All this guts talk.....here is what a Quality Amp's guts should look like damnit!

[SteinbergerHack]

I'm just coming into this thread, and I really don't get it.

 

Having worked in electronics design and medium-volume manufacturing, I'd like to point out that the vast majority of guitar amp designs suck in terms of manufacturability, consistency, and reliability.

 

Reasons:

 

1) PTP manufacturing is not easily repeatable, and the resulting reliability is extremely dependent on the person actually doing the soldering.

 

2) Most PCB designs use low-grade PCBs that have poor temperature performance, too-thin plating, and poorly sized thru-holes. All of the above lead to reliability issues and inconsistency,

 

3) Many (not all) designs rely on soldered board connections to support such components as input/output jacks, pots, tubes sockets, caps, etc. [The proper way is to retain these parts to the board with mechanical fastening, and use the solder only as an electrical connection point.

 

There are more reasons that have to do with manufacturing techniques, but I won't keep going. Anyone who understands electronic assembly techniques for volume manufacturing knows where I'm going.

 

The good news is that a hand-wired PTP design made by a really good technician is generally better than a cheap PCB job. However, it's FAR more expensive, due to the insane labor content. The bad news is that a PTP design will never be as consistent as a proper PCB design, because the wires will never be in exactly the same place, so there will always be differences in the reponse.

 

The better news is that some of the high-end amp designers (Bogner I'm sure of, and I've heard that a few others have gotten it right) have figured out how to do a proper PCB design. If you use heavier plating, better base material, proper mechanical mounting techniques, and proper hole-sizing and thru-plating, you can get a VERY high-quality product with a PCB. This is still more expensive than a cheap PCB, and taes more time to design. However, in volume, it will end up being less expensive than PTP, and will be more reliable.

[SteinbergerHack]

I've only done a couple of amps (my own personal ones), but I've been in industrial electronics for over 15 years, and hold a number of patents.

 

Frankly, I'd have been fired long ago if I used the designs and layouts used in most off-the-shelf guitar amps.....

[mentoneman]

Originally posted by blargh Two Rock

 

man they've come a long way in regards to layout...

 

the early amp shots looked like guido sneezed a mouthful of spaghetti and licorice into the chassis.

 

 

like a pile of coat hangers it was....but two rock tone is a grail for me.

[SteinbergerHack]

Originally posted by Roccaforte Amps "the vast majority of guitar amp designs suck in terms of manufacturability, consistency, and reliability." That's really not true. [...] I can name many amplifier companies who build very reliable products that are very consistent, I know because I service them. Manufacturability? Who's having trouble? I'm not trying to argue with you, but I just don't agree. Doug

 

OK - I'm looking at the amps (that I've been inside - admittedly a limited sample) vs. what I would be expected to provide in a design that would need to last 20+ years in a harsh environment.

 

I'd bet that 80% or more of the amps on the market today would not consistently pass the 3-axis "shake'n'bake" test - a combination of vibration and thermal cycling. The board and component support used in a lot of these designs just isn't up to snuff, so it can be expected to fail sooner than something that is designed right. Using a component as a support point is a no-no here, and this is something that is far too commonly done in amps with pots and jacks. Single-ended support of heavy components is just a bad idea, but seems to be tolerated in this industry - I don't know why.

 

 

There are a couple of relatively high-profile amp companies who have products on the market today that have suffered from numerous build quality problems; I'd rather not point fingers, but their designs just ain't robust.

 

As far as manufacturability - I'm comparing to the steps that a mid- to high-volume producer uses to reduce fallout and cost. One of the first things you do is get rid of leaded through-hole components wherever possible. Hot-melt is a no-no, as well.

 

Can you build an amp this way? Sure. Is it the most cost-effective and highest-reliability way to do it? No.

 

Make sense?

[AmpliFIRE]

Originally posted by Bob Savage Pfft, I see all kinds of wires that are the wrong color.

 

[SteinbergerHack]

Originally posted by Roccaforte Amps But you said "the vast majority", yet you've only been inside of a few amplifiers. Anyway, take care, I need go now.

 

No, I said it was a 'limited sample'. I haven't been inside everything on the market (haven't looked inside a Diezel or Krank yet), but I've certainly looked over more than a few.

 

Are you disagreeing with any of the specific observations I've described, or are you just trying to say I'm full of it on general principles?

[Nik]

Originally posted by charliedango I posted these in another thread, but since this one started, I might as well repost them here.

 

Now, those are really poorly designed PCBs!

[SteinbergerHack]

Originally posted by Nik Now, those are really poorly designed PCBs!

