Folks, I seem to have a hard time finding the 22.1 ohm resistor. I've searched around in the forum, and found a thread which taugth me that these "strange" values are there just to remind you about the needed precision (hope I got it right).
Anyway, I can't even find 20 ohm resistors. I found some nice parts rated at 10 ohm, 0.1%... Well, I was wondering if I can put two of those in series, to satisfy that R8 value.
Thank you,
Giacomo
Anyway, I can't even find 20 ohm resistors. I found some nice parts rated at 10 ohm, 0.1%... Well, I was wondering if I can put two of those in series, to satisfy that R8 value.
Thank you,
Giacomo
Hi Giacomo
There has been a lot of discussion in the past about versions of the circuit that different people have used.
I believe the latest was the one marked r0 6/4/07. Thats certainly the one that I used and if I remember correctly there were no 22R1 on that circuit. Maybe why Jacco is questioning R8.
just a thought
Ed
There has been a lot of discussion in the past about versions of the circuit that different people have used.
I believe the latest was the one marked r0 6/4/07. Thats certainly the one that I used and if I remember correctly there were no 22R1 on that circuit. Maybe why Jacco is questioning R8.
just a thought
Ed
Uh... I'm referring to the R8 which is shown in the actual PDF on www.firstwatt.com
I downloaded it again a few days ago... What am I missing?
Giacomo
I downloaded it again a few days ago... What am I missing?
Giacomo
I'm playing with the F4 in the Sims department and have increased the voltages to 30 volts. Is this a bad idea? I increased the jfets source resistance to limit current. The sim says that the mosfets are passing about an amp.
This is more of an tutorial exercise than a plan. I'm enjoying the sim software a great deal.
This is more of an tutorial exercise than a plan. I'm enjoying the sim software a great deal.
giacomo_pagani said:
Looks like the earlier (11/08/06) version has snuck back up on www.firstwatt.com.
The latest version was referred to as R0 and dated 6/4/07
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giacomo_pagani said:
Now it would be very interesting to know which one is actually better... Maybe the fact that the old one has been brought back on site means something?
I have to freeze with my shopping, 'till I get an answer now. Thank you for pointing that out
Giacomo
OK, I searched and found that this last version is better, period (being recommended by Nelson, and being the one on Peter Daniel's boards).
And I'm lucky with parts, too (except for the 750 ohm resistor, but I'll stick with two 1.5 kohm in parallel).
Giacomo
Can I change IRFP 240 with IRFP 044 in the f4 circuit without any changes or it's a bad idea?
Bc/Philips capacitors 22.000/40 volts maybe a good choice for power supply? (I've a good amount of these capacitors, but I don't know if they are really good for audio).
What's the power (safe value) for each channel transformer?
thanks a lot
Bc/Philips capacitors 22.000/40 volts maybe a good choice for power supply? (I've a good amount of these capacitors, but I don't know if they are really good for audio).
What's the power (safe value) for each channel transformer?
thanks a lot
As stated above, I am so impressed by the F4 that I want to see what is possible with a version without any compromises...I am looking for your experiences / opinions:
1. ON the 220uf on the Board: I have currently Silmic II, which should be one of the better ones I guess as recommended by Nelson. If I want to try Blackgates in this position:
- FK
- NX solo
- Two NX which are soldered in parallel, but with opposite direction, so that errors are canceled out (see http://www.thlaudio.com/bgcapitme.htm )
which version would you recommend in this position ?
2. On the resistors in general (I guess this is a Peter Daniel-Question):
- Caddock MK132 ?
- texascomponents.com: TX2352 or TX2575 ?
3. May I ask a maybe stupid question ? Why are the 0.47-resistory specified as the Panasonic 3W-Types ?
Why not simply use the MK132-Type of Caddock as well ? There goes 0.21 Volts over my 0.5-Version which mean basically 0.42 Amps. So, this would mean a heavy 0,21*0,42= 0,0882 Watt, right ? So why aren't we using here the best resistor possible as well ?
Looking forward for your thoughts.
1. ON the 220uf on the Board: I have currently Silmic II, which should be one of the better ones I guess as recommended by Nelson. If I want to try Blackgates in this position:
- FK
- NX solo
- Two NX which are soldered in parallel, but with opposite direction, so that errors are canceled out (see http://www.thlaudio.com/bgcapitme.htm )
which version would you recommend in this position ?
2. On the resistors in general (I guess this is a Peter Daniel-Question):
- Caddock MK132 ?
- texascomponents.com: TX2352 or TX2575 ?
3. May I ask a maybe stupid question ? Why are the 0.47-resistory specified as the Panasonic 3W-Types ?
Why not simply use the MK132-Type of Caddock as well ? There goes 0.21 Volts over my 0.5-Version which mean basically 0.42 Amps. So, this would mean a heavy 0,21*0,42= 0,0882 Watt, right ? So why aren't we using here the best resistor possible as well ?
Looking forward for your thoughts.