Here's the audio file I created on short notice tonight. I tweaked the EQ just a little so it sounds like I hear it live. No FX, no boost pedals up front. Mostly the clean channel until the last minute or so of the file (about 9 min in?). Next post will detail every change I made. I really welcome any change anyone might suggest. LOVE the clean channel. The best way to use this amp now is set your CLEAN Ch. for the ideal breakup point...add a boost or fuzz pedal for extreme taste...then use the GAIN CH. o set it up for a nice bit of sustaining boost...or extreme gain/sustain. Most transitions form clean'ish' to sustain grit is using the Clean CH. and dialing from 6.5 to 10 on the guitar volume control. (Again, tex mex Fender pickups)
Jcm800 4211 Conversion?
- Thread starter myersbw
- Start date
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Here's the audio file I created on short notice tonight. I tweaked the EQ just a little so it sounds like I hear it live. No FX, no boost pedals up front. Mostly the clean channel until the last minute or so of the file (about 9 min in?). Next post will detail every change I made. I really welcome any change anyone might suggest. LOVE the clean channel. The best way to use this amp now is set your CLEAN Ch. for the ideal breakup point...add a boost or fuzz pedal for extreme taste...then use the GAIN CH. o set it up for a nice bit of sustaining boost...or extreme gain/sustain. Most transitions form clean'ish' to sustain grit is using the Clean CH. and dialing from 6.5 to 10 on the guitar volume control. (Again, tex mex Fender pickups)
Here's the extreme change log...sorry, no diagram. If you want to quick-peek at it, print out a 2210 preamp schematic and pencil in these changes... (sorry for the length...I have no drafting software to create with yet on my mac).
JCM800 4211 chassis mod. Only difference on the 2210 preamp schematic...there is no C39 on this specific version.
1 - remove all clipping diodes. Including D1
2 - Remove C45
3 - Remove C1 and add shorting jumper
4 - Add 47K resistor directly at V1a grid. (With only 10K, JJ's are ok...but Tung-Sol's oscillate)
5 - Change R2 to 1.8K & C2 to 1uF tropical fish cap (what I used)
6 - Change C7 to .1uF (didn't have the 0.047 the ENGL Blackmore used...closest I could get)
7 - Add 2.2M resistor to ground at C7/R11 junction
8 - Change R12 to 470K
9 - Change R3 ro 1.8K & parallel a 22uF cap
10 - Change C8 to .1 uF
11 - Remove VR4B (2nd 'gain' control) by clipping off the outermost pot leads and cutting the wiper trace. Then redirect the C8 jumper wire (underside of board) to the C16/R20 junction
12. Replace C16 w/ 330K resistor (remove R20)
13. Parallel a 220K resistor across R5...or replace with a 250K pot. (Resistor was in my drawer...no extra pot)
14. Change R24 to 3.3K and C18 to 10uF
15. Change R27 to 330K
16. Change R28 to 0.22uF cap, R23 to 100K, leave rest of tone stack as-is for now
17. Add 330K from FX Send to ground. (Easy tag on at the jack)
18. Change R25 to 3.3K & add 22uF cap across it.
19. Add 0.0012 silver mica across R30 (lol, what I had!)
That's about it. It is a mostly an ENGL Blackmore with the exception of tone-stack placement. The first stage is similar to a Soldano SLO. FX loop levels are fine...Reverb works better than you can hear in the audio file. Wish I had more time to get a true image of the gain channel...it sound MUCH sweeter in person.
JCM800 4211 chassis mod. Only difference on the 2210 preamp schematic...there is no C39 on this specific version.
1 - remove all clipping diodes. Including D1
2 - Remove C45
3 - Remove C1 and add shorting jumper
4 - Add 47K resistor directly at V1a grid. (With only 10K, JJ's are ok...but Tung-Sol's oscillate)
5 - Change R2 to 1.8K & C2 to 1uF tropical fish cap (what I used)
6 - Change C7 to .1uF (didn't have the 0.047 the ENGL Blackmore used...closest I could get)
7 - Add 2.2M resistor to ground at C7/R11 junction
8 - Change R12 to 470K
9 - Change R3 ro 1.8K & parallel a 22uF cap
10 - Change C8 to .1 uF
11 - Remove VR4B (2nd 'gain' control) by clipping off the outermost pot leads and cutting the wiper trace. Then redirect the C8 jumper wire (underside of board) to the C16/R20 junction
12. Replace C16 w/ 330K resistor (remove R20)
13. Parallel a 220K resistor across R5...or replace with a 250K pot. (Resistor was in my drawer...no extra pot)
14. Change R24 to 3.3K and C18 to 10uF
15. Change R27 to 330K
16. Change R28 to 0.22uF cap, R23 to 100K, leave rest of tone stack as-is for now
17. Add 330K from FX Send to ground. (Easy tag on at the jack)
18. Change R25 to 3.3K & add 22uF cap across it.
19. Add 0.0012 silver mica across R30 (lol, what I had!)
That's about it. It is a mostly an ENGL Blackmore with the exception of tone-stack placement. The first stage is similar to a Soldano SLO. FX loop levels are fine...Reverb works better than you can hear in the audio file. Wish I had more time to get a true image of the gain channel...it sound MUCH sweeter in person.
Sounds good.
I was just playing my project earlier and found the bug that was intermittently causing some odd hum.
Came up with yet another way to use it. Seems like I am finding a new way to set it up every time I play it. That is what is nice about having having amps with at least two channels and dual modes on each channel. I will put a clip up one of these days.
I was just playing my project earlier and found the bug that was intermittently causing some odd hum.
Came up with yet another way to use it. Seems like I am finding a new way to set it up every time I play it. That is what is nice about having having amps with at least two channels and dual modes on each channel. I will put a clip up one of these days.
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