B1 with Korg Triode

which positions you're speaking of?

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I have soldered my two 100 Ohm resistors at the output positions. The below left and right middle positions are left open. But I could reposition. 20210517_220212.jpg
 
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if nobody chimes in, I'll decipher that tomorrow

without proper parts nomenclature shown on pcb, I need to find pcb traceout and see where in schematic these positions are

Pa is lately too much indulging Greenhorns, to ease assembly life to them (part value on pcb, instead of position mark) ....... making problems for troubleshooting process
 
if nobody chimes in, I'll decipher that tomorrow

without proper parts nomenclature shown on pcb, I need to find pcb traceout and see where in schematic these positions are

Pa is lately too much indulging Greenhorns, to ease assembly life to them (part value on pcb, instead of position mark) ....... making problems for troubleshooting process
Thanks for looking into this. The open 100 Ohm positions are next to +F in the schematic. The soldered 100 Ohm positions are next to OUT.

View attachment 952598
 
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Hi, I started soldering the resistors. Now I have a small problem. The partslist mentions only two 100 Ohm resistors. So now I'm short on two nice 100 Ohm Dale resistors.
I do have a few spare resistors. I have 70 Ohm or I can make 110 Ohm from 2x 220 Ohm. What is advisable?

Thanks, Jaap
View attachment 952578

It's typo normaly in BOM 100R need to be 4 pcs.
Patience , give to B1K the best , low ppm precision resistors, no compromise.
:) Kind regards
 
if nobody chimes in, I'll decipher that tomorrow

without proper parts nomenclature shown on pcb, I need to find pcb traceout and see where in schematic these positions are

Pa is lately too much indulging Greenhorns, to ease assembly life to them (part value on pcb, instead of position mark) ....... making problems for troubleshooting process

I'm a paint-by-numbers DIYer and FWIW, I'd rather have the color in a lookup table. :)

Helps me more easily figure out the correlation between the schematic and the PCB, since it's a 1-1 mapping.
 
I've decided to buy another Korg B1 to use as a buffer between the head unit in my car and the DSP to make for some tube sound in my three way front plus subwoofer in the boot setup. I've sourced a 12volt DC to 24volt DC converter and I'll shock mount the B1 to help prevent microphonics. Photos' to follow.

My build is battery powered, so I can confirm that is not an issue (provided caps are spec’ed to handle any extra voltage, if applicable). However, the Nutubes tend to be microphonic, some more than others… including some of the extreme variety. Vibration can be induced via air or mechanical. My amp is stationary and it took plenty of experimenting to tame the issue. Time helped tame my Nutube too. I suggest not affixing the Nutube to the pcb with double stick tape; I did… they became fused and all vibration reaching pcb was transferred to Nutube. I share your interest, but not your optimism. Best of luck.
 
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I've looked through the thread and not found a clear answer. If I want to use this as just a headphone amp, are there any changes to make? One person suggested using a 30uF coupling cap at the output instead of 10uF. Is that worth doing? Any other changes?

What is the impedance of your headphones? The capacitor value effects the bass cutoff...the lower the impedance headphone the larger this cap will need to be. 30uf is, in my opinion, to small for ANY headphone. Should probably be more like 1000uf plus. You can use this calculator to calculate the cutoff frequency.

RC pad corner frequency upper and lower cutoff frequency calculation filter calculate time constant tau RC voltage power calculator capacitance resistance - sengpielaudio Sengpiel Berlin

But really the Korg B1 as is is not going to be a great headphone amp. It has low current abilities because its not meant to be a headphone amp. If you added a mosfet or BJT buffer after it would be great but it doesn't have a lot of drive capability as-is as it's not meant for that.