first amp, weird stuff

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this is the first amplifier i've ever built.
not really good at it yet.
but i suppose if i'm going to learn how to do it,
i need to learn how to do it

so,
i'm building an amp that models a 5E3's electronics.
Why?
because it's a fender deluxe.
(and because someone had a kit with all the parts,
and it seemed cheaper, and i'm broke, heh)

got a hammond 16x8x2 blank chassis from mouser,
got a ruler, protractor, bought some hole saw bits,
got all excited and stuff

got the kit from triode electronics,
they included a pre-drilled/tagged turret board,
or whatever it's called heh
i put the components onto it,
and went ahead and measured, marked,
and layed out my chassis while i waited for my
bits, screws, bolts, spacers, etc to arrive in the mail

got my bits, got it drilled,
turned out looking alot better than i thought it would
(not that it's real sexy or anything),
but i was *so* excited to see the chassis finished, heh,
i was all like, "i did that hahaha"

so i mounted my transfomers, sockets, jacks, pots, etc,
started to look about wiring my stuff to the board.
WELLL,
first thing weird was,
i didn't exactly take into consideration what *side*
of the board mostly dealt with tubes,
and which side mostly dealt with jacks/pots.
and so, my 50/50 chance of getting lucky
didn't get me lucky.

i *could* have turned the board around,
but then my power stage would have been on the
opposite end of the chassis as my PT.
(not good),
so it was either, Mount my board upside Down,
or run my connections to my chassis compents
ACROSS the width of the board, to the
opposite side of the chassis.
(oops)

i decide to run the wires all the way across the board
(and through each other),
but, being somewhat embarassed about the whole thing,
put the wiring mostly underneath the board.
this way, it hides the fact that the wires are coming from
all the way across from the other side of the board.
and nobody knows.
by this point, i'd probably already made some
bad turns for the worst for this poor amp.

i'm wasn't giving up though.
i was becoming *SO* eager to hear it sing,
i just wanted to know if i could get it to work at all.
so i oriented the board the way i figured best,
wired everything up (and unfortunately rather quickly,
yet remained careful to watch how well my points were soldered, etc)
i used a "star grounding" system,
because i'm naive, and thought i was doing something smart.

plugged the thing in, and my heart was racing.
turned it on, and the light came on.
then the heaters turned amber.
then my baby's first cry faded in,
a subtle, but aggravating hum.

i plugged my guitar in,
turned the volume up,
AND.... i turn into a downhearted man

the volume was almost at Headphone-level,
even with the volume all the way up,
but even through the quiet output signal,
i could hear that the guitar was distorted.
as distorted as it Should have sounded with the
volume pot turned all the way up.

i stopped working on it for about 4 hours, then
couldn't take it any longer,
i went mad and started studying/debugging it,
losing sleep, becoming obsessed,
i felt like frankenstein

i first discovered the volume problem.

i had pins 6 and 7 reversed on my 12AX7,
my inverter.
i put them the way they Should have been,
and it SANG, ohhh, it sang loud as thunder.

still had bad hum, though.

the grid on my second preamp stage was
running over top of the heater wiring in between
both of the 9-pin tubes,
and those heater tubes were against the chassis.
i moved the grid wire against the chassis,
and the heater wires over top of them, through the air,
and it took 90% of my hum away.

i could crank it and the tone rocked.
but only through my first set of inputs.
(the ones that don't end up hooking so quickly to the
tone stack BEFORE getting to the
second preamp)
i dunno if that's bright or normal right now

anyway.
it was the only set of inputs that worked,
the SECOND set of inputs,
Oh, man.
it was Awful.
if i turned up the volume, it would start WAILING,
Howling, Putting, Whistling, Oscillating,
it's almost like i built an "otherside receiver" that
picks up voices from the dead

Also, my tone knob would do similar stuff,
even to my First set of inputs,
especially turned to extremes.

i went through all of this nonsense,
and found out that my pots were hooked up
Ridiculously Wrong,
after going through a couple schematics,
i realized that the pots didn't hook up the same,
either that or i'm interpreting one of them wrong,
whatever.
THEN,
i found out that the "Switch" on TWO of my pots was
*NOT* touching the hot pin when unplugged.
i bent them towards the hot at their base with a srewdriver,
got them to switch, but very lightly.
but they Do make a contact.

