Is the PASSDIY B1 board the complementary version

[rickmcinnis]

Just wondering.

Now that the store no longer has the matched devices I am hoping I can get them in the kit.

Thanks,

 

[WalterW]

No it's the version with 2 x matched 2SK170BL in each channel

 

[AndrewT]

the standard B1 and the DCB1 need selected Idss for the two jFETs in the CCS loaded Follower.
They do not need to be matched.
Select an Idss that is within about 1% to 2% and the output offset will be acceptable to most users.
The output offset should be negative indicating that the jFET with the slightly lower Idss is fitted in the CCS position.

If you read the D.Feucht paper on the jFET Follower you will see how easy it is to remove the output offset.
eg if you measure a -18mVdc offset with a pair of near 8mA BL/B grade devices, then a 2r2 in the source of the Follower virtually removes the offset.

 

[rickmcinnis]

Thanks for your note, Andrew.

I am determined to use the complementary version if I can find the devices.

Otherwise, I will use ZEN MOD's diamond buffers once he gets the boards ready.

 

[schubert]

Get them from Spencer at FET Audio

 

[rickmcinnis]

Thanks for the recommendation,

I found they were not that hard to get as long as you are willing to pay for them!!!

 

[schubert]

True - and they won't get any cheaper!

 

[rickmcinnis]

I figure when a TOSHIBA FET costs as much as a TELEFUNKEN 12AX7 "tube" people will think FETS sound good.

Yes, I know you are right. They are precious things!

 

[Bare]

True - and they won't get any cheaper!

Curious that. Given they are in Current production.

 

[schubert]

Not by Toshiba.

 

[AndrewT]

Some say the Linear parts are as good as the Toshiba parts.
Some say they are better and yet others say that Toshiba's were better.

If Tosh are not available then we have to use what is current.
Either LSK in To92, or find smd equivalents.