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MagnaWatt!

Started by GrindCustoms, June 04, 2014, 08:48:46 PM

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GrindCustoms

Yo! Here's the 1watt power amp that i've been talking about in other threads.

I based it on the output section of the Firefly amp project, despite the small amount of components i've spent good time fettling with the bias resistor, suggested value was 430R when supplied at 265V, having a supply clocked at 190V this was'nt working great. Tube was getting nasty hot and i had very little output volume.

Using the values i have under hand in the required wattage, this part is still «rounded», i'm sure i can get more out of it, but i need to order much more resistor values, like... everything from 100R to 4K7 1W so i cover all the possibilities for this and be better equiped to work on more projects.

Tomorrow i'll experiment with the PSU and see if i can get stable output over 200V...that could be a game changer, because i still have enough current available.

I omitted the input cap because it was messing with the one at the output of the preamp.

Added a MV in case it would be able of Lemmy approved volumes   :P 









Magnavox 12AU7

AmpMaker 4watt OT

And again, thanks to Cleggy for some pointers while i was getting electrocuted on this....  :D
Killing Unicorns, day after day...

Building a better world brick by brick:https://rebrickable.com/users/GrindingBricks/mocs/

cooder

Another killa tube build in pedal size, holy moly....!!! This will go well with the JCM 800 pedal to scream at bedroom approved levels I guess...
Are you gonna do a pcb or layout of sort for that JCM800 pedal? That would be  sweeeeeet... 8)
BigNoise Amplification

GrindCustoms

Quote from: cooder on June 04, 2014, 09:40:21 PM
Another killa tube build in pedal size, holy moly....!!! This will go well with the JCM 800 pedal to scream at bedroom approved levels I guess...
Are you gonna do a pcb or layout of sort for that JCM800 pedal? That would be  sweeeeeet... 8)

Thanks! I still have some tweaking to perform on this, to see if it's worth something or if it's just a novelty, but still happy of the outcome.

We are actually working on these layouts. :)

Killing Unicorns, day after day...

Building a better world brick by brick:https://rebrickable.com/users/GrindingBricks/mocs/

alanp

Rej, that is pretty damn cool!

But please, please, PLEASE, heatshrink the transformer lugs and wire connections. Inside the enclosure is one thing, once it's buttoned up, but out in the open is another :)

Sorry if I am being rude, but when I saw "265V"...
"A man is not dead while his name is still spoken."
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cooder

Quote from: alanp on June 04, 2014, 10:09:56 PM

But please, please, PLEASE, heatshrink the transformer lugs and wire connections.
Good point that is...  :o
BigNoise Amplification

GrindCustoms

Quote from: alanp on June 04, 2014, 10:09:56 PM
Rej, that is pretty damn cool!

But please, please, PLEASE, heatshrink the transformer lugs and wire connections. Inside the enclosure is one thing, once it's buttoned up, but out in the open is another :)

Sorry if I am being rude, but when I saw "265V"...

Thanks Alan :)

265V is what is supplied by a PowerTransformer accordingly to the Firefly amp specs wich is also at a higher current.

It's now at 190V, with an approximate 650mA power draw, maybe less, i have to recalculate it.

It sure could benefit of some protection but since i'm not done with it completely it will stay like that until i'm happy all around.
Killing Unicorns, day after day...

Building a better world brick by brick:https://rebrickable.com/users/GrindingBricks/mocs/