Tube Chassis Layout

[pdf64]

With regard to the full cathode bypass, I was thinking of early stages, especially the input stage. Though the loop level recovery stages might also be regarded as equivalent to an input stage.
Heater circuit elevation refers to applying a positive DC bias to the heater circuit, derived from the HT, rather than the typical 0V reference. Your heater circuit looks to be missing any DC reference.

[JJH0906]

Yes, based on your observation and then we reviewing the drawings that I posted, I'm definitely missing parts and pieces of various circuits.

I will go back through it over the weekend and repost it for review as soon as that's done.

[pdf64]

What is the D output of the line output circuit?
What's that intention of the line output, eg what were you planning to connect it to?

[JJH0906]

That is an error on the line out sheet. The D You're supposed to be the reference on the output stage section, I mark it as C by mistake.

The purpose of the Line Out was intended to bring the signal to a recording board, PC software, etc.

[pdf64]

Ok, so that stage might be adapted to include wet - dry mixing for the reverb effect.

[JJH0906]

Yes, I believe so. I also missed a connection from the output of the reverb tank over to the recovery triode and also anothwr connection just prior to the 12AT7 to loop around for the reverb mix.

I attempted to redo the drawing but my PC "diee" so I will give it a go in the AM to straighten all that out.

[mwelch55]

I have used Ceriatone Layouts as a guide to build some of my amps. They have pictorial layouts for most of their amps. I have always had good results following their layouts.

Mike

as an FYI many of the ceriatone amps were directly cribbed from the amps here . I.e. you're saying their layouts look good but they're not really 'their layouts' they're HAD's ( or whoever built the one they used for other amps they sell.) As far as I know basically next to nothing is 'original' with ceriatone, they're all clones of existing designs.

~Phil

I knew the layouts were probably ripped off from somewhere. I have built a couple of amps based on the chupacabra drawing. I would like to thank whoever came up with that one because it works great.

Mike

[pdf64]

…
The purpose of the Line Out was intended to bring the signal to a recording board, PC software, etc.

The line out circuit, with its 220k pot, will be a high impedance signal (except at low settings). That will result in high frequency roll filter, whose corner frequency is determined by the pot setting and the capacitance of the cable connected to it (assume around 1nF unless a short, or high spec instrument grade, cable is used).
A line out that samples the speaker output signal is better, as it can be much lower impedance.
eg https://el34world.com/charts/Schematics ... _schem.pdf

To avoid ground loops occurring between your amp and other items of mains equipment it’s connected to, you may wish to consider building it such that the circuit 0V is isolated from the chassis, apart from a single point, eg as per R23, CR5&6 of https://el34world.com/charts/Schematics ... manual.pdf

[JJH0906]

Very good points, thanks! I'll check out those sites to get some better ideas who had to handle that.

Good suggestion on the 0 volts and physical earth ground. Probably my drawing does not reflect that they are separate. Turns out my PC operating system has decided to check out, so it will be a bit before I can get back to my files and revise them to be a little more pertinent!

[chaccmgr]

What is the 1 Meg Pot for below the slope resistor in the tone stack? Apart from not knowing the purpose, you will have HT on that pot. They are not built for high voltage.

[JJH0906]

This came from Merlin Blencowe's book that he referred to as a "shift pot" that will move the notch frequencies a little lower or higher, depending on the resistance of the pot.

Good point about the power, I will see if there was a specification on the size/watts.

[sluckey]

Good point about the power, I will see if there was a specification on the size/watts.

Wattage is not an issue because there is no dc current flowing through the pot, therefore zero watts dissipated. But voltage is an issue. A PEC pot would be a good choice for that pot.

[JJH0906]

I may scrap it but the example he provides as far as the notch shift seemed like an advanced way of shaping the tone outside of the 3-bamd EQ.

Again, he may have specified a certain kind of pot but I'll have to read through again to find out.

[sluckey]

I may scrap it but the example he provides as far as the notch shift seemed like an advanced way of shaping the tone outside of the 3-bamd EQ.

Again, he may have specified a certain kind of pot but I'll have to read through again to find out.

Follow Merlin's advise (highlighted) and you don't have to use a robust pot...

[JJH0906]

Yup, that's what I was referring to in his book. Hadn't completely read through the details but I see what he's saying now. Will do!