Amp Books: Gerald Weber

Happyorange27 · September 30, 2011, 06:45:16 AM

Guys, cactuskeeb told me to read some amp books so I picked up one of Gerald Weber's books; Tube Guitar Amplifier Essentials. It's really wonderful and easy to read. It's a bunch of very short chapters and it starts you off with the very basics and coaxes you to keep reading. He reveals some great techniques and ideas that you can do to your amp. Simple things that can improve your tone or fix problems you might have like hum or oscillation. Anyway for a nerdy engineer that isn't afraid to solder, i'm all about this book. I thought it would be way over my head but it's just very straight forward stuff dudes. Anyway it's way worth reading even if you are not going to feel like doing some of the physical changes yourself. You will at least know way more about your amp and what to do in all situations.

raisingfreen · September 30, 2011, 09:47:26 AM

Quote from: Happyorange27 on September 30, 2011, 06:45:16 AM
You will at least know way more about your amp and what to do in all situations.

I say go ahead tinker around in there whats the worst that could happen.
http://www.youtube.com/watch?v=_WheLp0RdLQ

Happyorange27 · September 30, 2011, 09:53:02 AM

Nice! If you are not blowing you capacitors...YOUR ARE NOT PLAYING LOUD ENOUGH!!!

picture_of_nectar · October 02, 2011, 01:57:51 PM

I think I need new tubes, but I'm not sure. Im pretty clueless when it comes to amps and electronics.

Happyorange27 · October 02, 2011, 10:02:52 PM

Quote from: picture_of_nectar on October 02, 2011, 01:57:51 PM
I think I need new tubes, but I'm not sure. Im pretty clueless when it comes to amps and electronics.

Look at your tubes. Do the plates have A bunch of carbon on them? Compare to a new tube. How many hours do you have on them. Output and phase inverter wear twice as fast as the rest if the tubes. Change those first. You'll basically add more punch and highs. Always get matched output tubes and always bias them. Do you have a bias pot installed inside?

I am so happy with this book. I know so much about tube amps and easy mods now.

Read this book!

IamWILSON · October 02, 2011, 10:55:08 PM

I'm definitely gonna have to pick up this book and do some reading. Just last night I changed the preamp tube in my little Fender Champion 600 amp. I swapped the made in Korea 12ax7 for a USA 12ax7 that a friend gave to me. Don't know what kind it is, but he said it was old and still works good and I should try it in one of my amps. I am very impressed with how it changed the overdrive sound on the amp as I turned it up.

I need to get myself a soldering gun and some shit to practice sodlering and de-soldering so I can start doing some simple mods to the Champion for some practice for when I'm gonna want to do some Billm mods to the Blues Jr I ordered last week. Any good tips for practice?

Happyorange27 · October 03, 2011, 08:04:48 AM

Wilson, I got started on soldering mods only because a couple years ago my wah pedal was having crosstalk (still doing the wah) when the pedal was switched off. I found out that my switch needed replaced. I found many wah mod sites, but liked the Whipple Wah one because many folks liked his inductor. So i bought a soldering iron NOT A SOLDERING GUN..THOSE ARE NOT WHAT YOU USE. I bought a 3PDT switch to replace my crappy stock switch. This let me have true bypass and also add an LED to my Cry Baby. I also got some different value resistors so i could play with bass, vocal, input and mids on the wah. I also installed the new inductor. This was all very straight forward and let me get familiar with desoldering and soldering. Do yourself a favor. Get a solder sucker; i bought one for 1 dollar on ebay. You just push the slide on it (spring plunger) and hold it over the hot solder you want to remove and then you press the sucker button. It removes all the solder around that joint in a half second. It makes life pretty easy.
You will want to practice because it takes many trials to figure out how to get your rhythm down. Try to get on and off a piece fast so you are not burning up components and lifting traces of the pcb. If there is anyone who does point to point work around here they are going to laugh at us pcb dudes but oh well. Welcome to the 21st centrury:)

When you get ready to get into the Blues Jr. you better watch Billm's video a couple times to see how he takes the pcb out. It's a bit involved. I've done it several times now and it gets easier each time. Just be very slow and careful. Good luck. You can try to call me sometime if you need some more personal advice on this.

ShockedAndPersuaded · October 03, 2011, 06:07:44 PM

Just a friendly PSA.

Amplifiers retain EXTREMELY HIGH voltages in certain parts. Some in excess of 400 volts. This is more than enough to kill you. If you are uncertain about these areas it's best to not poke around.

This concludes our friendly PSA.
Thank you.

Happyorange27 · October 03, 2011, 07:50:34 PM

Quote from: ShockedAndPersuaded on October 03, 2011, 06:07:44 PM
If you are uncertain about these areas it's best to not poke around.

That's what she said

IamWILSON · October 03, 2011, 08:49:36 PM

"Amplifiers retain EXTREMELY HIGH voltages in certain parts. Some in excess of 400 volts. This is more than enough to kill you. If you are uncertain about these areas it's best to not poke around."

I am aware of this, but am uncertain as to which areas. I'm not gonna just start tooling around in my amps without some good instruction. Care to enlighten me on on precautionary measures and where not to stick a screw driver or something?

Happyorange27 · October 03, 2011, 09:02:08 PM

Mostly this large electrolytic caps need to drain. If you have your amp on for a minute or two and you turn it directly off, not stand by, those caps will drain. Unplug just to be safe. Measure all large caps with positive volt meter and black lead to chassis. You should only see like a fraction of a volt. If you are curious as to see the actual high voltage, measure this while amp is on. Be super careful! You'll measure like 400 some volts! Anyway I did this so I knew I could watch the volts discharge. Use alligator clip leads if you want but hook them up in the presumed discharge state. Always assume there is a charge to be safe when connecting.
Also a second measure is to take a resistor in series with an insulated lead and ground those caps to the chassis.
You really should do more online research on this subject and don't just take all my advise. But once you do it a couple times you will know where to check. I always do this lead draining even when I know I turned off a warm amp, just to be safe. Be redundant! Be safe. I've never been hurt because I go slow and think before I touch.

IamWILSON · October 04, 2011, 08:07:29 PM

Thanks Happy. I definitely will err on the side of caution. And it will be a while before I ever get to do any mod work on my amps. I'm too busy these days between teaching lessons, doing my music therapy internship, and a couple band rehearsals a week. I also just told my sister I wanted this book for my birthday which is coming up. So my guess is after my internship is done in another couple months I'll get some reading done and decide what to start modding in my Fender Champion 600 before I start messing with the BJr.