Higher quality components

[Koreth]

Greetings. I was recommended here by members of The Boogie Board. This is my first post here, so I hope I've put it in the right section.

I have a couple of amps, a Mesa/Boogie Nomad and a Peavey ValveKing. What would happen if I were to take my Nomad, Valve King, or perhaps some other amplifier, and go through and replace all of the components with higher quality ones of the same value but tighter tolerances? For example replacing, all the 330K 1/4 watt 5% +/- tolerance carbon film resistors with a 330k 1/4W 1% metal film resistor or something with an even tighter tolerance (assuming it exists). Would this cause a bad effect - taking away a mojo caused by slight variation in components - making the amp too tight, sterile, lifeless and too hi-fi? Would it have an good effect - giving a warm delicious clarity to everything - making the amp that much more awesome? Or would it be an expensive way to have no effect other than making yourself feel good that you now have a higher quality amp than before?

Would the same effects carry over to solid state amps and stomp boxes as well?

[stokes]

I think it would be an effort in futility.The point of modding an amp is to arrive at something concrete.Is there something about the amps you dont like or want to improve?If so,there are easier,less expensive,more direct ways to get there.With your suggestion you will go thru a lot of work and expense to possibly make no difference,or if there is some sonic change,you wont even know for sure which change caused it.You could possibly end up with an amp with better parts and one bad solder joint that sounds much worse,again having to go thru the entire amp finding the problem.In my opinion its kinda like a case of fixing what aint broken,not a good idea.

[Enzo]

A 5% tolerance is not much. And just because they are 5% parts, that doen;t mean they are all over that range anyway. Personally - and others may disagree - I think it is more likely you will cause a problem changing out every resistor in there, than helping at all.

You will find the camps gathered around carbon comp resistors versus carbon film versus metal film. No I won;t take sides there. But all of those can be dead on accurate and still offer potential sonic differences.

You will find pots are notoriously inaccurate. If your 250k volume pot is part of a larger voltage divider circuit, then if it really measures 180k or 310k, that WILL make a difference in the amps gain or level.

I won;t get into brand preferences in caps either, but those preferences are religiously guarded as well. And likely would make more difference than resistor values. There are silver-mica caps, ceramic caps, film caps of various sorts. Not to mention the electrolytics du jur.

SO I think the project as described is not worth the trouble. If you wanted to explore some premium caps or something, maybe I'd like that better. Because I don't think in current production amps that resistors wandering off value is much of an issue any more.

We'll see if this position has any support or not.

[Koreth]

No, there isn't any particular change I'm looking to make or any one particular thing I dislike about the amp that's causing me to think about such a project. Such a project idea was more one of curiosity. My nerd is showing - it's in my nature to want to take things apart to find out how they work and possibly make them better. I figured it would be good to get input from someone who knew what they were talking about/doing before taking the idea beyond the "hey, I wonder..." stage.

There is a change I'd like to make to my Nomad, which involves lowering some resistor values to improve the reverb on the distortion channels. That mod clearly shows what needs to change and where, and states what to expect from it. From the idea that idea that changing the resistors could improve the reverb came the idea that perhaps other other changes could bring about other improvements. Maybe if I used higher quality or tighter tollerance the reverb would be even better!. Maybe If I replaced every component in the whole amp...yeah, that one kinda snowballed there.

But that's a ways down the road. I've only recently got to a point where I feel confident enough with my soldering ability to try to mod my boss distortion pedal, which I never really liked. Tube amps, being much more complex and requiring greater electronics skill are a ways out. It is good to know that the project idea isn't likely to be a practical one though.

[defaced]

Complexity is relative. To me, I'd rather build a high gain amp than play with stop boxes. That's why my first real amp build was/is cloning a 4 gain stage amp with AC coupled cathode followers after the PI to drive the 4 x KT-88 output section. So set aside what the device is (except for when you think about sticking your hand inside the amp while the power is on or the filter caps are charged) and remember that they're just parts soldered to a PCB.

