I don't know. But would it be cheaper to buy an ACA kit, a B1 kit (supposed I could find one) and connect the 2 boxes with a good (expensive) interlink? Possible, but I can't imagine.
Yes, but it is a good starting point to ensure all components are ok before they are used. When the caps are soldered to the PCB I don't want to swap that many times. It is also my intention to pair the resistors so I get two identical ACA's. That it why I have 10 of each resistor. They are cheap so why not? .....if I can get down to 0.1 % instead of 1% by investing 1 hour of measurement. That is the fun part of DIY......at least for me
What music source do you use? if you stream music and use a DAC some of them has both a fixed output mode and a pre-amp mode. My DAC has that. Then I can switch between the modes. Until now the fixed output mode and use of a passive pre-amp (pot = 24 step attenuator) has been the best solution.
I think the problem by using a passive pre-amp with the ACA (e.g. a 10k pot) is that when you change the volumen setting you also change the amount of NFB.....as I have understood how it works. It could work OK using a 10k or 5k pot. It has to be tried. You get more and more NFB when you turn up the volumen. Then when you have turned all the way up so there is direct connection to the source the ACA works as specified. Someone could correct me if I am wrong.
The first version of ACA has less NFB....and sounded ok? ....therefor it might work by using an e.g. 5k pot as volumen control? That is my logic without beeing an amplifier expert
What music source do you use? if you stream music and use a DAC some of them has both a fixed output mode and a pre-amp mode. My DAC has that. Then I can switch between the modes. Until now the fixed output mode and use of a passive pre-amp (pot = 24 step attenuator) has been the best solution.
I think the problem by using a passive pre-amp with the ACA (e.g. a 10k pot) is that when you change the volumen setting you also change the amount of NFB.....as I have understood how it works. It could work OK using a 10k or 5k pot. It has to be tried. You get more and more NFB when you turn up the volumen. Then when you have turned all the way up so there is direct connection to the source the ACA works as specified. Someone could correct me if I am wrong.
The first version of ACA has less NFB....and sounded ok? ....therefor it might work by using an e.g. 5k pot as volumen control? That is my logic without beeing an amplifier expert
It is probably wrong what I wrote.......you will start with more NFB than specified and then when you turn up.....it will be lesser.....if you use a pot without a buffer......
Thanks for your reaction, MEPER. The only source I use is a cd player. What I would like to buy is a class a integrated amp kit with 5 or 6 watts per channel and a good manual. I'm considering an Elekit 8200 (Elekit TU-8200 Stereo Tube Amplifier Kit
| TubeDepot.com) which would suit my needs and costs 699 dollar. But if there was an ACA integrated - with or without a buffer, I don't care as long as it works properly - I would buy it instead of the Elekit. Because probably it would be easier to build and I wouldn't have to buy new tubes every couple of years.
if you can drill a hole and do some mechanical work , we can help you to get ACA integrated
in case that you (properly) mount pot at back side , and with extending shaft to front button , hole in front panel isn't critical any more , as is in case when you want pot mounted on front plate , needing bigger recess in back side of it ........ due to 10mm thickness
in case that you (properly) mount pot at back side , and with extending shaft to front button , hole in front panel isn't critical any more , as is in case when you want pot mounted on front plate , needing bigger recess in back side of it ........ due to 10mm thickness
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Thanks for your constructive reaction, Zen Mod, but I don't have a drill and due to an accident I can only use two fingers of my left hand, so I think the mechanical work will be a problem. But if someone can do it for me I'm prepared to pay for it.
You talking to me?
I think you are and I think I'm thanking you for answering my question(s); You and Zen, of course.
Zen Mod, thanks a lot. : ) I don't know people who can help me with the tricky tasks, but the solution doesn't have to be speedy. I've a working stereo here, so I can wait. Mounting the pot at the back with an extending shaft to the button on front (I just found a nice black one in the store) is a very good idea in my opinion. So I understand a 'dumb' pot will work properly in the ACA? 'Rekterx' mentioned something about a changing NFB (negative feedback?) when using a pot without a buffer. If he's right, would it be a problem?
No, no, no Spencer .... rekterx mentioned nothing about "a changing NFB (negative feedback?) when using a pot without a buffer. "
rekterx is only trying to ascertain that you and Zen answered my questions about the ACA now being in one physical box as opposed to two separate mono-blocks.
Have I fallen down the rabbit hole?
rekterx is only trying to ascertain that you and Zen answered my questions about the ACA now being in one physical box as opposed to two separate mono-blocks.
Have I fallen down the rabbit hole?
I think it was me that mentioned about the changing of NFB when using a pot without a buffer. The pot will be in serie with the 10k input resistor so amp will "see" a higher value than the 10k input resistor.....and Rin is part of the NFB loop. If you use a 10k pot and turn op a bit so it stays at 5k then Rin is 10 + 5 = 15 instead of 10 and that will change the amount of NFB as far as I can see. If not I have to read a bit more about the inverting op amp......Zen Mod was mentioning in an previous post. The solution may work ok........but has to be tested I think.
O dear... Sorry rekterx, my fault. It was MEPER who said it. I apologize. Maybe it was the flu.. Friends again?
'ACA Integrated'
'I was thinking about buying 4pcs of LSK170B from store , along with ACA kit
then making picolo sort of B1 buffer on small veroboard
problem solved
either that , or having picolo B1 in small plastic box , as standalone unit .......'
A picolo sort of B1 buffer INSIDE the ACA sound great to me. I just found out a LSK170B is a J-fet, but I've no idea what a veroboard is.. : ) Never mind. Do I understand correctly you're going to try this to see if it works?
'I was thinking about buying 4pcs of LSK170B from store , along with ACA kit
then making picolo sort of B1 buffer on small veroboard
problem solved
either that , or having picolo B1 in small plastic box , as standalone unit .......'
A picolo sort of B1 buffer INSIDE the ACA sound great to me. I just found out a LSK170B is a J-fet, but I've no idea what a veroboard is.. : ) Never mind. Do I understand correctly you're going to try this to see if it works?
I know it works
yup
though , we can go up to 20K , altering two resistors in FB by factor of 2 , but 20K is still too low for pot in front of it
