I want to use 12S LiFePO4 batteries: -30VDC<-Ub<-43.8VDC from full to empty.
Schematics is 2SJ28 with CCS.
My question is: I will lost on output power ok, but do I increase distorsion?
I don´t want to waste battery power with regulated supply!
Schematics is 2SJ28 with CCS.
My question is: I will lost on output power ok, but do I increase distorsion?
I don´t want to waste battery power with regulated supply!
The CCS is... constant current, so you only lose power when the voltage reduces, and so saturate asymetrically, but is not a problem since this amp already saturates asymetrically, anyway; the sweet spot and THD is maintained.
Since this is an hot class A SE amp, I recommend to use an large "L" aluminium with good gauge, with good flat coupling to main large heatsink. Use thin good quality "mica" (insulating washer) with high-quality thermal grease, applied gently only to fill voids (I used some hi-grade grease for CPU).
@DIYBras
as always instructive.
One question beyond audio: is the brasilian cuisine so spiced? I had a bean salad with, in my opinion, too much "Provence" herbs!
as always instructive.
One question beyond audio: is the brasilian cuisine so spiced? I had a bean salad with, in my opinion, too much "Provence" herbs!
An other question: would I kill the SIT if I lost the bias voltage before the supply voltage?
Thanks to CCS, if you have no bias the SIT only becomes saturated, and survives OK... but the MOSFET in CCS becomes more stressed (it see the full supply voltage), and is OK for various minutes (or even indefinite) if you have an good heatsink.
My country is really big (of course...🙂), and has several variations of cuisine throughout the territory. I do not know even 30% of the cuisine here, but in general, especially further north in the country (toward NorthWest, or "Nordeste"), the food tends to be tempered with more spice or with stronger spices (sometimes VERY strong 😱 ).
In the south region, which is where I live, the cooking has more European influence, and often have spices a bit smoother, but exceptions exists. So for my tastes the "northern" food is heavy spiced...
Beacuse of this, products for exportation of course will be more "brazilian" (from center to north Brazil).
Also in music, various regional rhythms exists, and some quite different from samba.
Two solutions for battery power:
- using existing components,
- or complete new development.
Pros and cons.
New development:
- Pros: 4S + 16S with only one and the same BMS: you lost both voltage at the same time
- Cons: $$$ and time
Using COTS:
- Pros: $, garantie, safe
- Cons: needs two different battery packs with two independant and different BMS
Here one choice for the +/-Ub supply:
MTML-Trading Fahrradakkus - Sattelrohrakku 36V 10Ah LiFePo4 Prophete Phylion Zhenlong Umbausatz lang
309€ with charger! Ok, only 360Wh, but you can run fast charging and the cycles are even good.
- using existing components,
- or complete new development.
Pros and cons.
New development:
- Pros: 4S + 16S with only one and the same BMS: you lost both voltage at the same time
- Cons: $$$ and time
Using COTS:
- Pros: $, garantie, safe
- Cons: needs two different battery packs with two independant and different BMS
Here one choice for the +/-Ub supply:
MTML-Trading Fahrradakkus - Sattelrohrakku 36V 10Ah LiFePo4 Prophete Phylion Zhenlong Umbausatz lang
309€ with charger! Ok, only 360Wh, but you can run fast charging and the cycles are even good.
Hi Jps1964
More distance between transistors on heat sink give better heat dissipation and longer service life.
Fancy special aluminium connecteur good for audio ?
Classic copper wire soldered to pcb are the best imo.
Great work anyway congratulation but you need make real prototype with soldered components before pcb's make in serie.
Some of builds details are not included in software.
Try & see
Have fun
Can the L'amp chock loaded and CCS version survive a 4 ohm load?
4 ohm midrange with choke loaded and 4 ohm tweeter with CCS version.
4 ohm midrange with choke loaded and 4 ohm tweeter with CCS version.
How low does the midrange go in frequency (xover point)?
What is sensitivity of driver?
How loud do you listen to music?
started to make bias supply this morning on perf board, use all my voodoo parts that i have for bias supply. my configuration:
* B+ supply : 68mF - 0R1 - 68mF - 1R - 68mF - 0R1 - 68mF - 300mH 3A M6 core
* B+ after choke ~ 21V
* Voltage drop on 1R ~ 2V so it's as designed as it should be ~ 2A
* temperature on SIT case 32°C, on L-plate 33°C, on heatsink 32°C
* speaker 4ohm 88dB
and again i have no issue 😀 no thump, noise or hum. music plays beautifully, however this is only one channel completed, another one maybe tomorrow or next week.
with AlephJ stereo, i usually set my dcb1 potensio to 12 o'clock, now with SIT single channel i set to 3 o'clock. I still have extra headroom
well it's time to sleep while listening my audiophile collection with SIT L'amp. Thanks to Uncle Mike for this great design 🙂
* B+ supply : 68mF - 0R1 - 68mF - 1R - 68mF - 0R1 - 68mF - 300mH 3A M6 core
* B+ after choke ~ 21V
* Voltage drop on 1R ~ 2V so it's as designed as it should be ~ 2A
* temperature on SIT case 32°C, on L-plate 33°C, on heatsink 32°C
* speaker 4ohm 88dB
and again i have no issue 😀 no thump, noise or hum. music plays beautifully, however this is only one channel completed, another one maybe tomorrow or next week.
with AlephJ stereo, i usually set my dcb1 potensio to 12 o'clock, now with SIT single channel i set to 3 o'clock. I still have extra headroom
well it's time to sleep while listening my audiophile collection with SIT L'amp. Thanks to Uncle Mike for this great design 🙂
Attachments
Last edited:
The sub is 89.5 db, mids together are 90, tweeter is 95.
So it's about a 90 db limiting factor.
Was going to use the mids down to 10hz to 125 hz to keep the sub section non-directional. At the moment using 6 db 300hz crossover point because I was limited by parts on hand. It sounds ok at 300.
I don't listen at very high levels. Probably don't break 1 watt output.
The sub section will use a F5t and it has plenty of gain.
Would probably need to cut it back.
Also have am F6 for mids if needed. Would like to use the SIT amps for their qualities in the mids and highs.
Attachments
@ Gadut
Joy of first sit
Congratulations for electronic hooby passionate work of DIY Champion
Simple beauty this perf board with wire tracks hmmm excellent that the spirit 🙂
Yeah always cool projects from Uncle Mike.
Thanks Gentlemans
Attachments
Last edited:
If you keep the crossover point above 200Hz you definitely won't have issues.
Feel free to experiment going lower in frequency. Once you start noticing problems just increase the crossover point higher in frequency.