Please share BOM list whoever build SX amp that will be great.Bonsai its urgent to update BOM list with all available parts for SX.
Yes Bonsai, we need the latest BOM list as many of the components listed under SX on the hifisonix site is outdated and no more available in the market. If somebody has built the SX recently please publish the BOM list.
I gave up making a complete BOM when building the SX. However - took one component at a time. Searched and searched again. Crosschecked between the pcb and schematics and manual. Had some questions for Bonsai and he answered them. Making sure it was good. Took some time but there arent that many components in that amp. Thend made a good order at mouser. Some components I had to order other places. (VAS transistors for instance). Those are hard to find.
Of course I can share the "order"?
Of course I can share the "order"?
Here is one list I used at Mouser.
Remember that the number of parts are in some lines way over the numbers needed for this project.
The bc550/bc560 for instance in which I ordered some so I could match them.
Also the main transistors because I would like to have some to another project.
This list is for complete dual mono with 2 PSUs. It does not contain transformers or TIS/VAS transistors I had to source those other places.
This is just a picture. Unable to upload .xls.. Got an error.
Remember that the number of parts are in some lines way over the numbers needed for this project.
The bc550/bc560 for instance in which I ordered some so I could match them.
Also the main transistors because I would like to have some to another project.
This list is for complete dual mono with 2 PSUs. It does not contain transformers or TIS/VAS transistors I had to source those other places.
This is just a picture. Unable to upload .xls.. Got an error.
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Hey everyone.
I will build Nx-amp and I have a problem with the purchase of certain things. That's why I have a few questions.
Can I swap KSA1381 KSC3503 on KSA1142Y KSC2682Y?
Can I swap BC547C BC557C on KSA992 KSC1845?
I have a power supply from the previous amplifier 53V (8x4700uF 63V) and speaker protection on uPC1237 whether they can now use it?
If not, can I use IRFB4110PbF (FET N-MOSFET 100V 180A 370W 4.5mR) instead of PSMN4R3-100PS?
I will build Nx-amp and I have a problem with the purchase of certain things. That's why I have a few questions.
Can I swap KSA1381 KSC3503 on KSA1142Y KSC2682Y?
Can I swap BC547C BC557C on KSA992 KSC1845?
I have a power supply from the previous amplifier 53V (8x4700uF 63V) and speaker protection on uPC1237 whether they can now use it?
If not, can I use IRFB4110PbF (FET N-MOSFET 100V 180A 370W 4.5mR) instead of PSMN4R3-100PS?
tjbox, for the nx-Amp:-
1. For Q7 use KSA1142Y in place of KSA1381
2. For Q6 use KSC2682 in place of KSC3503
3. For Q12, use KSC2690 in place of KSC3503
4. For Q13, use KSA1220 in place of KSA1381
Can you use KSA992 KSC1845 in place of BC547 and BC557?
These look like very nice transistors. You can use them - however, please note that the pin - out is different to the BC547 and 557 originally specified. You might want to look at the BC560 and BC550 for Q8 and Q10 which have the correct pin-out.
For Q9 and Q11 you must use a 65V transistor - I specified the BC546 and BC556. Note that in some copies of the nx-amp write up, these transistors are shown as BC547 and BC557 - this is wrong - you must use the BC546 and BC556 65V types.
I have a power supply from the previous amplifier 53V (8x4700uF 63V) and speaker protection on uPC1237 whether they can now use it?
This will be ok - you can use it - see note below though ree your proposal on the mosfets
If not, can I use IRFB4110PbF (FET N-MOSFET 100V 180A 370W 4.5mR) instead of PSMN4R3-100PS?
The Drain - Source breakdown voltage on the IRFB4110PbF devices is 100V. While your supply V- to V+ will be 106V (2 x 53 V if I understand correctly). You therefore run the risk in the long term that the mosfets fail. Try to find devices with >110V drain-source breakdown. The Rds(on) needs to be below 10 milli-Ohm, with <6milli-Ohm better still.
Always make sure with the nx-Amp speaker protection mosfets that the drain-source breakdown voltage is equal to or greater than the total power supply rail.
1. For Q7 use KSA1142Y in place of KSA1381
2. For Q6 use KSC2682 in place of KSC3503
3. For Q12, use KSC2690 in place of KSC3503
4. For Q13, use KSA1220 in place of KSA1381
Can you use KSA992 KSC1845 in place of BC547 and BC557?
These look like very nice transistors. You can use them - however, please note that the pin - out is different to the BC547 and 557 originally specified. You might want to look at the BC560 and BC550 for Q8 and Q10 which have the correct pin-out.
For Q9 and Q11 you must use a 65V transistor - I specified the BC546 and BC556. Note that in some copies of the nx-amp write up, these transistors are shown as BC547 and BC557 - this is wrong - you must use the BC546 and BC556 65V types.
I have a power supply from the previous amplifier 53V (8x4700uF 63V) and speaker protection on uPC1237 whether they can now use it?
This will be ok - you can use it - see note below though ree your proposal on the mosfets
If not, can I use IRFB4110PbF (FET N-MOSFET 100V 180A 370W 4.5mR) instead of PSMN4R3-100PS?
