Debunking Tube-Amp Tone Myths

[Adambomb]

Found this article on Reverb and thought it was really interesting to hear what all the boutique builders had to say. Check it out.
https://reverb.com/blog/daves-corner-de ... ?_aid=tank

 

[garey77]

Great read! I love it when engineers wax about this.

 

[JTyson]

Yep, good read

 

[controlled_voltage]

So........sloppy wiring might add to the overall color of tone in a positive way and cheap value capacitors are better than high end ones
hmmmmmm
pretty cool

I have read that when marshall ran out of a part they would use whatever they had on hand so there are variances from amp to amp in the same models like the plexi’s
that was a cool post
thanks~!

 

[fretout]

That's a cool little read. I wish it gave more examples from the builders...like if Bogner explained that he tried expensive caps in the Fish and realized changing to cheap caps in XXX value sounded better.

I really like looking at some of the gut shots of amps and seeing how the builders decided to layout the amp. Then some other amps just throw a rats nest in the amp.

It's funny that many amp builders have two common traits...

1. They are never happy with even great amps. For example, Marshall tried to improve upon the old and great 2203s and put out an amp that wasn't as popular. Same with Mesa/Boogie and their Mark series (or even all the revisions of all their Mark/Rectifiers)

2. When builders run out of a certain part, they throw whatever they have on the shelf. Mesa is notorious for this, and I've read a few comments from Randall and Mike about how they would run out of parts, or they would have extra parts lying around and would put them in amps. That's why some Rectifiers and Marks have different transformers in them that don't follow the serial numbers.

 

[V2a]

So........sloppy wiring might add to the overall color of tone in a positive way and cheap value capacitors are better than high end ones
hmmmmmm
pretty cool

I have read that when marshall ran out of a part they would use whatever they had on hand so there are variances from amp to amp in the same models like the plexi’s
that was a cool post
thanks~!

Sloppy wiring is usually problematic, but good wiring (electrically, not visually) is not necessarily visual art like you see on Hiwatts. All that straight wire and 90-degree bends increases wire length (bad) and tends to put wires in parallel (often bad).

There are some "rules" for wiring that result in a quiet, stable amp. The wiring usually looks neat but not artistic.

 

[stephen sawall]

There is so much hype around gear..... Probably like most things the main reason you do not see huge advancements is there is such a limited market. Someone could build the ultimate digitally controlled analog amp and would probably only sell a few thousand or less... More like 150.... The same as most new gear.

 

[FourT6and2]

So........sloppy wiring might add to the overall color of tone in a positive way and cheap value capacitors are better than high end ones
hmmmmmm
pretty cool

I have read that when marshall ran out of a part they would use whatever they had on hand so there are variances from amp to amp in the same models like the plexi’s
that was a cool post
thanks~!

Sloppy wiring is usually problematic, but good wiring (electrically, not visually) is not necessarily visual art like you see on Hiwatts. All that straight wire and 90-degree bends increases wire length (bad) and tends to put wires in parallel (often bad).

There are some "rules" for wiring that result in a quiet, stable amp. The wiring usually looks neat but not artistic.

Sigh. No. Just no.

Parallel wires are a good thing in many cases. Why do you think heater wiring is twisted? It's twisted because it keeps every point of wire A in parallel with wire B every step of the way. Look at the heater strings in many amps (like soldano for example) that simply use straight runs of bus wire that are kept parallel to each other. Some wires need to cross, some wires need to be parallel. Stop spreading misinformation.

Increased wire length is another myth. Depending on the specific point in the circuit of course. There's hundreds of feet of wire inside the transformer. Another few inches here and there isn't going to hurt anything unless it's in a specific place that would cause parasitic oscillation or cross-talk. The amp circuit isn't going to suffer from capacitance issues and a loss of high end to the degree an instrument cable would. There are much higher voltages going on inside an amp than in an instrument cable. So I doubt—again—a few extra inches (or even feet) is going to matter.

 

[V2a]

So........sloppy wiring might add to the overall color of tone in a positive way and cheap value capacitors are better than high end ones
hmmmmmm
pretty cool

I have read that when marshall ran out of a part they would use whatever they had on hand so there are variances from amp to amp in the same models like the plexi’s
that was a cool post
thanks~!

