Now, first things, first. Re: Filter cap's effect on tone ???



Rich Koerner wrote:

Newbie Doobie wrote:

ok... thanks all I'll consider replacing the caps.

I am concerned about noise (hum) and am attempting to make all the
right moves to minimize it. I have just been through tweaking my other
amp with all new filter caps (only slightly higher values than
origional), re routing leads (inc. better zoning of grounds), installed
2 100k Rs in the "make do" heater CT and floated the circuit at +35v,
shielding on preamp signal wires, isolating input jack (did the stereo
jack trick), isolated the speaker (bypassed the jack), replaced B+
carbon comps with flameproofs, replaced any coupling or tone caps that
hummed when I waved my finger near, installed mostly all new and
matched tubes, replaced all cathode bypass caps, re-built the PI (and
subbed in a choke as a tail), installed individual bias pots, cleaned
all pots and tube sockets, re-soldered any suspicious contacts,
Installed a 500 ohm 25 w R after the ss rectifier (before the choke),
and to further address the noise issue drew a deep breath and yelled
"GET OUT!" !!!
This amp now sounds better than it ever did but the hum is still
apparent (not bad but still there... ya know) and even though I
thoroughly shielded and star grounded the guitar and use a 2 conductor
guitar cable with full foil shield grounded at one end only....I still
get a reaction in the eletrical sounding buzz when I touch the guitar's
metal parts or touch the amp chassis (the buzz goes away)....WHAT UP !
When I record, am I gonna have ta stick a wire down in my my boot to
quell the buzz ?
(yes I'll risk death to eliminate the noise !) sheesh....

Short of going DC on the heaters (some report difficulties in
regulating and getting all voltages right),

Would it be a benifit to add more B+ filtration ?

STOP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Throw yourself into EMERGENCY *STOP*!!!!!!!!!!!!!!!!!!!!!

Damn,...... you're giving me a headache.

Now, take a deep breath, and throw that soldering iron out the window, and be sure to unplug it
first.

Have 2 beers, a pizza, and relax.

Then, after you've done that, come back and read the rest of my comment.

I'll stop back in here later, and see ya in about a half an hour.


OK, you are going about this, the wrong way, and are getting no where fast.

You have to stop trying to run, before you can walk.

The right way to go about learning the subject of vacuum tube electronice, is to go to the books
written on the subject. The authors of these books come from a scientific background, and are
written as such.

That's where you will learn what the subject is all about.

There are no short cuts in the road of real learning. Where, you become the expert in the subject.

Let me real clear about that.

Find some old high school books on basic vacuum tube electronics, is you best move first. Go to the
town library, and see what they have.

Without knowing what a FREE ELECTRON *IS*, you can't get past square one. Without that knowledge,
it's always going to be a mystery behind the Voodoo. A voodoo, that can kill you, any day in your
life.

But you know it by another name. It's called electricity.

Yep, there is an endless supply of those critters just a sittin inside of that wall socket. Without
them critters, that amp going to make a sound.

But, you're going to load your amp up with them critters, and you think you are going to control
them, by just some guys telling you *** on the internet. Hot damn. I could have saved a lot of
my money I wasted on school, and just hooked up to the internet.


Anyway, you have to know the basics, of what the electronic components are, and what they do in the
vacuum tube circuits. You have to understand how a resistor, capacitor, a coil of wire, etc... all
makes the free electron critters behave.

Without that knowledge, you ain't going to control squat. Them critters will have ya tap dancing
higher than Twinkle Toes and the boys over there on the left side of the room.

You sure don't want to do that. Do ya.

Now, as far as those books go you will find written on thr subject of musical instrument amplifiers,
most were written from the prespective of a musician turn electronics expert. Some of the books are
a joke, and others a little more right than wrong. All of them have technical mistakes that I've
seen.

Don't ask, I won't comment on them. I don't like any of them. They leave out stuff that is
contained written from the scientific approach from years ago. Those thing that are not a
consideration any longer that gives yield to the march of the polished turds that are turned out
from the amp mills the flood the likes of the music stores in todays world.

Common *electronics* industry standards and practice in the design and manufactureering of QUALITY
vacuum tube products is a thing of the past today. Now they lower those standards, no longer apply
them, and it's all in the name of profit. High quality with LONG service life, is not even a
thought today.

Or, could it be, that the amp manufacturers have lost that detailed knowledge from the past, and
that talent pool no longer exists. Maybe, because of the tendency, to be always going after the
short cuts, it has become a lost art.

Now, if I were to address all your questions, hold your hand, get you through this amp, will there
be a next time, to be followed by more next times.

When will you know enough to stand on your own. At what point does that happen.

This you have to figure for yourself.

Are you going to dependent, or independent.



Regards,

Rich Koerner,
Time Electronics.
http://www.timeelect.com

Specialists in Live Sound FOH Engineering,
Music & Studio Production,
Vintage Instruments, and Tube Amplifiers
.