I'm not sure where you saw the KSC1845 nor the 845, what's in there is a KSC815 (HG) and is a valid alternative.
Cheers
Hi Charlie
Good to see your going well and still have sense of humour. Yeah I did change the VAS current to help with it. I am now working on a audio spectrum analyser to install into this amplifier to make it look pretty. I will experiment myself with that LC cap to see if sound changes. Please tell your nurse that if you have to strip down and get poked with a needle then you should be able do the same to her with your needle.
Regards
Simon
Yeah!.... gonna do it Simon
Give a try with the original current (increase heatsink size) and compare.... if you did it, them let me know as i would like to confirm or dennie some tries i have made here with my own amplifiers.
If you like you post it...if not, then go to old uncle charlie mail box, you are always welcome there:
nanabrother@hotmail.com
carlos.eugenio1951@yahoo.com
Make videos Simon.... you make very good comparison videos man!
regards,
Carlos
Give a try with the original current (increase heatsink size) and compare.... if you did it, them let me know as i would like to confirm or dennie some tries i have made here with my own amplifiers.
If you like you post it...if not, then go to old uncle charlie mail box, you are always welcome there:
nanabrother@hotmail.com
carlos.eugenio1951@yahoo.com
Make videos Simon.... you make very good comparison videos man!
regards,
Carlos
I am representing the beginner builder and have questions that reflect this. Having said that I am working on a digikey BOM for the power supply section of the amp, and have a few questions regarding some component choices. I would like to attain the full output potential of 150w @ 8r. Thanks in advance.
- The build guide recommends the Antek AN-8445 transformer for the power supply and is shown with two 1V20 power supply boards for a dual mono configuration. I am planning to use the two 1V20 boards as shown but am curious. In the first few pages of this thread it was suggested that a builder could alternatively use two 400VA transformers instead of the single 800VA transformer. This option was not mentioned in the build guide, are two transformers not recomended? Is it more difficult to achieve equal output from both channels?
- It has come up in other threads that Antek rates the output of their transformers differently than other manufacturers. Other members have suggested that users move up to the next VA selection to achieve the same performance as other brands. Was the 150watt @ 8r output measured with the AN-8445? Will other brands of transformer change the output measurements of the amp?
- Can anyone recommend where to source 10-12,000uf caps that are 30mm in diameter, 10mm lead spacing, snap in, and rated at or above 75V (and reasonably priced). I have found a few options at digikey in the 10-12,000uf range that have the right diameter and lead spacing but they are only rated to 63V. My calculation for a 45V secondary after rectification is 63.64V. This does not leave any elbow room for voltage fluctuation. The prototype amp appears to have 12,000uf 63V elna caps in the power supply, so am I missing something or were these just used for illustration purposes?
Sorry if this has been covered in the thread already, and thanks to everyone who helped put together this great project.
It won't be a true dual mono with a single 800VA from Antek. Both secondary windings will be wired to both of the PS boards if you go that route. With two 400VA you could have true dual mono amplifier, with completely separate power supplies. This would be ideal, but not if the cost difference is great, and it will take up more room.
I haven't read any mention of this, and maybe there is proof, but Antek's ratings seem fairly straight forward. Either way, the 800VA Antek is more than capable for Honey Badger.
1. I indicated there that only the PSU was in a dual mono style configuration. Having separate rectifiers and their own cap bank per channel would still help for better channel separation. Of course using two separate transformers is ideal, I did not mention it in there to keep it simple.
2. I have not seen nor experienced any problems with the Antek tranny that I used in the prototype, if you are in doubt, then please feel free to use your own personal brand of transformer. The 150W @ 8R was tested by OS himself with +/-60V supplies. He also recommends 500VA to 600VA for two channels.
3. Your calculation of the VDC is spot on, but the Antek primary is rated at 230V and I live in a 220V country so I get a small reprieve. You are also correct about the "allowance" thing, you are not missing anything, we just like to be at the edge and push these things to the limits, of course I suggest you get a 75V or 80V cap for your build.
Here at DA Central, I try my best to put these projects at the edge, I do my very best to torture this amps too (I hope Jason and Mark does not read this
) in the hopes of giving beginners some form of "build tolerance" and leave the dangerous things to us. 
Happy building!
Jojo
Thanks for the replies, I used antek transformers in my gainclone and plan on using them for this build too. I think they are well made and a great value. As for the caps I will have to keep searching. Finding caps that will fit the psu boards may be difficult without having to lower rail voltage. Though I don't want to sacrifice performance to keep from having to make my own boards for the caps. If anyone has a suggestion as to where to source reasonably priced 10-12kuf 75v caps that fit these boards let me know.
P.s. I did not mean to imply that you guys had forgoten other power supply configurations, I was just asking if was not included because of poor performance characteristics. Thanks again, im itching to get started on this!
P.s. I did not mean to imply that you guys had forgoten other power supply configurations, I was just asking if was not included because of poor performance characteristics. Thanks again, im itching to get started on this!
If I understood him correctly ostripper, the designer of the board, said that the caps on the diyAB board itself were enough, that all it needed was a transformer and diodes. Now around here we like to overdo everything, and people have different opinions on everything, but you certainly don't need the amount of capacitance that a typical class A amp would require, Class A and Class AB are different things.
So 8k uF or less are probably just fine. Well according to os, anything would be fine.
If you have 2 PSU boards then the caps can be even smaller also..
Definitely populate the caps right on the Honey Badger (diyAB) board though. Its good to have some capacitance so close to the amp circuit.
Mark
That may have applied to earlier version, but the final BOM calls for 470uF-1000uF on the DiyAB board. That's about 1/12th the requirement for a 150W amplifier.
So 24k uF of capacitance for 2 channels? There are 8 caps on the diyAudio PSU board, so for 150w/ch they could each be as low as 3000 uF each? Just to clarify for us all.. The PSU board also takes four 35mm caps as an option. So they could ea be about 6000 uF ?
In my opinion, yes. 24,000uF total is enough for a 2 channel, 150W/8R amplifier. If you are driving low impedance loads (or doing sine wave testing) you will want more... But, for a basic diyAB build 10,000 to 12,000uF per channel with a 600VA to 800VA transformer is enough. Anymore than 20,000uF per channel would be excessive.
I agree, I have tested two channels with just a single 10,000uf per rail and it worked ok.
Using the PSU 1V20 boards with 4 pieces 4,700uf or 6,800uf caps in 80V ratings should be ok for two channels, But if you expect to drive low impedance loads I'd use two PSU 1V20 boards, one for each channel just like in the prototype I built. Or increase the overall capacitance per rail as much as you can.
It is too bad the board does not take larger diameter caps because I have some great 15000uF/63V Panasonic snap-in caps (from Apexjr, now sold out) but they are 40mm
Perhaps a new version of the PSU board could also support other cap lead spacings? I don't think large capacity caps (screw type; for class A) can be used with the board as it is.