RM3 = VGSP / 23.2mA
1.57V / 0.0232 = 67.6...
RM3 = 67.6R
RM4 = VGSN / 23.2mA
1.09V / 0.0232 = 46.9...
RM4 = 47R
----------------------------------------------------------------------
1) Jacques Antoine, France - 1 set
2) Patriz 1 set
3) nfsgame, Germany - 2 sets
4) baswamin, India - 3 sets (1 set each for baswamin, Samuel Jayaraj, Manniraj, common shipping to baswamin)
5)Thimios-2 sets(4 pcb)
6)ravid, India - 3 sets
7) BDL, Romania - 1 set
8) Luke - 2 sets
9) vvs07 - 2 sets
------------------------------------------------------------------------
Thank you!
1) Jacques Antoine, France - 1 set
2) Patriz 1 set
3) nfsgame, Germany - 2 sets
4) baswamin, India - 3 sets (1 set each for baswamin, Samuel Jayaraj, Manniraj, common shipping to baswamin)
5)Thimios-2 sets(4 pcb)
6)ravid, India - 3 sets
7) BDL, Romania - 1 set
8) Luke - 2 sets
9) vvs07 - 2 sets
------------------------------------------------------------------------
Thank you!
----------------------------------------------------------------------
1) Jacques Antoine, France - 1 set
2) Patriz 1 set
3) nfsgame, Germany - 2 sets
4) baswamin, India - 3 sets (1 set each for baswamin, Samuel Jayaraj, Manniraj, common shipping to baswamin)
5)Thimios-2 sets(4 pcb)
6)ravid, India - 3 sets
7) BDL, Romania - 1 set
8) Luke - 2 sets
9) vvs07 - 2 sets
10) nounouchet - 1 set
------------------------------------------------------------------------
Thank you Fab
1) Jacques Antoine, France - 1 set
2) Patriz 1 set
3) nfsgame, Germany - 2 sets
4) baswamin, India - 3 sets (1 set each for baswamin, Samuel Jayaraj, Manniraj, common shipping to baswamin)
5)Thimios-2 sets(4 pcb)
6)ravid, India - 3 sets
7) BDL, Romania - 1 set
8) Luke - 2 sets
9) vvs07 - 2 sets
10) nounouchet - 1 set
------------------------------------------------------------------------
Thank you Fab
Interested in USSA5
Is there a BOM for this amplifier?
Is there a adjustment procedure also for this amplifier?
What is VCC-VEE specified voltage range?
What is the best bias value?
I contacted FAB to get these information's, but google translator do not find it to me in a French Forum long thread.
I suppose it must be informed in the thread to help people to decide assembly or not. Thank you in advance.
Regards
Is there a BOM for this amplifier?
Is there a adjustment procedure also for this amplifier?
What is VCC-VEE specified voltage range?
What is the best bias value?
I contacted FAB to get these information's, but google translator do not find it to me in a French Forum long thread.
I suppose it must be informed in the thread to help people to decide assembly or not. Thank you in advance.
Regards
1) Jacques Antoine, France - 1 set
2) Patriz 1 set
3) nfsgame, Germany - 2 sets
4) baswamin, India - 3 sets (1 set each for baswamin, Samuel Jayaraj, Manniraj, common shipping to baswamin)
5)Thimios-2 sets(4 pcb)
6)ravid, India - 3 sets
7) BDL, Romania - 1 set
8) Luke - 2 sets
9) vvs07 - 2 sets
10) nounouchet - 1 set
11) PJN, US - 1 set
2) Patriz 1 set
3) nfsgame, Germany - 2 sets
4) baswamin, India - 3 sets (1 set each for baswamin, Samuel Jayaraj, Manniraj, common shipping to baswamin)
5)Thimios-2 sets(4 pcb)
6)ravid, India - 3 sets
7) BDL, Romania - 1 set
8) Luke - 2 sets
9) vvs07 - 2 sets
10) nounouchet - 1 set
11) PJN, US - 1 set
Interested in USSA5
Is there a BOM for this amplifier?
Is there a adjustment procedure also for this amplifier?
What is VCC-VEE specified voltage range?
What is the best bias value?
I contacted FAB to get these information's, but google translator do not find it to me in a French Forum long thread.
I suppose it must be informed in the thread to help people to decide assembly or not. Thank you in advance.
Regards
I am interested, but I need more information to decide.
Hello r_merolaInterested in USSA5
Is there a BOM for this amplifier?
Is there a adjustment procedure also for this amplifier?
What is VCC-VEE specified voltage range?
What is the best bias value?
I contacted FAB to get these information's, but google translator do not find it to me in a French Forum long thread.
I suppose it must be informed in the thread to help people to decide assembly or not. Thank you in advance.
Regards
Yes there is a very well done manufacturing manual with the list of components and also detailing all the adjustments and settings.
The power supply can be from +/- 22V up to +/- 30V maximum.
For the bias is your heat sink that will guide you but it is 1A minimum.
Do not ask for the manual because only Fab transmits it with the purchase of the pcb.
Hello r_merola
Yes there is a very well done manufacturing manual with the list of components and also detailing all the adjustments and settings.
The power supply can be from +/- 22V up to +/- 30V maximum.
For the bias is your heat sink that will guide you but it is 1A minimum.
Do not ask for the manual because only Fab transmits it with the purchase of the pcb.
