PAL Fx JCM 800 Emulator

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

PAL Fx JCM 800 Emulator

Postby roseblood11 » 16 Feb 2017, 11:45

Great pedal... Looks a bit like a runoffgroove design.
Any info about this one?
The picture in the video might be good enough for tracing.
https://youtu.be/I1QHo7-9O58
roseblood11
Opamp Operator
 
Posts: 1649
Joined: 23 Aug 2008, 15:21
Has thanked: 294 times
Have thanks: 291 times

Re: PAL Fx JCM 800 Emulator

Postby J0K3RX » 16 Feb 2017, 23:44

Looks like the standard JFET JCM800 direct copy of the tube amp values with maybe a few resistor value changes and a couple other mods..

probably not far off from this..
http://www.uk-electronic.de/Download/Be ... JCM800.pdf

For this message the author J0K3RX has received thanks:
bmxguitarsbmx (14 Jun 2017, 19:19)
User avatar
J0K3RX
Degoop Doctor
 
Posts: 929
Joined: 29 Jun 2011, 02:25
Location: US Florida
Has thanked: 267 times
Have thanks: 422 times

Pal jcm 800 emulator

Postby jimiguitar » 25 Feb 2017, 16:06

Has any one seen the videos of the pal 800 emulator and their other products
I
jimiguitar
 
Posts: 44
Joined: 15 Jul 2011, 19:54
Has thanked: 3 times
Have thanks: 0 time

Re: Pal jcm 800 emulator

Postby roseblood11 » 25 Feb 2017, 20:34

Yes, it's great. I'd really like to see a schematic.
roseblood11
Opamp Operator
 
Posts: 1649
Joined: 23 Aug 2008, 15:21
Has thanked: 294 times
Have thanks: 291 times

Re: PAL Fx JCM 800 Emulator

Postby roseblood11 » 02 Mar 2017, 00:45

yupp, might be close. But I'd really like to know the details. I built many Marshall emulators, and they all were good, but this one might be even closer to the real amps sound.
Butt off course it's quite easy to get that kind of sound with a vintage Les Paul and an Orange Stack...
roseblood11
Opamp Operator
 
Posts: 1649
Joined: 23 Aug 2008, 15:21
Has thanked: 294 times
Have thanks: 291 times

Re: Pal jcm 800 emulator

Postby toneman » 03 Mar 2017, 05:44

gut shots first.......
from effectsdatabase:
http://www.effectsdatabase.com/model/pal/800

"This pedal 100% handmade uses the same circuit schematic that you will find on a JCM800 amp
using especially selected transistors instead of vacuum tubes."
Hmmmm....maybe a little bit of "mojo"??

if the pcb does not use surface mount parts it should be cloneable.
8)

P.S.
http://drtube.com/schematics/marshall/jcm800pr.gif
Tone-to-the-Bone
User avatar
toneman
Solder Soldier
 
Posts: 246
Joined: 17 Jul 2007, 14:05
Location: sacatomatoes, Kali
Has thanked: 73 times
Have thanks: 9 times

Re: PAL Fx JCM 800 Emulator

Postby Cub » 03 Mar 2017, 10:14

I don't think the Pal is a million miles away from the three in the links below and though it sounds really good, I'd say that the 9V JFET amp-emulators has been surpassed by other types of technology.
Guitar FX Layouts: Marshall JCM800 Emulation
JCM 800 Emulator pedal build
JCM800 Emulator vero - Sabrotone

Our brother KMG, for example. He used LND150 MOSFETs at the original "plate" voltage and in the clips he posted, I couldn't tell the difference between the solid state and the tube version !
Fet version of the JCM800

Even at runoffgroove, they have moved on from JFET only and are implementing clipping diodes with great results.
Thunderbird - Plexi Super Lead
Azabache - Vintage Fenders
Britannia - VOX AC-30 Top Boost
I wish I were a chestnut tree, nourished by the sun.
With twigs and leaves and branches and conkers by the ton.
User avatar
Cub
Resistor Ronker
 
Posts: 268
Joined: 29 Aug 2011, 08:14
Location: The Netherlands
Has thanked: 50 times
Have thanks: 52 times

Re: Pal jcm 800 emulator

Postby Zool » 04 Mar 2017, 00:30

In this video there are some pictures showing the inside of the pedal:
https://youtu.be/I1QHo7-9O58

Also here is this JCM800 emulation from years ago:
http://tagboardeffects.blogspot.hu/2014 ... ation.html

I am not good at electronics, just building pedals from layouts, but they look close to me. Both of them has the same number and type of capacitors, resistors, trimmers, potentiometers. I am not good at decoding the resistor color codes in the video (would take me an awful lot of time to do it), and I'm on mobile right now and cant read the capacitor values, but I think it's worth a check.
Zool
 
Posts: 1
Joined: 06 Feb 2014, 01:10
Has thanked: 0 time
Have thanks: 0 time

Re: Pal jcm 800 emulator

Postby toneman » 04 Mar 2017, 01:06

good links, zool :!:

had not seen them b4 and they didnt come up in my previous search.

i HAVE seen the Thunderchief schematic @ RunoffGroove :wink:
and the modded schematic with a tonestack.
but have never built any of the jfet overdrives.

Love those J201s :!: :!:
8)
Tone-to-the-Bone
User avatar
toneman
Solder Soldier
 
Posts: 246
Joined: 17 Jul 2007, 14:05
Location: sacatomatoes, Kali
Has thanked: 73 times
Have thanks: 9 times

Re: PAL Fx JCM 800 Emulator

Postby bmxguitarsbmx » 15 Jun 2017, 05:19

PAL800 CIRCUITBOARD TOP.jpg

pal 800 pcb bottom copper.jpg

JOK3RX seems to be dead on with this one. Check his link posted above. Let me know if you need anything.
You do not have the required permissions to view the files attached to this post.

For this message the author bmxguitarsbmx has received thanks:
modman (20 Jun 2017, 12:05)
bmxguitarsbmx
 
Posts: 48
Joined: 25 Mar 2010, 22:15
Has thanked: 87 times
Have thanks: 27 times

Re: PAL Fx JCM 800 Emulator

Postby J0K3RX » 16 Jun 2017, 19:04

Nice one bmxguitars... I guess this one can be added to the "modern sb traced" catagory now. :wink:

For this message the author J0K3RX has received thanks:
bmxguitarsbmx (20 Jun 2017, 20:10)
User avatar
J0K3RX
Degoop Doctor
 
Posts: 929
Joined: 29 Jun 2011, 02:25
Location: US Florida
Has thanked: 267 times
Have thanks: 422 times


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

Who is online

Users browsing this forum: Google Feedfetcher, Majestic-12 [Bot] and 14 guests