AMT Electronics - S1 Legend series [schematic]

[BuryMeInSmoke]

Uploaded some more pics to my dropbox and started two new threads for the above. Cheers.

[Ice-9]

Uploaded some more pics to my dropbox and started two new threads for the above. Cheers.

Completely missed these photo's , cheers for the upload

[zoliba]

Dear Everyone!

Could somebody show me te real AMT P1 schematic? I found some in this topic, but I don't know which one is the true one. And could you please show me the P1PCB layout and netlist and Gerber file, all of the stuff which I need to build the P1. Beacuse if I would have PCB plans I would give it to somebody to build me the PCB, and I would solder the parts myself. So I need all parts through-hole form.

I'm hungarian, and this pedal is quite expensive to me.
And yes, english is not my native language.

[Ice-9]

Dear Everyone!

Could somebody show me te real AMT P1 schematic? I found some in this topic, but I don't know which one is the true one. And could you please show me the P1PCB layout and netlist and Gerber file, all of the stuff which I need to build the P1. Beacuse if I would have PCB plans I would give it to somebody to build me the PCB, and I would solder the parts myself. So I need all parts through-hole form.

I'm hungarian, and this pedal is quite expensive to me.
And yes, english is not my native language.

Everything you ask for is in this thread, all you have to do is read it. good luck zoliba.

[tra]

Dear Everyone!

Could somebody show me te real AMT P1 schematic? I found some in this topic, but I don't know which one is the true one. And could you please show me the P1PCB layout and netlist and Gerber file, all of the stuff which I need to build the P1. Beacuse if I would have PCB plans I would give it to somebody to build me the PCB, and I would solder the parts myself. So I need all parts through-hole form.

I'm hungarian, and this pedal is quite expensive to me.
And yes, english is not my native language.

Everything you ask for is in this thread, all you have to do is read it. good luck zoliba.

There are gerbers in this thread? I haven't found them. I can mill a board or two for anyone that has gerbers available.

[Angle Loss]

Would anyone happen to know what they did on the version 2 (S2, P2, etc) versions of the pedals to allow them to be run in front of an amp on the 'drive out' jack?

[J0K3RX]

Would anyone happen to know what they did on the version 2 (S2, P2, etc) versions of the pedals to allow them to be run in front of an amp on the 'drive out' jack?

Probably bypass a gain stage or two..

[J0K3RX]

Would anyone happen to know what they did on the version 2 (S2, P2, etc) versions of the pedals to allow them to be run in front of an amp on the 'drive out' jack?

Probably bypass a gain stage or two.. and maybe ports it through a buffer of some sort..

[espflash]

Hi! I need M1 schematic. Please help!

[RockKenny]

Sorry y'all, pictures are a bit sloppy, will hunt out my tripod and take some better photos in better light tomorrow. I'll at least manually write out any component values and will start a proper thread for each too.

Here's what I've got so far if anyone wants a look:

P2 - https://www.dropbox.com/sh/64bky30w666agtw/JRAw9jmpQC
TC-3 - https://www.dropbox.com/sh/wm676vwji8zy47z/G8ABxWORWK

(Open image > right click > 'View Original' for high res)

Broken(((

[J0K3RX]

Broken(((

P2 has been traced here already.
viewtopic.php?p=260896#p260896
or, start at the beginning... most of the other Legend 2 series have been traced as well under the "AMT - Legend Amp Series 2" thread topic.
viewtopic.php?f=7&t=26365

Same goes for the TC3
viewtopic.php?f=1&t=20648&hilit=TC3

[temol]

Any chance that someone has AMT P1 laying around (original or a clone with 2SK20R inside)? I'm looking for drain voltage readings.
Also I'd like to verify Q1 model, and Q1 source cap value. I have three P1 schematics and they differ slightly
Q1 - 2n5458 and 240n
Q1 - 2SK208R and ? (symbol of electrolytic cap)
Q1 - 2SK208R and 220n

T.

