AMT Electronics - S1 Legend series  [schematic]

All about modern commercial stompbox circuits from Electro Harmonix over MXR, Boss and Ibanez into the nineties.

AMT Electronics - S1 Legend series

Postby Ice-9 » 20 Jan 2012, 14:35

Last night I sold my MXR badass 78 distortion, so this morning put the money towards an AMT S1 legend series Soldano pedal/preamp ordered from Thomann (i'm sitting by the letter box waiting). I really want to have a look inside and work out what makes this pedal tick. If there is any info available already it would be good is someone can point me in the right direction please.

I know the designer behind it has had quite a bit to do and say on these and other forums. From the clips at the AMD website all these Legent series pedals sound amazing so I am looking forward to having a play through it before looking inside.
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

No silicon heaven ? preposterous ! Where would all the calculators go ?

For this message the author Ice-9 has received thanks:
ALDOUSCROSS (09 Apr 2013, 15:17)
User avatar
Ice-9
Transistor Tuner
 
Posts: 1057
Joined: 31 Mar 2009, 16:29
Has thanked: 138 times
Have thanks: 357 times

Re: AMT S1 Legend series

Postby Pruttelherrie » 20 Jan 2012, 18:26

I have the E1 (ENGL clone), here's gutshots:

https://www.dropbox.com/gallery/1708162 ... 1?h=59d5e6

It looks like they used the same PCB for different Legend Amps pedals, see the components (Q's and R's) they left out.

For this message the author Pruttelherrie has received thanks: 3
lugburz2000 (16 Apr 2012, 15:38), modman (03 May 2015, 22:55), sugab (05 May 2012, 17:22)
User avatar
Pruttelherrie
Solder Soldier
 
Posts: 238
Joined: 18 Feb 2011, 20:35
Location: The low lands
Has thanked: 48 times
Have thanks: 105 times

Re: AMT S1 Legend series

Postby Ice-9 » 20 Jan 2012, 22:26

Thanks for the pictures Pruttelherrie, They show a lot of info and I will give them a good look over while waiting for my pedal to arrive. From your pics and others I have seen it definately looks like a few pedals share the same PCB by omitting certain components on one from the other. Makes a lot of sense if you can design 1 pcb for multiple pedals.

I will get some pics of mine when it arrives, I have been given a DHL tracking number so can watch it make its way across europe to my door :)
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

No silicon heaven ? preposterous ! Where would all the calculators go ?
User avatar
Ice-9
Transistor Tuner
 
Posts: 1057
Joined: 31 Mar 2009, 16:29
Has thanked: 138 times
Have thanks: 357 times

Re: AMT S1 Legend series

Postby Ice-9 » 25 Jan 2012, 12:34

The pedal arrived yesterday so the first thing I did was plug it in and run it through a couple of different amps to hear what it sounded like. First I went through my Marshall 9005 valve power amp and I have to say I'm impressed with the sound. Secondly I put it through a crappy sounding Marshall VS265 and it can transform a bad amp into something very usable so first off I'd like to give this pedal some :applause:

This is what you get. 1 pedal, booklet, warranty card and a box. For something I bought new the box is very tatty so I believe they send me an old stock or display pedal
(Well done Thomann :whappen: )

Image

Here are a few photograph of the guts.

PCB bottom
Image

PCB top
Image

PCB top with some caps remove so I can see whats going on
Image

The PCB is used for more than one pedal as there are three tick boxes which donate what pedal has been buils. This PCB has boxes for S1, M1, R1 so the soldano, marshall, Mesa Rectifier.
This pedal has had most of the values removed from the mylar (green) caps, understandably. A lot of work has gone into these pedals and are totally unique in there own right.
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

No silicon heaven ? preposterous ! Where would all the calculators go ?

For this message the author Ice-9 has received thanks: 3
darthoverdrive (25 Jan 2012, 13:37), lugburz2000 (16 Apr 2012, 15:38), modman (03 May 2015, 22:55)
User avatar
Ice-9
Transistor Tuner
 
Posts: 1057
Joined: 31 Mar 2009, 16:29
Has thanked: 138 times
Have thanks: 357 times

Re: AMT S1 Legend series [gut shots]

Postby Ice-9 » 25 Jan 2012, 18:37

Hello everyone, just adding a bit of an update, today I've been tracing the circuit out and have about 90% finished theschematic. Bselow is a picture of the PCB with all the tracks that i have traced coloured in to show what has been done and what is left to do.

What is left to do ? Well the circuitry around the led indicator hasn't been looked at yet and the cabinet sim also hasn't been done. There is also a section around the bypass switch which I have ignored for now and there is a section around VT7 which Ihavent figured out yet.

Image
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

No silicon heaven ? preposterous ! Where would all the calculators go ?

