So I received a couple of boards from Bloqhead a while ago but haven't really had the time to build them out until now. Thank you so much for the boards and thanks to Prazi for the layout and Lineup for the design. I don't know where in Sweden you reside but if you're near Sthlm you're welcome to stop by for a beer and a listen when I'm done if you still haven't heard it. 
The plan is to start populating the boards in the days to come, tap the heat sinks and get things ready. This is my first class a and my first venture outside of a few kits, a chipamp or three and some parts upgrades to Chinese class d modules, so there will probably be some newbie questions popping up in this thread. Is this right? Is that where those are supposed to go? And biasing...
I will power them with two 20v 3.4a laptop supplies I found the other week for 2€ a piece. I do have a 15v 80va toroidal transformer in my stash box and at some point I'll probably build a power supply for the amp. But for now it'll be the smps's. I'll probaly run it in the kitchen with a Chinese dac as preamp and with small fullrange speakers. But I'll probably drag my Klipsch KG4.2 out of storage some weekend when the gf is away and play some tunes for the neighbours.
The first question I have is what do people use for power switches and can you just put one on the dc-side or do you need some form of additional circuitry? Or should I just leave it and use a strip with a switch?
Eager to get building!
/Vilding
The plan is to start populating the boards in the days to come, tap the heat sinks and get things ready. This is my first class a and my first venture outside of a few kits, a chipamp or three and some parts upgrades to Chinese class d modules, so there will probably be some newbie questions popping up in this thread. Is this right? Is that where those are supposed to go? And biasing...
I will power them with two 20v 3.4a laptop supplies I found the other week for 2€ a piece. I do have a 15v 80va toroidal transformer in my stash box and at some point I'll probably build a power supply for the amp. But for now it'll be the smps's. I'll probaly run it in the kitchen with a Chinese dac as preamp and with small fullrange speakers. But I'll probably drag my Klipsch KG4.2 out of storage some weekend when the gf is away and play some tunes for the neighbours.
The first question I have is what do people use for power switches and can you just put one on the dc-side or do you need some form of additional circuitry? Or should I just leave it and use a strip with a switch?
Eager to get building!
/Vilding
Hi Vilding
As for your question about power switch use a double pole switch if you are using 2 power supplies, however you could probably get away using the one PSU as I used a higher bias (2x0.5ohm instead of 2x0.6ohm resistors in the CCS) which draws 1.25 amps per board.
You could consider using Mark's SMPS filter as well which may be a route I would have tried if I'd have known about it at the time:
https://www.diyaudio.com/community/...all-warts-preamps-hpa-korg-nutube-etc.354213/
As for your question about power switch use a double pole switch if you are using 2 power supplies, however you could probably get away using the one PSU as I used a higher bias (2x0.5ohm instead of 2x0.6ohm resistors in the CCS) which draws 1.25 amps per board.
You could consider using Mark's SMPS filter as well which may be a route I would have tried if I'd have known about it at the time:
https://www.diyaudio.com/community/...all-warts-preamps-hpa-korg-nutube-etc.354213/
I have a few of those and plan to use them here, as well as some speaker protection boards. And about the psu's... I have two and they were practically free plus dual mono is pretty sexy... 😁 Hell! I might even make some 4 watt mono blocks... I've sorted out the parts and started stuffing the boards, but haven't had the time to make smoke and metal chips yet.
Thanks for your reply, do you know what formulas to use for those calculations? to be sure i'm getting 7 watts on the 4 ohm speaker and by how much increase the current, at least theoretically ...sorry i have no clue, cheers.
hi,
finally got some time to build this amp and populated most parts, but I need some help for parts values;
I have not 100k VR but 50k on hand, may I use it?
used 100pF silver mica cap instead of 47pF, is it ok?
also used a 330pF X7R cap for CL, is it ok too?
does it strictly necessary to use fuse in case 19-20v dc?
thanks in advance.
finally got some time to build this amp and populated most parts, but I need some help for parts values;
I have not 100k VR but 50k on hand, may I use it?
used 100pF silver mica cap instead of 47pF, is it ok?
also used a 330pF X7R cap for CL, is it ok too?
does it strictly necessary to use fuse in case 19-20v dc?
thanks in advance.
