Hi all,
After the release of the Bigbottle MC only phonostage (thread here: Bigbottle MC only Valve/JFET phonostage Group Buy - diyAudio) i was asked why there was no MM option by a few members. I didn't need MM so i hadn't considered it. Eventually i was approached by Andy who generously offered to redo the PCB design if we wanted to add in MM capabilities. Obviously i wasn't going to turn him down 😀
Alan redesigned the phonostage to offer MM & MC.
A few months has passed and we now have a few prototype PCB's here and rather than release them untested or as a work in progress like i did last time, we thought it would be a good idea to ask for volunteers/guinea pigs who would be willing to construct the phonostage and report back if there is any unexpected results. The idea being that when it is finalised, there will be less updates and a cleaner start to finish build process.
Obviously, you will need to have the ability to troubleshoot the PCB as it is very difficult trying to help people via phone or email. This is a lesson i learned from the first board. I'll do my best to help (I am only a "middle man" after all!) and Alan will too so you dont need to be an absolute expert but a bit of knowledge will be beneficial.
So, we have 3 PCB's available. All i ask is that it's built in the near future and that you report back any findings or measurements that need looking at.
If you are interested, please drop me a PM. Please remember, this is a not-for-profit project so all help is appreciated greatly.
I'll add a few pics of the PCB later today.
After the release of the Bigbottle MC only phonostage (thread here: Bigbottle MC only Valve/JFET phonostage Group Buy - diyAudio) i was asked why there was no MM option by a few members. I didn't need MM so i hadn't considered it. Eventually i was approached by Andy who generously offered to redo the PCB design if we wanted to add in MM capabilities. Obviously i wasn't going to turn him down 😀
Alan redesigned the phonostage to offer MM & MC.
A few months has passed and we now have a few prototype PCB's here and rather than release them untested or as a work in progress like i did last time, we thought it would be a good idea to ask for volunteers/guinea pigs who would be willing to construct the phonostage and report back if there is any unexpected results. The idea being that when it is finalised, there will be less updates and a cleaner start to finish build process.
Obviously, you will need to have the ability to troubleshoot the PCB as it is very difficult trying to help people via phone or email. This is a lesson i learned from the first board. I'll do my best to help (I am only a "middle man" after all!) and Alan will too so you dont need to be an absolute expert but a bit of knowledge will be beneficial.
So, we have 3 PCB's available. All i ask is that it's built in the near future and that you report back any findings or measurements that need looking at.
If you are interested, please drop me a PM. Please remember, this is a not-for-profit project so all help is appreciated greatly.
I'll add a few pics of the PCB later today.
Here are a few pics of the board.
Please note, a BOM will be provided to anyone looking to help with the Beta testing.
Please note, a BOM will be provided to anyone looking to help with the Beta testing.
Yeah, go on Ollie, I'll take one. I'm obsessed with phono stages at the moment [emoji3]
PM coming
PM coming
Good solid board. One point I have found needs addressing so far; the ECC83 valve filament (pins 4 and 5) is traced as a dead short on the board. Haven't looked further back. The PCC88 filament traces seem ok.
A question; what is the function of the switch SW1 or is it some hangover from the MC board. It limits the case that can be used or maybe I'm up a gum tree?
A question; what is the function of the switch SW1 or is it some hangover from the MC board. It limits the case that can be used or maybe I'm up a gum tree?
James,
Use my email address as DIY is doing my nut in lol
The switch is there so you can use the phonostage in MM or MC.
You only need to connect "1 & 2" and as long as a switch is wired in, you can put a case mount switch in place. So I'm told lol
O
Ignore my previous post - pins 4 and 5 are wired together as ECC83 has a centre tap from pin 9. For some reason I can't edit my post above.
Yep, no worries,
It's due to the different voltages that are required for the valves. As you know now anyway lol.
It's due to the different voltages that are required for the valves. As you know now anyway lol.
Hi,
The old MC board is not available currently.
The new MM/MC is now fully built and will be off for testing this week.
Oliver.
Hi Oliver, I would definitely be interested in a board when it is finally available. Many thanks for everyones efforts.
Kevin
Kevin
Hi Kevin,
No problem. The new board is undergoing a bit of refinement so hopefully will be ready to go in time for Christmas! Maybe lol
Excellent.
Just awaiting the gerbers and then it will be a quick lash up to check all is well and they will be available as a Group Buy.