So, how did you feel the first time you fired up an amp and it worked perfectly?

[G._Hoffman]

I've been rebuilding my first amp (a GDS 18 Watt kit that I had, erm, modified over the last few years).  I guess I must be done, because I just fired it up and everything seems to be working, but I'm a bit baffled.  Every time I've done this before, I had to spend days or even weeks, but at least hours, trouble shooting everything.  This time?  It just works. 

I'm confused. 


I'm also trying to figure out with the rest of my vacation, which I took with the express purpose of finishing and then fixing my amp (because, of course, I was going to have to fix what I had messed up!)  Now what am I going to do with myself!  I guess I'll have to go to a museum or something.

But under it all, I guess I'd have to say I'm pretty happy.  Much love, by the way, to Kevin O'Connor and Merlin Blencowe, since most of what I did in here came out of their books.

I'll try to post some pictures, if I can get a camera tonight.  Its a little weird, but I think its cool!  Oh, and that local NFB on the overdrive stage I asked about a month ago?  Not what I was expecting!

 



Gabriel

[jjasilli]

Deaf.  It was so dead quiet I thought it wasn't working.  So I dimed it.  Still dead quiet.  Struck a chord.  Wrong move!

[G._Hoffman]

I guess its a good thing this one is only 18 watts!


Gabriel

[Iannone]

You've been around the forum long enough to have heard PRR's immortal advice, "Plan to be wrong about something."  This time, you were wrong about planning to be wrong, showing once again how truly wise PRR is.  On the bright side, you now have more time to play your new amp!

[alerich]

I'm 3 for 4 so far but I have not yet built an amp from scratch.

I rebuilt a '77 Vibro Champ that had been hacked. That was my first foray into amp building/rebuilding. Somehow, I installed a 2k2 grid resistor on the 6V6 instead of the 220K the circuit calls for.  I looked at that amp until I was almost cross eyed until I finally found my mistake.

I completely gutted an old 6V6 push pull mono hi-fi amplifier that started it's life out as one of those ubiquitous kits from the early 60s and built a more or less clone of a Marshall Studio 15 into it. Fired up first time. That one includes the Dana Hall VVR.

I gutted a Pepco Riviera 725 amp which is basically some really cheap 60s Canadian made Fender Princeton knockoff in a head format and rebuilt it into what is essentially a slightly hot rodded Fender Princeton amp in a head format. Fired up first time.

I gutted a Knight KN3220A public address amp (12AX7, 6AV6, 2 x 7189 and a 6CA4 rectifier) and rebuilt it with more guitar oriented circuit values. Fired back up first time but it is still a work in progress. I have not decided whether to leave it alone or if I want/need yet another high gain amplifier.

I have a chassis from an old Park G10 solid state practice amp that I am going to one day wedge a 2204 into just for kicks. That will be my first build from scratch build. I scrapped the idea of building one of those low-watt Firefly type amps in my KISS lunchbox. Just not enough real estate to do it the way I want to.

[G._Hoffman]

You've been around the forum long enough to have heard PRR's immortal advice, "Plan to be wrong about something."  This time, you were wrong about planning to be wrong, showing once again how truly wise PRR is.  On the bright side, you now have more time to play your new amp!

Well, and its not that I didn't miss anything - I forgot two resistors, had a broken solder connection, and fixed a bit of less than ideal wire routing.  But I caught all of those on my check against the schematic last night before I even thought about firing it up.  Once I turned it on - it works! 

I'm afraid, however, that this could be a seriously bank account emptying problem.  I want to built more!!!!  This is as bad as building my first guitar ever was.  I have a badly made AC-30 laying around (my workmanship, as of about 3 years ago).  I might have to get a decent chassis for it, and give it another go!

[G._Hoffman]

Some pictures



Gabriel

[Ritchie200]

This time?  It just works.

Shhhhhhhhh!   What the heck is the matter with you!!!!!!!!

Jim

[tubesornothing]

Its kinda freaky...

The only one of the few dozen I have built, that have worked first time, was a tweed champ.

