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Marshall 2061X Clone MOD to Komet 19

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Mr. Lime:
Now I'm working on that circuit as well and got some problems with blocking distortion.
Already added 33k grid stoppers on 2nd stage and PI without success.
The mid control I suggested is put on a switch but doesn't contribute much to the tone.

I agree that it's quite bright with poor bass response.

darkbluemurder:
The issue with all the Trainwreck inspired amps is that the compression of all stages going into overdrive is a part of the design - that way you can set the amp so that your guitar sounds overdriven cranked and by digging in and then can be cleaned up by lightening your touch and/or backing off the volume control, and due to the compression having the clean tone not lose volume. The downside is that setting the amp this way is freaking loud -even with only two small tubes like 6V6s or EL84s. If you cannot crank the amp to that point it is not working as intended. A master volume does not help much as you will lose the power amp and power supply compression.

This is my experience from having built a Liverpool Light (only two EL84s in the power amp) and later converting the preamp to the Komet specs.  With the search function you can find both threads. The preamp by itself is bright and has a lot of hiss, even at low volumes. It is a very specialised design for sure.

Probably the best way to solve the loudness issue is to include a VVR. Maybe the guys who built one with a VVR can chime in?

Cheers Stephan

darkbluemurder:
I have also heard that using the right cab is critical.  A 4x12" would be good as the signal is spread to four speakers, thus bringing the volume down a bit. A 4x10" would achieve the same thing but as the amp is bright you may want the additional low end the 4x12" can provide. And I would recommend inefficient speakers to further bring down the volume.

Mr. Lime:
I had some frustrating hours with my amp but finally found the error causing nasty distortion.
The schematic is missing a PI input cap.
Now that I added one I got the sound I was expecting.
It is a very bright amp and I understand what Leadman wrote about.
I have added a conjunction filter like a VOX Hi Cut which helps but the amp still needs some tweaking.
VVR is also included.

Like Stephan wrote the speaker is critical as well. Probably because of the PA that has no negative feedback.
I didn't like it with my Jensen Blackbird but had good results with a Mesa VS-12.

Leadman:
Any final schematic about that design?

Best Regards.

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