[Ice-9]

Any chance that someone has AMT P1 laying around (original or a clone with 2SK20R inside)? I'm looking for drain voltage readings.
Also I'd like to verify Q1 model, and Q1 source cap value. I have three P1 schematics and they differ slightly
Q1 - 2n5458 and 240n
Q1 - 2SK208R and ? (symbol of electrolytic cap)
Q1 - 2SK208R and 220n

T.

I'm pretty sure I still have one of those pedals somewhere. I will see if I can have get the readings you want when I get back home.

[Ice-9]

Any chance that someone has AMT P1 laying around (original or a clone with 2SK20R inside)? I'm looking for drain voltage readings.
Also I'd like to verify Q1 model, and Q1 source cap value. I have three P1 schematics and they differ slightly
Q1 - 2n5458 and 240n
Q1 - 2SK208R and ? (symbol of electrolytic cap)
Q1 - 2SK208R and 220n

T.

I'm pretty sure I still have one of those pedals somewhere. I will see if I can have get the readings you want when I get back home.

Found the pedal, a genuine original AMT P1 so here goes.


Q1 (first jfet in the circuit is actually labelled as VT9 on the PCB and is a 2N5457 (SMD marking is 61S)
The capacitor on its source which has a ? on most schematics measures 233n with a meter and the cap removed from the PCB so taking into account the tolerance is very likely a 220n.
Voltage measurements for this VT9 (Q1) are drain 5v source 1.45v


Other jfets are marked JR = 2SK208R, the first JR in the circuit measures Drain= 7.32v and source 366mv

[temol]

I am very, very grateful for this information! 2N5457.. this explains high drain voltage reading.. With 2SK208R as Q1 I got 8,2V.. with 2N5458 it's 4,6V. I'll try 5457 as soon I get back home.
I have 220n installed now, so no change here.

Thx!

T.

[temol]

MMBF5457 in, measuring voltage... 6,7V.. checking 61S code - it's MMBF5458 . SMD marking code for 5457 - 6D.
I've just checked several 58's - drain voltage seats between 4,5V and 4,7V. If the drain resistor is 4k3 than maybe source resistor is not 1k5 but 1k8.. with a 1k8 there is a 5V.

Would you be so kind and measure voltages on Q3 to Q7.

I've just measured Q2. With 12k drain and 620R source resistor, drain voltage is 5,6V. 7,2V with 5k8 drain resistor.
Q3 - 6,2V
Q4 - 4.12V
Q5 - 5V
Q6 - 5V
Q7 - 4,35V

T.

[Ice-9]

My Bad, 61S is 2N5458 not 57
source resistor is defo 1k5 .. but you may find they are selecting their jfets to match the resistor so no harm in adjusting the source resistor to match the correct voltage readings.

[temol]

No problem

I do not see a point for building pedal like P1 without knowing exact voltages on each transistor... I have a pedal that plays. But I doubt that it closely emulates the 5150. There is seven transistors.. so many options..

T.

[Ice-9]

No problem

I do not see a point for building pedal like P1 without knowing exact voltages on each transistor... I have a pedal that plays. But I doubt that it closely emulates the 5150. There is seven transistors.. so many options..

T.

So what is it you want as i can give you voltage readings, but i have no idea what schematic you are working from and the original component markins will differ from your schematic labelling most likely.
Let me know exactly what you want measured and i will attempt to do this.

[temol]

I hope you did not take my message as personally directed to you. This is a general observation, nothing personal.
Of course I'm very grateful for any help in the subject.

On two schematics transistors are marked Q1 to Q9 (from IN to OUT), on third schematic VT and corresponding number.
Q1 - VT9,
Q2 - VT4,
Q3 - VT5,
Q4 - VT6,
Q5 - VT7
Q6 - VT8
Q7 - VT10
I omit cabsim part. Schematic

T.