 

Agreed. Look at the way the filter caps are attached - single-ended radials with no retention other than the leads. This is a vibration failure waiting to happen.

 

Also, none of the point-soldered leads are retained in any manner other than their solder connection (or removable connector). A handful of zip-ties would go a long way here....

 

None of the pots are the type that have separate mechanical mounting tabs.

 

Also, look at the distance between the mounting screws that support the board - there's a lot of flex potential there. Again, this is a vibration/fatigue failure waiting to happen.

 

Sockets? The same.

 

I won't even begin to go into the trace issues - what layout package did this guy use? It looks like an old tape-masked design, done by someone who never took drafting. [There are sometimes reasons to use such strange routings, but I have a hard time believing that this is optimized.

[Negative K3 fan]

Originally posted by Duesentrieb I never knew that there are so many tech experts in this forum - I hope that they all will join the more sophisticated discussions and threads too.

 

haha righton

 

btw. the herbert and the hiwatts are my favorites in a couple of days ill post my own work for you to judge

[Negative K3 fan]

Originally posted by carlygtr56 Looks like a PC inside to me.

 

this makes clear that you dont have enough knowledge of the technical aspects of both tube amplifiers and personal computers to be able to have a valueable opinion about matters like this.

[Negative K3 fan]

Originally posted by LaXu ... unlike many boutique pedals which are basically just painted Hammond boxes.

 

also very true!

[thenakedarab]

And the winner is...

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Originally posted by DeathMonkey Hiwatt, mother{censored}ers, Hiwatt.

 

Was there ever any doubt?

[Nik]

Originally posted by SteinbergerHack I've only done a couple of amps (my own personal ones), but I've been in industrial electronics for over 15 years, and hold a number of patents. Frankly, I'd have been fired long ago if I used the designs and layouts used in most off-the-shelf guitar amps.....

 

+1

from another pro electronics design engineer.

[Pigsinzen]

Originally posted by SKYNETRP One more thing....if you took the best amp out there today built with PCB, and rewired them PTP (if that is possible), it would sound even better.

Debatable.

[SteinbergerHack]

Originally posted by Roccaforte Amps Thanks. Here's the channel switching Rockie;

 

That looks like a pretty good PTP job. All the wiring is dressed properly, and none of the chassis-mount components are used as support for the board. There also appears to be pretty good separation between signal and power (read: noise) lines.

 

It's certainly far better than the average product out there today...

[FourT6and2]

This is an amp I built two years ago for a project in one of my physics classes.

 

The wires could have been routed much better and made shorter leads....but for a first time effort with absolutely no knowledge of electronics...it went well.

 

It sounds really good though. Especially with a little delay.

 

http://acapella.harmony-central.com/forums/attachment.php?s=&postid=14195524

 

http://acapella.harmony-central.com/forums/attachment.php?s=&postid=14193928

[Negative K3 fan]

Originally posted by FourT6and2 This is an amp I built two years ago for a project in one of my physics classes. The wires could have been routed much better and made shorter leads....but for a first time effort with absolutely no knowledge of electronics...it went well. It sounds really good though. Especially with a little delay. http://acapella.harmony-central.com/forums/attachment.php?s=&postid=14195524 http://acapella.harmony-central.com/forums/attachment.php?s=&postid=14193928

 

cool my first amp was for a physics project last year too, did you build more afterwards?

[FourT6and2]

Originally posted by Negative K3 fan cool my first amp was for a physics project last year too, did you build more afterwards?

 

Not yet.

 

I really want to though. Maybe something that does high-gain, like a Plexi clone or something.

[SteinbergerHack]

Originally posted by Roccaforte Amps Since you're asking, don't get offended. The answer is both. You have no experience with guitar amplifier manufacturing, repairing ect.... yet you threw out a comment like you do. To say "the vast majority" means to me "most", correct? If I'm right about your statement, and also right about your experience with guitar amplification, you really shouldn't be making comments like this.

 

I'll go back to my initial statement. I've pointed out design deficiencies that ARE present in most current amp designs. Do you have a technical response to this, or do you want to continue to attack me personally?

 

Frankly, I find it a bit immature to question whether someone who has executed multi-processing designs with a 20-year design life for harsh conditions can make a reasonable judgement as to the design quality of a much lower-tech item. Bluntly, the designs I am responsible for can get people killed if they fail, so I think I have a clue about electronics design.

 

How many designs have you completed and rolled into actual factory production? At what volume? How many design FEMAs have you conducted? What's your average first-pass yield? Field failure rate at 5 years? What level of six-sigma certification have you achieved?

