Thanks for that. I think my next adventure will be the F5M once the essentials kit is back in stock!
I ordered two Amp Camp Amps last March to build and got sidetracked with other projects. I also ordered the premium parts updates based upon Tungston’s list which is below. I am now finally getting ready to start the build and I have a few questions:
Lastly, I will start with the two power bricks but will add in power supplies at a later stage. I want to get these two built and learn from the process, as I have everything for an F5M build.
Thanks in advance.
Tom
On board, drop-in replacements
C1: 4700 uF, 35V; Nichicon KG series "Gold Tune"
C2: 1000 uF, 16V; Nichicon RNL series Aluminum Organic Polymer
C4: 100 uF, 35V; Nichicon RL8 series Aluminum Organic Polymer
R11: 20 kOhm, 1/4W, 1% metal film
R12: 90.9 kOhm, 1/4W, 1% metal film
On board add-on components
R4b: 2.0 Ohm, 2W, 2% metal oxide; added in parallel w/ R4
C101: 10 pF, 500V, 5% Silver Mica; added in parallel w/ R12
Off board substitution
Bridging Resistor: 68.1 kOhm, 1/4W, 1% metal film
- I thought that the off board bridging resistor was what required a trace cut and went into the R16 position. In rereading through the threads and the most current schematic it appears this now appears to be a 200 ohm resistor. Am I mixed up? And what are the complete specs of that 200 ohm resistor?
- I see that it is now recommended to use a 5700 uF Nichicon Gold Tone resistor, but outside of Amazon at $24 for two and other sellers I am not sure I trust, they are no longer available. Anyone know a source for these? For some reason I purchased 12 of the 4700 so my inclination is to stay with them, but it does seem like the 5700 gets rave reviews.
- Should I go with adding the 2.0 to 4b or get the 3watt 0.5ohms resistor since I am starting from scratch? Is this Vishay/Dale a good choice? CPF3R50000FNB14
- Any other suggestions or things I should consider?
Lastly, I will start with the two power bricks but will add in power supplies at a later stage. I want to get these two built and learn from the process, as I have everything for an F5M build.
Thanks in advance.
Tom
On board, drop-in replacements
C1: 4700 uF, 35V; Nichicon KG series "Gold Tune"
C2: 1000 uF, 16V; Nichicon RNL series Aluminum Organic Polymer
C4: 100 uF, 35V; Nichicon RL8 series Aluminum Organic Polymer
R11: 20 kOhm, 1/4W, 1% metal film
R12: 90.9 kOhm, 1/4W, 1% metal film
On board add-on components
R4b: 2.0 Ohm, 2W, 2% metal oxide; added in parallel w/ R4
C101: 10 pF, 500V, 5% Silver Mica; added in parallel w/ R12
Off board substitution
Bridging Resistor: 68.1 kOhm, 1/4W, 1% metal film
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The original parts list still works just fine. I used a 5600 uF cap at C1 in my more recent version with the higher transconductance IXTQ75N10P Mosfet at Q1 (either IRFP140 or IRFP048 at Q2). My process was documented.
If you are starting with a fresh build, then it makes sense to use a pair of 0.56 OHm resistors at R3 and R4.
R16 is not a bridging resistor. It is a filter for the Drain pin of Q4. Be careful making the trace cut. There are pictures of how folks have done this. 200 Ohms is the basic value to use for a standard 24V supply. Go higher if you eventually build a higher voltage linear supply.
If you are starting with a fresh build, then it makes sense to use a pair of 0.56 OHm resistors at R3 and R4.
R16 is not a bridging resistor. It is a filter for the Drain pin of Q4. Be careful making the trace cut. There are pictures of how folks have done this. 200 Ohms is the basic value to use for a standard 24V supply. Go higher if you eventually build a higher voltage linear supply.
@TungstenAudio thanks for the information. Very helpful. I was able to find detailed info and some pics of the bridging resistor installation so I am now clear on that.
A few additional questions:
A few additional questions:
- The IXTQ75N1OP for Q1 does not need to be a matched pair? I believe you already provided that information in a prior post, but I can't seem to find it again. Sorry.
- For the 200 Ohm (or larger) resistor how many watts should it be?
- For R3 and R4 is the resistor .50 or .56?
Thanks.
@chermann
In regard to the schematic I see there are changes in red and those go with the premium parts changes. I also see some in blue. One of which is the addition of a bridging resistor at R16, which I am clear on. However, I also see changes at R5 and R6, but I don't recall those two changes as part of the upgrades. Can you clarify for me?
Lastly, for anyone who had built the premium version can you point me to source for a .56ohm 3Watt resistor? I can find .56ohm at 1 Watt and .50ohm at 3 Watt, but not .56ohm at 3Watt. I can just go with the adding the recommended R4b, but thought I'd ask.
@chermann
In regard to the schematic I see there are changes in red and those go with the premium parts changes. I also see some in blue. One of which is the addition of a bridging resistor at R16, which I am clear on. However, I also see changes at R5 and R6, but I don't recall those two changes as part of the upgrades. Can you clarify for me?
Lastly, for anyone who had built the premium version can you point me to source for a .56ohm 3Watt resistor? I can find .56ohm at 1 Watt and .50ohm at 3 Watt, but not .56ohm at 3Watt. I can just go with the adding the recommended R4b, but thought I'd ask.
I found the thread related to the trace cut and installation at R16. The below picture appears to be the preferred installation location. I will be doing the trace cut before installing anything on the board. It appears that I just need to cut through the trace on top, but I want to confirm. And then in this picture how is the resistor locked in place? Is it just the solder? Or do I need to drill two holes through the two ends created by the trace cut so that it is locked in place like the other components?
Hi
No. it is for 24V power supply, SMPS or linear.
as written in post 1443 by TA
R16 is not a bridging resistor. It is a filter for the Drain pin of Q4. Be careful making the trace cut. There are pictures of how folks have done this. 200 Ohms is the basic value to use for a standard 24V supply. Go higher if you eventually build a higher voltage linear supply.
if you want to go higher with your supply Voltage e.g. 30V you have to be careful about the max power (voltage x current ) of the Q4. so therefore you have to change the R16.
kr
chris
No. it is for 24V power supply, SMPS or linear.
as written in post 1443 by TA
R16 is not a bridging resistor. It is a filter for the Drain pin of Q4. Be careful making the trace cut. There are pictures of how folks have done this. 200 Ohms is the basic value to use for a standard 24V supply. Go higher if you eventually build a higher voltage linear supply.
if you want to go higher with your supply Voltage e.g. 30V you have to be careful about the max power (voltage x current ) of the Q4. so therefore you have to change the R16.
kr
chris