Amptweaker - Tight Metal  [traced]

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jymaze
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Post by jymaze »

The track that just hangs down is actually the ground. Not totally sure why it is like that, but it may actually be the lamest attempt at a copper-fill known to man...

That thing twisted my brain good when extracting the schematic, but after all, it is not that bad of a circuit, pretty easy to understand. At least it is original, not a spin-off of a TS, BSIAB, or a Guv'nor. Just for that, kudos to the designers!

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azrael
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Post by azrael »

Thanks for all the work, guys!

So the gain pot is dual ganged?
I may have missed it, but what are the two sets of pads? One is an FX Loop, but there are two?

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J0K3RX
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Post by J0K3RX »

azrael wrote:Thanks for all the work, guys!

So the gain pot is dual ganged?
I may have missed it, but what are the two sets of pads? One is an FX Loop, but there are two?

A little late to the party I see... wtf took you so long?

Just joking hardy har har... :lol: :lol:

Yes, it is dual ganged gain/gate pot... The gate increases with increase in gain, kinda cool dont'cha think! That's why you see 2 sets of pads.

The FX loop is before and after the effect via a switch on the bottom of the board... Just one loop that toggles to the front or to the back

And the best part, lots a pretty little LEDS strung across the board like Christmas lights.... :lol:

By the way, you any good at laying out circuits? :hmmm:

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J0K3RX
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Post by J0K3RX »

jymaze wrote:The track that just hangs down is actually the ground. Not totally sure why it is like that, but it may actually be the lamest attempt at a copper-fill known to man...

That thing twisted my brain good when extracting the schematic, but after all, it is not that bad of a circuit, pretty easy to understand. At least it is original, not a spin-off of a TS, BSIAB, or a Guv'nor. Just for that, kudos to the designers!

No need for copper fill on this mutha... It's about 75% filled up with copper spaghetti anyway!

Agreed on the kudos to the designer!! This is just about what I have always been looking for... I think the Tight Rock might be better for leads, gonna have to get one and rip it up! I really like the sound demos of that one also!!

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coldcraft
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Post by coldcraft »

with the clipping arrangements, I would encourage someone to plug in a TLC2262 at 9v and see how it sounds, just don't put in 18v, it will fry.
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Post by azrael »

J0K3RX wrote:
azrael wrote:Thanks for all the work, guys!

So the gain pot is dual ganged?
I may have missed it, but what are the two sets of pads? One is an FX Loop, but there are two?

A little late to the party I see... wtf took you so long?

Just joking hardy har har... :lol: :lol:

Yes, it is dual ganged gain/gate pot... The gate increases with increase in gain, kinda cool dont'cha think! That's why you see 2 sets of pads.

The FX loop is before and after the effect via a switch on the bottom of the board... Just one loop that toggles to the front or to the back

And the best part, lots a pretty little LEDS strung across the board like Christmas lights.... :lol:

By the way, you any good at laying out circuits? :hmmm:
Ah, I see! Man that one at the end is kind of useless, no? Might as pull the effect after the actual pedal at that point haha.

And thanks for clearing all that up. :)

As far as layouts....I'd like to think I am? Haha.

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J0K3RX
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Post by J0K3RX »

Hey lukatosh... where are you man? We need your mad genius layout skillz yo!! :lol: I figured you would be all over this like one a hobo on a ham samich :lol:

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Post by apollomusicservice »

Congratulations guys at work. Here's my version of Eagle file, since I could not open an existing I drew again the scheme according euronymous0001. :thumbsup

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Post by bajaman »

Hi folks - I've been redrawing Jim's Sprint layout file and tidying it up, correcting layer mistakes and component placement etc. It is starting to look really good now :D
One thing I have noticed is the very elaborate biasing chain for the supposed half rail voltages. Do NOT assume that vref is exactly half of the supply voltage at ALL points of this circuit, because IT IS NOT :wink:
The schematics need to be redrawn CORRECTLY to show this fact - there is also a major error with the first decoupling resistor - is it 6k8 or 68k ????? (or possibly 680 ohms perhaps ?).
Very interesting circuit - zener diodes have completely different clipping characteristics to standard small signal types like the 1N4148, 1N914 etc.
I will post my final version of the Sprint layout file soon - have to go to work to make some money to pay some bills now :cry:
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Post by bajaman »

