A small and simple amplifier that designed by me 😎 😀
https://anistardi.wordpress.com/2015/09/05/emprit-amplifier/
https://anistardi.wordpress.com/2015/09/05/emprit-amplifier/
Nice!
I have etched Tekukur Amplifier, I did however made my own PCB lay-out. I will share the DIY pdf files when I have tested the amp.
Sir Bimo, when you still have the time, mind if you can at least check my attempt of a generic Blameless (attached schematic) I have simulated and built it. Sounds nice but it's giving a 0.03vac when no signal applied (an audible hum).
Sorry OT
I have etched Tekukur Amplifier, I did however made my own PCB lay-out. I will share the DIY pdf files when I have tested the amp.
Sir Bimo, when you still have the time, mind if you can at least check my attempt of a generic Blameless (attached schematic) I have simulated and built it. Sounds nice but it's giving a 0.03vac when no signal applied (an audible hum).
Sorry OT
Attachments
There's a ground trace all the way around the edges of the pcb, it may need to be cut somewhere to avoid a ground loop.
Umm guys, I may have confused you, my hum problem is with the Blame60TMC (the schematic) I wanted Bimo (a seasoned simulator expert) to have a look at it. I have yet to complete my build of Tekukur amp, that pcb design lay-out was tested on my P3a and it works perfect, never encountered any problem with it I copied the same pattern and applied it the Tekukur amp.
Last edited:
I give from me 😉
It can have better performance if it use better transistor choice. Of course, it must be modify if use other transistors, specially VAS transistor to optimize it performance.
Wow, very nice of you!...and yes I'm thinking of using a CRT horizontal driver for VAS (low cob high ft)..
Thank you Bimo I will be contacting you via pm at this point...I don't meant to threadjack this nice small amp of yours....😉
Thank you Bimo I will be contacting you via pm at this point...I don't meant to threadjack this nice small amp of yours....😉
A friend who built this amplifier claimed it better than LM1875.
Another friend said he change 2SA1015 with 2SA992 and 2SC1815 with 2SC1845 then claimed have better result using those transistors.
I built it too. I like the result. Good bass, good mid, but high is not as good as Blameless 100, my another amplifier that designed by me.
Another friend said he change 2SA1015 with 2SA992 and 2SC1815 with 2SC1845 then claimed have better result using those transistors.
I built it too. I like the result. Good bass, good mid, but high is not as good as Blameless 100, my another amplifier that designed by me.
Very nice amp, Bimo. Conventional, but with very obvious care with dimensions; degen on the LTP and the VAS, and lag comp on the VAS and the Lender drive for example. These are empirical values you must have spent a lot of care to choose.
It is the details that make a beautiful amplifier, I take a bow, Pak........
YTH
Hugh
It is the details that make a beautiful amplifier, I take a bow, Pak........
YTH
Hugh
Attachments
Last edited:
I like it as well. Combination of Lender drive and EF2 OPS allows pretty light compensation, which is good for the sound. It also allows rather compact layout with short traces. Elegant simplicity for excellent result.
Great job Bimo!
Cheers,
Valery
Great job Bimo!
Cheers,
Valery
But high frequency is not as good as I tough. A friend choose NJW0281/NJW0302 for output transistors and said the high frequency is slightly better.
Try 215R for R24, use 100nF polystyrene for C15 and increase base resistors on the outputs to 10R. And I'd use around 12-15pF for lag comp, silver mica.
HD
HD
I would also try ksc3503/ksa1381 at Q5, Q6 positions with higher idle current for these drivers -> say, R24 = 100R
This is going to speed-up the OPS and ensure lower distortion at high swings.
Originally, I design this amplifier for Indonesia people who difficult to get good transistors. So, I used transistors which easily to find at small city in my country. This amplifier fit to newbie 🙂
But, any suggestion are welcome. May be, my friends who already built it can try your suggestion.
Hi Rio,
My suggestions were to improve the HF performance by increasing drive and interemitter cap of the drivers. I should have suggesting 2SC4793/2SA1937 Toshiba drivers which I've always found outstanding transistors, but they may be tricky to buy in Indonesia.
Hugh
My suggestions were to improve the HF performance by increasing drive and interemitter cap of the drivers. I should have suggesting 2SC4793/2SA1937 Toshiba drivers which I've always found outstanding transistors, but they may be tricky to buy in Indonesia.
Hugh
Also be careful with the speed-up capacitor. They often ruin the HF. I suggest to use ears and if no improvement heard just remove the cap (or try bigger capacitance).
If R24 change below 330R, Q5 and Q6's power dissipation is too high. If Q5 and Q6 are BD139/BD140, R24 can change to 220R without need a heatsink.
This is the simulation with several modification, but the result is slightly worse than the previous one.
This is the simulation with several modification, but the result is slightly worse than the previous one.
- Status
- Not open for further replies.