Ceriatone Molecular 50 Mods?

[Detroit ABA]

I picked up a Ceriatone Molecular 50 watt amp about a month ago. It is an awesome amp but I am wondering if some simple mods would make it even better. The edge switch to the right just isn’t very usable, to the left is awesome. Am I reading the schematic correctly that the bright cap to the right is 2200pf & left is 1000pf? Would a value below 1000pf be a better choice or higher than 2200pf like a 4700pf. The tone with all the switches in the center is cool but wondering what options would make it better? Anything with the feel switch, up is cool, down not so much. Full disclosure I don’t have the skill set to do the mods myself but would like to have some ideas before I take it to a tech. Also, I have read all the other threads here about this amp but I thought it made more sense to make a new one vs bumping an old one, thanks in advance

 

[RedPlated]

4700 pf would make the amp sound fuller with more of a low mid emphasis. 2200pf is actually a good value in these circuits typically. Tighter and more attack.

I personally like a PI plate resistor "fizz" cap lower than 100pf. 100pf can get a little round and smooth on the low strings. Try a typical 47pf for more sharp attack, or any value in-between 47 and 100pf.

Adjusting that 1 meg trimmer between the 470k after the first coupling cap will also affect the feel and tightness of the amp.

 

[glpg80]

Bypass the 68k hi input grid stop resistor with a 0.01uf ceramic. I really like to do that to Marshall circuits, it really woke mine up.

I’m not a fan of a 330k plate on the first stage, a bit much for my taste, but that’s personal preference. I know Friedman likes it too.

 

[psychodave]

lol. We’re all on the same page. I saw that fizz cap and thought nope! same with that 330k plate…too much.

 

[Detroit ABA]

4700 pf would make the amp sound fuller with more of a low mid emphasis. 2200pf is actually a good value in these circuits typically. Tighter and more attack.

I personally like a PI plate resistor "fizz" cap lower than 100pf. 100pf can get a little round and smooth on the low strings. Try a typical 47pf for more sharp attack, or any value in-between 47 and 100pf.

Adjusting that 1 meg trimmer between the 470k after the first coupling cap will also affect the feel and tightness of the amp.

Thanks for the reply, what are your thoughts on using a lower value like a 440pf, 560pf, or 750pf in place of the 2200pf? Also, how many different trimmer adjustments are in the circuit?

 

[glpg80]

Thanks for the reply, what are your thoughts on using a lower value like a 440pf, 560pf, or 750pf in place of the 2200pf? Also, how many different trimmer adjustments are in the circuit?

I like 0.001uF for a bright cap. Gives the upper mid Marshall bump. Remember that the cap is out of circuit when the gain is on 10.

 

[RedPlated]

Thanks for the reply, what are your thoughts on using a lower value like a 440pf, 560pf, or 750pf in place of the 2200pf? Also, how many different trimmer adjustments are in the circuit?

They can all be great. Just really depends on the rest of the circuit and your preference. A 100-220pf will give you more of a lower gain classic rock tone. The best way to find what you like is to buy a bunch of values and alligator clip them in to test so you can hear them. It’s a great way to dial in an amp.

 

[Detroit ABA]

How close or not so close is the Molecular component wise from the Atomica?

I am really just looking for it to be a bit more aggressive when the clipping diodes are not engaged and I can add a boost/overdrive. I have tried an SD-1 with it but also want to try the Friedman Golden Pearl. The Era left and right don’t really need a boost/overdrive. The edge switch to the right which I assume engages the 2200pf bright cap is more tolerable with the gain at 1 o’clock or higher.

 

[RedPlated]

The bright cap is less in circuit as you raise the gain. You can put a resistor between one leg of the cap and gain pot lug to reduce the overall effect of the cap.