I know different people have different opinions but...

[Spookyman]

Where to you place the tone circuitry in the preamp and what effects your decision? Do you prefer to see the tone circuitry immediately prior to the phase splitter? Do you prefer to put a gain stage after the tone controls before the splitter?

Also, I have seen it suggested in other threads that a cathode follower should be used as the tone circuitry is very current hungry. Of the few old schematics I have seen, I have not seen an amp circuit that does. Can anyone tell me of a production amp that used a cathode follower to feed the tone stack, so that I have something I can use as a reference?
Cheers!!

[CitizenCain]

Tweed Bassman, lots of Marshalls ... classic cathode follower-driven tone stacks.

I'm interested in the opinions on this as well.

[MWJB]

I think Fender/ATT&T's idea to feed the tonestack from a cathode follower was mainly to reduce gain & distortion, retaining fidelity as much as they could...compared to say a latter day Blues Deville/Deluxe etc, which is reasonably similar when considering the normal channel, but fed from plate rather than CF.

They dropped the CF tonestack simply because they figured how to incorporate the whole kaboodle with one triode less in the channel's circuit & could therefore give each channel it's own tone controls (they really thought a whole bunch of musicians would play through the same amp & figured that this was desirable). An upside of this is that the tone controls appear to do "more" when they follow a single input triode. People often feel that there is less "adjustment" availabe on the Tweed/Marshall circuits.

However, you really want to think about the final sound of the amp & the character you're trying to impart, the CF imparts it's own character (compare 5F6A to Normal Channel of a Concert/Super Reverb), so if you want that tweed/Marshall CF character...you might want to keep it in there. If you want the possibility of a more scooped mid character then maybe look at a more BF/SF style arrangement. Don't think about things like the tonestack in isolation of the other stages, work out what features & sound you want & work round it accordingly.

Also bear in mind factories weren't just adding tube after tube into the circuits willy nilly, typically manufacturers aimed to use the fewest number of tubes/stages possible (whatever additional features like trem & everb allowed) to keep costs down & profits up (compare the progression of 6G# amps with 2 or 3 tube tremolo circuits & associated circuitry to BF/SF amps with just 1 trem, tube).

So I don't necessarily agree that you "should" use a CF fed tone circuit, if it suits the big picture then do it by all means. Since the BF/SF circuits came out guys have worked on tweaks to give them Tweed/Marshally characeristics, so there are options.

[jrfrond]

The question being asked here is really too broad. It all depends on application and sound, and is highly subjective. There are many variables and schemes, and subtle or even radical differences between them. Placement in the circuit is just one issue. Type of tone network is another. Simple controls like the 5E3 have virtually no loss except at high-frequency rolloff. These do not require a recovery stage, nor do they need the surplus current delivery of a cathode follower, as traditional Fender-style B/M/T controls ("stack") do. There's also the Baxandall circuit, which is less common but works best in bass amps. There are myriad variations, all with a purpose.

If you want MY personal opinion, I favor simple circuits like the 5E3 tone control, which has been used in other amps too e.g. Ampeg Jet, et al. The way I see and hear it, the less gain stages you have (aka "shortest distance between two points" i.e. input/output), the more guitar tone reaches the speaker. Multiple gain-stage amps, where there is a lot of boosting, cutting and shaping going on, just fall flat on their faces for me. I like good basic tone that can be modified to taste using quality EFX pedals. When I play direct into an amp, it has to sound open and "wet" (oh baby! ) and feel responsive. This is why amps like Tweeds, Plexi's and Blackface's sound so damn good when they are running perfectly, because there is not really a whole lot of tradeoff going on. The more bells and whistles you have, the less tone you are likely to achieve.

Sorry for my rambling. We now return to our regularly-schedule program.

[daz]

Speaking strickly as a guitar player, not a tech, i just prefer they be after all any preamp generated distortion because i like to be able to EQ the distortion. For low gain cleaner amps i don't know, but it surely would matter much less.

[Steve Conner]

With high gain amps I like one set of tone controls at the beginning of the preamp and another at the end. More or less like what Dumble and Mesa do, though I think Dumble made one of his tone stacks out of trimpots and hid it inside the amp.