Getting good chord definition on a high gain build

[EtherealWidow]

It seems like in most current production, high gain amps, chord definition is not too much of a priority, which is understandable because it seems most high gain players are mostly power chord focused. As far as actual chords go though, like a minor add 9, the notes are less than distinct.

What are good designs to implement for better definition?

So far, I would imagine SS rectifier, class AB, hi pass filtering in early stages, fixed bias power tubes, and NFB.

Of course the parameters of each of these could be fiddled with to yield better or worse results.

Are any PI's better than others for this goal?

What other things could help or hurt?

Thanks guys!

[JazzGuitarGimp]

Howzabout a hex pickup and six hi-gain amps? That would be cool!

[EtherealWidow]

Haha. Yes. All Plexis! I've tried doing something like that in the studio by recording one note of the chord per track, but it always sounds really unnatural. :/ Not to mention when arpeggiating the chords, your timing has to be more than decent.

[Roe]

for chord definition its better with even harmonics than odd harmonics. Lots of 3rds and 7ths will not work that well

[EtherealWidow]

Ah. Yes. So a DC cathode follower would definitely be a good idea.

[Super_Reverb]

Another way to increase even (harmonious) harmonics is to use 68K to 82K plate load resistors. I have done it on several builds and it does sweeten up the sound. It does decrease stage voltage gain relative to the typical 100K-220K load, but I am assuming you have multiple gain stages and are using resistor dividers in several locations anyway. Suggest trying in one or two stages.

rob

[EtherealWidow]

Alright. Sounds like I'm on the right track. Thanks guys!

[Gaz]

I have built 4 and even 5 stage amps, and I would still say the best road to definition that you speak of is overdrive pedals and a clean amp. But, if you're going to go with tubes overdrive (which of course I still prefer), then I would say: Lots of filtering, high preamp voltages 350+, limit bass in early stages, good amount of NFB, more gain stages with more interstage attenuation vs. maxing out each stage, and plently of low pass filtering to get rid of noisy unmusical fizz (don't try to be Ken Fischer).

[LeftyStrat]

I don't in any way claim to be an expert. But to my ear, "clarity" and "note definition" have to do with providing upper end response while taming the nasty high end hash that comes from multiple gain stages.

[roberto]

In my opinion Gaz and Lefty are both right.

Definition comes from avoiding too much overload and harshness from single stages, and of course from the right sequence of stages (both preamp and poweramp configuration).

I've found my own nirvana with a certain amount of lows to be removed comparing to mids and highs, and really few highs to be removed (only one snubber in 4 gain stages plus CF, plus some miller tricks) or bypassed (only one 2.2n//470k just before the gain.

I've found that the less you preequalize, the clearer it sounds, but you have to remove lows.

As for the NFB, I prefer to have not so much NFB, because the amp sound more natural, and gives more harmonic content even at low volumes.

Just some hints

[EtherealWidow]

Awesome. Thank you so much Gaz. That's pretty much what I was thinking, although didn't consider higher B+. And yes, Lefty, I think that's the battle. It just sucks that I feel like most amps don't focus more on it. Seems like I can easily find great hi gain tones, but the chord definition is lacking. In my own Mesa 5:25, I replaced the first and third tubes with 12AU7's and use a compressor pedal. I still get enough distortion, but much more clarity.

[Tone Lover]

In my opinion Gaz and Lefty are both right.

Definition comes from avoiding too much overload and harshness from single stages, and of course from the right sequence of stages (both preamp and poweramp configuration).

I've found my own nirvana with a certain amount of lows to be removed comparing to mids and highs, and really few highs to be removed (only one snubber in 4 gain stages plus CF, plus some miller tricks) or bypassed (only one 2.2n//470k just before the gain.

I've found that the less you preequalize, the clearer it sounds, but you have to remove lows.

As for the NFB, I prefer to have not so much NFB, because the amp sound more natural, and gives more harmonic content even at low volumes.

Just some hints

Roberto could you give us an example of how you would go between stages in a drawing format if possible Im a little slower than some but you always teach me something when I eventually get it.
Thanks Bill

[iknowjohnny]

I don't in any way claim to be an expert. But to my ear, "clarity" and "note definition" have to do with providing upper end response while taming the nasty high end hash that comes from multiple gain stages.

Exactly, plus you have to do it w/o thinning the tone a lot. I spent years getting that right and i finally nailed it dead perfect, at least to my ear. The trick is removing a LOT of lows and low mids without making it sound thin/tinny, and once the lower mud is gone you hunt for tweaks to give it body and perceived bottom even with a lot of the bottom removed via small couplers and cathode bypass caps. If you just remove a lot of lows and low mids without finding ways to make it still sound full it WILL sound tinny. I find once that mud is removed it takes tweaking areas and things that are not to EQ it further, but certain things like WHERE within the gain stages the gain happens. For example, you gan take gain away in one place and add it back in another and see huge changes in how the amp responds to the removal of mud. Different ways of filtering the PSU and the voltages, everything affects it.

As for the NFB, I prefer to have not so much NFB, because the amp sound more natural, and gives more harmonic content even at low volumes

Agree with this big time too. I have a large (250k) NFB pot in series with a 33k resistor to set the max NFB. I find i use it full up (min NFB or almost 300k) most of the time because of just what you say. If i remove NFB completely it becomes apparent that 300k is close to no NFB, but the bit it supplies at 300k is just enough to give the clarity of no nfb but not quite the harder edge and brightness no nfb gives. It calms that just enough. Using normal amounts like 100k or less just seems to make it feel less full sounding and not as you say as "natural". Almost like using a bad compressor.

[roberto]

Ahahah, seems a forum where everyone plays to be a bit dumb just to have more information I've just explained it more in depth on the higain thread, and in tons of posts on sloclone forum. I'm a mod overthere.

[Roe]

What type of amps have good chord definition and clarity under distortion? A SLO100? An express or an Alessandro?