F6 - dual mono
Kind of a slow day here on the quarantine scene, so thought I would post a picture and thank everyone for the help and inspiration that this site and thread gave me. Especially Nelson for the design and support.
I needed to do a rebuild due to outside issues and thought I might as well try to squeeze more parts into this box, inspired by other's posts here. It's tight, but is working well and is quiet.
Thanks again everyone
Kind of a slow day here on the quarantine scene, so thought I would post a picture and thank everyone for the help and inspiration that this site and thread gave me. Especially Nelson for the design and support.
I needed to do a rebuild due to outside issues and thought I might as well try to squeeze more parts into this box, inspired by other's posts here. It's tight, but is working well and is quiet.
Thanks again everyone
Attachments
Hello.
I am gathering parts for F6.
This is first time to build firstwatt amp.
I am considering to order r-core power transformer(300VA-400VA) from phenix.
Their transformer have one primary and two secondaries.
So I have a question that I should have one CL-60 or two in parallel
or go for soft starter.
I am gathering parts for F6.
This is first time to build firstwatt amp.
I am considering to order r-core power transformer(300VA-400VA) from phenix.
Their transformer have one primary and two secondaries.
So I have a question that I should have one CL-60 or two in parallel
or go for soft starter.
I am not sure but form instruction from website,
Because high u oriented Hi-b core,lower magnetic resistance and coil resistance.
Less coil resistant for primary makes better regulation but more inrush current.
???????_??????R-CORE_TRANSFORMER
Inrush is a function of the transformer VA and the filter capacitor uF. Regardless of transformer type, you need inrush suppression. (CL-60 or soft start circuit)
I have all my parts on order to complete the F6.
So excited but shipping delays!! Arghhh
It’s a single PS standard build with 400VA trafo from Primrose Audio.
I’m thinking of going integrated with the B1 Nutube as the pre.
I think this will be a nice combo?
Is there any detriment supplying the B1 from the same power supply as the F6?
I.e from the +ve rail and ground? Should have enough headroom?
Do I need to isolate in any way?
Using DIY audio Universal board with 74000uf per rail.
Cheers
So excited but shipping delays!! Arghhh
It’s a single PS standard build with 400VA trafo from Primrose Audio.
I’m thinking of going integrated with the B1 Nutube as the pre.
I think this will be a nice combo?
Is there any detriment supplying the B1 from the same power supply as the F6?
I.e from the +ve rail and ground? Should have enough headroom?
Do I need to isolate in any way?
Using DIY audio Universal board with 74000uf per rail.
Cheers
jqmce -Keep me posted I am on the same journey -- I ordered the B1 Korg kit that won't be available until 3rd quarter so I'm starting on the F6 - I have most of the parts - I got the kit when it was available - I think the combo will be great
To quote Papa from the build guide:
"The preamp can be made to work with other supply voltages, but you will find yourself adjusting resistors and also needing a distortion analyzer to set the Nutubes for the desired distortion character. Easier to use 24V. If you use a linear power supply, you will want to have it regulated, as we need a constant DC value regardless of AC line voltage."
A small hard wired 24V SMPS run off the AC line inside the chassis would be the simplest most reliable way to get the job done, and keep the two circuit supplies separate. About the same price as the original spec external Triad supply:
https://www.mouser.com/ProductDetai...=sGAEpiMZZMsPs3th5F8koBFO1FnQkaDCUHGsdtbrlqs=
A isolated DC-DC converter off the + V should also work but maybe someone could weigh in on possible ways it could affect the F6 sound? Doesn't save any money:
https://www.mouser.com/ProductDetai...GAEpiMZZMvGsmoEFRKS8NQI34ISr4%2B/bVK7nGRtBrg=
From the Korg B1 article:
"Also, the circuit has a turn-on turn-off thump. You can leave it on, and it draws .06 amps at
24V, and it won't impact your electric bill. Alternatively, you can be sure to turn it on first and
turn it off last in the system."
This may an issue if you build the B1 Korg and F6 as an integrated.
"Also, the circuit has a turn-on turn-off thump. You can leave it on, and it draws .06 amps at
24V, and it won't impact your electric bill. Alternatively, you can be sure to turn it on first and
turn it off last in the system."
This may an issue if you build the B1 Korg and F6 as an integrated.
Adding a pre to an F6 is IMO a curious desire. Clearly the intent of someone who doesn't own /use one.
Suggest listening to the F6... before... adding to it.
An F6 is 100% Dead silent . Also accepts a Simple Stepped attenuator as a pre ( or if Flush .. a transformer volume control)
beautifully for a Straight wire from the source clarity. Adding a pre is unlikely to improve on that clarity.
Suggest listening to the F6... before... adding to it.
An F6 is 100% Dead silent . Also accepts a Simple Stepped attenuator as a pre ( or if Flush .. a transformer volume control)
beautifully for a Straight wire from the source clarity. Adding a pre is unlikely to improve on that clarity.
Agreed! I use the original B1 with my F6 (not in the same case) and it is a great combo, but would not want to be locked into it. Want freedom to try others. Plus don't want to share the F6 supply with any other gear - I'm power greedy!
If using internal SMPS, just wire B1K to AC always on and only switch AC to the F6 supply.
^ Agreed. No need to turn off the B1K, but the F6 does draw some power. It will need time to warm up before sounding its best.