hey i got the led to light up but i cant get anything but hum.
http://www.shedradios.com/images/crate_cr-112_04.jpg
at the vcc+ im getting 44 v. almost double the 24 thats supposed to be coming to the IC 2. the only thing before the IC 2 is a 5% 1w R and a led.
ive got 44v going to IC1 also. IC 1 and 2 are supplied by the same trace. could this be a grounding issue? help
Quote from: clamup1 on January 02, 2011, 04:52:19 PM
hey i got the led to light up but i cant get anything but hum.
http://www.shedradios.com/images/crate_cr-112_04.jpg
at the vcc+ im getting 44 v. almost double the 24 thats supposed to be coming to the IC 2. the only thing before the IC 2 is a 5% 1w R and a led.
ive got 44v going to IC1 also. IC 1 and 2 are supplied by the same trace. could this be a grounding issue? help
Are you measuring from vcc+ to ground or vcc+ to vcc- ?
ive got the ground clipped to the heat sink with an aligator clip and the pos on the vcc+. is it different for amps ?
what i have hooked up is green wire attached to a piece of steel and the board ground attached to the metal face plate that i put on the front of the amp. it still hums
Quote from: clamup1 on January 02, 2011, 04:52:19 PM
hey i got the led to light up but i cant get anything but hum.
http://www.shedradios.com/images/crate_cr-112_04.jpg
at the vcc+ im getting 44 v. almost double the 24 thats supposed to be coming to the IC 2. the only thing before the IC 2 is a 5% 1w R and a led.
ive got 44v going to IC1 also. IC 1 and 2 are supplied by the same trace. could this be a grounding issue? help
Check you have 24VDC at C37.
If you get 40 VDC there then Zener D4 is likely futt, Replace.
Phil.
Quotegreen wire attached to a piece of steel
And what is the piece of steel attached to?
Can you post a picture?
Thanks.
@phatt- ill check it out
@fahey- its screwed into the side of the amp-would the green wire need to be grounded to the same thing the board is grounded too. ie the face plate?
Hi clamup
Unfortunately that doesn't answer my doubt.
Is that "piece of iron" attached to a wooden side?
Does it touch the chassis?
Do you measure any resistance between the green/yellow wire attached to the iron piece and the chassis? How much?
Thanks.
@fahey- hey there isnt a chassis. the closest thing i have to a chassis is the metal that the pot knobs will stick through when i get this thing working. the green wire gets really hot. i burned the carpet a little.
yes the piece of iron is screwed into the side of a wooden cab
Quote from: clamup1 on January 04, 2011, 05:43:11 PM
@fahey- hey there isnt a chassis. the closest thing i have to a chassis is the metal that the pot knobs will stick through when i get this thing working. the green wire gets really hot. i burned the carpet a little.
yes the piece of iron is screwed into the side of a wooden cab
Sounds like you have a short.
@phatt- at c37, +side 44, at -side 38
@joe- would a futt diode cause a short?
@fahey- i get -2.6mv at the peice of steel. is that the resistance you were talking about?
Quote from: clamup1 on January 04, 2011, 07:48:26 PM
@phatt- at c37, +side 44, at -side 38
@joe- would a futt diode cause a short?
@fahey- i get -2.6mv at the peice of steel. is that the resistance you were talking about?
Resistance would be measured in Ohms. Although if it was grounded you should have 0v, so something is amiss there.
To Clampup,
I Strongly suggest you seek professional advice because the way you are going you will land yourself in the ER.
Put it down and read up until you grasp what the hell you are playing around with. :grr
The green wire is for safety backup it goes to the metal chassis,,, which you do not have :duh
I'm sorry chum but that is flaunting death and stupid. :loco
Yes I can't stop you from flying a *non air worthy* plane without a parachute but at least
you get a warning when the engine conks out,,, but with electricity it's instant,, and often fatal.
Sure you might say but it's only You that gets hurt. But what if you accidently kill someone you love because you thought you knew what you where doing?
How smart would you look then? 8|
learn the basics (And safety issues) then you will be able to understand the answers you are getting.
Just Google any word you don't grasp and spend some time absorbing how things work.
Magnitisium, Transformers, DC circuits, AC circuits. there's some for you already:)
How stuff works will even be able to help with this.
Good luck. Phil.
I think Phil has a good point. I sometimes forget that people don't always have all the basic knowledge needed for this type of stuff just because I know it. It's not a hard topic to learn either, just take a bit of time, sit down and read.
