Amptweaker - Tight Metal

J0K3RX · Post by **J0K3RX** » 10 Jun 2013, 23:25

I do not like the gate in tandem with the gain pot!! It's a great idea but, I personally would like to be able to adjust the gate rather than have it follow the gain!! Makes it impossible to find the sweet spot! It leave artifacts (if that's what you call them) as the notes decay... If I could adjust the gate lower with the highest gain setting I could find a happy medium but not as it stands with the dual gang pot. I would HIGHLY recommend 2 separate pots!!!

apollomusicservice · Post by **apollomusicservice** » 11 Jun 2013, 16:16

Okay here's my version of the pedal. Audio track was recorded directly to a PC with settings: Gain3, Gain max, Gain12, Tone3, Tone max: Tone12,
Tight max, Tight12, Tight min, Thrash ON Gain3 Tone3. As soon as I have more free time I will make better audio record.

J0K3RX · Post by **J0K3RX** » 14 Jun 2013, 06:48

I built rcustoms layout using the TL074/TL072 combo, it works really well but lacks the huge amount of gain that the original has? It has "high gain" but nowhere near the real pedal... investigating?

J0K3RX · Post by **J0K3RX** » 14 Jun 2013, 07:49

Ok, I changed R11 from 22k to 330 ohm but now has a built in shortwave radio?

Just whistles with high pitch noise that changes frequency/pitch with turning of the knobs... I can kinda hear faint guitar in the background but it's whistling like a teapot so loud that I can hardly make it out? Very annoying and shrill, seems to really bother the dog since she gave me a bewildered/confused look, urinated on the carpet and hauled ass outa the room

bajaman · Post by **bajaman** » 14 Jun 2013, 08:03

cancel that last amended schematic - my mistake - I was confusing the 330 led chain resistor.

Maybe it is 2k2 though

or perhaps R5 is 4k7 not 47k

sorry
cheers
Steve

Greg · Post by **Greg** » 14 Jun 2013, 08:39

bajaman wrote:cancel that last amended schematic - my mistake - I was confusing the 330 led chain resistor.
Maybe it is 2k2 though or perhaps R5 is 4k7 not 47k
sorry
cheers
Steve

Deleted it for ya..

J0K3RX · Post by **J0K3RX** » 14 Jun 2013, 16:09

R10 in series with the Tight is 15k not 1.5k - brown/green/black/red/brown.

Going over other resistors for errors...

jymaze · Post by **jymaze** » 17 Jun 2013, 12:51

I thought you used your multimeter...? Anyway, even with the values here on the current schematic it should have a massive amount of gain (about 70.000).

Anything more than that will start to whistle, like you experienced. You must be having a problem elsewhere. The resistor in series with the tight pot is really not critical, minor difference, but i think it is 1.5k as it is not the resistor by the pot on the same side (which is R9, 15k), but the one on the other side, which looks like brown/green/black/brown to me.

By the way, R9 is 15k and not 1.5k as on some schematics. not sure why it was labeled like that later as it was definitely correct on my first hand-drawn schematics that served as templates for the further iterations...

J0K3RX · Post by **J0K3RX** » 18 Jun 2013, 23:07

jymaze wrote:I thought you used your multimeter...? Anyway, even with the values here on the current schematic it should have a massive amount of gain (about 70.000).

Anything more than that will start to whistle, like you experienced. You must be having a problem elsewhere. The resistor in series with the tight pot is really not critical, minor difference, but i think it is 1.5k as it is not the resistor by the pot on the same side (which is R9, 15k), but the one on the other side, which looks like brown/green/black/brown to me.

By the way, R9 is 15k and not 1.5k as on some schematics. not sure why it was labeled like that later as it was definitely correct on my first hand-drawn schematics that served as templates for the further iterations...

You're right, R9 is 1.5k and R10 is 15k... In any case, I did use a meter. Look at the traced pictures I posted with the values, they are correct. Somehow R9 got changed to 1.5k on the schematic, mistake I presume? As for the whistling, that was caused by mistake when bajaman told me that R11 was 330 ohm and not 22k and I tried it but then he realized that it was part of the LED chain... That has been corrected.

1.5k for R9 makes the Tight pot not work properly.. It gates or drops off at about 3/4 of the way up and doesn't sound good! 15k work as should. Everything works properly except that it has substantially less gain than the original.

For what it's worth, I do not like the noise gate on a dual gang pot with the gain and I am speaking about the original pedal.. It works much better on another pot and adjustable by itself! Too much gate at full gain, kinda kills the notes. It's ok for fast chuggin stops and starts but it kills leads and you can hear it decay... like I said earlier. And it really sux on the clone pedal since it's not reaching full gain like the retail version!

jymaze · Post by **jymaze** » 19 Jun 2013, 00:26

So you used your Sprint Layout? I wonder what can be wrong, I could not find any mistake on it...

J0K3RX · Post by **J0K3RX** » 19 Jun 2013, 01:11

jymaze wrote:So you used your Sprint Layout? I wonder what can be wrong, I could not find any mistake on it...

