So what in solder "sounds" bad, and what can be done about it?

[pdf64]

[QUOTE=Alan0354;234196]Also the metal film vs vintage carbon resistors, both work from DC to microwave frequency. There should be absolutely no differenceQUOTE]

RG Keen provides a rationale by which the resistance value of a carbon comp resistor, modulated by the voltage across it, might (under certain conditions prevelant in an amp) add a degree of harmonic distortion to a circuit, see:-
http://www.geofex.com/Article_Folder...carboncomp.htm

[Mike Sulzer]

There is a solder called silver solder I got from Radio Shack thats supposedly better and it is an electronic solder, don't really know anything about it. Well, if you use enough distortion it pretty much masks everything anyway. Making a beautiful clean sounding amp is the hard part ;-)

Yes, there is: Silver-Bearing Solder (1 Oz.) - RadioShack.com

It might be great stuff, although I always have some doubts about high priced little things from Radio Shack ($5.69 per ounce). (although they are often a needed supplier of last resort!)

Sorry about that remark about burning up circuits.

[Mike Sulzer]

[QUOTE=pdf64;234302]

Also the metal film vs vintage carbon resistors, both work from DC to microwave frequency. There should be absolutely no differenceQUOTE]

RG Keen provides a rationale by which the resistance value of a carbon comp resistor, modulated by the voltage across it, might (under certain conditions prevelant in an amp) add a degree of harmonic distortion to a circuit, see:-
http://www.geofex.com/Article_Folder...carboncomp.htm

Yes, as Keen shows it is the plate resistors that can matter, but it is not just in the stage before the phase inverter as he says. The guitar signal is large, and so even the first stage can have a high voltage swing across its plate resistor. Also, the feeback he mentions, around the phase inverter, is not present in many guitar amps, and so the reduction of such distortion would not happen through feedback. However, it does tend to be canceled by a push pull design.

This effect is small compared to the tube distortion when they are overdriven, so I am not convinced it is important except maybe in "clean" playing.

[Mike Sulzer]

Also the metal film vs vintage carbon resistors, both work from DC to microwave frequency. There should be absolutely no difference

RG Keen provides a rationale by which the resistance value of a carbon comp resistor, modulated by the voltage across it, might (under certain conditions prevelant in an amp) add a degree of harmonic distortion to a circuit, see:-
http://www.geofex.com/Article_Folder...carboncomp.htm

Thinking about this some more, I am not convinced that it is nearly all even harmonics as Keen implies, or actually mostly second harmonic as he writes. As the audio signal swings one way, we are increasing the voltage across the resistor. When the audio signal goes the other way, the voltage across the plate resistor decreases. This produces odd harmonics. These do not cancel in a push pull design. In a master volume guitar amp adjusted for near clean playing, nearly all of the stages have large outputs, and so this effect could really be significant.

[FunkyKikuchiyo]

Yes, there is: Silver-Bearing Solder (1 Oz.) - RadioShack.com

It might be great stuff, although I always have some doubts about high priced little things from Radio Shack ($5.69 per ounce). (although they are often a needed supplier of last resort!)

Sorry about that remark about burning up circuits.

I've used it. It is good stuff and flows nicely - probably the only RoHS stuff that I like to use. Unfortunately cost prohibitive unless you happen to be insane.

[J M Fahey]

That solder was the weirdest stuff, every joint looked like a cold-solder joint, no matter how many times I re-flowed, it cooled with that non-shiney dull look as if it was a cold joint,

I also sometimes bought mystery brand solder ar "dollar shop" type places, also in a hurry on Saturday afternoon or Sundays.
It´s always labelled "60/40" , my guess is simply it´s not.
At best it might be "50/50" which works, sort of, if you don´t move the joint *at all* while it sloooowly cools or simply dishonest "40/60" or whatever.
These non-dedicated retailers couldn´t care less.
Rather than "lead free" it´s "lead full", because it´s way cheaper.
Flux must also be low quality.

[RedHouse]

I'm amazed at people that dismiss things that others can plainly hear, being blinded (or deafened) by their own brightness.