The Drain - Source breakdown voltage on the IRFB4110PbF devices is 100V. While your supply V- to V+ will be 106V (2 x 53 V if I understand correctly). You therefore run the risk in the long term that the mosfets fail. Try to find devices with >110V drain-source breakdown. The Rds(on) needs to be below 10 milli-Ohm, with <6milli-Ohm better still.
Always make sure with the nx-Amp speaker protection mosfets that the drain-source breakdown voltage is equal to or greater than the total power supply rail.
A few people have contacted me wrt the sx and nx Amplifer BOM's.
Both these amplifiers were designed and first built in 2012. since then (4 years ago) a number of devices have been discontinued (BC547, BC557) while the 1381 and 3503 Fairchild and Sanyo variants can no longer be found in hFE matched complements. This is unfortunate.
However, there are good replacements as shown in post #1790 so these amplifiers can still be built with good results.
Both these amplifiers were designed and first built in 2012. since then (4 years ago) a number of devices have been discontinued (BC547, BC557) while the 1381 and 3503 Fairchild and Sanyo variants can no longer be found in hFE matched complements. This is unfortunate.
However, there are good replacements as shown in post #1790 so these amplifiers can still be built with good results.
Bonsai Thank you for your reply.
I have read the datasheet KSA992 / KSC1845 and I know about the pin-out. Most likely I will use my old power supply and speaker protection so I will not have the problem of finding replacements mosfet.
Can you tell me about be the value of R41 / R42. Which is correct 33 ohm or 0?
I have read the datasheet KSA992 / KSC1845 and I know about the pin-out. Most likely I will use my old power supply and speaker protection so I will not have the problem of finding replacements mosfet.
Can you tell me about be the value of R41 / R42. Which is correct 33 ohm or 0?
There is no advantage to using bc547/557
Any of the 546/547/548/549/550 can be used for the NPN
and 556/557/558/559/560 can be used for the PNP.
The specified lowest noise are the 549/550 & 559/560 and these may offer a slight noise advantage for the first stage.
The 546/556 is the only version with 60Vceo and must be used for the second stage.
Any of the 546/547/548/549/550 can be used for the NPN
and 556/557/558/559/560 can be used for the PNP.
The specified lowest noise are the 549/550 & 559/560 and these may offer a slight noise advantage for the first stage.
The 546/556 is the only version with 60Vceo and must be used for the second stage.
Most of these parts will continue to be available in SMD - SOT23.
Manufacturers are moving away from TO-92 because the margins are low and installing new lines does not pay back.
However, SMD is very easy to solder well and get a good looking job - SOT23 is a piece of cake as are SOIC opamps. I can solder down ucontroller with a 0.8 mm pin to pin pitch. At 0.6mm pin to pin pitch it starts to get messy unfortunately.
I suspect mainstream TO-92 probably has another 10 years and it's game over. So enjoy while it lasts.
Manufacturers are moving away from TO-92 because the margins are low and installing new lines does not pay back.
However, SMD is very easy to solder well and get a good looking job - SOT23 is a piece of cake as are SOIC opamps. I can solder down ucontroller with a 0.8 mm pin to pin pitch. At 0.6mm pin to pin pitch it starts to get messy unfortunately.
I suspect mainstream TO-92 probably has another 10 years and it's game over. So enjoy while it lasts.
Although risking of going a bit off topic, I cant help to mention that I can’t believe my eyes… did AndrewT now really beseech to obtain a piece from Jims Audio? 🙄 After all those crusades against Jims Audio. Even the original KSA-100 threads name was changed to besmirch Jims reputation. And now this… wow, I am kinda shocked. Now, dear AndrewT, since Jim is nowadays even accepted by you, would it not be nice if the KSA-100 threads name was restored as well?
Back on topic. Being a loyal customer of Jims Audio I saw that he was offering the nice boards designed by Bonsai. After checking the hifisonix.com website I had to have them 🙂. Really nice work Bonsai, it is so nice that you are offering so much support and posted the Gerbers! I am slowly progressing and collecting all the bits and pieces required. Although not complete, the first parts are already soldered to the board. It will probably be a long term project since I have too many projects going on. However, I will post updates (and probably ask some questions 😛) when progressing.
EDIT: By the way, before I forgot; although it probably does not matter that much there is a discrepancy between the silkscreen (FODM3011) and the BOM (FODM3012) regarding the opto-coupler. I’ve ordered the FODM3012. Hopefully that is okay 🙂.
Back on topic. Being a loyal customer of Jims Audio I saw that he was offering the nice boards designed by Bonsai. After checking the hifisonix.com website I had to have them 🙂. Really nice work Bonsai, it is so nice that you are offering so much support and posted the Gerbers! I am slowly progressing and collecting all the bits and pieces required. Although not complete, the first parts are already soldered to the board. It will probably be a long term project since I have too many projects going on. However, I will post updates (and probably ask some questions 😛) when progressing.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
EDIT: By the way, before I forgot; although it probably does not matter that much there is a discrepancy between the silkscreen (FODM3011) and the BOM (FODM3012) regarding the opto-coupler. I’ve ordered the FODM3012. Hopefully that is okay 🙂.
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