Hello! Newbie here...

[Siboney]

Hi all,
I've bounced into this forum from time to time, but figured I'd become a member and formally introduce myself. I've been playing guitar for many years and like many am always trying to maintain what I percieve as perfect tone in my gibson guitars and tube amps. I'm playing mostly jazz nowadays but like a little of that hair sound on top of really compressed warm and mellow notes. Kinda Jim Hall type of thing.
Anyway, I live in Hawaii and cannot find an amp tech that gives a darn. That "mostly" goes for just about everything here, but especially hunting down amp problems while trying to preserve that vintage amp sound. So, that is my only motivation, is the fact that I CANNOT take my amp to a good tech who cares. Believe me, I've tried many a time with sad results.
My main question for today, is, can anyone point me in the right direction for reading schematics and making heads or tails of the connections and board layout. I've read some books and am familiar with basic amplifier service safety. I realize how slow things have to go, in order to troubleshoot safely and systematically.... but man, the schematics are mystifying me with regards to which resistors/caps are which etc... I've resorted to actually counting how many of a certain component there are and tracing the endless possibilities of connections and common connection points! Is that it, or is there a better way to learn and decipher? I'm really only interested on working on old Gibson Tube amps. I appreciate everyones input here on this forum.. Thanks, Siboney

[Alby]

Welcome to the forum Siboney!. I didn't know too much about reading schematics or troubleshooting problems either so I did exactly what you are doing, I asked lots of questions from forums like this one.

My biggest piece of advice would be to find an amp, in your case a Gibson one, that has a layout as well as a schematic. The layout is a birds eye view of the guts of the amp using actual wire routing and location of components. Once you get your head around the layout you can compare the two as you follow along the signal or high power wiring. Once you do this a few times it really takes the mystery out of a schematic and you start to see the circuit as parts of a whole. It also makes it easier to start with amps that are pretty basic and add more complicated ones once you are better at identifying the different parts of the circuit.

Try building a GA5 or another small amp, you would be amazed how much you will learn along the way.

What island are you on?

Alby.

[tubeswell]

Well this book is pretty straightforward for starters, and its (still) free...

Jack Darr Book, chapters 1 - 8

All about the basic parts of any geetar tube amp and how they work etc

[Enzo]

There are many voices here willing to help, but starting from zero on how amps work, how to read schematics, and electronics in general is to hand someone a saxophone and have them ask how to understand John Coltrane. It ain't simple.

I would say from my experience that in learning about amps, old Gibsons would not be my first choice. Their component boards tend to have parts crammed together with a lot of parts out of sight on the reverse side, and no convenient way to get back there.

An old Fender would be a much better amp to learn on, then take those skills and apply them to the Gibson. Fender documentation is redily available, the older simpler models all had layout drawings as well as schematics, and hte amps consistently agreed with the drawings. Gibson on the other hand is NOTORIOUS for not matching the schematics - often using completely different tubes and circuits in the same model. I have SIX different schematic versions for one Gibson model GA15 or GA19 or something in that area, I forget which now. I am too lazy to go get the file. I know when I am looking at a schematic that doesn;t fit, but to a novice it would be most confusing.

[Siboney]

Thanks for that link! I will drink that in for a few days before I post any more questions! It is much appreciated.
As for the starting point advice and the Fenders, I guess it wouldnt kill me to take on a 5f1 or something? But are there any of the Gibsons that anyone can locate ANY layouts for? I searched quite a bit and couldnt find anything. I see what you mean about the Fenders and available info though... Do you guys recommend all the usual amp kit makers? Are anyones components much better sounding than the rest? Are there any that you feel stand out for one reason or another? I've always liked Webers service and products in the past.. Never bought an amp kit though...
Alby, I'm on Oahu. Where most of everything is... Except with old VW's and Amps you're almost entirely on your own!! I've got the Vdubs down, but am at the bottom of a steep learning curve with the amps...
Thanks for your input!!!!!

[tubeswell]

5F2A is a good start (almost identical to a 5F1, but with a tone control thrown in, and a bit of extra filtering). I built one using trannys of the following specs (and it can be run with a 6V6GT or, for a bit more output power a 6L6GC, with a bit of adjustment to the biasing and changing the rectifier to a GZ34 and swapping the output tranny to 4k load resistance).

PT (secondaries)
320VAC-0-320VAC 120mA
6.3VAC 2A (center tapped - i.e. 3.15VAC-0-3.15VAC)
5VAC 2A
with end covers (helps to cut down on stray EMF hum)

OT
15W Single-ended
8k primary (reflected load resistance)
4 Ohm, 8 Ohm and 16 Ohm secondaries (for running the 6L6, you halve the primary load resistance by plugging your speaker into a secondary tap that is 1-knotch up from what your speaker is rated as - e.g.; plugging an 8R speaker into the 16R tap gives you a 4k primary load resistance)

[Enzo]

Fender published layouts for many of their amps along with the schematics.

Gibson - assuming the schematic matched the amp in the first place - rarely if ever had layouts. You'd have to find one someone drew themselves. You were lucky to get a tube layout.

Look at it this way. If a novice kid came to you wanting to learn about working on cars, would you tell him to start work on some VWs or Fords or would you tell him to work on a old LAncia Fulvia or a London cab or some other rare beast? I think the VW or Ford would be a better place to learn the basics, myself.

[Siboney]

Thanks for the advice. Yeah, I see what you mean. Gotta take a detour to learn it looks like. My main goal is still to get my Gibsons in PERFECT shape, but your point is well taken! Chevy's and VDubs it is!