What is "ridiculous" is the notion that one can compute others personal taste/preferences to the extent of tossing it out of the conversation, and then validate/dismiss what other people hear for the sake of posturing intellectual self-efficacy.

Music is a audio thing, and more to the point sound is a personal preference thing not just organised noise to be defined by equation or observation. Why debase everything into a "prove it" discussion, ...ad nausium, ...ad infinitum.

Someone mentioned amps, well, sure most guitar amps are very much alike, but most people CAN hear a difference between a JTM45 and a Fender Bassman, or a Twin Reverb from Mesa Boogie, or a Dumble from a Trainwreck, and most can hear the difference between a Plexi and a JCM800 and most people can hear a Strat from a Danelectro, a Gretch from Les Paul etc. But more importantly it's the tone and response (not freq response) which is harldy measurable, the tactile feedback, the nuances, the differences in these things that inspire or bummer a player when they play.

If they get something that inspires them, they play well, and we're done (for now) but if they don't get inspired by their tone, then we're back to the work bench making new stuff. Simple as that.

Audio and sound while truly measurable, are fortunately/unfortunately perceived and interpreted by everyone with their own ears regardless of computations/theory/math. No end user crunches numbers then audition's tone.

Adding science to a discussion is fine, and can be interesting, can be interpreted differently, but lets not steer all threads into scientific discussions, the "prove it" thing really gets old.

[RedHouse]

...These non-dedicated retailers couldn´t care less.
Rather than "lead free" it´s "lead full", because it´s way cheaper.
Flux must also be low quality.

I'd agree with that, probably not intentional mis-representation on the part of the retailer, but their sources are likely supplying dodgey stuff.

I was thinking it was the flux, maybe it had some contamination of some kind in it because it flowed weird too, kinda blobbing instead of wicking as best I cab describe it.

[Steve Conner]

Someone mentioned amps, well, sure most guitar amps are very much alike, but most people CAN hear a difference between a JTM45 and a Fender Bassman, or a Twin Reverb from Mesa Boogie, or a Dumble from a Trainwreck, and most can hear the difference between a Plexi and a JCM800 and most people can hear a Strat from a Danelectro, a Gretch from Les Paul etc. But more importantly it's the tone and response (not freq response) which is harldy measurable, the tactile feedback, the nuances, the differences in these things that inspire or bummer a player when they play.

All of those things are measurable in theory. It's just impossibly fiddly, tedious and boring in practice, to figure out what changes in the sound waves correspond to what subjective impressions. That means the most practical way of making amps and instruments is to cook something up, taste it, experiment with changes if it tastes bad, and so on.

But I'd have to argue that the sonic impact of different kinds of solder isn't measurable even in theory. It causes no change in the sound waves coming from your amp.

As long as the stuff actually succeeds in making a joint, which cheap solder might not.

The resistance of a piece of conductor is equal to the resistivity of the metal, times the length, divided by the cross sectional area. Solder is not all that good a conductor (it has about 6x the resistivity of copper) but when current flows through a solder joint, the piece of solder it goes through is short and of large area, as opposed to the wires which are long and thin. So the copper wires still end up dominating the resistance of the circuit. We hope.

And even though solder might be a poor conductor, it still isn't a non-linear one. It obeys Ohm's law and generates no distortion. (again unless it's a dry joint)

[Mike Sulzer]

Someone mentioned amps, well, sure most guitar amps are very much alike, but most people CAN hear a difference between a JTM45 and a Fender Bassman, or a Twin Reverb from Mesa Boogie, or a Dumble from a Trainwreck, and most can hear the difference between a Plexi and a JCM800 and most people can hear a Strat from a Danelectro, a Gretch from Les Paul etc. But more importantly it's the tone and response (not freq response) which is harldy measurable, the tactile feedback, the nuances, the differences in these things that inspire or bummer a player when they play.