Here are two good links:
This one for the safety concerns - read section C (you can read the whole thing if you want, but it pertains to tube amps): http://www.ax84.com/safety.html
And this one for electronics theory: http://www.utwired.engr.utexas.edu/rgd1/index.cfm
OK, thanks for taking a sensible position.
ok point taken. i have some stomp boxes i need to build and then read up on this. thanks for your help
Quote from: clamup1 on January 05, 2011, 09:14:34 AM
ok point taken. i have some stomp boxes i need to build and then read up on this. thanks for your help
Good to hear. Stomp boxes are a great starting point. That's actually how I started in this hobby.
Go step by step and in no time you will be repairing and building great amplifiers.
I always suggest everybody to start reading *Physics* before getting into electronics proper , which, after all, is part of it.
Learning first, from a Physics point of view, what's a capacitor, a resistor, an electron, a Volt, an Ampere, a Watt, a conductor, an insulator, a battery, a transformer, etc. makes much easier and solid what comes next.
As you see, all parts I mentioned *are* used in electronic products, so you are not wasting time at all .
I suggest my friend and clients who ask me so, to get the "Elecricity and Magnetism" chapters of Physics books which are used in High Schools or equivalent, when you are around 17/18 years old.
School systems have different organization around the world, but the age group should be an indication.
After that, get a copy of Jack Darr's "Guitar amplifiers". I started with it and never stopped.
Quote from: J M Fahey on January 05, 2011, 03:32:36 PM
...
After that, get a copy of Jack Darr's "Guitar amplifiers". I started with it and never stopped.
I might have to get myself a copy of that. Here is the newest version of it (4th edition) on Amazon: http://www.amazon.com/Electric-Guitar-Amplifier-Handbook-Jack/dp/1882580486/ref=sr_1_2?ie=UTF8&s=books&qid=1294261307&sr=1-2
That book is *GOOD* !!!!!!!!!!!!!!!!!!!!!
Check that the new ones cost U$27 and the *used* ones go from U$45 to over U$200 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Why?: because when you have it you don't let it go !!!!
I bought one in 1969; my first build was a Gibson GA5 ; then a Fender Bassman (2x6L6) ; then an Ampeg BT15 preamp coupled to a Motorola 120W SS amp.
I have already made over 10000 amplifiers since February 1969.
Being in Argentina helped a lot, of course; it would have been impossible in the US.
Quote from: J M Fahey on January 06, 2011, 10:46:47 AM
That book is *GOOD* !!!!!!!!!!!!!!!!!!!!!
Check that the new ones cost U$27 and the *used* ones go from U$45 to over U$200 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Why?: because when you have it you don't let it go !!!!
I bought one in 1969; my first build was a Gibson GA5 ; then a Fender Bassman (2x6L6) ; then an Ampeg BT15 preamp coupled to a Motorola 120W SS amp.
I have already made over 10000 amplifiers since February 1969.
Being in Argentina helped a lot, of course; it would have been impossible in the US.
10,000 amps! Wow. I've made like...7. I have another one in the works though.
i want to build the AX84 P1-extreme Tube Guitar Amplifier Kit - here http://www.ax84.com/ under amp kits. possible after i read the book and after i fix the crate.
@Fahey- i found an online physics book and read the recommended chapters. i want to take a physics class now lol. the book is on its way
Quote from: clamup1 on January 07, 2011, 09:15:01 AM
@Fahey- i found an online physics book and read the recommended chapters. i want to take a physics class now lol. the book is on its way
That drive for wanting to learn will help you immensely in this field.
ha we got censored. thats funny
Quote from: clamup1 on January 08, 2011, 08:31:09 PM
ha we got censored. thats funny
Where? Did I miss something?
fahey was telling us about his amp business. if shipping wasnt so expensive from Argentina he prob would of sold 2 yesterday lol.
Thanks.
Working to solve that problem, some way or another.
Definitely, the real solution is to send a cubic meter of anything (not kidding) by ship, to any point in US, and then distribute/resend within the borders, which is relatively cheap.
That's what I'm doing to sell in Brazil (*huge* market, just starting).
Individual Air Mail from Argentina is out of the question.
And yes, the
Quotereal straight forward no b.s. look to them
, both in cosmetics and electrical design is the driving idea behind them.
See you.
Quote from: clamup1 on January 09, 2011, 08:22:10 AM
fahey was telling us about his amp business. if shipping wasnt so expensive from Argentina he prob would of sold 2 yesterday lol.
Ah, I split the thread, that part is now here: http://www.ssguitar.com/index.php?topic=1994