Please send mine at your convenience have nutube bought as soon as heard about the b1 korg unit .Regards spades
I bought a Nutube from the DIY store here in anticipation of the commercially available board, hopefully with JFETs and resistors. I have caps, diodes, chassis, power supply (on way) so I am ready to screw the pooch on the project.
Maybe I've missed this somewhere along the line but I was hoping someone could tell me what the input (without the pot) and output impedance is. I was thinking of doing away with the Pot as both my DAC and SQB Touch have volume controls.
can't go wrong looking at post #1
most left , 50K
though , if your sources are capable of driving it , you can go lower .... to 10K
or , delete it from schm , as is adequate for your case
most left , 50K
though , if your sources are capable of driving it , you can go lower .... to 10K
or , delete it from schm , as is adequate for your case
Yeah, I'm not sure me looking at a schematic helps me work out the input impedance or output impedance 🙂
input impedance is practically 110K , sans volume pot
when volume pot used , Rin is roughly value of it
output impedance is roughly 1/S , where S is xconductance of JFet used
in case of 2SK170BL , S is 22mS , so 1/22mS= 46R
NB that S , when JFets are in case , is marked ad Yfs
me , being toob guy , used to call it S
when volume pot used , Rin is roughly value of it
output impedance is roughly 1/S , where S is xconductance of JFet used
in case of 2SK170BL , S is 22mS , so 1/22mS= 46R
NB that S , when JFets are in case , is marked ad Yfs
me , being toob guy , used to call it S
Ok, just so I got this right;
Without the POT and feeding the signal straight into the 10uf cap the input impedance is 110k
If I use a 50k POT the imput impeadence is 50k
(I had to look up "sans" 🙂 )
Without the POT and feeding the signal straight into the 10uf cap the input impedance is 110k
If I use a 50k POT the imput impeadence is 50k
(I had to look up "sans" 🙂 )
Thanks!
Under construction
Now that I'm adequately caffeinated, going to get this thing going. For convenience, I ordered up one of these from Mr. Broskie:
Phase Selector switch & PCB for switching between plus-mute-minus
One of many useful things for sale on his site. This new version also has a mute which should be handy for powering up and down.
Now that I'm adequately caffeinated, going to get this thing going. For convenience, I ordered up one of these from Mr. Broskie:
Phase Selector switch & PCB for switching between plus-mute-minus
One of many useful things for sale on his site. This new version also has a mute which should be handy for powering up and down.
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welcome to the club 
though , it's always nice , later, finding something you need , already in the drawers
though , it's always nice , later, finding something you need , already in the drawers
That's for sure! Though at this point I'm not sure whether my parts pile is an investment, a stash or a hoard.
🙂
🙂
A while back I bought two pairs of Edcor chassis mount transformers, WSM600/600 and WSM600/2.4K. I was thinking of splicing them onto the output of the earlier non-Korg B1 to get some gain and/or balanced outputs. I would like to drive either a pair of ACA monoblocks or my eventual Aleph J. The NuTube gain stage seemed like the perfect addition to this wackoo scheme, so I jumped on the Xmas offer.
The tentative plan so far is to hook up a pair of transformers to the JFet output and drive XLR cables directly from those into the amps. Just crazy enough? Or too crazy?
The tentative plan so far is to hook up a pair of transformers to the JFet output and drive XLR cables directly from those into the amps. Just crazy enough? Or too crazy?
You could add a high quality output transformer like a Jensen JT-11-FLCF to balance and isolate the signal ahead of the Glassware polarity reversing switch.