😀 Merci!
So shopping list:
2.2uf MPA capacitors
2R2 resistors
Copper bars
12 x 0.1F capacitors
anything else?
So shopping list:
2.2uf MPA capacitors
2R2 resistors
Copper bars
12 x 0.1F capacitors
anything else?
Hi,
Have another good look at the way I've drawn the ground lines. Connect them like that.
joris
Have another good look at the way I've drawn the ground lines. Connect them like that.
joris
Will do i will do a mock up setup of it all wired up before finalising it all and post on here Joris, i have a multimeter, oscilloscope etc so can learn and do some tests.
Hi,
What caps do you plan on buying? please show us so we can verify they are the correct type. Remember, pure capacitance is not the only parameter. esr and such have an impact as well. Also, check the datasheets for size. try and make a mock up inside the chassis to see if all will fit. Use a roll of toilet paper according to the size of the cap in the datasheet.
Joris
What caps do you plan on buying? please show us so we can verify they are the correct type. Remember, pure capacitance is not the only parameter. esr and such have an impact as well. Also, check the datasheets for size. try and make a mock up inside the chassis to see if all will fit. Use a roll of toilet paper according to the size of the cap in the datasheet.
Joris
don't use ordinary cement resistors here. spend the money en get some mills wirewounds at partsconnexion for the resistors. it's worth the money.
Thank Joris:
Using Mouser as there prices are very good and more selection available, here is a few i am thinking to purchase
KEMET ALS70A114KF040 110000 UF 40V ESR 13mohms (high?)
ALS70A114KF040 KEMET | Mouser United Kingdom
UNITED CHEMI-CON E36D350LPN104TDA5N 100000uf 35V ESR 8MOHMS
https://www.mouser.co.uk/datasheet/2/420/1687836876505b6669848e0-1100623.pdf
these are just some of the ones i am looking at, dont worry there is plenty of space in that chassis, ill make it all fit!
Using Mouser as there prices are very good and more selection available, here is a few i am thinking to purchase
KEMET ALS70A114KF040 110000 UF 40V ESR 13mohms (high?)
ALS70A114KF040 KEMET | Mouser United Kingdom
UNITED CHEMI-CON E36D350LPN104TDA5N 100000uf 35V ESR 8MOHMS
https://www.mouser.co.uk/datasheet/2/420/1687836876505b6669848e0-1100623.pdf
these are just some of the ones i am looking at, dont worry there is plenty of space in that chassis, ill make it all fit!
Agreed, thoughts were with the choke and resistors in place it wont be anywhere near 40v, rail voltage maybe 29-32v? So 40V should be ideal, being 50V adds more money to the equation!
Hi,
Nice caps, they will work. Me, i would look for caps rated at 105 C and longer service life but that's personal preference. I would choose the kemet's for the rated lifetime.
Joris
Nice caps, they will work. Me, i would look for caps rated at 105 C and longer service life but that's personal preference. I would choose the kemet's for the rated lifetime.
Joris
using the clcrc schemati i provided 35-40 v rating at the caps will do fine. gives enough margine for ac supply variations from the home ac supply as well
Excellent! ok ill keep looking but i was thinking the KEMETS! Did you see the rectifiers?30A Class A Amplifier Power Supply Rectifier Filter Kits Schottky Rectifier DIY | eBay
Also what wattage should the resistors be? Thinking to by ARCOL, the ones in the heatsinks
Some things to consider:
- keep in mind the dissipation of the output transistors; with a ~ +/- 30 VDC supply, and the necessary current for 30 watt of pure class A output power, your output transistors will not live long no matter the capacity of the heatsinks. For this output power you would need to double the output transistors (~30W max per power transistor is about max for long term reliability).
- don't be too focused on absolute DC power supply voltages; the difference between a 20 or 30 watt amplifier is rather useless in terms of maximum loudness.
- power supply quality is of major importance in whatever amp, and especially in class A amps because of continuous current draw. Risk of a buzzing power supply is lurking around the corner in every class A amp.
My advice is to focus first on a good performing power supply; I think the common mode LCRC option might be best in the end.
- keep in mind the dissipation of the output transistors; with a ~ +/- 30 VDC supply, and the necessary current for 30 watt of pure class A output power, your output transistors will not live long no matter the capacity of the heatsinks. For this output power you would need to double the output transistors (~30W max per power transistor is about max for long term reliability).
- don't be too focused on absolute DC power supply voltages; the difference between a 20 or 30 watt amplifier is rather useless in terms of maximum loudness.
- power supply quality is of major importance in whatever amp, and especially in class A amps because of continuous current draw. Risk of a buzzing power supply is lurking around the corner in every class A amp.
My advice is to focus first on a good performing power supply; I think the common mode LCRC option might be best in the end.
For this output power you would need to double the output transistors (~30W max per power transistor is about max for long term reliability).
How do i double the output transistors? Buy bigger and better ones? or are you saying i need to have four output transistors?
- power supply quality is of major importance in whatever amp, and especially in class A amps because of continuous current draw. Risk of a buzzing power supply is lurking around the corner in every class A amp.
My advice is to focus first on a good performing power supply; I think the common mode LCRC option might be best in the end.
This is my plan, hence this thread, want to build the best power supply i can with the purchase of R core trannies, Lundhal chokes etc and Jazz help on designing a PSU. Going for the common mode LCRC option
How do i double the output transistors? Buy bigger and better ones? or are you saying i need to have four output transistors?
- power supply quality is of major importance in whatever amp, and especially in class A amps because of continuous current draw. Risk of a buzzing power supply is lurking around the corner in every class A amp.
My advice is to focus first on a good performing power supply; I think the common mode LCRC option might be best in the end.
This is my plan, hence this thread, want to build the best power supply i can with the purchase of R core trannies, Lundhal chokes etc and Jazz help on designing a PSU. Going for the common mode LCRC option
Hi,
Please listen to Pieter. He has far more knowledge and experience compared to me. just go with the lcrc option and let go of doubling output transistors and such. You will get the best sounding amp you can get with the components at hand.
grtz
Joris
Please listen to Pieter. He has far more knowledge and experience compared to me. just go with the lcrc option and let go of doubling output transistors and such. You will get the best sounding amp you can get with the components at hand.
grtz
Joris
Thanks Joris
I will stick to what i have and push onwards with the PSU :O) thank you so much for your help!
Pieter, i still need help with regards to the smaller capacitors, do i need 2.2uf and say polarised 100~220uf in the PSU?
Do you also agree with the resistor rating of 2r2 or should i buy others to try?
I will stick to what i have and push onwards with the PSU :O) thank you so much for your help!
Pieter, i still need help with regards to the smaller capacitors, do i need 2.2uf and say polarised 100~220uf in the PSU?
Do you also agree with the resistor rating of 2r2 or should i buy others to try?
2r2 is the value for the clcrc schematic. For the lcrc you'd want something like 0,1Ohm. One 5w rated mill's would do nicely.
Hi,
Just a quick post to say that Pieter T will not be posting again until sometime Sunday. He wanted you all to know that he is not ignoring you all.
Just a quick post to say that Pieter T will not be posting again until sometime Sunday. He wanted you all to know that he is not ignoring you all.