i got the jacks to work *supposedly* better,
at least, i think so.
but i can't turn my volume pot up All the Way,
or it gets "hissy" and the tone sounds Awful.
the tone knob still putters/farts/squeals when you
turn it to either extreme i think.
the Second set of inputs just doesn't want to work right,
i can hardly mess with any of my jacks/knobs.

i've tried unhooking all of them, trying different ideas,
i dunno

i figure, i'll just break it all back down,
and start it again from scratch.
remove the star ground,
redo my whole jacks/pots deal.
maybe even run wires from the TOP of my board,
so that i can see them.

i listened to my guitar through the first input one last time.
it didn't sound as good as it did when i first heard it.
it was now *hissy* when turned up with any good volume,
with some sort of strange white noise,
enough to disappoint me.

i'm sad you guys,
i'm so sad.

if you've got a fast internet connection,
and a computer that was built after 2005,
you might be able avoid disastrous catastrophe if you
click on this link and look at some hi-res pics i took
of the amp BEFORE i started to mess with my original wiring.
i took the pictures high-res so that my Wiring would be visible.
so, you can see how my jacks are *ALL* goofed up still,
etc.
also, like as i said earlier,
most of my wiring to/from the board/chassis is
UNDERneath the board, heh


i dunno

i'm ashamed/disappointed/uneasy/desperate


"Help me, Music Electronics Forum....
You're my Only Hope...."

[cminor9]

Dude...are you like, a frustrated poet? That is the most unique post I have ever seen here. Anyhow...

Get a new chassis. Drill it right this time. I made the same mistake on my first amp (well, not the exact same mistake, but close enough). Now you have learned the hard way to plan your chassis better. Like I said, I made that mistake too.

After you get your new chassis all installed, get a few copies of the chassis layout for the 5E3. Check, double, and triple check EACH connection. Mark it off on the layout diagram ONLY after you are sure it's correct.

Looks like your output jacks are right against the tone stack. That might be a problem. I would recommend following the chassis layout exactly. I made a head as opposed to a combo, so I did have to change things just a bit. But if you put the wrong things together, then you are asking for hum, buzz, hiss, and oscillation.

You said it was your first amp and I figured I'd see a mess. Your lead dress is actually quite good. You might have some bad solder joints too, but none that I can detect from the pic.

While you are ordering that new chassis (I'd recommend tubesandmore.com) here are a few things I will recommend you purchase:
2 orange drop caps, .022 µF. You'll most certainly want to replace your coupling caps with those (the first two orange caps in the circuit.)
4 68k metal film resistors, 2 1M metal film resistors, a 1500 ohm and an 820 ohm metal film resistor. Replace the input stoppers and 1M bright resistors, and the cathode resistors on the preamp and PI. This will cut a lot of hiss. I actually got a kit from triode electronics too and I thought it was really good (they only gave me one color of wire ) . The 5E3 circuit is too bassy for humbuckers and the carbon comp resistors are nice ofr certain things but add a lot of hiss when used on the preamp. I made those changes and was very happy. While you are ordering a chassis, that's another $8 or so worth of parts that I don't think you'll regret. If nothing else, get the caps. There, some unsolicited advice for you.

[tubeswell]

Can you post any photos of your build?

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hehaha,
thanks for the replies,

Dude...are you like, a frustrated poet? That is the most unique post I have ever seen here. Anyhow...

heha,
spoken language, phonetic inflection, syllable accents, typed language,
internetz, forumz,
and my communication breakdown and me

honestly, though, i don't mean to aggravate people with
making them have to read my strange,
screwed up way of talking on these things.

i *hate* how typed text RIPS something out of my speech, tho,
i need that spoken word..mojo in there..or something
like uh, for Amps,
(and i know this sounds corny),
but, if speaking to someone is like Tubes,
typed text is like solid state PC soundcards.
or something.

Over the Years of typing through this stuff,
i've *slowly*, somehow, developed some eccentric means of
more efficiently pushing my attitude/mood across when i
talk to people over these machines. (for Me)
[i'm also insane, i have no idea what i'm talking about right now]

i didn't Mean to start doing it, necessarily.
i mean, i don't Think i did..

heh,
i write songs alot,
you know, one of "those guys" who "writes songs alot", heha

but i do it alot, and since i was Young.

now, if i saw somebody else saying this, i would laugh, and be like,
"heha, jesus, ok" and go read something else immediately, but
maybe my habbit of structuring ideas into Stanzas,
i mean, i sometimes entertain the idea that maybe it's
come across when i write to people on forums, etc.
like,
i don't want them to have to "work" to dissect my ideas,
or even phonetics hahahah

whatever..