Interesting you note to do not ask manual as FAB wrote to ask him in one answer. This was the reason I contacted him for this information.
I use to simulate circuit to know circuit behavior and get some objective information from simulation.
I suppose there is a place in the forum for vendor and here is a place for DIY with open information.
Anyway thank you for your time.
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This is a good proposal as I still waiting the information from DIY Forum area.
Nice build and excellent review ggetzoff!!!
Having build many iterations of this amplifier (USSA1, 2, 3 and 5), I can only confirm what you're saying. It is my main amplifier (USSA5 and finishing the USSA3) connected to my Troels Gravesen ATS-4 speakers. Love it!
This was my first iteration of the USSA 5
Amplificateur USSA: Dans le ventre de la bete - construction par Pinnocchio - Page 5
And the final amplifier
Amplificateur USSA: Dans le ventre de la bete - construction par Pinnocchio - Page 7
Again, congrats on your build!!
Do
Having build many iterations of this amplifier (USSA1, 2, 3 and 5), I can only confirm what you're saying. It is my main amplifier (USSA5 and finishing the USSA3) connected to my Troels Gravesen ATS-4 speakers. Love it!
This was my first iteration of the USSA 5
Amplificateur USSA: Dans le ventre de la bete - construction par Pinnocchio - Page 5
And the final amplifier
Amplificateur USSA: Dans le ventre de la bete - construction par Pinnocchio - Page 7
Again, congrats on your build!!
Do
To whom it may concern I will not respond to possible threats or lectures about what someone should do or should not do.
I gain no profit from this and I have put a lot of work into it to have a fully working and stable class A amplifier with a manual about the complete building instructions, parts list, tests results on my build, adjustment procedure, test procedure for your build and how to measure a few parameters. The documentation is at the level of a byiung kit but it is not a sold kit. Only pcb is sold at cost price because the layout was careafully done to get the best results. It is only the partial manual that I can share by e-mail using PM. I have been contributing on this forum for about 14 years but it is the first time I offer a complete project so please respect my way of doing. I had no problem on another forum so why does it need to be a problem here ?
Thanks for your comprehension
Fab
I gain no profit from this and I have put a lot of work into it to have a fully working and stable class A amplifier with a manual about the complete building instructions, parts list, tests results on my build, adjustment procedure, test procedure for your build and how to measure a few parameters. The documentation is at the level of a byiung kit but it is not a sold kit. Only pcb is sold at cost price because the layout was careafully done to get the best results. It is only the partial manual that I can share by e-mail using PM. I have been contributing on this forum for about 14 years but it is the first time I offer a complete project so please respect my way of doing. I had no problem on another forum so why does it need to be a problem here ?
Thanks for your comprehension
Fab
Hi
Extract from manual:
Specifications of USSA-5 (obtained on 1 channel of 1st unit)
• Gain: 20db (or x10)
• Input sensitivity: 1.8 V-peak for output (20W rms)
• Damping Factor (100 Hz , 8 ohms): [30 – 35]
• Output impedance: [0.23 - 0.27] ohm
• Input Impedance: 22K ohms
• Max power into 8 ohms before clipping: <25Wrms (at Supply voltage of +/-23Vdc, 0.9A Bias current)
• Power in Class A (8 ohms): depending of bias current
• DC offset: trimmable to < 3mv
• Rise time (10 to 90%) < 1.3us
• Typical T.H.D. (1 KHz) (mostly 2nd and 3rd):
1w << 0.02% (below noise of THD meter)
6w < 0.06%
10w <0.08%
15w <0.15%
20w < 0.3%
--------------------------------------------------
Now later on this year with a better THD meter and with 1,3A bias and better PSU:
1w : 0,005% (2nd harmonic about 8db over 3rd)
4w : 0,011%
6w : 0,02%
10W: 0,03%
15w: 0,05%
20W: 0,08%
25W: 0,4%
Of course this is not impressive numbers since a simple design but have in mind that I do not care so much about THD except that higher harmonics need to be much lower than 2nd and 3rd.
I was also able to get a higher damping factor with higher bias , bigger PSU and more accurate load impedance measurement. DF about 40 to 45 from what I remember which is within my target range.
USSA-3 has similar THD results and same potential for power.
In 4 ohms you get half power in class A for same bias but potentially close to 1,7 time the power in class AB (really depends on your PSU capability) compared to 8 ohms since it is a push-pull configuration.
Fab
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Can someone help me please with all the resistor values for this amp? Parts connexion has 25% discount sale on the PRP and other resistors also at this week I would love to order them before the sale end.
I do own the same PC boards from Fab and most of the caps and semiconductors. I printed out the BOM but to me it confusing, how I see several amplifiers BOM's are together. Please, someone, help me with this. I am disabled with PTSD so I having difficulties
focus sometimes on one project several hours. I just need the resistors for these project, the rest I got it. Thank you, guys! It would be great if I could order the resistors together with the other project while the sale last.
Thanks one more time!
I do own the same PC boards from Fab and most of the caps and semiconductors. I printed out the BOM but to me it confusing, how I see several amplifiers BOM's are together. Please, someone, help me with this. I am disabled with PTSD so I having difficulties
focus sometimes on one project several hours. I just need the resistors for these project, the rest I got it. Thank you, guys! It would be great if I could order the resistors together with the other project while the sale last. Thanks one more time!
