Fet version of the JCM800

Greenmachine · Post by **Greenmachine** » 20 Nov 2012, 15:51

Tight! I want one.

KMG · Post by **KMG** » 20 Nov 2012, 18:33

Same controls setting except master volume turned to MAX position
Mini Head Full Power

KMG · Post by **KMG** » 04 Dec 2012, 11:57

Additional samples
Mini head, gain at 2 hours, presence 2 hours, Depth & TS at middle positions
Mini head, gain at full position, Depth, presence & TS at middle positions

KMG · Post by **KMG** » 24 Dec 2012, 07:12

The planned mini-head design
Budget version

Custom version

KMG · Post by **KMG** » 27 Dec 2012, 11:04

Another several samples
High input, gain at 3.5, TS, presence & depth at middle
High input, crunch
Low input, gain at 8, TS, presence & depth at middle
Low input
Low input + reverb in loop

KMG · Post by **KMG** » 10 Jan 2013, 09:47

Test of Prototype.

With SS & Tube preamps.

Because they have the same board connectors pinouts, swapping was very easy.
Controls settings are the same for different preamps while recording.
Fet_vs_Tube
Archive contains mix & only guitar tracks.
Legend:
SX_Y
X - track number
Y - preamp number
SX_YG - only guitar without mix.
Try to estimate who is who.

Pruttelherrie · Post by **Pruttelherrie** » 12 Jan 2013, 11:06

KMG wrote:Try to estimate who is who.

I do know that I like preamp 2 slightly better, it's a little bit darker sounding, a bit more muffled, but I really can't tell which is which. Amazing!

KMG · Post by **KMG** » 14 Mar 2013, 11:48

First "production" item of SS JCM800+5W

KMG · Post by **KMG** » 03 Apr 2013, 16:08

Video test by Konstantin Dolotov (camera mic)

KMG · Post by **KMG** » 20 May 2013, 11:55

FET JCM800+5W (Clean, input Low) video test by Konstantin Dolotov

KMG · Post by **KMG** » 20 Feb 2014, 20:04

Marshall style design of the F-800
[url=http://"http://milas.spb.ru/~kmg/files/projects/jcm800mv/fet/lnd150/head/frontn.jpg"]

[/url]
[url=http://"http://milas.spb.ru/~kmg/files/projects/jcm800mv/fet/lnd150/head/rearn.jpg"]

[/url]
[url=http://"http://milas.spb.ru/~kmg/files/projects/jcm800mv/fet/lnd150/head/topn.jpg"]

[/url]

apollomusicservice · Post by **apollomusicservice** » 21 Feb 2014, 12:47

Well done, that man. Tell us little about output transformer made for this amp.

p.s I cannot zoom these photos

KMG · Post by **KMG** » 21 Feb 2014, 16:43

Tell us little about output transformer made for this amp.

5W PA transformer:
Core cross section 20x16 mm
Each half bobbin:
120 turns 0.25 mm (1/4) primary
75 turns 0.5 mm secondary (for 8 Ohm load)
120 turns 0.25 mm (1/4) primary

p.s I cannot zoom these photos

Sorry, incorrect links in previous post, follow these links:
http://milas.spb.ru/~kmg/files/projects ... frontn.jpg
http://milas.spb.ru/~kmg/files/projects ... /rearn.jpg
http://milas.spb.ru/~kmg/files/projects ... d/topn.jpg

KMG · Post by **KMG** » 24 Feb 2014, 13:28

BlueMeany · Post by **BlueMeany** » 17 Feb 2015, 22:29

Sorry for resurecting an old thread but I've only just stumbled upon this. It looks great!

How accurately does this technique replicate a tube cathode follower? Does it soft clip?

KMG · Post by **KMG** » 11 Mar 2015, 13:39

How accurately does this technique replicate a tube cathode follower? Does it soft clip?

Read this article Some nuances of using mosfets as followers in tube guitar amplifiers
And futher researches by Victor Kempf (Designer of AMT electronics) Source follower on the high voltage MOSFET as cathode follower

file1 · Post by **file1** » 02 Jul 2017, 22:17

Dear All,

because of problem reaching KMG (milas) site is it possible to somebody upload his jcm 800 project with fet's ?

Thank you,
Rest of us

file1 · Post by **file1** » 03 Jul 2017, 08:05

Please , can send me somebody JCM800 fet version? Thank you in advance

karul · Post by **karul** » 03 Jul 2017, 16:19

file1 wrote:Please , can send me somebody JCM800 fet version? Thank you in advance

You may find it here

https://web.archive.org/web/20160801121 ... ex_en.html

file1 · Post by **file1** » 04 Jul 2017, 07:53

Ok. Thank you