i guess, if you even jokingly Saw It as Poetry,
i'm going to jokingly take that as a
strange but flattering compliment
(people have mentioned something similar Before)

*/end useless, space-wasting rant*


your Priceless Advice, heh:
unsolicitely Speak to me in the Moonlight, man

you make alot of sense to me

as much as it makes me feel nauseous at first,
i need to scrap my firstborn abomination

in Today's Times, i suppose these tube instruments are all about
**Good Sound**, in the First place (unless you're a student,
or you're working with cooking people with high freq radiation, etc),
Why Comprimise that for Any Reason,
Looks, Shame, Pride, Time, Money (time is money), Work,

i need to 'fess up and Accept that i'm copying
Someone Else's Design,
Trust their wise, archaic judgement, and
build my design around the design of the design i'm using.

it makes sense that that should most likely sound close to the Best.

i can't be making blind, confident leaps into much originality yet.
although, i must say,
i might learn faster by screwing up so much
but seriously who has the money for that.
minimum wage is one gallon of gas per hour
(no offense if you have the money for that)

i'm gonna buy that second chassis

and i'm gonna buy the components you recommended,
then while they're coming in the mail i'm going to open my books up again,
read what you typed about them, and figure out why i'm ordering them hahahhaha
(i'm very humble)
[nobody take advantage, plz]

Can you post any photos of your build?

well uh,
i think this place uses phpBB, so,
i *know* how to post an image, but uh,
the only ones i've got so far are the raw, high-res pics that came
directly from my camera,
and they are much like trying to study archived microfilm articles.

and photoshop is like, all the way over on my start menu right now

i would love to show you, though.

i'm gonna try to get some rest tonight,
and tomorrow evening i'll pull out the ol' 'shop and
size some choice ones down for the forum,
or at least down to the size of my car



lmao, i feel entirely too good tonight,
but what's up is that i have manic depression,
and the meds honestly only do *so* much,
please disregard my curious, out-of-place-yet-entertaining-for-me elation.
I Assure You,
it will Entirely disappear very soon


peace

[dai h.]

didn't look that close but I'd say the layout and lead dress look to be problematic. It looks like the output transformer is on one side of the chassis, and while this can work if done correctly it looks like the worst possible situation in your chassis with the leads out of the output tranny in super close proximity to the preamp section, input area and associated wiring. If you ever put your pickup and brought it really close to your speaker(s) and got nasty squealing, well that is the sort of situation inside the amp but worse since with a gtr. you can back away from the speaker (and revert to a stable state) but with the amp wiring it doesn't move, so leads to a situation of permanent instability unless dealt with. Maybe you can move the output transformer more towards the middle close to the PT if this isn't a problem with the chassis (weight, structure) as well as the output jacks so the circuit is more physically in order--1,2,3,4,5...

the grounding could be part of the problem as well.

[cminor9]

"as much as it makes me feel nauseous at first,
i need to scrap my firstborn abomination"

I wouldn't totally scrap it, your board looks great. Just reroute things a bit. Another poster pointed out something you won't learn from the Fender layout: move your OT more toward the PT and away from the preamp.

You could use that chassis if money is tight, it just will have extra holes and won't look pretty. Also, if you are trying to save money then just buying the new caps will make the biggest difference. Search some other threads here that complain about the 5E3 being to bassy. Also, before you go ordering parts and especially a chassis, think. When I built my first amp I wasted so much money panic ordering parts I thought I'd need. Don't do that. Collect your thoughts and plan before breaking anything down or building back up. You'll get the amp working soon enough if you really want to, but being hasty will just make you sorry.

Another $0.02 for ya.

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ok cool

If you ever put your pickup and brought it really close to your speaker(s) and got nasty squealing, well that is the sort of situation inside the amp but worse since with a gtr. you can back away from the speaker (and revert to a stable state) but with the amp wiring it doesn't move, so leads to a situation of permanent instability unless dealt with.

Wow, Excellent explanation, man, great stuff

Maybe you can move the output transformer more towards the middle close to the PT if this isn't a problem with the chassis (weight, structure) as well as the output jacks so the circuit is more physically in order--1,2,3,4,5...

