B1 with Korg Triode

[kbergsson]

wakoo Frenchy

put some mesh in front , to protect sissy critter

Not sure its needed as the Korg triodes seem to be resonably robust.

 

[Vunce]

Wouldn’t the 6p1 be easily susceptible to microphonic noise? Especially if it’s mounted in the open air?

 

[jphabc54]

Thanks for the BOM! Most useful in getting a head start.

Suggest using Nichicon MUSE UKZ series for the 10uf coupling caps. Have used the MUSE in my M2x with great results.

Great tip! I was actually updating the BOM yesterday with some higher grade Nichicon and Panasonic caps. I had originally flagged the UFG1J100MEM audio grade cap, but the UKZ2A100MPM1TD also looks good for the 10uf. The UKZ is a bit bigger, but I assume the slightly larger diameter and 3.5mm lead spacing won't be an issue.

 

[rpafenberg]

jphabc54,

your BOM was a great start and like the idea of going with the higher grade Muse as well.

Mouser has these two 1000 & 2000 uf at 35V with the proper spacing 647-UKA1V102MHD and 647-UKA1V222MHD.

I found your idea of using a 24V power supply and the adjustable regulator to be interesting but question whether it wouldn't be better to take it to the next voltage level and get the 28V version (709-GST25U28-P1J). Because of the 1.5V drop in the regulator, it looks like the best you could get out of your setup would be 22.5V. The 28V version has a slightly lower amperage (0.89A) than the 24V version you suggested but I seem to recall soundhappy reporting that the 24V supply that was used in the First Watt version was around that amperage.

 

[Gyuri]

They arrived:

 

[Soundhappy]

@ Gyuri

yummy sweet bonbons

 

[Soundhappy]

What kind of wood is that?

It's the bamboo.
Cut and drilled at home with this tools

 

[Soundhappy]

Not sure its needed as the Korg triodes seem to be resonably robust.

Yes the Korg glass envelope is thicker than the huge DHT power triodes for example

 

[Soundhappy]

wakoo Frenchy

put some mesh in front , to protect sissy critter

Out of the golden mesh cage security, "the bird" taste his freedom prototype adventure

 

[Gyuri]

I like that Peugeot drilling machine.
Made in PRC, or at Sochaux plant?

 

[Soundhappy]

Peugeot license, but made in PRC just ok for metal work on the chassis or the wood occasionally.
Not Makita or Hilti tools quality btw

 

[6L6]

Mount the NuTube with two-sided foam tape, they are very microphonic.

 

[jphabc54]

jphabc54,

your BOM was a great start and like the idea of going with the higher grade Muse as well.

Mouser has these two 1000 & 2000 uf at 35V with the proper spacing 647-UKA1V102MHD and 647-UKA1V222MHD.

I found your idea of using a 24V power supply and the adjustable regulator to be interesting but question whether it wouldn't be better to take it to the next voltage level and get the 28V version (709-GST25U28-P1J). Because of the 1.5V drop in the regulator, it looks like the best you could get out of your setup would be 22.5V. The 28V version has a slightly lower amperage (0.89A) than the 24V version you suggested but I seem to recall soundhappy reporting that the 24V supply that was used in the First Watt version was around that amperage.

My backordered Super Regulator board just arrived this week, so now I'm thinking of using the positive side of that for +24v in the B1/Korg..

Plan would be a 24 VAC wall wart (Jameco GPU572402000WA00) --> Bridge Rectifier (GBPC3502) --> CRC (2200/3x .47R/2200) --> Super Reg adjusted for +24v DC. I think the 24VAC once rectified and filtered should leave enough headroom for the Super Reg voltage drop.

Is this complete overkill once the integrated DC filter on the board is accounted for?

 

[Soundhappy]

Mount the NuTube with two-sided foam tape, they are very microphonic.

Guitar or instrument amplifiers have incorporated speakers who shake the box.
Hi-Fi preamp with external smps work in tranquility conditions.
Plenty of solutions anyways: B1 with Korg Triode + 3D printing etc.

 

[Soundhappy]

Mr.Pass speak about B1Triode circuit and microphony

Burning Amp 2017 - Nelson Pass

don't worry be happy

 

[Soundhappy]

Datasheet show filament max voltage is 0.8V typical 0.7V,
max bias ~3.5V so I do need to verify what I get first time inside of my prototype.
Jfet's Idss is better ~ 7mA or 10 mA ? Need correction with add of the resistors ?
What's the principle logic is ?

 

[avdesignguru]

Mouser Project Link

Here's another preliminary BOM geared toward USA builders.

Here is a link to the Mouser parts saved as a project
Mouser Electronics

 

[tubesguy]

Thanks!

 

[Nelson Pass]

max bias ~3.5V so I do need to verify what I get first time inside of my prototype.
Jfet's Idss is better ~ 7mA or 10 mA ? Need correction with add of the resistors ?

Best to check the bias voltage. Korg warns that if the filament is red then
it's too high. This is regulated by the 9,1V zener, so check that as well.

I have been using Toshiba Jfets Idss 3 to 5 mA, work just fine. Fairchild
J113 parts about 8 mA Idss.

Source resistor for the DIY board current source is for setting high Idss
Jfets to lower value.

Plans are that the kit will have the Fairchilds with the appropriate
Source resistor values, typically 100 to 221 ohms.

People with matched parts and also Idss at 8 mA or less can short the
Source to Ground on the current source Jfet.

 

[Steve Luck]

Will there be an ACA style full kit matching case and all parts?

I'd love that especially if the Nutube was visible in a window on the front face.

I wanted a low output amp for 106db per watt speakers after my Integrated valve amp packed up before xmas. Not too many folks doing Amps with such low output but good quality. ACA was just right for the job and budget available. I'm feeding the ACA from Cambridge DAC magic plus as a temporary set up but I need a pre-amp and a phono stage too. Got the bug to build some more now - many thanks.