Nope, I used rcustoms layout. I etched the one I did but have not populated it yet due to lack of time but another guy did and it's not working for him. Well, it's kinda working for him but has way too much noise that cancels out the original guitar signal? I need to go over rcustoms layout but it uses the TL074 in place of two of the TL072's.. not sure it if that has anything to do with it? I wouldn't think so?? It works now 99% except for the gain loss??

It sounds just like the apollomusicservice demo... not even close to the gain of the original!?

I also built the triple wreck and now that thing has some gain let me tell ya!!! This should have the same amount of gain as the TW!!

jymaze · Post by **jymaze** » 19 Jun 2013, 02:33

Yep, always wanted to build a Triple Wreck, but it looked like a PIA on a vero. And I never etch anything... But I should!

J0K3RX · Post by **J0K3RX** » 19 Jun 2013, 02:56

jymaze wrote:Yep, always wanted to build a Triple Wreck, but it looked like a PIA on a vero. And I never etch anything... But I should!

Yeah, I hate etching actually... I usually etch a bunch of things at one time so I don't have to do it again for a while! Drilling sucks even more!! If you do etch the triple wreck is flawless, works perfectly! I used the madbean upper decker layout with on-board pots. well worth the effort!

I actually like the Tight Metal better (the real one)... but the Triple Wreck is a very close second! They sound very similar but the tight metal has more of a engl type midrange and fat ass lows! It's a little punchier and tighter than the triple wreck but they both sound brutal! I don't like the boost on the triple wreck and it surely doesn't even need it, at all! I really hope to get this TM working!!! It really kills!!

By the way, I am also tracing out an Ibanez TBX preamp. The wife picked up an Ibanez TBX15R at a garage sale for $10.00 and I am floored by the sound of this thing!!! This thing is wicked as hell!

jymaze · Post by **jymaze** » 19 Jun 2013, 04:20

I found the problem:

On RC's layout for IC1A the pin 2 and 3 are INVERTED. Pin 3 goes to VA.

The rest of the layout seems fine to me looking casually, but this mistake jumped at me.

Yep, I am on the ball!

apollomusicservice · Post by **apollomusicservice** » 19 Jun 2013, 04:34

For my first TM version that I made I used a 100k dual (not 500k) pot for gain. For R10, seeing that TIGHT control does not work well with 1K5,
I found that the lower limit for is TIGHT is 6k8. With a strat guitar and such changes I made demo.

J0K3RX · Post by **J0K3RX** » 19 Jun 2013, 04:58

apollomusicservice wrote:For my first TM version that I made I used a 100k dual (not 500k) pot for gain. For R10, seeing that TIGHT control does not work well with 1K5,
I found that the lower limit for is TIGHT is 6k8. With a strat guitar and such changes I made demo.

ah... maybe the rcustoms layout has an issue then? I have a layout like yours but throughhole, maybe I should try it? Do you have any sound demos using the correct gain pot?

If I could increase the gain by about 50% on the rcustoms build it would be about right...

jymaze · Post by **jymaze** » 19 Jun 2013, 11:53

Once again:

On RC's layout for IC1A the pin 2 and 3 are INVERTED. Pin 3 goes to VA.

That is the problem!!!

I am not even sure how it is letting any signal through at all! I imagine IC1A can only let a faint signal through and kill the signal to noise ratio

rcustoms · Post by **rcustoms** » 19 Jun 2013, 13:50

jymaze wrote:Once again:

On RC's layout for IC1A the pin 2 and 3 are INVERTED. Pin 3 goes to VA.

That is the problem!!!

I am not even sure how it is letting any signal through at all! I imagine IC1A can only let a faint signal through and kill the signal to noise ratio

sorry guys my mistake
here the new one

layout final.pdf: (25.73 KiB) Downloaded 391 times

jymaze · Post by **jymaze** » 19 Jun 2013, 14:54

Thanks RC, but it is not correct again.

On your previous layout, the track going to 2 was supposed to go to 3, and the track going to 3 was supposed to go to 2. Pins 2 and 3 are not tied together.

Basically you can revert the + and - input on IC1A in your schematic and update your rat nest in Eagle, you will see the difference.

IC1A needs to be wired as an inverter.

Thanks for your help on the layout!

rcustoms · Post by **rcustoms** » 19 Jun 2013, 15:07

jymaze wrote:Thanks RC, but it is not correct again.

On your previous layout, the track going to 2 was supposed to go to 3, and the track going to 3 was supposed to go to 2. Pins 2 and 3 are not tied together.

Basically you can revert the + and - input on IC1A in your schematic and update your rat nest in Eagle, you will see the difference.

IC1A needs to be wired as an inverter.

Thanks for your help on the layout!

oops ,yeah my ratsnets fail.see this one

layout final ver 3.pdf: (25.74 KiB) Downloaded 479 times

please check for more mistakes ,to correct all of then

Amptweaker - Tight Metal [traced]