £10 for a valve it's a good experiment to try.

Regards,
ICMPacknMove,
packers and movers in delhi
https://www.facebook.com/icmpackers