Hybrid amp design

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The misses didn't want me spending 60 bucks on a transformer, so I down graded to a head phone amp. I'll replace the 12.6 with this guy 166L16 Hammond Manufacturing | HM533-ND | DigiKey I'm still going to build the 40w amp just not in the immediate future.
My Hybrid's power transformer cost £10, which I think is $16. 80VA 22V toroidal. And this **** is more expensive in the UK. Shop around.
 
I fount this transformer, VPS28-6250 Triad Magnetics | 237-1282-ND | DigiKey and run my total again. I think I will use the 40W chip-amp. Anything wrong with electrolytic cap in the signal path, I have heard mixed things about it.
Do you mean at output? It's unnecessary unless you are doing single sided supply. I can't see a electrolytic on your 40W schematic.

If you mean input, remember this isn't hi-fi, it's guitar, so you only have to pass things from 80Hz. If you set the input cap for 40Hz you can do this with a cheap film cap easily. The 0.1u on your schematic is fine, the 10u unnecessary, as I've already said.

For single sided guitar amp speaker cap, where a bit of distortion is ok, it's not a problem to use electros really, provided you get the value and voltage right. You don't want it rolling off the bass, or being burned out by the signal peaks.

If you want to do it completely right, you make sure that the input cap has a higher roll-off than the speaker cap and nfb cap. That way the good quakity cap (at input) does the work, and the electrolytics don't
 
I fount this transformer, VPS28-6250 Triad Magnetics | 237-1282-ND | DigiKey and run my total again. I think I will use the 40W chip-amp.
What power amp will you use?
The LM2876 or the 2822?
This power transformer suits none of them.
Sorry.

Anything wrong with electrolytic cap in the signal path, I have heard mixed things about it.
You'll already have a few electrolytics in the signal path, if you build tube, and even more if you go SS, so .....
Besides, it's a *guitar* amp.
People who build one or two amps or factories who build 10 amps a year worry about them; those who make millions, do not.
Think Marshall/Fender/Peavey/Laney/ ...... (insert 2000 more) ..... /Vox/etc.

As a guide, I suggest everybody who wants to design (fine with me), to take a hard good look at *many* successful commercial designs.
Darwinist competition sure cleans the ranks very fast and leaves only the fittest.
Not to copy anybody, but to get a general feel of what "works".
At the beginning of this thread (which already surpasses 100 posts) I suggested , given the stated goal, to build a straight Orange Tiny Tube cropped and adapted to drive a chip amp.

By the way, ***Orange*** themselves are doing this too !!!!!
They call it "Micro Terror". Probably use an LM1875 .
http://www.youtube.com/watch?v=XzDohmkXeJs
 
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After some thought I have come up with this design, I'm actually pretty sure it will work this time. I have double checked the cap values with a simulation. I'm 76.2% sure I have the tubes biased right. The second stage uses local negative feedback. The tube supply transformer will be VPS230-570 Triad Magnetics | 237-1272-ND | DigiKey I still need to draw up a supply. For the power amp section I decided to cheat and go with this Kemo M033N 18 Watt Universal Mono Amplifier Module 320-553 I'm not sure if the specs provided on the parts express website are correct they seem kind funny to me, but i'm going to take a gamble. To power the amp module and tube heaters I'm going to use this ALS75-24 Triad Magnetics | 237-1296-ND | DigiKey I have double checked the specs on all supply's and transformers and they should supply sufficient power. I value your guy's input so please let me know if I'm in error. Oh and the tubes are clipping fairly symmetrically I used B2 spice to model everything, thanks in advance.
 

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