Fixed a MKII Boogie Yesterday - Bad Coupling Cap

Question:

If i built a 45 watt British head kit from Stewie Mac, how difficult would it be to add an FX loop???
 
Amp Mad Scientist said:
Lesson on Resistors:
Resistors contain smoke.
If you let the smoke out, the resistor will not function anymore, until you put the smoke back.
(The "ohm meter" tells you how much smoke is left inside the resistor) According to Ohm's Law.

In order to put the smoke back, you must appease the 4 Gods of electricity:
1. Volts
2. Amps
3. Watts
4. Gotcha

You must sacrifice 2 virgin fluorescent tubes to the Gods of electricity.
I hope this explains resistors.

One time, I dropped a whole box of 1 Meg resistors, and ohms were everywhere. I had to sacrifice, like a whole box of fluorescent tubes before the Mojo returned.
I hope you learnt something from my stupidity.
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OH BOY Amp Mad, I am gonna have to really scratch my head on this one. I use to think I understood resistors, now I can't even figure out number 4. Does that mean you got shocked, or Gotcha is, we have a fully functioning circuit?

NOW that sacrificial Fluoro tube comment really must be an inside joke I won't understand till I reach Electronics 400 level courses.
 
jtcnj said:
+1 on the Uncle Doug (I was bummed when Rusty passed) and Robrobinette.com.

I need to rewatch some of those; it seems whenever I go back having learned a little more along the way, I understand either more of the video or the content more clearly / subtleties I had missed earlier.

this one on tube bias tremolo is good too:

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I agree, JT. I think I could put Uncle Doug, Mr Carlson's Lab, Rob Robinette, Gerald Weber ( another amp guru I have learned from) all on a 24/7 loop and just absorb them in my sleep and still learn stuff. Awww at Rusty dying, I hadn't realized or remembered he passed. Musta been an awesome doggie.
 
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chilipeppermaniac said:
OH BOY Amp Mad, I am gonna have to really scratch my head on this one. I use to think I understood resistors, now I can't even figure out number 4. Does that mean you got shocked, or Gotcha is, we have a fully functioning circuit?

NOW that sacrificial Fluoro tube comment really must be an inside joke I won't understand till I reach Electronics 400 level courses.
Click to expand...

Gottcha will gettcha.
 
Amp Mad, Thanks for coming to our Forum. It sure is good having you around.

Hard to imagine how many folks we have on here, who either recreationally or for income have pursued electronics and amps etc for recreation or for income. We who simply use amps and seek to understand them, sure are richer for folks like you.
 
Robert Herndon said:
I feel as though i need to avoid plunging down this 45 watt Rabbit Hole right now...
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Might be a good idea, Robert. However, I bet if and when you ever want to build an amp, folks like Sysco are near enough to you and could help walk you through it. Plus the other guys here who can type you through it.
 
All this amp talk, and circuitry got my brain to just have a ( dumb question) pop into it.

I know what a variable resistor is, so, Is a bias pot considered a variable resistor? MY guess is yes.
 
chilipeppermaniac said:
Amp Mad, Thanks for coming to our Forum. It sure is good having you around.

Hard to imagine how many folks we have on here, who either recreationally or for income have pursued electronics and amps etc for recreation or for income. We who simply use amps and seek to understand them, sure are richer for folks like you.
Click to expand...

I was in this band called Dragon Soup. The Soup Dragons copied our name.
When our amps and equipment broke down, there was nobody who could really fix it.
The label said: "no user serviceable parts inside."
Then I said fck it, I'm opening this thing up anyway.
That's when I started fixing amps and equipment.
Pretty soon, I was working at a local music store. Then I was a PV service center.
After that, it sort of took over my life.

Don't follow my example. :rolf:You will regret it later.
No seriously I had a lot of fun but it never made very much money so it was only for kicks.
 
Nice story, Ampmad,

Hey before I forget, I was scrolling back to the beginning of the thread and remembered I had a question I wanted to remember to ask with regards to my Laney I posted.

I seem to remember reading about " cascading" in the AOR Pro Tube Lead circuit/design. Mine is an 8 knob head 50 watt
version. From a post on Rigtalk,

Turn up all the tone controls to 10 and pull out all the boosts on them. Spend your time dialing in the 4 preamp/vol controls for different sounds when checking the amp out. the 'pull gain' knob is a cascading preamp which is footswitchable. There are 4 12AX7 preamp tubes in it.

I had one for years and I liked it. A bit noisy, but it cleaned up well with the guitar volume. Mine had metal corners and sounded a bit different than the plastic corner ones you usually see. Mine did not have the diodes in it compared to the plastic corner ones. Never could fine any info on why my head was different.

From a post I found on TDPRI,



Yeah thats the doom metal holy grail right now. I was actually wrong earlier as well.. The six knobber is simply called the Pro Tube Lead. Those are basically Laney's version of the JCM800. The AOR (Advanced Overdrive Response) are the higher gain heavy metal ones. That one your friend has is a Series 1, you can tell by the way the 4 knobs on the right are marked. From right to left theyre labeled Preamp 1 Volume, Preamp 2 Volume, Preamp 1 Level, Master Volume. A Series 2 I guess is actually a two channel amp, and the two knobs on the far right are Preamp and Master and the label AOR is underneath them, and the next two are Preamp and Master and marked channel one underneath. I couldve sworn my AOR30 said Series II on it, but mine had the layout of the Series 1 as far as the gain goes, exactly like the one in Baysides picture. There IS also an earlier six knob AOR, that only has Preamp and Master Volume instead of the Preamp 1/2 knobs. I read that these ones were actually PTP wired, mine was on a PCB.

There are some other differences between the two..
Series I:
Pull boost on the Treble knob
Impedance switch on the back with two speaker jacks

Series II:
Bright boost is on the Master Volumes for each channel instead of Treble (the eq is shared between both channels)
No impedance switch, multiple hardwired speaker jacks instead
Line out right next to the effects loop

That one in your pic is basically a single channel amp with a boost that kicks in an extra gain stage. It took me awhile to figure out how the volume knobs worked too. I sold it a few years ago so I had to dig out the manual to find the block diagram in it.. The signal comes in and goes through Preamp 1 Volume -> Preamp 2 Volume -> EQ -> Master. This bypasses the first tube completely and youre only hitting V2 and V3. Now if you pull the Preamp 1 Volume knob the signal hits that first tube (V1) at the beginning before it goes to the Preamp 1 Volume knob and into the next two tubes. When the boost is on, the Preamp 1 Level knob is after the Master Volume in the circuit for some additional volume control. If the boost is off that knob does nothing.

If you plug into the Low Input, it bypasses both the extra Preamp 1 tube, and the first gain stage and your signal goes right to the Preamp Level 2 knob and then EQ -> Master. You CAN still pull the boost on and use the Preamp 1 level as an additional Master as well.

So its basically a JCM800 with a switchable extra gain stage for more overdrive on the High Input, and an additional Master Volume knob on the Low Input.

Im assuming the Series II doesnt have as much control over the gain staging since instead of the dual preamp knobs, it actually has a seperate AOR channel that only has a Preamp and Master knob.
Click to expand...
 
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Robert Herndon said:
Question:

If i built a 45 watt British head kit from Stewie Mac, how difficult would it be to add an FX loop???
Click to expand...
Post #80 Brother Robert...

Tube Screamers

For live work, i use a second Boss GE-7 for a lead EQ and boost... It's a great way to boost. I use the built-in EQ in my Mark 5 to do the same thing. Most people use them to get that scooped midrange sound but that doesn't work for me, I like a lot of mids, so I set it to cut bass, stay...
www.thetonerooms.com
 
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