Let's build an amp! Greg's journey to electrocution

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Greg_L
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Re: Let's build an amp! Greg's journey to electrocution

Post by Greg_L »

JD01 wrote: ↑Thu Jul 05, 2018 9:58 am Yeah, that must be really interesting when you've worked it out and you start to work out what little bits do and what effect they have on the ultimate tone of the amp - which I guess is what matters!

I was interested in building myself a TubeScreamer for a bit of fun... I kind of want one but don't want to spent money on what is basically the most ubiquitous green box in music... but then I can't be arsed, 'cos while I could follow a diagram and stick things together easily enough (my crap soldering excepted) I want to know why all the bits know what they do and be able to change things and mess about with things with some idea of what the changes should do and try and kind of design my own pedal to a certain extent.... which I guess is kind of what you're doing with the amp now that you have all this shit sorted.
What you would need is a "breadboard". It's like an exploded version of a circuit on a board with jillions of little holes in it. You build a circuit on that board and just patch things together for testing. It's like a physical, tangible version of a schematic. When you get something that works you figure out how to fit all of that into some kind of enclosure. That's probably how most pedals have been born.

For me, I'm not trying to redesign anything. I'm just trying to make a known ancient design work like it's supposed to. :redface:
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SweetDan
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Re: Let's build an amp! Greg's journey to electrocution

Post by SweetDan »

Greg_L wrote: ↑Thu Jul 05, 2018 9:43 am There's a lot more to this shit than just sticking wires together...
JD01 wrote: ↑Thu Jul 05, 2018 9:58 am ...I was interested in building myself a TubeScreamer for a bit of fun... I kind of want one but don't want to spent money on what is basically the most ubiquitous green box in music... but then I can't be arsed, 'cos while I could follow a diagram and stick things together easily enough (my crap soldering excepted) I want to know why all the bits know what they do and be able to change things and mess about with things with some idea of what the changes should do and try and kind of design my own pedal to a certain extent.... which I guess is kind of what you're doing with the amp now that you have all this shit sorted.
Since I built those two pedals a few months back, I've really wanted to grok what's going on under the hood. I'm far from being able to look at a schematic and understand what it will do, but I'm starting to recognize common patterns of arrangement of components that are a subset of the circuit network. I don't know if I'll ever "graduate" to anything big, like an amp, but this has all been very interesting so far.

Anyway, here are a couple links that have helped me understand a bit (in order of simplest to most complex/theoretical):

http://www.generalguitargadgets.com/how ... istortion/

http://lcamtuf.coredump.cx/electronics/

https://wiki.analog.com/university/cour ... /chapter-9

That, plus some of the videos from the guy that runs http://www.diyguitarpedals.com.au/ (https://www.youtube.com/user/chromespherecom), though I always watch the videos at 2x, since he can ramble. Also, getting off into the weeds, some of the discussion at http://tagboardeffects.blogspot.com/ is useful, but usually centered around any one specific circuit.
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JD01
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Re: Let's build an amp! Greg's journey to electrocution

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Cheers, Dan
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Lt. Bob
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Re: Let's build an amp! Greg's journey to electrocution

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Greg's gonna end up being a full-fledged amp guy.

The biggest requirement is being interested enough to put some time into learning it which he is, plus having a mind that can understand math type concepts.

Greg tends to disparage himself but I consider him one of the smartest and most talented guys I know and ask yourself, how often do I say such things about anyone? (never would be the answer)

Greg's a freakin' great drumber ...... a GREAT rhythm guitarist ...... his leads are as good as he cares to be ...... I'm betting he was a great car guy and now he's gonna be a great amp guy.

I feel fortunate to know him ..... someday he'll give me a GREAT eulogy.

:D
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Re: Let's build an amp! Greg's journey to electrocution

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Lt. Bob wrote: ↑Thu Jul 05, 2018 1:56 pm Greg's gonna end up being a full-fledged amp guy.

The biggest requirement is being interested enough to put some time into learning it which he is, plus having a mind that can understand math type concepts.

Greg tends to disparage himself but I consider him one of the smartest and most talented guys I know and ask yourself, how often do I say such things about anyone? (never would be the answer)

Greg's a freakin' great drumber ...... a GREAT rhythm guitarist ...... his leads are as good as he cares to be ...... I'm betting he was a great car guy and now he's gonna be a great amp guy.

I feel fortunate to know him ..... someday he'll give me a GREAT eulogy.