Another poster pointed out something you won't learn from the Fender layout: move your OT more toward the PT and away from the preamp.

gotcha, makes sense

so, okay,
aside from the obvious "controls/tubes on wrong sides" problem,
OT definitely has to move,
it's wiring *needs* get away from over my preamp wiring.

so, the choices basically are:
a. move the OT somewhere close to the center of the chassis,
b. move the OT and PT beside each other on one end,
making sure to orient them so that their flux couples the least,
c. completely revamp my chassis design onto a new chassis and
rethink the whole arrangement.

the reason moving the OT to the center makes me apprehensive,
is because these hammond chasses available,
i really didn't understand how thick .004" was,
but i got this thing, and honestly, it's flimsy as all hell,
looking closely, i think my PT is beggining to
make my chassis top Sag downward on the innermost side,
despite it's close proximity to three edges.

i can imagine an OT in the middle turning yuck

either i need to find a thicker-walled chassis,
move my OT over on the side where my PT is
(don't wanna do that, really)
or put some sort of ingenious support system underneath the
mid-section of the chassis for the OT

the underside support thing sounds tough with this amp,
the way that board runs down the chassis length

but i think i like the OT-in-the-middle choice the Best


and yeh, my jacks/pots need to arrange better for the circuit path

i think i definitely need to get a new chassis,
maybe i can also find one that's thick enough to
naturally support an output transformer in the middle,
and if not, well,
i can think about ideas for supporting it.


**** OH YEH

by the Way.

have you guys ever heard of hearing your guitar from

**INSIDE YOUR AMP**


i swear it, you can hear it,
with the volume cranked,
it sounds like i've got a pair of headphones
lying on the floor somewhere, hooked up

it's coming from somewhere around my output transformer,
but i can't seem to pin it, heha
it was tripping me out, i've never heard of anything like that


OH and thanks for all the help!!!

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ALLLLright

I Kept my tagboard,
and i replaced all the early stage resistors to metal film,
like you Suggested cminor9.
the reason i didn't replace the caps was because i'm a
stubborn noobie sort-of-type i suppose,
and i wanted to hear if i liked how it passed frequencies First,
then i would be able to realize what i would me Missing, or at least
Know how i was Helping, if i were to change the caps.

anyway,

I got a Completely New Chassis, Mostly because of where my
OT should be, according to you guys,
which is sorta in the middle kinda,
so,
i got a chassis that was alot Thicker so it won't Sag under the OT's weight.
(but the only chassis i could seem to Find at that thickness was
also shorter in length [but greater in height] than my previous chassis)

Also,
I put the order of my stages in the *opposite* direction, haha,
so that they lined up with with the tagboard Right-Side-Up.

I took my "not good" star-ground idea, and chucked it,
grounded the unit more according to fender's layout,


THIS THING ROCKS
hahahah

my buddy's got a 4x10, 200watt, 8ohm "Line 6" cabinet,
and This Thing is a Nuke, Cranked,
i had to hold my ears in that room.
I was so pleased.

and Practically ZERO hum,

it felt so awesome

here are some pics of it,
my first "working" amplifier
(and Yeah, I know,
sorta bad layout,
those preamp tubes will *NOT* be so close to the 6V6's next time, just for good measure,
and that 5Y3 could have been farther behind the PT away from them, Too)

http://timfelix.org/misc/5e3/v1.0


This Would Not Have Happened without your priceless advice


and OHHHhh yeah,
i have a question for you guys

at First,
i had my Heater Supply's center tap grounded,
but almost DESTROYED my PT,
it must have reached 300F before i smelled it and turned things off.
i'm *LUCKY* it didn't bite the dust.
So,
I disconnected the center tap, and just left it unhooked,
and grounded One Side of my heater supply,
and it worked Fine, my transformer was fine

i can't make sense of why i cooked my PT by grounding my heater supply's
center tap, in the First place,
but especially how it was Fine when i grounded a Side of it.

*curious*

[cminor9]

I like the look of your amp. It's definitely got a nice funky look to it. Glad to hear it sounds so good! That little guy is a real burner, isn't it? Still rocking the heck out of mine too. Those are Tung-Sols you have in there? Are those NOS or reissues?

In short, I don't know why grounding the center tap of the heater winding would cause trouble. Looked at your pic, and it looks like the green wire with the yellow stripe is grounded. Mine is grounded. Maybe check the voltage on the three wires against ground to make sure they are tagged right? Some power transformers have no center tap, so you just run the heaters to ground at the end of the run and put I think a 100 ohm resistor between the heater and ground. If you look for "lifting heater supply" you should find this explained. I think you just found the other way to run a heater supply. If you ever have hum problems, you might want to try putting a 100ohm resistor at the end of the heater run before you go to ground.