B1 with Korg Triode

[qwertyl]

Wow, thanks for a detailed answer. So now they are $250 preamp ornaments?

Yes, but who knows where the future takes me

 

[Centurion53]

Thanks tsmith1315 for the reply. Sage advice indeed. I'm new to this forum and there is such a vast amount of material here that it's easy to fall down rabbit holes .

 

[Soundhappy]

https://www.diyaudio.com/forums/tub...g-nutube-6p1-article-millett.html#post5696663

https://www.audioxpress.com/files/attachment/2672

 

[Eric]

Thanks for posting Pete's article! Looking at this again, I keep seeing the same data: Vf=0.7v and If = 17mA.

My measurements show that with a 24.0v regulated supply, my Nutube is running at Vf = 0.704v and If = 18.9mA being drawn across the 475R for both channels. Is this a long-term problem? It seems that I'm outside of the SOA...

 

[avdesignguru]

Yes, but who knows where the future takes me

Jensens would be most useful in inverting the polarity of the B1 Korg outputs to avoid having to invert the loudspeaker connections.

 

[Bassivus]

Jensens would be most useful in inverting the polarity of the B1 Korg outputs to avoid having to invert the loudspeaker connections.

That was my consideration... I could salvage a pair of JT-11-BMCF to use

 

[R-K Rønningstad]

http://www.jensen-transformers.com/wp-content/uploads/2014/08/jt-112p-2hpc.pdf

 

[Rewind]

Got my Nutube från the DIYAudio shop. It took 15 days to Norway.

 

[qwertyl]

A few boards + nutubes posted today: see here

 

[mcgillroy]

Thx qwertyl!

 

[Morfeus]

Thank you so much, qwertyl!

 

[difool]

Yes, thank you qwertyl and puggie for the service you are supplying.

 

[rchomeless]

Many thanks to Nelson pass, dewdrop
What wrong of my nutube build for the measurement from GND to L IN / R IN approx. 10v?
T1=24v, T3=22.7v, T4=9.65v, T5=0.67v, T6=0.67v, T7 and T8 set to 10v
nutube lite up as blue.
PS=24Vdc

 

[R-K Rønningstad]

Jensens would be most useful in inverting the polarity of the B1 Korg outputs to avoid having to invert the loudspeaker connections.

With the risk of ruining the delicious simplicity of the B-1 I started thinking of a balanced input my B-1 Rev. 1. The background being my RIAA (Borbely) and DAC (Teac) both being balanced (XLR out).
How about a long-tailed pair at an input XLR?

 

[Eric]

What wrong of my nutube build for the measurement from GND to L IN / R IN approx. 10v?

Nothing is wrong, mine measures the same way. It is the impact of having the caps in place. Your other measures match my own as well. Connect a source and an amp and you should be in good shape.

Having said that, I ALWAYS test with disposable speakers first...

 

[Algar_emi]

Hi. I'll make myself a pcb for the B1-Nutube, check the picture. It is the Firstwatt circuit, with optional on board power supply using a Meanwell 24V supply and additional CLC filtering, before the original B1 CRC filtering. There are pad on the board to still connect an external dc power supply if you wish. It still support 2 inputs and two separate volume pot.

The PCB size fits the Hammond 1455N2201 chassis.

I can make just one pcb for me, or if there is enough interest I can arrange a small GB. Let me know by private email.

Thanks
SB

 

[DougL]

With the risk of ruining the delicious simplicity of the B-1 I started thinking of a balanced input my B-1 Rev. 1. The background being my RIAA (Borbely) and DAC (Teac) both being balanced (XLR out).
How about a long-tailed pair at an input XLR?

I would get a second B1 board and run it "Quad Mono".
Any LTP you devise is going to have extra gain you will need to burn.
Since the channels are unity gain, they are going to gain match even if the device gains are different. The only issue I see is that there will be no additional CMRR, and it will not convert Balanced to single ended..
If your amps are balanced, great. if not, its worth a larger discussion.

 

[R-K Rønningstad]

Good advice... CMRR is one thing, but my power amp is single ended. Thank you anyway.

 

[Nelson Pass]

I believe we could make an LTP with the Korg tube(s) if that's what you want,
in fact I think it would be easy using a CCS on the Cathodes.

 

[R-K Rønningstad]

Splendid idea!
One NuTube per channel.