Express/ Liverpool Cold Clipping

[Amwatts]

Is anyone interested in the schematic of my musings .... after many hours of changing the values of components, chopping /changing and trying all the possibilities I can think of , I have finally come up with my own recipe for this amp. You may find a better recipe.

It's combining the Rich Gordon designed Ken Fisher inspired single tone / single volume Preamp, with a 5E3 Fender Tweed deluxe Cathodyne PI and cathode biased output section , and adding a Pot to adjust V2A's Cathode bias cold clipping section to create what I believe to be a killer 15/18 watt amp , that operates with the same characteristics as Kens Express.

The Volume control on your guitar is all there , the over the top sustain/grind is achievable , the clean crisp and full organic tones are all there under your finger tips , Add and EQ pedal and it's tone heaven .

I'm happy to share the schematic if you're interested ... after all It's not my design, just my recipe based of others designs ... but that what it's all about isn't it .

[martin manning]

Sure, post it and see what people have to say.

[Amwatts]

Amwatts Grande Expresso Schematic.jpg

Here it is , I really like the 2M input , over the standard 1M ...

[ChopSauce]

Thanks for summarizing "things" ...

If you don't mind one question from an ignorant: how about that tone control?

[LOUDthud]

Here it is , I really like the 2M input , over the standard 1M ...

As drawn, the input impedance is 63.9K on either input.

[jabguit]

I really like the 2M input , over the standard 1M ...

Why, may I ask?

cheers,

[Amwatts]

I really like the 2M input , over the standard 1M ...

Why, may I ask?

cheers,

It adds a little sparkle overall, It's not like a bright cap , just an audible difference which I like, hard to explain but you can definitely hear it . I first saw it my 1946 Fender Model 26 Deluxe , It was on the Mic input jack , That channel always sounded better than the Instrument channel , I like to add it to all my builds , Just another option

[Amwatts]

Here it is , I really like the 2M input , over the standard 1M ...

As drawn, the input impedance is 63.9K on either input.

The grounded resistor on the jack is the 'input resistor.' It sets the amp's input impedance to 1,000,000 ohms (1M) or 2,000,000 (2M) to boost the signal voltage from the guitar. The 2 x 33k resistors are 'grid stopper' resistors. They help stabilize the amplifier by removing much of the audio signal above human hearing.

[Amwatts]

Thanks for summarizing "things" ...

If you don't mind one question from an ignorant: how about that tone control?

Not sure what you're asking , it's an alternative to the standard TMB tone control

[LOUDthud]

The grounded resistor on the jack is the 'input resistor.' It sets the amp's input impedance to 1,000,000 ohms (1M) or 2,000,000 (2M) to boost the signal voltage from the guitar. The 2 x 33k resistors are 'grid stopper' resistors. They help stabilize the amplifier by removing much of the audio signal above human hearing.

As drawn, the "Other" 33K is always grounded if you are only using one input.

Express_AMW.GIF

[LOUDthud]

Perhaps what you want is more like this:

Express_AMW_2.GIF

[ChopSauce]

Thanks for summarizing "things" ...

If you don't mind one question from an ignorant: how about that tone control?

Not sure what you're asking , it's an alternative to the standard TMB tone control

Thanks! I'll have to study how that behaves. Seems that you are satisfied with it, at least.

[Amwatts]

Perhaps what you want is more like this:
Express_AMW_2.GIF

Thanks for fixing that for me , I get what you're saying now
I changed it to an on/off/on toggle so It gave options ,1M, 0 , 2M It's very subtle , but it's there .
I have a close friend who put his harmonicas through it , definitely needed the 2M for his mics

Screenshot 2023-05-11 at 6.07.15 pm.png

[Amwatts]

Thanks! I'll have to study how that behaves. Seems that you are satisfied with it, at least.

It was to fit in with the single tone tweed deluxe guise layout of the faceplate . It's Rich Gordons mod, I simply incorporated it , I haven't played with the values yet though it seems pretty good with Rich's specs
The cathodyne Phase inverter of the 5E3 deluxe was notorious for flubbing out in the bottom end , so I wouldn't want more bass there , it can still flub if you turn the tone down & use the next pickup and low strings , and it has enough top end to get near tele icepick if that's your thing , so I think Rich nailed the values there, I leave it around 11 o'clock

[ChopSauce]

Thousand thanks!

Did you really made for an 0M grid leak resistor option on input?

I don't think that would be sustainable...