How to get more clean range

[Ranalog]

Hi every body.

I build this amp and its amazing, I only want to get a little more clean range.

How can I do it?

[tubeswell]

That schematic is badly drawn in as far as if your'e using a FW bridge rectifier, then you don't ground the HT winding's centre tap = its either one or the other, and if it's the centre tap, then you need a 2-phase rectifier.

Now if it so happens that you haven't grounded the HT winding's centre tap and are just using a FW bridge, then you will be okay.

Re: the clean headroom, you can change the rectifier to a 1/2-wave voltage doubler, and you should be able to get between 450-500V out of it, which is enough to ensure you can raise the B+ throughout and get more clean headroom. YMMV.

[Merlinb]

Obvious option: Turn your guitar volume down.

Alternative option which you may or may not like: Remove the cathode bypass cap on the power tube.

[Merlinb]

Re: the clean headroom, you can change the rectifier to a 1/2-wave voltage doubler, and you should be able to get between 450-500V out of it, which is enough to ensure you can raise the B+ throughout and get more clean headroom. YMMV.

Caution: This implies that the transformers can handle four times more power, which may not be the case. Also, four times more power is not a great deal louder, so I'm not sure how much cleaner it would make the amp appear...

[roberto]

I see different faults:
- treble and bright switches need a resistor to avoid pops;
- couple the CF directly, then do the voltage divider on the cathode;
- is NFB on the right side of the fx loop recovery cathode resistors?
- what's the purpose of the 1R on the cathode if you already have 470R?
- the bridge rectifier cannot be drawn like that.

[roberto]

A SE design is not the choice if we want loud&clean in the same amp.
That's even worse if we choose a not-so-clean preamp.

It dependo on what's really needed tonewise.

[strelok]

Yeah there's probably not going to be a way to squeeze much more clean volume out of it. But if you want raise the point that the preamp breaks up at you could start by reducing the value of the plate resistor on V1B. 220k is quite high, lower values will give you less gain and more headroom.

[roberto]

That's not totally true.
You have to check how that stage, together with the coupled CF, work together. My suggestion was in fact to make them work better together.

[Ranalog]

Hi,
I know that the rectification are badly draw but in the real amp I have a half rect.

Also I know that i need a resistors on the switch.

In the Real amp I have 100k plat resistor on V1b.

I dont undertat what are you say with CF? Iam sorry my english..... sucks.

I put R 1ohm to mesure the current.


I know that SE it'snt the best to get a loud clean but I only need a little more range.

My HV is 190-0-190 If I put other tranformer with 250-0-250 Can I take more clean? I need to change any value on the power amp stage?

Sorry for the draw its a old draw that I did before the changes.

[10thTx]

Use a 5751 or 12AY7 for V1

Use a 12AY7 or 12AV7 for V2.

Use 5uf cathode caps on V1-3 & V1-8 instead of 22uf.

With respect, 10thtx

[roberto]

One more thing, use a dpdt to switvh on and off the amp, not a single one.

[Phil_S]

CF=cathode follower

[Ranalog]

what do you recomend to do on the CF?

[Leo_Gnardo]

A SE design is not the choice if we want loud&clean in the same amp.

Deafinitely true, there is no substitute for power if you want loud & clean. Efficient speakers help too.

From a long-ago article by John Meyer (founder of Meyer Sound, super high quality sound reinforcement gear and studio monitors) "our ears interpret distortion as power." It's amazing how loud you can stand a clean signal, and how much power you can use up producing it.

[R.G.]

I know that SE it'snt the best to get a loud clean but I only need a little more range.

Can you explain in as much detail as possible what YOU mean by "clean range"?

There are multiple possible meanings of these words in English, and it's possible that readers may think of different things.

For instance, do you mean "louder output before I hear distortion"?

Or "I can turn up the volume control further before I hear distortion"?

Or something else?