 

As far as passing table shaking, and oven testing, I can name a million consumer products we use daily that wouldn't pass those types of testing. They really don't need to.

 

Sure an iPod, desktop PC, or home theater receiver doesn't need to. However, the intended use of a guitar amp is far more like an industrial product than most consumer items. They undergo significant vibration (sitting on a 4x12 cab at 120dB DOES create some vibration). They get transported regularly, with all the shock loading that this entails. They get subjected to and operated in uncontrolled temperatures - ever run an outdoor gig in August? The expected design life of guitar amps is far higher than a PC or plasma TV; those products are intentionally designed to fail at 5-7 years because they are intended to be disposable. I, for one, don't like to see amps designed at this level.

 

The gut shots you showed appear to have a very high level of craftsmanship - I applaud you for that. However, craftsmanship and proper DFX/DFM are NOT the same thing.

[NITEFLY182]

Why dont you just tell us what youve designed and made at high volumes. I dont understand the ambiguity of your statements, it isnt helping your credibility at all.

[SteinbergerHack]

Originally posted by NITEFLY182 Why dont you just tell us what youve designed and made at high volumes. I dont understand the ambiguity of your statements, it isnt helping your credibility at all.

 

I can't, due to requirements from my company. My industry is really small, and identifying what I work on would effectively identify myself and my company, thus making everything I say on this board a reflection on my employer.

 

I've already been through this on another board and have been warned no to allow any linkages back to my day gig, under threat of termination.

 

Sound stupid? Yes, but I can't do anything about it until I change jobs or retire.

 

 

As for my credibility, I don't see where that's at stake. Noone has yet refuted ANY of the observations I've made.

 

 

 

BTW, Doug, if you're limiting your statements to tube amps, I think I come a lot closer to agreeing with you.

 

To put a cap on it, when I said vast majority, I was including EVERYTHING on the market, not just the good stuff. If you look at the low-end products out there, most of which are SS, I'll stand by my statement. I don't think that these products are designed to stand up to touring, and they are clearly not designed by the 'A-team'.

 

Roccaforte Amps Now, if you want to talk about solid state guitar amplifiers, I'm with you 100%. A couple of the big longtime survivors who build both tube and SS amplifiers way under design their SS amps. Using 1watt zener diodes that blow where a 5watt will last. Why I don't work on crap like that anymore.

 

 

I have a hybrid head from one of the majors that is flat horrible in its design. Sounds good, but it's pretty atrocious inside. I burned one up within 2 years of steady gigging (multiple failures); bought another and keep it at home for recording and practice now.

 

There are too many tube guitar amplifiers being built as we speak that will last many years of touring, and vibrations. I know, I build them, and work on many others.

 

Yes, there are some very good designs. I think the Bogners are good - I have an XTC, and I expect it to work well for a long time. Frankly, yours looks pretty good (if a bit labor-intensive). There is also some pretty poorly built junk out there; it may sound good, but that doesn't mean it will last.

 

I can agree, though, that if you limit the discussion to tube amps, the overall quality gets much higher. This is really the high-end of the market, so the companies that do both tend to put their best stuff in the tube models.

[Negative K3 fan]

Originally posted by FourT6and2 Not yet. I really want to though. Maybe something that does high-gain, like a Plexi clone or something.

 

im building my 4th right now... but i wouldnt call a plexi hi gain cehck out lots of schematics at schematicheaven.com, 18watt.com and ax84.com and make a decision!

[FourT6and2]

Well, by "high gain" I meant higher gain than the champ clone I built.

 

I'm looking at the High Octane from ax84. The Silvatone version looks and sounds very nice over at www.silvatone.bravepages.com

 

Only problem is I don't have a drill press to make a chassis or make holes in a turret board.

 

There's a nice version as well at www.ceriatone.com but they preassemble the board for you...and that takes all the fun out of it. And I don't like the layout as much as the Silvatone version.

[Nik]

Originally posted by FourT6and2 Well, by "high gain" I meant higher gain than the champ clone I built. I'm looking at the High Octane from ax84. The Silvatone version looks and sounds very nice over at www.silvatone.bravepages.com Only problem is I don't have a drill press to make a chassis or make holes in a turret board. There's a nice version as well at www.ceriatone.com but they preassemble the board for you...and that takes all the fun out of it. And I don't like the layout as much as the Silvatone version.

 

Well, start by making your own drill press. That's real boutique.

[FourT6and2]

Originally posted by Nik Well, start by making your own drill press. That's real boutique.

 

Should I make my own caps, resisters, pots, switches, wire, transormers, etc... too?

 

That's real boutique right there.