:D
Haha thanks a lot Boob. I agree with all of that. :biggrin:

Most of this stemmed from the same reason I got into cars - I just wanted to do it myself. The more I learn about amps, the more I realize that it's amazing that they can even work at all. Lol. And I'm only about 125 years behind the curve. :lollers:
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Re: Let's build an amp! Greg's journey to electrocution

Post by SweetDan »

...I'm far from being able to look at a schematic and understand what it will do...
Thank goodness there's stuff out there like this: https://www.electrosmash.com/mxr-phase90
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Re: Let's build an amp! Greg's journey to electrocution

Post by WhiskeyJack »

SweetDan wrote: ↑Thu Jul 05, 2018 2:33 pm
...I'm far from being able to look at a schematic and understand what it will do...
Thank goodness there's stuff out there like this: https://www.electrosmash.com/mxr-phase90
Which lead me to this and answered my question i had about a week ago as to why that black gunk was all over the board.

Great share SD. :like: :like: :like: :like:
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Re: Let's build an amp! Greg's journey to electrocution

Post by Greg_L »

Did a pretty serious mod to the amp.



Purple pilot lamp jewel
Image
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Re: Let's build an amp! Greg's journey to electrocution

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Tidy. Did Prince use one?
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Re: Let's build an amp! Greg's journey to electrocution

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rayc wrote: ↑Sat Jul 07, 2018 8:14 pm Tidy. Did Prince use one?
Lol. I think Prince was a Mesa guy.
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Re: Let's build an amp! Greg's journey to electrocution

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Greg, you need a logo. Would fit perfectly to the left it the purple light.
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Re: Let's build an amp! Greg's journey to electrocution

Post by rayc »

JD01 wrote: ↑Sun Jul 08, 2018 4:46 am Greg, you need a logo. Would fit perfectly to the left it the purple light.
Gregtronics Rebastard
What was your name for it Greg?
Dualchronic?
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Re: Let's build an amp! Greg's journey to electrocution

Post by Greg_L »

Lol. I don't know. I call it the bastard or deluxe retard, but since it's spent about two months sprawled all over my wife's nice dining room I'll probably name it after her.
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Re: Let's build an amp! Greg's journey to electrocution

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That light looks bright as fuck!
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Re: Let's build an amp! Greg's journey to electrocution

Post by Mr Clean »

That was an excellent, albeit long read. Cheers for all the detailed info Greg. I really enjoyed it.

You should call it "The Babygirl" :coolstorybro:
Cheap Gear - In A Square Room! Getting the job done! :coolstorybro:

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Re: Let's build an amp! Greg's journey to electrocution

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Mr Clean wrote: ↑Tue Aug 07, 2018 9:28 pm That was an excellent, albeit long read. Cheers for all the detailed info Greg. I really enjoyed it.

You should call it "The Babygirl" :coolstorybro:
Ha, thanks.

The amp is sweetening up little by little. Breaking in. It's really pretty awesome. I still can't believe I did this.

I've tried a few minor mods just to try stuff out. A few Silverface mods....none of them stayed. None of them made the amp any better.

One thing I have done and stuck with was I upped the 470 screen grid resistors to 1k just to get a little more spread between the plates and grid voltages. Not really a tone thing, but more a stability/longevity thing. So far so good. I have bashed on this amp pretty hard and it's still going strong.
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Re: Let's build an amp! Greg's journey to electrocution

Post by einstein magoo »

Reckon what this thing would sound like through a single 15 in a nice tight cab? I think some of the old surf guys used fender combos with 15s?
Probably never know cause you are a Marshall cab guy Greg. Just a thought.
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Re: Let's build an amp! Greg's journey to electrocution

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einstein magoo wrote: ↑Tue Aug 07, 2018 11:41 pm Reckon what this thing would sound like through a single 15 in a nice tight cab? I think some of the old surf guys used fender combos with 15s?
Probably never know cause you are a Marshall cab guy Greg. Just a thought.
Well, for me, I am not a fan of 15" speakers. Fender had single 8, single 10, single 12, two 12s, four 10s, single 15...lots of cab/speaker options came with this "blackface" amp circuit. None of those cabs were "tight" though. Most of them being ported or fully open backed doesn't equate to "tight".

I'm not so much of a Fender amp purist that I have to have a Fender type cab and speaker. I'm not chicken-pickin or playing Texas blues. The intent from day one was to have it work with my Marshall cabs.
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Re: Let's build an amp! Greg's journey to electrocution

Post by einstein magoo »

Understood! It was just a fleeting thought. I really have no experience with single 15" in a guitar cab, just curious if you ever had experimented with them.

Thanks for the reply!
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Re: Let's build an amp! Greg's journey to electrocution

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actually, a good 15 has about as much highs as a 12 ..... they just have more lows.

For a full-tange sound a good 15 is great.
That's why pedal steel players often use them.
But rock guitar isn't really a full-range sound .... too hi-fi sounding.
Last edited by Lt. Bob on Wed Aug 08, 2018 1:12 pm, edited 1 time in total.
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