What is it?
Location: fuck off
Posts: 2,033
I'm fuckoff.
What is it?
Location: South downs
Posts: 3,477
I'm James.
A preamp... Sort of !
Technically its a buffer with a potentiometer on the input. Supposed to be the best of both worlds, with the transparency of a passive pre-amp and the drive of a good active pre-amp... I cant comment either way yet as I've only just got the thing working - If you see this Rob [Puffin] the fault was the CCD's, they were working but letting far too much current through [as much as 30X too much in one case!]
Yes, the curse of shitbay! Glad you got it sorted. Let us know what it sounds like in due course.
Buy Bose...And get your parking validated!.
https://youtu.be/ZCBe7-6rw4M
No Highs...No Lows....It Must Be Bose!
Location: South downs
Posts: 3,477
I'm James.
Nice B4 glad you got it working
I use one myself and they are neutral and transparent after a couple of weeks left switched on 24/7 but get t in a box first so its safe.
Alan
Location: South downs
Posts: 3,477
I'm James.
Cheers
It wasnt all plain sailing though ! I Originally got the board from Rob fully populated but not working & with significant track damage around the volume pot... Managed to get it working with new CCD's & thought I fixed the tracks but they were just too far gone & channels would randomly cut in & out So I robbed all the components off the PCB & fitted them to a new B4 board.
Extended listening showed it to be dynamically squashed & it just seemed to steal the fun out of music. I discovered this was down to the standard BOM quoting naff values... I followed it & had R5=10k/C5=1uF which as confirmed by PD gives a 10ms time constant, 3dB rolloff at 16Hz [audible loss of deep bass.] I've now jumpered the input & output caps and fitted 5K trimmers @ R3/R103 adjusting the offset to 0vdc. It now sounds absolutely fantastic... If your power amp has input coupling caps you really should remove them from the B4 ! ... If keeping the 1uF input caps you can change R5/R105 to 30k which will fix the bass issues.
I've got all the bits to build it into an acrylic case but as always just cant seem to get 'round to it !
You Da Man! Well done.
Buy Bose...And get your parking validated!.
https://youtu.be/ZCBe7-6rw4M
No Highs...No Lows....It Must Be Bose!
Yes the CCds are probably the most common cause of failure to the board, I also changed my R5 for 25k / C5 1uf NOS Russian polysyrene, still have an output cap (wet Tant) in there and I will get round to experimenting with removing it eventually, but anyway glad you got there in the end
The modushop.biz cases are very nice
Alan
Location: Slovenia
Posts: 5
I'm Tilen.
Hello, check out my first diy project! My vision was to create 2.1 sound system with amplifire, which will not only fill the room with good sound, but also to be a work of art. What do you think?
Nice job Tilen.
It is impossible for anything digital to sound analogue, because it isn't analogue!