Sloppy wiring is usually problematic, but good wiring (electrically, not visually) is not necessarily visual art like you see on Hiwatts. All that straight wire and 90-degree bends increases wire length (bad) and tends to put wires in parallel (often bad).

There are some "rules" for wiring that result in a quiet, stable amp. The wiring usually looks neat but not artistic.

Sigh. No. Just no.

Parallel wires are a good thing in many cases. Why do you think heater wiring is twisted? It's twisted because it keeps every point of wire A in parallel with wire B every step of the way. Look at the heater strings in many amps (like soldano for example) that simply use straight runs of bus wire that are kept parallel to each other. Some wires need to cross, some wires need to be parallel. Stop spreading misinformation.

Increased wire length is another myth. Depending on the specific point in the circuit of course. There's hundreds of feet of wire inside the transformer. Another few inches here and there isn't going to hurt anything unless it's in a specific place that would cause parasitic oscillation or cross-talk. The amp circuit isn't going to suffer from capacitance issues and a loss of high end to the degree an instrument cable would. There are much higher voltages going on inside an amp than in an instrument cable. So I doubt—again—a few extra inches (or even feet) is going to matter.

I guess we'll agree to disagree. I know you like your SLO style builds, and I don't care to suggest you alter your build style. In return, please don't tell people I am spreading misinformation.

Yes you can get away with breaking rules and running wires in parallel or like spaghetti. As Bruce Egnater stated recently about heater wiring, the theory (rules) doesn't always apply in practice. But that certainly doesn't mean that wires can be as long as you want or that they should be run alongside any other wire.

 

[GuitarGuyLP]

For heater wire different rules apply to DC heaters vs AC heaters too, so to say twisted is wrong, or parallel is wrong without context is just wrong.

 

[V2a]

Context matters: true.

There are different 'twist' rules for AC and DC heaters: also true, at least to an extent. Twisting accomplishes a bit more than what is mentioned a few posts earlier. For one, it puts the opposite-direction current flow in parallel. It also makes the electromagnetic fields as small as possible. Finally, it makes for a sturdy wire and thus prevents movement-related problems. SLO-style heater wires are mounted in an extremely sturdy manner, which helps minimize problems (i.e., enables someone to break rules for the sake of visual aesthetics and simplicity - twisting heater wires is no fun). But although the wires are parallel, they are not close and so they are not ideal in terms of reducing the size of the fields. As for DC wiring, you might still benefit from increased sturdiness. At the very least there is no downside to twisting DC heater wires.

 

[Faded Abyss]

depending on the polarity, running wires next to each other, or "parallel" with each other will either combine magnetic fields or cancel magnetic fields. When magnetic fields are combined, heat can occur depending on the amperage. That goes for AC anyways. Twisting wires will also help to cancel magnetic fields. Or a shield "shields" by taking the induction into itself, into ground, rather than the signal wires you wish to keep isolated. Running wires perpendicular will also help to avoid signal interference.

I'm an electrician, not an engineer. So I don't care to know any of this stuff and if I'm wrong, I won't be offended.

 

[Faded Abyss]

Oh and scatter wound pickups and transformers has always been mind boggling to me. These theories are nothing more than accidents that happened to sound good, imo. Please somebody enlighten me

 

[adrianb]

That's a cool little read. I wish it gave more examples from the builders...like if Bogner explained that he tried expensive caps in the Fish and realized changing to cheap caps in XXX value sounded better.

It seems like Bogner didn't use anything cheap in that preamp, judging from what the 1990 NAMM flyer says:

 

[Faded Abyss]

I want experience some bogner magic some how. That would be very awkward if I left the g out of bogner. Mainly because of Chris poland and dirt by aic . I also want to experience the Saldano Magic. Idk how I ever would though.

 

[southpark tube lab]

you try to seperate the power section from the preamp section. you have to conect the heaters in phase. the old marshalls had it right anything you can do helps. tubes are valves you hear it all

 

[barnesjd]

Cool article. My biggest takeaway is the reminder that guitar amplifiers are not for reproduction but for art. Imperfections are necessary.

 

[FourT6and2]

you try to seperate the power section from the preamp section. you have to conect the heaters in phase. the old marshalls had it right anything you can do helps. tubes are valves you hear it all

Truly, words to live by:

"You try to seperate the power section from the preamp section.

you have to conect the hetaers in phase.

the old marshalls had it right anything you can do helps.

tubes are valves you hear it all"