Finished my Nutube build. Only thing waiting on are vibration damping mounts for the Nutube PCB which I can retrofit when they arrive. Thinking about whether I should make a cutout in the top plate with a gauze grill so you can see the Nutube glowing 🙂
to dtaylo #1945
Good Morning dtaylo,
I wouldn't say a stellar idea. Perhaps it was the result of my braindamage? 🙄
Have a good day!
Dirk
Good Morning dtaylo,
I wouldn't say a stellar idea. Perhaps it was the result of my braindamage? 🙄
Have a good day!
Dirk
i understand well the output buffer fonction but is the first input buffer really needed with a low impedance source ? we could have one coupling cap out of the circuit ?
iwas thinking just to take out the first input part ( Fist cap and jfet) and keep the second coupling caps for biasing.
i was thinking of an autoformer in place of the first buffer but it can be another
proof of my natural nonsense 😀
I have taken the DCG3 output and used this as input to the B1-Korg. As I read that the mounting holes of the Korg board itself acts like ground from the NP article, who does the grounding connections are done. Presently all the input/output RCA jacks are isolated from chassis. So IEC ground goes to the chassis, HP ground of one channel from DCG3 goes to this same chassis point. But the Korg is right now mounted on the bottom plate and the cabinet is black anodised, so I presume this is more or less isolated even though mounted. Should I connect one of the mounting holes of Korg board to this chassis point and disconnect the HP ground from DCG3? Or should I maintain the HP ground and still connect the Korg board? There is some hiss kind of a sound when idle coming from my speakers, not sure if this something to do with the grounding of the boards.
thanks
thanks
Any kind of ground to chassis you like, since you are already running grounds to
the RCA, and the chassis doesn't have to provide that.
the RCA, and the chassis doesn't have to provide that.
Thanks Nelson, but not sure I understood your response.
My RCA jacks are isolated from the chassis and all the grounds of RCA to the respective grounds on the Salas I-Select input selection board. The output of the RCA goes via the volume pot to the Salas DCG3 inputs (including the grounds). The left side headphone out of the DCG3 is connected to the chassis ground. This is my existing setup, and now with the introduction of Korg board the outputs (including all grounds) from DCG3 now go to the Korg and from korg outputs go to the RCA jacs on the chassis (again these RCA jacks are also isolated from chassis but connected together). The Korg boards all the mounting points are now on the chassis bottom plate. So all the PCB boards only the DCG3 HP ground is right now connected to the chassis and rest of all the grounds are isolated.
put plastic screws (or isolate present one with plastic bushings and washers) and be done with that
audio gnd needs to be connected to case only in one point,generally
exceptions can be made , but only if you're big boy and have no needs to ask anything in forums
me - I'm still sticking with one point rule
audio gnd needs to be connected to case only in one point,generally
exceptions can be made , but only if you're big boy and have no needs to ask anything in forums
me - I'm still sticking with one point rule
Thank you ZM, I also prefer to have a single point for ground🙂
Will use some nylon spacers on the Korg board to isolate them from the chassis and just use the existing HP ground connection from the DCG3 to the chassis. By the way the Korg makes a sweet addition to the preamp 😉
Will use some nylon spacers on the Korg board to isolate them from the chassis and just use the existing HP ground connection from the DCG3 to the chassis. By the way the Korg makes a sweet addition to the preamp 😉
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I was only asking if others had considered it or had existing ideas as I might very well consider playing with the idea just for the hell of it and the fun factor.
What to gain? I dunno possibly trying to keep the nutube in a tight operational range limiting its swing and hence possibly seeing how it affects THD.. hey thats the fun bit right...
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B1 NUTUBE finished
Hello members,
I finished my B1 NUTUBE today. Backplate arrived from SCHAEFFER AG.
So lets do some final assembly.
This little baby is playing wonderful music for the last few days. 😀
It is feeding my BA-3 poweramp. This combination is very nice.
Experiments with adjustments as mentioned by Nelson Pass will follow.
Greets
Dirk
Hello members,
I finished my B1 NUTUBE today. Backplate arrived from SCHAEFFER AG.
So lets do some final assembly.
This little baby is playing wonderful music for the last few days. 😀
It is feeding my BA-3 poweramp. This combination is very nice.
Experiments with adjustments as mentioned by Nelson Pass will follow.
Greets
Dirk
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