To me, what it sounds like you're really interested in doing is seeing how different kinds of parts of the same value affect the sound of your amp. My approach to this, and I'm an inexperienced builder so this may not actually work but it's just my notion, is to play around part types in the first gain stage of the amp.

Just like changing tube brands in the V1 slot, because the sound from V1 is amplified throughout the rest of the amp, any small changes here will make a bigger change in the sound than mods done elsewhere in the amp. Any tests you want to do will run you no more than about 20 bucks in parts. Since there's a grand total of about 3 to 6 parts that you can play with in most common V1 slots, is will be easy to track down any problems should they arise. This is in effect taking what Enzo was giving as examples and seeing what your thoughts are on the topic(s). Who knows, you might like the sound of the cheapest Rat Shack parts you can find. Part quality and tonal quality aren't necessarily linked.

[stokes]

Like Mike said,"complexity is relative",I also find tube amps to be almost second nature,but solid state or stomp boxes arent my cup of tea.Depends on how you look at a tube amp also.To me,if you can understand whats going on in a simple Champ or like circuit,every other tube amp is pretty much the same basic circuit,just add a gain stage or reverb,tremolo and you have a "complex" Champ.What constitutes quality parts can vary from person to person,we all have our preferences,and from my own experience I can give you this example.I came into quite a few Astron paper in oil caps,generally considered "high quality" caps.The first amp I tried them in they sounded great,so I started replacing all the coupling caps in the rest of my amps and was very dissapointed in the results,I only left them in two of the 11 amps I tried them in,the rest of the amps sounded better with the "lower quality" Russian military caps I got from a guy in Lithuania.I did end up getting a decent price for most of those Astrons from a Hi-Fi guy I know.So I gotta agree with Enzo,it aint necessarily worth it.Any amp can be tweaked to taste and improved to a particular users taste,but to just change everything across the board aint the way to go.

[Froumy]

Well... Some of those things could be improvements, some not. If they are all on PC boards you could damage some traces while you're at it. The biggest "improvement" in tone is likely to come from speakers, then transformer, then components. (Don't forget glass)

I changed one box cap out in a JCM800 and I swear it sounded better. Conversely, use an Allen Bradley as a plate resistor, and there are those that say the tone looses dimension, even though they love them in other places. Some love Sozo caps in a vintage build but don't like them in a modern high gain build.

If you were familiar with each component, and how it relates your opinion of great tone, it might be worth it. Otherwise, you might be left off worse than you started, with a hacked up PC board. Speakers and Trannies can offer quite a difference, but they're not cheap to just start swapping out. I would personally save the $$$ for a new build. Good luck.

[6267]

All the crappy parts is what made vintage amps each kind of unique even from the same year, line etc. That being said, I've learned to despise the carbon comp resistor, I live in a very humid climate and they like to hiss. Ceramic caps, on the other hand *can* sound amazing. I had a Motorola "High-Fidelity" Cabinet which was p-p 6bm8, all ceramic caps. Damndest sounding vocals I've ever heard, even from mp3s. It could make your skin crawl with music that's just kinda blah on my sony solid state. It's not the parts that make the amp, it's the design and how the parts are used. You'll get much better improvements by examining the design and making improvements based on that.

[tubeswell]

+ what all the others have said.

Say you changed all your parts to be 1% tolerant. Next time you changed a tube it would throw everything out a little bit anyway - due to the variability between tubes. What's more, as the tubes age with use, they change (like we all change with age ) - which changes everything slightly (or sometimes dramatically at the end of tube life) as do all the other parts in the amp anyhow. The heat changes everything continually and eventually wears everything out. So what the point? The universe is chaotic. You can only approximate a constant state under ideal conditions. Wasting your life away trying to achieve stasis is a futile anal pursuit. So go with the ebb and flow that aging brings. On the other hand if you want to change everything in your amp, why pay attention to what others have to say?

