they might be fake eBay is known that counterfeits are sold there that is why I always buy in Mouser or Digikey can you use Toshiba instead? TTC004B NPN TTA004B PNP
Oloppolo, if it’s from eBay, there’s a good chance they are fakes. I urge you to only buy from Mouser, RS, Farnell or Digikey. .
Careful, TTC004B and TTA004B SOA not nearly as good as ksc2690/ksa1220, especially at high voltages.
Yes. The PCB mounting holes are the same for the transistors. The PCB mounting holes are slightly moved, but I never use those personally because the transistors secure the board to the heatsink.
Rallyfinnen capacitor
I prefer without Rallyfinnen capacitor. I have a bad sound with it. I have checked the connection many times. Negative to anode D1 positive to collector Q7.
I prefer without Rallyfinnen capacitor. I have a bad sound with it. I have checked the connection many times. Negative to anode D1 positive to collector Q7.
Please stop buying from e-bay!
Especially semiconductors, it's the only way to stop thieves!
Yes agree. Years ago a friend bought for me some power transistors in Italy, fake of course! 😉
Yes - make sure that both Q7's (ie left and right channel) hFE is within 5% of each other. This will ensure the standing current between the two channels is the same. if you have big differences (say 200 and 600) you can get up to 60 or 70mA difference between the channels.
Hi, after months I couldn't get a good sound, despite your help. I did something wrong. Today I move on to another project. Thank you.
Davide, I am sorry to hear that, but cannot help feeling part of your problem was to do with buying parts off eBay. You really have to get components from reputable suppliers (Mouser, RS and Digikey) and stick to the design and selected components.
The direct coupled feedback nature of most CFA amps can also present someone new to DIY audio with some real challenges if your build has problems (which happens more often than not).
A good way to get going is to build something really simple and then progress from there - have you tried Nelson’s Amp Camp design ( Amp Camp Amp - ACA ) or perhaps a JLH?
Anyway, good luck in your quest!
🙂
The direct coupled feedback nature of most CFA amps can also present someone new to DIY audio with some real challenges if your build has problems (which happens more often than not).
A good way to get going is to build something really simple and then progress from there - have you tried Nelson’s Amp Camp design ( Amp Camp Amp - ACA ) or perhaps a JLH?
Anyway, good luck in your quest!
🙂
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KSA1220AY and KSC2690AY
Hi
If that is the only issue you have then I have more than 10 parts of each bought at Digi-Key.
I can measure closest hfe and then spare 2 pairs of each for your project.
You would only have to pay for shipping.
Fab
Hi
If that is the only issue you have then I have more than 10 parts of each bought at Digi-Key.
I can measure closest hfe and then spare 2 pairs of each for your project.
You would only have to pay for shipping.
Fab
Attachments
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Both transistors are available from RS Components or Farnell
I had problems with the original design as previously noted on this forum (mainly solved by the addition of Q1/Q2 collector resistors). However, most of the problems appeared to have been running 2 ripple eaters, one per channel, from a single transformer.
Do you have access to an oscilloscope and signal generator available? If so, it makes it easy to check the waveforms and proceed from there if any problems are found.
I'm very satisfied with my build since I ran both channels from a single ripple eater. Waveforms (sine and square) are 'spot on', minimal noise (< 1mV), and the sound is very good.