Search found 172 matches

by KMG
11 Mar 2015, 14:39
Forum: Ready-To-Build Effect Projects
Topic: Fet version of the JCM800
Replies: 59
Views: 10882

Re: Fet version of the JCM800

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 f...
by KMG
28 Feb 2014, 16:15
Forum: Capacitors
Topic: The 'Sound' of Capacitors..
Replies: 695
Views: 211919

Re: The 'Sound' of Capacitors..

My tests show difference about 2 dB in area 2-3 kHz at level about -25 dB from highest peak at 150 Hz. Under spectrum difference I don't mean low signal frequency response, but different amount of produced harmonics. In overdriven tube stages interstage capacitors works differently than in "linear" ...
by KMG
28 Feb 2014, 10:04
Forum: Capacitors
Topic: The 'Sound' of Capacitors..
Replies: 695
Views: 211919

Re: The 'Sound' of Capacitors..

The main difference in spectrum is between Wima & other types of capacitors.
I think this is due to the difference in construction - Wima has "comb" construction, other types rolled construction.
SBE715_WIMA.jpg
But the difference between rolled types of capacitors is also "hearable".
by KMG
27 Feb 2014, 12:09
Forum: Capacitors
Topic: The 'Sound' of Capacitors..
Replies: 695
Views: 211919

Re: The 'Sound' of Capacitors..

Subtracting tracks is not good way.
Better way is to subtract cumulative spectrums.
Human ear does not "feel" exactly small difference in total volume, but skewness in spectrum products at the same level it "feels" distinctly.
by KMG
26 Feb 2014, 09:58
Forum: Capacitors
Topic: The 'Sound' of Capacitors..
Replies: 695
Views: 211919

Re: The 'Sound' of Capacitors..

Interesting test of the different types of capacitors in tube amplifier (unfortunately in russian, use google translate) http://forum.guitarplayer.ru/index.php?topic=301773.0 Comments: - Used reamp to eliminate difference of playing - Same controls & mic position while recording - Measured capacitor...
by KMG
21 Feb 2014, 17:43
Forum: Ready-To-Build Effect Projects
Topic: Fet version of the JCM800
Replies: 59
Views: 10882

Re: Fet version of the JCM800

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 http://milas.spb.ru/~kmg/files/projects/fetpa/mp/FetPaMSchS.jpg p.s ...
by KMG
20 Feb 2014, 21:04
Forum: Ready-To-Build Effect Projects
Topic: Fet version of the JCM800
Replies: 59
Views: 10882

Re: Fet version of the JCM800

Marshall style design of the F-800 [url=http://"http://milas.spb.ru/~kmg/files/projects/jcm800mv/fet/lnd150/head/frontn.jpg"] http://milas.spb.ru/~kmg/files/projects/jcm800mv/fet/lnd150/head/frontn_th.jpg [/url] [url=http://"http://milas.spb.ru/~kmg/files/projects/jcm800mv/fet/lnd150/head/rearn.jpg"...
by KMG
20 May 2013, 12:55
Forum: Ready-To-Build Effect Projects
Topic: Fet version of the JCM800
Replies: 59
Views: 10882

Re: Fet version of the JCM800

FET JCM800+5W (Clean, input Low) video test by Konstantin Dolotov
https://www.youtube.com/watch?v=1PUBfrtLzK0
by KMG
03 Apr 2013, 17:08
Forum: Ready-To-Build Effect Projects
Topic: Fet version of the JCM800
Replies: 59
Views: 10882

Re: Fet version of the JCM800

Video test by Konstantin Dolotov (camera mic)
https://www.youtube.com/watch?v=cB5XaE_vEJk
by KMG
23 Mar 2013, 17:18
Forum: Amplifiers
Topic: Orange Micro Terror
Replies: 40
Views: 55680

Re: Orange Micro Terror

I'm not sure about class D, PA looks like TDA or LM based
Image
http://www.squier-talk.com/forum/amp-ri ... error.html
by KMG
14 Mar 2013, 12:48
Forum: Ready-To-Build Effect Projects
Topic: Fet version of the JCM800
Replies: 59
Views: 10882

Re: Fet version of the JCM800

First "production" item of SS JCM800+5W
Image
Image
Image
by KMG
10 Jan 2013, 10:47
Forum: Ready-To-Build Effect Projects
Topic: Fet version of the JCM800
Replies: 59
Views: 10882

Re: Fet version of the JCM800

Test of Prototype. http://milas.spb.ru/~kmg/files/projects/jcm800mv/fet/lnd150/head/Prototype1_th.jpg With SS & Tube preamps. http://milas.spb.ru/~kmg/files/projects/jcm800mv/tube/brdtop_th.jpg Because they have the same board connectors pinouts, swapping was very easy. Controls settings are the sam...
by KMG
27 Dec 2012, 12:04
Forum: Ready-To-Build Effect Projects
Topic: Fet version of the JCM800
Replies: 59
Views: 10882

Re: Fet version of the JCM800

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
by KMG
24 Dec 2012, 08:12
Forum: Ready-To-Build Effect Projects
Topic: Fet version of the JCM800
Replies: 59
Views: 10882

Re: Fet version of the JCM800

The planned mini-head design Budget version http://milas.spb.ru/~kmg/files/projects/jcm800mv/fet/lnd150/head/Head20_th.jpg http://milas.spb.ru/~kmg/files/projects/jcm800mv/fet/lnd150/head/Head21_th.jpg Custom version http://milas.spb.ru/~kmg/files/projects/jcm800mv/fet/lnd150/head/Head22_th.jpg http...
by KMG
06 Dec 2012, 09:29
Forum: Software Room
Topic: POLL: What is your preferred PCB design software?
Replies: 31
Views: 32646

Re: Preferred PCB design software

other = KiCad
Example 4 layer pcb
Image

JCM800 tube preamp
KiCad
Image
Real
Image
by KMG
28 Nov 2012, 12:39
Forum: Modern Stompbox Effects (1975 - ...)
Topic: AMT Electronics - SS-20
Replies: 12
Views: 10416

Re: AMT SS-20

by KMG
20 Nov 2012, 19:33
Forum: Ready-To-Build Effect Projects
Topic: Fet version of the JCM800
Replies: 59
Views: 10882

Re: Fet version of the JCM800

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