modern classic cascade mod

[Bieworm]

I can't stop tweaking the classic tremolo. When I use it for practice I can't play it loud enough to break up. I tried various boost pedals, but they all make the amp sound less beautiful.

So I came up with this: I never use the normal channel for I need to have access to tremolo all the time. I disconnected the normal channel and cascaded the tremolo channel into V1. At first it was a whole quest to get good tones out of it. But when I dime the tremolo channel I have a nice bit of crunch. (see the green drawings)
But when trem preamp is dimed and V1 is set at volume on 2 the tonepot of the trem channel is very little effective. Is it a stupid idea to tweak the tone on V1? Seems logic to me to shape the tone after the preamplification... Is the drawing in red a good start?

FWIW ..when I put a cap (.68 of 2.2uf) parallel with the cathode resistor on V1 it does increase drive, but it's pretty noisy then too, so I left it out...

tremolo cascade with tone mod.pdf

Josh

On the tremolo TMB you have a separate cathode RC combination on the 2nd preamp stage. What is the difference with a shared one? Does it make the OD more complex?

[geoff 1965]

if you are only using V1 for the cascade gain would'nt you be better configuring the volume & tone pot to the interactive tremelo type? i.e. the tone wiper feeding into the volume wiper rather than going to ground.

[Bieworm]

Thx Geoff..I'll try both. Good tip!

[Bieworm]

if you are only using V1 for the cascade gain would'nt you be better configuring the volume & tone pot to the interactive tremelo type? i.e. the tone wiper feeding into the volume wiper rather than going to ground.

Did the test. The wiper to wiper made the volume jump too abrupt. No good that way.. almost impossible to fine-tune.
Tone wiper to ground is superb. I also separated the cathode resistors of both triodes. So 1 goes to ground through the standard 820R resistor with a 47uf bypasscap. The other C goes to ground through only a 2k2 resistor. This amp rocks now.. even on low volume. So if I want clean I turn the trem preamp to vol 2 and cascade vol to 4. If i want crunch I turn the trem vol to 8 and the cascade preamp to 1.5. Nice thing is it still has all the touch sensitivity so with light picking it's also clean

[Bieworm]

here's the schematic for the ones interested...

18 watt tremolo cascade mod.png

[JMPGuitars]

here's the schematic for the ones interested...18 watt tremolo cascade mod.png

Looks interesting.......but where's the demo?

[Bieworm]

here's the schematic for the ones interested...18 watt tremolo cascade mod.png

Looks interesting.......but where's the demo?

upcoming ofcourse to be continued

[colossal]

Bieworm,

Nice work. On your schematic, you show a wire linking Pins 3 and 8 on your paralleled "normal" stage. Is this really the case? If so, then the stage is biased at 820R || 2k2, which is 597R. The way I read your post though, is that one triode is warm biased with 820R/50uF and the other triode is cold biased and unbypassed with 2k2, with both sharing the common anode.

[Bieworm]

Bieworm,

Nice work. On your schematic, you show a wire linking Pins 3 and 8 on your paralleled "normal" stage. Is this really the case? If so, then the stage is biased at 820R || 2k2, which is 597R. The way I read your post though, is that one triode is warm biased with 820R/50uF and the other triode is cold biased and unbypassed with 2k2, with both sharing the common anode.

Oops! Nice catch!!! The line between the 2 cathodes should be erased. They are not connected to each other

[Bieworm]

I changed the tone circuit of the cascade preamp to Josh's tone circuit on the modern classic 's normal channel. I found the previous circuit too dark. I needed more treble..way better!!

15992472849455669560481768259788.jpg

[geoff 1965]

that's what i meant earlier, it's the "lite2b" configuration, if you want to tweak it replacing the .0047 off the plate with a .01 will let more breakup through but you'll probably have to cut some bass with the cap from tone pot to ground. it works opposite in that position i.e. .0047 to .01 will cut bass.

[Bieworm]

Sound sample:
https://www.dropbox.com/s/czn6pj3s4heji ... d.m4a?dl=0
Sorry for the people who think reverb is not compatible to marshall type amps.. I prove the opposite here!!!
Don't know what you guys think, but I think that's a pretty nice preamp overdrive here. In real life it sounds more overdriven than the recording. And more trebly for that matter..

[lavrgs]

That sounds very good and clean(ish) 9-) What is your recording set up? If my amp sounded that good I may not step away from it.

[Bieworm]

That sounds very good and clean(ish) 9-) What is your recording set up? If my amp sounded that good I may not step away from it.

Lol!!
Well I do all my recordings with my samsung S10. Too lazy to really record it with my equipment. Don't have my computer in the same room. I think the samsung does a decent job anyway.
My goal was to make the amp go a little in OD on reasonable levels.. and I "think" I did a successful job. Tomorrow evening I will take it to practice and can judge the result better than at home. See how it performs among other amplified instruments.

[lavrgs]

even more impressive that you used a phone...I'm listening on a laptop speaker so they are well matched...I'll have to try that.
I wanted to do a comparison to my Mojotone 18W trem. Would you mind if I copied the file to do a left right compare?

[Bieworm]

even more impressive that you used a phone...I'm listening on a laptop speaker so they are well matched...I'll have to try that.
I wanted to do a comparison to my Mojotone 18W trem. Would you mind if I copied the file to do a left right compare?

Not at all. Be my guest

[Bieworm]

Took the amp to practice last monday... it sounded awesome!! Very pronounced and balanced with nice overdrive...
BUT... it is no match for the tremolo TMB IMHO. It didn't blend with the rest of the band as nice as the TMB. I missed the tremolo TMB... I love that amp sooooo much!!!
The modern classic cascaded has bigger and tighter low end though.. but I don't think that's better per ce. Just different... probably because the classic carries a 70th anniversary g12h30 and the trem TMB sports that nice early 70's g12h30...

[lavrgs]

even more impressive that you used a phone...I'm listening on a laptop speaker so they are well matched...I'll have to try that.
I wanted to do a comparison to my Mojotone 18W trem. Would you mind if I copied the file to do a left right compare?

Not at all. Be my guest

Things are on hold for a bit because of fire...I'm on the edge of the evacuation zone although I don't expect to have to leave...

[Bieworm]

7

even more impressive that you used a phone...I'm listening on a laptop speaker so they are well matched...I'll have to try that.
I wanted to do a comparison to my Mojotone 18W trem. Would you mind if I copied the file to do a left right compare?

Not at all. Be my guest

Things are on hold for a bit because of fire...I'm on the edge of the evacuation zone although I don't expect to have to leave...

Dang...

[colossal]

Things are on hold for a bit because of fire...I'm on the edge of the evacuation zone although I don't expect to have to leave...

Be safe, man. I have friends near Newburg that are on alert too.