OK, I’m done for now. Thanks for the guidance, Ben and Lucian.
If interested I can draw a small pcb(if you give me the exact dimensions) on which you can fit 4x k209.
Only problem with this approach is that you will need to match them first for which you will need a cheap(~10$) smd adapter.
Only problem with this approach is that you will need to match them first for which you will need a cheap(~10$) smd adapter.
The first 4 single channel pcbs ended up like this.
Somebody wanted them together with the power supplies.
Somebody wanted them together with the power supplies.
I think I will incorporate a bypass switch on the output caps. Leave it inside the pre next to the boards. Then I can fiddle with the DC offset and not take it all apart. Something like that. 👽
The output cap keeps safe your dc coupled amp and speakers in case of a line stage failure. For better sleep I would leave that cap in there.
But the trimmer pot was added to adjust the DC offset in direct output coupled applications. Why eliminate the fun? Stupid amp has a cap on the front door. 😀
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By adjusting the dc offset you degrade the thd performance (as Nelson says) so you can end with similar thd without the cap and 0mv dc offset.
Touching the 'magic' can be so delightful. I live such a reckless life.😉
Finished.
My FE2022 -preamp is in the cases.
Chassis 1: PSU
Chassis 2: preamp
Chassis 3: PAC (pre amp controller) = input selection and volume control (also used for other preamps)
Cheers
Dirk
My FE2022 -preamp is in the cases.
Chassis 1: PSU
Chassis 2: preamp
Chassis 3: PAC (pre amp controller) = input selection and volume control (also used for other preamps)
Cheers
Dirk
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Hello Aleph5,
I've posted about PAC. I'm not sure, but if I remember right, it was in the BA2018 - preamp thread.
But these pcbs are not from me. It is based on an ARDUINO NANO as controller. You can 'hang' a lot of input - pcbs and
volume control pcbs on it.
All the other pcbs (FE2022 / PSU) I did myself in KiCAD.
Can check if the PCBs for input and volume control are still available. German DIY-shop.
Cheers
Dirk
I've posted about PAC. I'm not sure, but if I remember right, it was in the BA2018 - preamp thread.
But these pcbs are not from me. It is based on an ARDUINO NANO as controller. You can 'hang' a lot of input - pcbs and
volume control pcbs on it.
All the other pcbs (FE2022 / PSU) I did myself in KiCAD.
Can check if the PCBs for input and volume control are still available. German DIY-shop.
Cheers
Dirk
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Hmm, I never thought about that extra modular approach. I'm digging it big time. I have found some new ideas based on these things I see here today. Time for me to make a plan. Cheers.
Excellent. I'm considering some kind of fancy volume with a display, preferably from scratch. Still pondering. Thanks.
After listening to precariously placed FE boards for a couple weeks, I installed them permanently in the amp. Rats' nest be damned, the things have a totally silent background. They sound great, of course. Just the right amount of gain.
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PROBLEM: I just completed my FE. Hooked it up to my system and turned on my CD player then my FE and then my ACA mini. When I turned on the mini I heard a good pop through the speakers. Hit play on the CD player and everything sounded really great! Also during idle there is a very faint hum in the speakers. It's mounted in a small Galaxy case.
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It looks like you have a V+ power supply. If that is the case R10 should be a jumper. That may solve your hum problem.