Tea-Bag

This last weekend I replaced the IRFP240 in my F2 Clone with the R100 SouthSemi Power-JFET.

tubes-guy used psychic powers to control my mind and force me to do it.

The bias dropped off the bat. I re-biased and gave it an A-B listen to the standard channel. Seemed to be a bit 'cleaner' sounding the the default channel.

Nelson has recommended the following changes to the circuit, which I hope to implement soon. I will be re-wiring these on Peter Daniels boards.
The Peter Daniel boards are still available I believe.
http://www.diyaudio.com/forums/group...group-buy.html

Papa sayz...

The F2's that I have updated with the JFETs need the
following changes:

R6 = 47k (changed to 8.2K of FW Site)

C1 = 10 uF

Z1 removed

The potentiometer must be re-adjusted for minimum
distortion at 4.5 watts (symmetric clipping) and readjusted...

This Blog is to post reference parts to achieve voltages and currents for your BiB boards.
This can help others meet their goals with less parts ordering and frustration.
Feel free to include parts in highlighted area, plus caps and transformers used.

Keep in mind that there are some 3 and 4 LED CCS versions.
Dx02-4 on 3 LED and Dx02A-B on 4 LED versions. These will run the CCS hotter (more ma) if using 4 LED, especially with 4 green LED's.

Make sure to reference BiB Build Guide Version 2 or ask list if uncertain about the below comments.



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Hello,
Can you show me what are the components for a target of 7V?.
thanks

1 red led, 1k resistor, 1k trimmer.

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I use the Legato 2...
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Here I am going to post some semi-commercial information regarding the minikits. Make sure to read the full BiB build manual before ordering parts. The link is posted below.

BIBguideRev2.pdf
It is essential you understand and purchase for the correct voltage type and range you need for this kit and additional parts.

The purpose here is to report what parts are included in the minikit, and which are not.
This will assist builders in getting the correct parts that are not included in the minikits.

The minikits are made for one of the three sections of the PCB. The board itself can hold two positive and one negative rail type supply.

The kits are purely optional, and are sold to assist the buyer who may not be able to access the resources needed to gather the specific parts.

There are four kit types described below. IRF for voltage 5.5v - 45v in positive or negative rail, and the BJT bipolar's which...

So I believe I am finished with the Mini-A version modified for SemiSouth R100 output. The MJ is not in reference to Michael Jackson, rest his soul. Simply a reference to Mosfet input, JFET output.

Technical pieces:
R8 is a 1K pot. This allow for some DC offset adjustment.
R18, This affects drain current to differential pair. This value is lowered. I chose 220R resistor since I have a bunch of them. Papa presented this as needed on mod's in general for the lower VGS of the R100 (~1.5v)
R19, gate resistor to Power JFET R100. This is lowered to 47R. We see with F1J and F2J that gate resistors are lower.


Rail Voltage is +/-24v
Source voltage is .425v and is largely determined by the 100K pot settings and heatsinks on hand. The real value of the pot is ~ 70-80k here. I let the IRF240's run no higher than 65c and R100's no higher than 70c.


Sound

Previously I had R18 at 392 default and R19...

So I am going to write some details down about the DCB1 Blue Edition Buffer. This is the best I can tell, the third or fourth iteration of this buffer/Power supply. The GB will certainly represent the third run of the buffer.

Salas added some tweaks to the design which CRT implemented. I will be offering these boards for sale.



Here are some things that make it different,
It's a larger board.
More room for filter caps.
They can handle 10mm pitch snap-in capacitors 25mm width capacitors.




There are positions for smaller MUR120 type diodes or MUR820 style TO-220 style diodes.

The vRef LEDS can now be bypassed with a 25mm Film cap or a 100uf electrolytic.

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