FAOW

[EUVL]

> Little perfect watt amp is a big challenge

LM3886 THD+N <0.002% from 1 to 10W.
Wrong forum for you ?

🙂


Cheers,
Patrick

 

[juanitox]

yess , too easy to find 😀

 

[Soundhappy]

LM3886 is 38 watt's into 8 Ohm load means out of the 1watt category and FAOW challenge 🙂
Wrong ? Simply not my " cup of thea " audio amp device

 

[MEPER]

Will it be in class A below 1W output in 8 ohm?
As long as both output transistors are "on" 100% of the time it is class A?


It is more simle with single ended…...it is always class A...….

 

[Zen Mod]

again , TBA810?

 

[EUVL]

Yes !!!!
0.3% distortion. Meets the spec. 🙂


Patrick

 

[Rodeodave]

TL431 perhaps?

 

[indra1]

... please modify the 120vcc version (keep the 120vcc psu) from 1w to somewhere near 5-6w (i wouldnt mind a bit of complexity if it is the case and keep that pure second harmonic signature)? ...

5-6W at 120V B+ needs rare or custom ~ 500 Ohm SE OT with 200 mA DC bias. I would suggest an easier to obtain 2K5 PSE OT rated for 100mA bias and raise B+ to 250V.

You can use the attached schematic a a starting point if you know what you are doing. Current production Diodes SOT223 input PMOS and Wolfspeed C2M100170D, can be adapted to Rohm SCT2450. 6.55W @ 2V rms input, K2 dominant Neg phase, DF ~ 3.85. Requires 1K/W HS or better per channel. VR1 sets bias, monitor at R1. Increase R1 (up to 6.8 R) if bias can not stabilize at operating temperature.

Please start a new thread if you have questions or need more help since this is OT.

 

[sergiu2009]

Thank you very much Indra.

 

[woody]

Edcore makes the CXSE25-600 A 600 OHM TRANSFORMER RATED AT 250MA FOR ONLY $ 99.39 .

 

[indra1]

Off course, the convenience for those who reside in the States. 🙂

 

[marconi118]

Just for fun while I'm working up the other stuff, here's a true junk box quickie:

.4% THD @ .5W 8 OHMS
Clips around 3/4 of a watt
Balance a couple for two massive watts
No adjustments
Can use a small TO-220 heat sink
Nice warm glow 🙂

could this work with irf710 and reversing the PSU polarity of course?!

 

[vdi_nenna]

Not that it matters now, but some time ago I had this fantasy of designing a power amp with parts available from Radio Shack. Idea was that anyone could walk into a national chain store and buy parts to make a power amp. They had a IFP510 or IRF610 and a bunch of different BJTs. Never thought anyone would care about an amp with 1 watt. This thread is proof I was wrong again. 🙂

Anyway, had that thought rolling around my head for a long time. Needed to let it out.

 

[Michael Rothacher]

could this work with irf710 and reversing the PSU polarity of course?!

It works, but in this particular case the bigger parts yield lower distortion. 🙂

 

[marconi118]

It works, but in this particular case the bigger parts yield lower distortion. 🙂

I will parallel some irf710 as I have many, it will increase yfs and decrease distortion?

 

[Michael Rothacher]

Yes, that will help. 🙂

 

[marconi118]

what about buk7575-55 ?
Should have a Gfs of 5 @ 1A drain current

 

[Michael Rothacher]

Sure, why not. 🙂

 

[marconi118]

if I go for the balanced version, with 2 mosfet and 2 buls, I feed + and - input to the gates via gate stoppers. Do I need to connect the ground of the DAC to the GND of amplifier (in this case VCC) or can I leave it floating, only connectiog + and - phases from the DAC to the amp?

 

[Zen Mod]

open separate thread for that , do some work on graphic explanation