*sigh*

[Steve_P]

I'm building a Weber reverb tank and trying to get everything correct the first time. I'm checking resister values with the meter and I'm getting annoyed that the 2.2 meg resistors are all measuring around 1 meg.

Knucklehead. I was touching both probes with my finger and measuring the resistance of my skin instead. :knob:

[zendragon63]

So, how did you feel the first time you fired up an amp and it worked perfectly?

Heh heh heh...it might feel pretty good...it just ain't hppened yet! 

Good for you--nice job! Regards

dennis

[G._Hoffman]

Well, and I should add that while it is perfectly functional, that doesn't mean I don't have anything to tweak.  Its just that this time, I'm tweaking it so it sounds better, not so that it stops squealing.  This will, I assume, be much more fun!


Gabriel

[Cygnus_X1]

It happens a lot less often than it should!

I'm amazed I haven't had more fireworks for the bonehead moves I have made
scratch building and converting old PA's.

Although I did completely fry an Ampeg V4 once.
Installed ALL of the filter caps 100% bassackwards.
Scared the bejesits outta me!

[tubenit]

I think I've done over 20 different amp builds now mostly from scratch. Alot of them repeat conversions of the same amp.  Probably over half of them fired up great the first try. And then I tweaked to taste.

First time it all worked right .......... threw me for a loop.  It didn't seem "right" to have it work properly right outta the chute. It was kinda disorienting.
 

With respect, Tubenit

[bluesbear]

I've had modified amps not work on me but every scratch build has worked first time... other than dialing in tone, gain, etc. I don't do "exactly like the schematic" so it's to be expected. The very first one was an amazing thrill! My wife took a picture of that first turn on. I was almost as shocked as if I'd stuck my fingers in the wrong place.
Dave
PS: found the pic

[GroundhogKen]

It's a great feeling.

The first tube amp I ever built went into a 1-10" solid state combo that I rescued from a dumpster.  My plan was to build a cathode biased push-pull 6v6 amp with reverb.  I quickly abandoned the reverb when I realized the chassis was to small to hold the circuitry.

I built it on 3 pieces of Keystone turret board--this is before I knew about Hoffman Amps.

When it was finished I powered it up on the bench under a low hanging 4ft fluorescent shop light.  My intention was to measure the voltages.  First I got ear piercing squeal, so I knew I had to swap the OT primary wires.  Then I powered it up again and got a lot of hum.  I knew it was amplifying something.  So I walked over to the light switch and clicked off the shop light.  The hum went away.  There was a big smile on my face because I was pretty certain right then that I had a working amp.

Ken

[Vair_dude]

I felt the same way I felt when I got my first junk Corvair running. I jumped up and screamed "YES". Getting my first Corvair running was a whole lot more work than my first scratch built amp though because it fired up right away.

[HotBluePlates]

So, how did you feel the first time you fired up an amp and it worked perfectly?

Nervous, because I was just sure that something bad was going to happen any second!

Then a little bit disbelieving, and finally really excited.

I don't know... There might be 5 stages of Grief, but only 3 stages of amp-building euphoria. 

[G._Hoffman]

First time it all worked right .......... threw me for a loop.  It didn't seem "right" to have it work properly right outta the chute. It was kinda disorienting.
 

EXACTLY how I felt.


Gabriel

[bnwitt]

The first amp I ever built made no sound at all until I discovered I had not grounded the circuit card preamp ground buss.  Since then I have built so many amps I can't honestly say how many.  Most of the time they start right up with no problem but I still make a mistake every now and then.  What I have learned is to never become over confident in your building skills as life is full of distractions.  Especially with kids in the house.  I still have a blown PT on the shelf that I created by starting up and amp without the light bulb limiter in place.  That amp had a filter cap put in the wrong way when things were a little hectic in my house.  So now I am always suspicious of my own work.  Never the less, it is always pleasing when they do work at first try.

[plexi50]

Scared that some thing is wrong! Always expecting some simple error. More positive these days with double checking all resistors before installing them. I got a batch of 100 ohm resisotrs that were actually 47 ohms. All of them. Color codes means little these days and creates a false sense of security. But yeah it feels good to flip the switches and like was mentioned the amp was so quiet you think it's not working until you hit a chord.