The ground trace hanging down is possibly being used as a shield :hmmm:
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Post by J0K3RX »

bajaman wrote:Hi folks - I've been redrawing Jim's Sprint layout file and tidying it up, correcting layer mistakes and component placement etc. It is starting to look really good now :D
One thing I have noticed is the very elaborate biasing chain for the supposed half rail voltages. Do NOT assume that vref is exactly half of the supply voltage at ALL points of this circuit, because IT IS NOT :wink:
The schematics need to be redrawn CORRECTLY to show this fact - there is also a major error with the first decoupling resistor - is it 6k8 or 68k ????? (or possibly 680 ohms perhaps ?).
Very interesting circuit - zener diodes have completely different clipping characteristics to standard small signal types like the 1N4148, 1N914 etc.
I will post my final version of the Sprint layout file soon - have to go to work to make some money to pay some bills now :cry:
Cheers
bajaman
Looking forward to it! Mine was kinda sloppy, bad alignment etc.. I just pressed on to get it done...

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Post by jymaze »

Yeah Bajaman, the hanging track is probably just a poor-man ground plan as I said above. I agree, the biasing circuitry is more complex than I put on my schematics.I will trace it tomorrow. I just gave up on tracing it, but now Jok3rx confirmed all the tracks, it should be easy. Until proven otherwise, the resistor you talk about is 6.8k. Jok3rx checked them all.

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Post by bajaman »

some of the sprint layout tracks are not correct - don't worry though I am on to it :wink:
the bias vref to the volume pot is interesting ( a lot lower than 1/2 the main supply rail voltage :wink: )
cheers
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Post by J0K3RX »

bajaman wrote:some of the sprint layout tracks are not correct - don't worry though I am on to it :wink:
the bias vref to the volume pot is interesting ( a lot lower than 1/2 the main supply rail voltage :wink: )
cheers
bajaman
Really? :hmmm: let me know which ones and I will double-triple-quadruple check...

I want to nail this thing 100% so, I am willing to remove all the components down to the bare board if that's what it takes! :twisted:

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Post by J0K3RX »

Damn-it! I keep getting "connection reset errors" in my browser when trying to get to FSB? I'm in, I'm out, I'm in, I'm out... :evil: Probably my sh!tty excuse for an ISP!

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Post by bajaman »

No - I have been having trouble with fsb tonight too. :wink:
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Post by jymaze »

Hey Jok3rx,

Sorry to ask again, but I have a problem with that track:
WeirdTrack.PNG
I cannot see it on your pics. You are sure it stand like that? Confirmed with a meter? Why would they just put 2 resistors in series when you can just put one?

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Post by coldcraft »

does anyone think the tight rock is just the metal with maybe a 250k Gain knob and different tone stack values?
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Post by jymaze »

I will have some minor corrections to the schematics tonight (the PSU, the tone-stack, the T notch filter) but I am waiting on Jok3rx to confirm that damn resistor by the tone-stack (3k32, right under the B10k tone-pot). The tone-stack actually looks more like a BMP-type, and the notch filter had a mistake for one of the 100n caps that should be in series with the thrash switch.

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Post by bajaman »

The gate switch blue track is surely not correct Jim - the switch is permanently set to on with this track fitted :wink:
And yes - the notch filter thrash switch is drawn incorrectly on the eagle schematics (also the bypass capacitor should be 22n NOT 220n ? ).
I too wondered about those two series connected resistors - they don't look right to my eyes. :wink:
I have redrawn Jim's sprint layout file and tidied up the connections - unfortunately I am now using Sprint Layout V6.0 (HIGHLY RECOMMENDED little program), and I think Jim is still using V5.0 :cry:
I will publish my layout here once the correct tracks and component connections are sorted out :D
Once this is done I will run some simulations and publish them for all to see. :wink:
I do like zener diode clipping behaviour soundwise - and the different vref bias voltages definitely play a large part in this circuit's operation. :!:
Cheers guys and gals
bajaman
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