CPU heatsink from local used/recycled goods market. 2 for 1 dollar.
Old Pentium II or celeron cartrige if my memory is good...Shann will be enough or will you adding a fan?
Marc
Hi shaan
seeing your pictures in post 918 makes my finger itchy!
what is the sound difference between this amp and the DOZ?
I have not got over the moon from the previous amp from you !
cheers
kp93300
Hi kp!
Nice to have you here. How are you? How's DOZ doing?So hands are itchy, eh?
VSSA and DOZ, sonics? Hm, easy.
DOZ is the perfect facial makeup, while VSSA is naked truth, symmetrical elegance, perfection itself.
Want to try? Hm?
p.s. DOZ isn't mine, she's Rod's gift to us mortals.
"we are like dwarves perched on the shoulders of giants" (Bernard de Chartres, 12th century)
Hi shaan
Thank you . I am fine and the soldering iron is heated on most days !
DOZ is doing daily duty and after building a few pre , i want to come back to amp now.
I have no skills in pcb making.
I will attempt a point 2 point bread board build.
Which is your latest schematic ?
I am about to start on another Rod project---P3A but this party here is getting hard to resist.
cheers.
kp93300
Thank you . I am fine and the soldering iron is heated on most days !
DOZ is doing daily duty and after building a few pre , i want to come back to amp now.
I have no skills in pcb making.
I will attempt a point 2 point bread board build.
Which is your latest schematic ?
I am about to start on another Rod project---P3A but this party here is getting hard to resist.
cheers.
kp93300
Hi kp.
Please see first post. You have your schematic. We all here are playing with different PCB designs, all based on the same VSSA schematic. It will be great to hear your thoughts about the sonics of this amp in its simplest config.
One request, please post links to your experiment related posts in the original VSSA threads too, as your build will not be strictly PeeCeeBee. I hope you will understand.
Thanks.
shaan
after lots and lots of helping me see this project finally VSSA untum I'm done with components that are still simple, thanks to Mr. Shaan, Mr. LC and my good friend Mr. Jhon Bali, Mr. Naf. I use a transformer 5A - 25AC and get Bias 1.5 V DC offset but still fairly high and I will try to make better.
Attachments
I did, they sound exactly the same as the 2SA1249S/2SC3117T pair I used in my initial build, which of course is fantastic. And no wonder, the specs are very similar. I would not hesitate to recommend giving the KSA1220AY/KSC2960AY a try. I also have 2SA1507S/2SC3902S (which I haven't yet tried) that will also likely sound the same, and again similar specs; but they cost twice as much and aren't as easy to get.
I have NOT used the KSA1381E/KSC3503D I bought because of the difference in gain being 2:1. These are all good devices and I can't imagine them sounding much different from one another as VAS devices.
Thanks Jason,
PMI and I needed this info. Now we know for sure that KSA1220AY/KSC2960AY are very good option for VAS.
How close did they measure?
Did you happen to measure the pairs of "E" ranked devices LazyCat sent us with his modules to see how close those were to each other?
I did not measure the 'E' rank devices LC sent with the VSSA modules.
As for the others I'll have to respond later when I'm home to be accurate but with the KSA1220A/KSC2960A devices I bought 100 pieces of each, bulk packaged. In that group I had gains as low as 210's and as high as 320's, with lots of devices in the 240-280 range to match up. I'm quite happy with these.
The 2SA1507S/2SC3902S were only bought in a quantity of 20 each and I believe they were tube packed (ie. Likely the same lot/die) and were lower gain but super consistent among others of the same polarity, but overall somewhat different between the PNP and NPN. I'm not planning on using these in the VSSA at this point. They are lower gain, pricier, and not as available.
The 2SA1249S/2SC3117T actually were very similar in gain to the KSA/KSC, and in looking at the hfe ranking on the data sheet you will see the 'S' and 'T' ranks overlap nicely. These were some devices I've had for many years and simply never used and therefore were put to use with VSSA with excellent results, IMHO.
You think the KSA1381E/KSC3503D are worth a listen anyway? I figured since they are miles apart they would find a use elsewhere, like maybe a Lin type design.
Honestly, no. You already have a better fit. It is just one of many things that contribute to good sound.
I DO think the parts LC sent out are worth measuring to see how close a complementary pair they make. I can try to do that, because I have not installed them yet, but someone else would have to provide a little direction.
So, to do this in a consistent manner, and get useful and repeatable results,
a) someone with more knowledge (thank me), would have to suggest a measurement method that makes sense, at least for this circuit.
b) a simulation would have to show how much distortion results from unmatched devices,
c) out of this we would have to find a reason to get the complementary "E"
ranked device, while they are still available at all.