[Madison]

Most of them have something a miss.My bad luck.
Can't remember all the problems.
Never fried anything serious yet but I have wanted to throw a few out the window.
I had one that had something as simple as a blown pilot bulb that made me scratch my head for a spell.
I think I've had one 5E3, a 36 watt, and a couple of Champs that fired up perfectly.
I come to expect "something will be wrong".

My first build, I literally got out an extension chord and stood across the room when I plugged it in.
The feeling was great when I got it tweaked.............and the addiction set in.

[Jim Coash]

I'm new to the forum so I have been enjoying looking at the old posts.  I hope I'm not doing the wrong thing by replying to this one but when I read it, it brought back some very intense memories from so long ago.  It was 1962.  I was 12 years old.  My Dad and I had just completed our first project, a Dyna Stereo 70, after more than a month of evenings at the kitchen table after supper.  It was a beautiful build.  My Dad is an engineer and it looked perfect inside.  When Jim Toornman and Bill Burke, owners of The Sound Room saw it, they said it was easily the best work they had ever seen in a kit.  I was breathless when Jim began rotating the Variac control.  The tubes began to glow, the ammeter stayed within limits and very low at first we heard music coming from the speakers.  I will never forget that moment.  It was the beginning of a lifelong love for me.  From them on all I wanted to do was play music, listen to music and work on audio projects.  I still feel the same.  Jim

[shooter]

My 1st build a tweed 5e1, built in an artsy very small cab, no chassis just wood, plate aluminum, never meant to be "fixed" n like someone said, NO sound, no hiss, nothing, til I plugged in n strummed!!!  the 4X12 cab shook the walls!
then, yes, you are right, the bank account did spike.

[EL34]

I don't remember, it was a long time ago
I am sure I was excited 

[eleventeen]

Well, this one worked first time, and frankly I was shocked! It's very tight. I call it "The Hewlett". It's about 90% done, I still have to mount the reverb can. It's just a single channel AB763 Deluxe Reverb. It's built on the chassis of a Hewlett Packard 413AR voltmeter. I used the PC board from the meter and stripped off all the traces, kept the two 9-pin sockets, and skunged the components for the first two tubes onto the bare board. It's so tight that I had to incline the board as you can see to get the tubes to fit into the cabinet! Front panel speaker and input jacks. Ugly knobs from an old Dumont scope. I took advantage of a trick I learned taking apart an old Conn organ: The transformer has two 6.3 windings, so I am using 12V6 output tubes. I can frequently find NOS 12V6 tubes in GE for under $10 a pair. I was going to add maybe a middle control and a master but I decided to leave it as is. Vol-Treb-Bass-Reverb


I was really surprised, I finished it, plugged it in, and it worked fine.

[EL34]

This was the first amp I built from scratch in 1993
The black 50 watt head on top of the 4 x 12 cabinet

I still have it and it still is the best sounding Marshall type amp I own


Here's a couple clips of it in action
http://el34world.com/Misc/Music/files/IGottheSixPlexi50.mp3


http://el34world.com/Misc/Music/files/CauseWeveEnedasLoversPlexi50.mp3

[jojokeo]

Doug, love the Beck stuff! Also enjoy people's responses on this. I can't think of any amp not firing up being honest but my biggest challenge to this day is to see how close I can design and make something to where it doesn't need any tweaking whatsoever. I think this has happened twice? I'm like tubenit in that even if it works "seemingly perfectly" I will adjust things even to see if it makes something worse & I'll know I had it as good as it can be. Satisfaction isn't in just sound or tone but also having the sweeps correct on all of the controls working through their entire ranges. It has to work through all settings possible or I can't live with it until it does. The tweaking (or voicing) process can easily take me longer than the time to actually build the amp in the first place.

[thermion]

Still hasn't happened! Seriously, I still get a little anxious firing up each new build.
I constructed and setup a theremin that worked perfectly right out of the chute. That was really gratifying!