[Koreth]

So, what you're saying is that it's better to understand what change in sound/feel/response/etc. you want to make and understand how the various parts of the circuit interact with each other to produce a certain sound/feel/response/etc. and make changes accordingly, rather than just trying to throw parts at an amp in a hope for better-ness? That does sound like a more practical way of going about things.

[6267]

Here are some links so you can get a sense of how tube circuits work and where you might want to change stuff etc:

http://www.angelfire.com/electronic/funwithtubes/
http://www.freewebs.com/valvewizard/
http://www.tubecad.com/articles_2003..._Amplifier.pdf

There's tons more, but that's a bit of reading anyway. Sometimes it's nice to get some tube-based junk amp from the dump or recycle center etc. and use it as an experiment. Make sure it has a power transformer and an output transformer, some cheap radios ran right off the socket and are firetrap electrocution hazards.This way if you melt the entire thing into a solid lump, you can just sell it for scrap metal and shed no tears. You may even end up with a pretty damn nice sounding (if ugly) amp!

[Froumy]

Exactly what I'm saying. 6267 hates carbon comps and likes ceramics, where other guys are exactly the opposite. Changing components will affect tone, the problem is that we all may have a different idea of what is an improvement. To furthur complicate things, the same component that improved the tone in one place may do just the opposite in another. Then add mods to taste. And there you have it in a nutshell. That explains why so many of us are sniffing solder every night, and why some clones are far better than others. And hell yeah, the right components in the right spot will offer improvement.

As far as tolerences go. Some of those vintage amps we play sound like they do BECAUSE the values have drifted or were off from the start. Sometimes for the worse, sometimes for something wonderful. Although there is a general consensus on what parts are good, experimentation is the only way to seperate hype from reality, and how it relates to your taste. I personally, wouldn't want to be developing those opinions on a PC board.....

[6267]

Right on Froumy...same deal with the 59 Bassman and the original Marshall. Same circuit, different parts with different tolerances. I'd agree with figuring it out on a point-to-point build instead of a PCB though, it gets hard to keep the traces and pads intact after trying 5 or 6 different values . $20 in the right junk/antique shop might get you transformers, a chassis, possibly working tubes, and maybe a speaker or two. The preamp tubes at least are usually still good.

[Koreth]

As far as tolerences go. Some of those vintage amps we play sound like they do BECAUSE the values have drifted or were off from the start. Sometimes for the worse, sometimes for something wonderful. Although there is a general consensus on what parts are good, experimentation is the only way to seperate hype from reality, and how it relates to your taste. I personally, wouldn't want to be developing those opinions on a PC board.....

Right on Froumy...same deal with the 59 Bassman and the original Marshall. Same circuit, different parts with different tolerances. I'd agree with figuring it out on a point-to-point build instead of a PCB though, it gets hard to keep the traces and pads intact after trying 5 or 6 different values .

If I'm understanding both of you correctly, you're talking about lifting pads or lifting traces on a PCB, which I've heard can happen if one is careless with soldering if the PCB is cheaply constructed. I'm not quite sure what that is, but I'm assuming it's a bad thing for the integrity of the PCB and the circuit. I thought the whole point of PCBs was durability and consistency -- aren't there less cheap PCB construction techniques that aren't susceptible to the lifting of pads and traces? With my Chinese-built Peavey, I can understand that being a concern, but my Mesa I would think it would be built much tougher than a Chinese Peavey.

I'm opening up a whole new can of worms, aren't I?

[BK-Amps]

+1 what 6267 said.

Mesa uses relatively inexpensive PCBs which makes experimentaiton a nightmare. Small traces and and light pads tend to lift just by looking at them. If you dare mod the amp (and I dare all the time!), heat the part lead and don't touch the board with your iron. It takes longer to remove the part, but minimizes the chance of lifting the pad. If you do happen to lift a pad or trace just take an exacto knife and scrape away the solder mask to reveal the trace that is still adhered to the board and solder the component there. Take you glue gun and squirt a little on the part for stability.

BK