About amp "immediacy"

[netfences]

That was a mistake.

Yes, the tried and true method has been refined so as to make GNF tolerable. I'd still prefer not having to use it. Are you familiar with Steve Dunlap and his output stage?

[nosaj]

Lets not forget the other parts of the instrument in this case the guitar and speakers. I kinda wonder if this is why Howard Du mble would require an audition before building someone an amp.
Nosaj

[eschertron]

Has anyone presented a list of amps that are 'immediate-sounding' versus ...whatever the opposite is? I'd think a little analysis of gain structure, headroom, slew rate, etc., may reveal some patterns.

How about small-signal gain versus gain near clipping? If tubes typically reach compression on their peaks - the beloved 2HD - then 'typical' gain measurements would indicate less gain than what's available for low-level signal at the beginning of a note event (finger or pick noise, what I think Galaxiex was defining as ‘immediacy’ in post 10). Conversely, adequate HR allows for the whole attack to come through. Are those “ice-picky” Fenders considered immediate-sounding?

Hmm. I just managed to present and nullify a hypothesis in the same paragraph.

[Chuck H]

Hmm. I just managed to present and nullify a hypothesis in the same paragraph.

I think that may be part of the point of this topic when it was first presented. Lots of opportunity for peripheral and confusing tendrils that could metastasize at the ends like a spreading cancer.

[nosaj]

To stir up crap, and not to mention it was started by a friend of the triad.
Notice how they moved away from the parking lot topics. Nobody posting there anymore and they moved to infect some other section with a topic so broad as to not have and end.

Maybe if they start with a schematic it could move, but when its all subjective it can never be resolved.
Nosaj

[Leo_Gnardo]

when its all subjective it can never be resolved.

Cue Limahl's UK 1984 hit "The Never Ending Story."

File along with endless threads from Sea Chief and his Belgian cousin bewildered Wil.

[Chuck H]

but when its all subjective it can never be resolved.

Presenting opportunities for debate and conflict. And it has an accountability exit door. "Who? Little, innocent me? I've been nothing but cordial and inquisitive." You have to respect the strategy. And working in packs too! f#@&ing pro man. Like an anarchy SWAT team.

[Pedro Vecino]

Has anyone presented a list of amps that are 'immediate-sounding' versus ...whatever the opposite is? I'd think a little analysis of gain structure, headroom, slew rate, etc., may reveal some patterns.

No. But knowing that nine out of ten Dual Rectifiers have a Ibanez Tube Screamer attached, put it on the "not immediate" list

[netfences]

I've learned several things in this thread so far:

1. tubes have unique qualities that silicon is only just now approaching.
2. tubes are much easier to cobble with but probably won't give me the product I want.
3. I will want my amp to have dominant 2nd order harmonics in its distortion profile.
4. presence is different than tone shaping and immediacy is likely dynamics/transient response.
5. You've all decided to hate yldouright and anyone who agrees with him

Even if this thread goes no further, I'd say there has been progress and I appreciate it. A thanks to all the participants.

[Mike Sulzer]

Yes, the tried and true method has been refined so as to make GNF tolerable.

That is not what happened at all. There was nothing wrong with the GNF used in nearly all amplifiers. The TIM people pointed out a potential problem as if were an actual common problem; it never was in all audio power amplifiers. GNF leads to the lowest distortion and should be used when you want to use an amplifier in the linear range. Therefore it does not apply to guitar amps.

Oh, and of course it was a problem in the 741 operational amp when it was used in low level audio circuits. It had a slew rate of about .5 volts/microsec, and thus could not produce a 20 KHz sine wave at +/- 15 volts. It is sad that some people actually used them in "high quality" audio circuits.

[Dave H]

...it was a problem in the 741 operational amp when it was used in low level audio circuits. It had a slew rate of about .5 volts/microsec, and thus could not produce a 20 KHz sine wave at +/- 15 volts. It is sad that some people actually used them in "high quality" audio circuits.

I guess they were able to get away with it because it was designed to amplify music not 20kHz sine waves. With a music signal the lower frequencies would be hitting the rails well before the high frequencies so it wouldn't need to be able to produce a +/-15V 20kHz sine wave.

[Chuck H]

I've learned several things in this thread so far:

1. tubes have unique qualities that silicon is only just now approaching.
2. tubes are much easier to cobble with but probably won't give me the product I want.
3. I will want my amp to have dominant 2nd order harmonics in its distortion profile.
4. presence is different than tone shaping and immediacy is likely dynamics/transient response.
5. You've all decided to hate yldouright and anyone who agrees with him

Even if this thread goes no further, I'd say there has been progress and I appreciate it. A thanks to all the participants.

On point's 2 and 3, a complete description of what you want and what it will be doing would help. Will this be a self contained guitar including a pre amplifier intended for guitar exclusively? Do you plan to used processed or digitized modules and use this project as a power amplifier? Is this even for a guitar? Are you going to build this amp OR have you ever built an amplifier OR is this just casual rumination on the matter?

As to distortion profile. You mentioned that you want this to be a clean amp. There's no reason a clean amplifier can't be built with tubes or transistors that contributes so little distortion to an already processed tone as to be ignoreable. Even if the amp were producing 2 percent distortion I seriously doubt it would be noticed amplifying a processed guitar signal. Especially so if that signal is a clipped wave form. There has been some foo about single ended amps preserving the magic 2nd order harmonics while push/pull amps do not because the 2nd harmonic is largely canceled in push/pull operation. This is a gross oversimplification. What's really happening is that much of the 2nd harmonic generated by the power amplifiers themselves is canceled. Any second harmonic generated in the pre amplification is still faithfully reproduced and the output stage does nothing to inhibit them. So, if this is to be a clean amp there would be so little 2nd harmonic distortion anyway that it couldn't possibly add or subtract noticeably from a processed guitar signal.

JM2C on second harmonic as it relates to guitar signals and unclipped power amps.

So... Pretty please with sugar on top, explain your desired amp and it's duties.

[Enzo]

You've all decided to hate yldouright and anyone who agrees with him

You have only just joined this board, and yet of all the things you pick to qualify it, you pick ONE guy's posts focus on. Plus you used the term "hate" which was only used by the others of his group. No one here ever said they hated anyone. All told, that makes one wonder. It sounds more like you came from the same place they did, merely to assist them.

Otherwise, we welcome fellow tech heads interested in electronics.

[DrGonz78]

All told, that makes one wonder. It sounds more like you came from the same place they did, merely to assist them.

"When I see hoof prints on the snow, I think horses and not zebras/unicorns" - Enzo

Did ya see what I did there...?

[Leo_Gnardo]

"When I see hoof prints on the snow, I think horses and not zebras/unicorns" - Enzo

Did ya see what I did there...?

You get snow in Scottsdale?