I completely agree: most people can hear the difference between guitar amps. And sure, the active electronics has a lot to do with it, but when you do some listening, you find that the most obvious differences are in the speaker driver. There are hundreds of different, for example, 12" drivers for guitar out there, and I doubt that very many sound the same. For good reason. Speaker drivers are complicated devices full of little resonances, and people are really good at hearing them. Nothing varies more in audio than the sound of speakers.

And then there are guitars. A strat might have a pretty bright alder body and a very bright, even sometimes harsh, maple neck with single coil pickups that get all the string harmonics. A Danelectro, well I do not even want to know what is in a Danelectro body, but it sure is no strat.

Of course they feel different: they are different in mechanical construction.

These are all things I take great pleasure in understanding. You might not; no problem.

[Alan0354]

[QUOTE=pdf64;234302]

Also the metal film vs vintage carbon resistors, both work from DC to microwave frequency. There should be absolutely no differenceQUOTE]

RG Keen provides a rationale by which the resistance value of a carbon comp resistor, modulated by the voltage across it, might (under certain conditions prevelant in an amp) add a degree of harmonic distortion to a circuit, see:-
http://www.geofex.com/Article_Folder...carboncomp.htm

The article is interesting. It is about the value change with voltage across. But if that is true, the effect should be masked by the second harmonic due to the tube. In normal preamp stage where the plate is connected to the HV by 100K resistor and have big swing. There is a lot of second harmonic generated by the tube already, the little effect of CC cannot match the distortion of the tube.

[Alan0354]

[QUOTE=Mike Sulzer;234312]

Yes, as Keen shows it is the plate resistors that can matter, but it is not just in the stage before the phase inverter as he says. The guitar signal is large, and so even the first stage can have a high voltage swing across its plate resistor. Also, the feeback he mentions, around the phase inverter, is not present in many guitar amps, and so the reduction of such distortion would not happen through feedback. However, it does tend to be canceled by a push pull design.

This effect is small compared to the tube distortion when they are overdriven, so I am not convinced it is important except maybe in "clean" playing.

Even in clean setting, the second harmonics of the tube should still drown out the little distortion from the CC resistor. Point is the major thing about the tube circuit that has a plate resistor generate a lot of second harmonics and even harmonics.

[RedHouse]

Are ya sure ya wanna be quoting RG Keen? he's kinda the Mike Sulzer of the DIYStompbox forum (no offence to Mike) and, well, we already have Mike here (no offense to RG).

[Alan0354]

I completely agree: most people can hear the difference between guitar amps. And sure, the active electronics has a lot to do with it, but when you do some listening, you find that the most obvious differences are in the speaker driver. There are hundreds of different, for example, 12" drivers for guitar out there, and I doubt that very many sound the same. For good reason. Speaker drivers are complicated devices full of little resonances, and people are really good at hearing them. Nothing varies more in audio than the sound of speakers.

And then there are guitars. A strat might have a pretty bright alder body and a very bright, even sometimes harsh, maple neck with single coil pickups that get all the string harmonics. A Danelectro, well I do not even want to know what is in a Danelectro body, but it sure is no strat.

Of course they feel different: they are different in mechanical construction.

These are all things I take great pleasure in understanding. You might not; no problem.

The biggest difference are speakers and cabinets, I think you hit it right on the nail.

Also there are major difference in design between modern Fender and old Marshall. Marshall has a cathode follower that drive the tone circuit that make it sound different from modern Fenders. The old Fender has that but they totally eliminate this stage even in the black face amp. Old Marshall put volume before the cathode follower then drive the tone circuit. Fender drive the tone circuit before the volume. Of cause, they sound different because they are different design. Those are the two major design that people copy.

Mesa is more like Fender but the problem is if you look at the schematic, there are too many stages, it amplifier the signal, then ATTENUATE the signal!!!!..........before driving the second stage. Then attenuate again to drive the third..........and so on. I never like Mesa sound, I tried so many of them, it just don't sound natural. I think the more stages that amplify then attenuate really kill the sound. I can't speak for others, I don't like Mesa at all.

[RedHouse]

(yawn)

The phrase "preach'in to the choir" comes to mind.