[EL34]

Doug, love the Beck stuff! Also enjoy people's responses on this. I can't think of any amp not firing up being honest but my biggest challenge to this day is to see how close I can design and make something to where it doesn't need any tweaking whatsoever. I think this has happened twice? I'm like tubenit in that even if it works "seemingly perfectly" I will adjust things even to see if it makes something worse & I'll know I had it as good as it can be. Satisfaction isn't in just sound or tone but also having the sweeps correct on all of the controls working through their entire ranges. It has to work through all settings possible or I can't live with it until it does. The tweaking (or voicing) process can easily take me longer than the time to actually build the amp in the first place.

Thanks,
love doing that Stevie Wonder/Beckish type tune

[shooter]

 
" I constructed and setup a theremin that worked perfectly right out of the chute."

On amp# 6 I did an all wood, no metal, chassis, tubes inside.  sounded ok til you walked up to it.  A musician was watching me probe around and said, "STOP, do that again", so I did and he said, "Dude, you have a great  theremin !", I now know what that is AND why my amp was a good one.  scraped for parts!!!

[NewYorker]

I almost had your experience on my first amp build.  It was a 100-watt scratch-built amp that I had no business attempting as a novice, but that's another matter.

The amp has NFB, and I knew that it would squeal if I got the OT polarity wrong.  Because of the of the OT that I was using and my inexperience, it wasn't clear what the "correct polarity" was.  So, take a guess and be prepared for the consequences.  Sure enough, it squealed when the standby switch was flipped to "on".  That was simple enough to fix.

Wow!

However, there was a lingering problem that was harder to debug - the treble/mid/bass controls did not work as expected, because I had inadvertently grounded something in the tone stack that should not have been grounded.  That took a while to find.

I've done a 10-watt kit amp since then, which was unresponsive when powered up the first time.  It was a dumb, simple-to-fix error, but dumb just the same.

Ed

[Jim Coash]

One of the three Dynakits my Dad and I built did not work right away because we had inverted a pot.  Simple fix.  Of the 70 Heathkits I built, all but five worked without a problem.  Being so close to the factory on Hilltop Road in St. Joseph, Michigan I just drove them over.  The techs knew me so well that they just popped the cover and went to work.  Two had defective parts, three had mistakes.  The biggest was in a varactor tuner I built for my first (and last) TV kit.  Once taken care of the set worked fine for many years.  The AA-1640 amps (3) I built were great.  The one I built for my brother-in-law still works like new.  So does the 2 X 12" Combo amp and the big guitar head unit.  Jim

[billcreller]

I've had decent luck with the simple amps I build.  Had to get help with the reverb on a Princeton Reverb project some years back.  Sluckey spotted a resistor of the wrong color !  There was a high DUH ! factor involved there..
I have an amp build on my bench that doesn't do much of anything, and it's a type/circuit that I've built seven examples of.  Must be the age thing clogging my brain a bit....

Happy New Year folks

[Tone Junkie]

Yes I have to say when it happens its really nice. I always seem to miss a ground somewhere. Ever notice when you smoke a power transformer it smells really bad. Don't ask how I know (LOL).
Bill

[Jim Coash]

When I worked in the service department at The Sound Room in Kalamazoo I had the experience of witnessing several service mishaps.  Old filter caps that smoked smelled really bad.  I do recall at least one transformer shorting out and that was interesting.  A few times there was a bang, a burst of loud noise or pop from one of the benches and we all went to see what had happened. All of the techs got a shock or two. On more than one occasion we did break out the fire extinguisher.  My own mishaps include watching several things smoke, melt or fry.  I once was fastening a chassis screw down while the amp was on and managed to puncture one of the A/C leads.  I found myself sitting on the floor a little dazed.  My Dad came to the basement in a hurry on one occasion to find me staring at the remains of a project still smoldering on my bench.  He made sure I was OK, unplugged everything nearby and reset the breaker to get the lights back on.  A good lesson learned!  Jim

[Ken Moon]

I don't understand the question