SecretSam wrote:Dave rather cheered me up when he wrote that power amp distortion is a bit of a myth (can't remember whether it was here or in The Other Place).
Apparently most distortion is in the preamp, which I would guess is a bit easier to delegate to pedals.
Next puzzle: if valves are so important, why are almost all the hallowed boutique pedals solid state?
Well, I lied Sam! No, not really but, like most things to do with Sound and especially guitar OD sound, it depends!
Take a 50W EL34 amp into a 4X12 100dB/W/mtr cab? Run the bits off it and yes, 'king glorious sound (gets old after 2 hrs with deffs on in a workshop tho' believe me!) but. Excruciatingly loud! Those valve are probably putting out 70-80 watts and the 10% distortion spec is 55W or so and THAT under lab conditions! So, OP stage is seriously distorting but, drop the power by ~3dB? At 25W that amp is pretty bloody hi fi, maybe 2 -4%thd super clean.
That preamble gets us to the main reason peeps come here, recording. Unless you have an extremely well proofed studio you cannot run that 50W rig at that level and most people at home cannot run at more than one or two 'valve' watts. The result is, most folks are looking for a good tone at lower volumes and that means the pre amp*.
Too many valve stages? Yes (again, sort of!) To get a good OD tone each stage need to distort in a particular way (one way is called "grid current" the other, "cut off) at the two extremes, or close to them, the valve gets very 'non-linear' but, go too far and you can shut it off momentarily and that sounds horrid. The reason there is an almost infinite variety of gitamp 'tones' is because we have a whole raft of frequencies, levels and EQs to play with and the ORDER of each stage can change the tone drastically.
Pedals: One effect of a pedal in front of a valve stage is to drive the first valve harder, maybe into some distortion. Even with the hottest passive pickup it is very hard to distort the first triode, but a pedal with say 20dB of gain and an output potentially some 6 volts or more peak to peak can do it easily and thus you start the OD process that much earlier in the chain.
Why does solid state sound ok in a pedal but put it in an amp and you get castigated? **** knows! You tell me! One of the best selling (and best amps IMHO) 'valve' amps on the market IS in effect a bloody good pedal circuit driving some valves but didn't the cork sniffing valve snobs give it a hard time!!
* Yes, there are power soaks that allow you to wear out your valves while you extract a few mW to harken unto without waking the chavvy. The very best of them get a very good rep, Motherload etc, but they are expensive.
The Series Ones seem to be available from PMT but not Andertons. They are very complex amplifiers (but still VERY reliable) with a unique power control system, very comprehensive tone controls and MIDI. Expensive but not as much as some 'boutique' amps.
Blackstar now market a huge range of products and I hope they are not over reaching themselves?
Dave (sorry for the ramble)