For this message the author Ice-9 has received thanks: 3
modman (27 May 2012, 11:14), papasaurus84 (20 Jul 2012, 08:32), roseblood11 (30 Jan 2012, 01:25)
User avatar
Ice-9
Transistor Tuner
 
Posts: 1057
Joined: 31 Mar 2009, 16:29
Has thanked: 138 times
Have thanks: 357 times

Re: AMT S1 Legend series [gut shots]

Postby Ice-9 » 25 Jan 2012, 21:17

Here's the start to the schematics I havedone upto now, I have had a bit trouble with photos but they are readable :oops: The two pics go together in line, where one ends the tone stack on the second carries on.

Still some stuff to work out to finish the schematic so if anyone wants to make any changes the PCB pictures are there to work from :D

Part 1
IMG]http://i90.photobucket.com/albums/k243/lenny1dog/P9080088.jpg[/IMG]

Part 2
Image
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

No silicon heaven ? preposterous ! Where would all the calculators go ?

For this message the author Ice-9 has received thanks: 2
modman (03 May 2015, 22:56), rocklander (28 May 2012, 04:36)
User avatar
Ice-9
Transistor Tuner
 
Posts: 1057
Joined: 31 Mar 2009, 16:29
Has thanked: 138 times
Have thanks: 357 times

Re: AMT S1 Legend series [gut shots]

Postby Ice-9 » 25 Jan 2012, 21:22

I'm sorry a typo in the post above missed out the first part of the schematic. As I can't edit the post I have to post again.

Here's the start to the schematics I havedone upto now, I have had a bit trouble with photos but they are readable :oops: The two pics go together in line, where one ends the tone stack on the second carries on.

Still some stuff to work out to finish the schematic so if anyone wants to make any changes the PCB pictures are there to work from :D

Part 1
Image

Part 2
Image
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

No silicon heaven ? preposterous ! Where would all the calculators go ?

For this message the author Ice-9 has received thanks: 4
Ihunda (28 Jan 2012, 23:05), jymaze (26 Jan 2012, 13:53), modman (27 May 2012, 11:14), rocklander (28 May 2012, 04:36)
User avatar
Ice-9
Transistor Tuner
 
Posts: 1057
Joined: 31 Mar 2009, 16:29
Has thanked: 138 times
Have thanks: 357 times

Re: AMT S1 Legend series [gut shots]

Postby jymaze » 26 Jan 2012, 13:55

Thanks so much,

That is awesome tracing work. I always wanted to know what was in theses AMT pedals!
jymaze
Resistor Ronker
 
Posts: 374
Joined: 06 Mar 2011, 23:19
Has thanked: 87 times
Have thanks: 160 times

Re: AMT S1 Legend series [gut shots]

Postby Pruttelherrie » 26 Jan 2012, 18:00

User avatar
Pruttelherrie
Solder Soldier
 
Posts: 238
Joined: 18 Feb 2011, 20:35
Location: The low lands
Has thanked: 48 times
Have thanks: 105 times

Re: AMT S1 Legend series [gut shots]

Postby Pruttelherrie » 26 Jan 2012, 18:04

Also, I find the AMT pedals very affordable and pretty good sounding. Although my E1 is pretty bass-heavy/boomy, I keep bass at 10:00~11:00 and treble at 1:00~2:00. Is the S1 boomy?
User avatar
Pruttelherrie
Solder Soldier
 
Posts: 238
Joined: 18 Feb 2011, 20:35
Location: The low lands
Has thanked: 48 times
Have thanks: 105 times

Re: AMT S1 Legend series [gut shots]

Postby Ice-9 » 26 Jan 2012, 18:10

Pruttelherrie wrote:Also, I find the AMT pedals very affordable and pretty good sounding. Although my E1 is pretty bass-heavy/boomy, I keep bass at 10:00~11:00 and treble at 1:00~2:00. Is the S1 boomy?


Yeah For the price I would say its a better deal to buy them thab try and make one. I will probs buy the P1 5150 pedal at some point. thanks for the link that will make good reading.

The schematics I have done are just 1st draft, there is still quite a bit to go over when i get a bit more time.
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

No silicon heaven ? preposterous ! Where would all the calculators go ?
User avatar
Ice-9
Transistor Tuner
 
Posts: 1057
Joined: 31 Mar 2009, 16:29
Has thanked: 138 times
Have thanks: 357 times

Re: AMT S1 Legend series [gut shots]

Postby Ice-9 » 26 Jan 2012, 18:24

Pruttelherrie wrote: Although my E1 is pretty bass-heavy/boomy, I keep bass at 10:00~11:00 and treble at 1:00~2:00. Is the S1 boomy?


I never noticed any boom, but I haven't been able to play it at any volume yet. The only time I can turn my amp up is Sunday mornings when I know my neighbours are at church. :wink: and i'm not bothering them.
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

No silicon heaven ? preposterous ! Where would all the calculators go ?
User avatar
Ice-9
Transistor Tuner
 
Posts: 1057
Joined: 31 Mar 2009, 16:29
Has thanked: 138 times
Have thanks: 357 times

Re: AMT S1 Legend series [gut shots]

Postby demym » 26 Jan 2012, 21:34

Interesting...

what are those diodes in stage 2 and 3 ? what are they supposed to do ?
demym
 
Posts: 12
Joined: 28 Jan 2010, 16:32
Has thanked: 0 time
Have thanks: 0 time

Re: AMT S1 Legend series [gut shots]

Postby Ice-9 » 28 Jan 2012, 11:15

demym wrote:Interesting...

what are those diodes in stage 2 and 3 ? what are they supposed to do ?


Pruttelherrie posted a link above to the AMT website where they explain how the circuit works and what the diode does, It's a good read on the design of there effects.
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

No silicon heaven ? preposterous ! Where would all the calculators go ?
User avatar
Ice-9
Transistor Tuner
 
Posts: 1057
Joined: 31 Mar 2009, 16:29
Has thanked: 138 times
Have thanks: 357 times

Re: AMT S1 Legend series [gut shots]

Postby demym » 28 Jan 2012, 12:35

Ice-9 wrote:
demym wrote:Interesting...

what are those diodes in stage 2 and 3 ? what are they supposed to do ?


Pruttelherrie posted a link above to the AMT website where they explain how the circuit works and what the diode does, It's a good read on the design of there effects.


Thanks very much. Yeah, i had read that article... But, maybe for the not perfect translation, i was not able to extrapolate the fundamentals of the rules of this kind of transformation; it's, in my opinion, sort of an evolved rog style fet4tube; will try to read better though.

Thanks once again
demym
 
Posts: 12
Joined: 28 Jan 2010, 16:32
Has thanked: 0 time
Have thanks: 0 time

Re: AMT S1 Legend series [gut shots]

Postby marshmellow » 29 Jan 2012, 14:25

Great work! Can you read the code(s) on the transistors?
marshmellow
Resistor Ronker
 
Posts: 435
Joined: 16 Aug 2007, 08:31
Location: Germany
Has thanked: 13 times
Have thanks: 115 times

Re: AMT S1 Legend series [gut shots]

Postby Ice-9 » 29 Jan 2012, 17:28

marshmellow wrote:Great work! Can you read the code(s) on the transistors?


Yeah I can read the codes on the Fets, I have an update to post of a more accurate schematic and will put the fet markings up then.. trouble is the codes are not great for info but someone may beable to work out equivelents. My quess would be j201's and 2n5457's will work well here.
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

No silicon heaven ? preposterous ! Where would all the calculators go ?
User avatar
Ice-9
Transistor Tuner
 
Posts: 1057
Joined: 31 Mar 2009, 16:29
Has thanked: 138 times
Have thanks: 357 times

Re: AMT S1 Legend series [gut shots]

Postby marshmellow » 29 Jan 2012, 18:30

There was a reason I asked for the codes... This might help :wink:.

For this message the author marshmellow has received thanks:
Ice-9 (29 Jan 2012, 19:27)
marshmellow
Resistor Ronker
 
Posts: 435
Joined: 16 Aug 2007, 08:31
Location: Germany
Has thanked: 13 times
Have thanks: 115 times

Re: AMT S1 Legend series [gut shots]

Postby Ice-9 » 29 Jan 2012, 19:15

marshmellow wrote:There was a reason I asked for the codes... This might help :wink:.



Yeah codes are no problem, there was a reason why I was waiting also :oops: I was drawing up the schematic and putting the info on there to post.
In the meantime here are the codes as there written on the fets and Diodes

VT1 - 8 JR
VT9 GiS 7 or 6iS 7
VT10-11 1F
VT12 W6Y or WGY

VD1-3 5C (I know these to be dual 1n4148 from another pedal i reversed MXR badass 78 distorion)
VD5 22W

Hope this helps.
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

No silicon heaven ? preposterous ! Where would all the calculators go ?

For this message the author Ice-9 has received thanks:
marshmellow (29 Jan 2012, 19:57)
User avatar
Ice-9
Transistor Tuner
 
Posts: 1057
Joined: 31 Mar 2009, 16:29
Has thanked: 138 times
Have thanks: 357 times

Re: AMT S1 Legend series [gut shots]

Postby KMG » 29 Jan 2012, 20:49

JR=2SK208 (Toshiba)
Gate-source diodes - small signal shottky BAT54
Be careful when selecting replacements, Victor Kampf selected for this design types of fet/shottky that matched by their curves.
Image

For this message the author KMG has received thanks: 2
bajaman (29 Jan 2012, 21:17), Ice-9 (30 Jan 2012, 00:48)
User avatar
KMG
Solder Soldier
 
Posts: 210
Joined: 02 Feb 2010, 21:26
Location: Russia
Has thanked: 5 times
Have thanks: 85 times

Next

Return to Modern Stompbox Effects (1975 - ...)

Who is online

Users browsing this forum: marvilla, phase396 and 8 guests