sorenb

nice drawing. assuming the fet Kevin pointed to: the RN60 goes between gate-source, and switch the text of input/output(like you mention in your edit) and you should be good to go.

....relevant for GRLV .... this is GRHV

Do you have a variac? or a lab supply? The 20k getting toasted can be caused by the LT1021 not working and/or the cascoded current source not working.

I'm looking for Xicon 273-series resistors: 273-240-RC 273-511K-RC 273-240K-RC 273-820K-RC 273-62K-RC 273-390K-RC 273-300K-RC 273-91K-RC 273-560K-RC 273-6.2K-RC 273-910K-RC 273-499K-RC 273-402K-RC 273-487K-RC 273-40.2-RC 273-287K-RC 273-82-RC Seems available from Mouser, but at 5000 minimum quantity. So, any hint's on where to buy in less quantity or some who might have those in stock and want to let go of, please let me know. Thanks.

no original Torres, but this

...well, you certainly got it plug'ed in number two ... how's the mafia DAC comming?

...only asking because I got a Torres from Spain a while back - took me a while to get use to this furious lady - but I guess you already have had that experience ;o)

any prior experience with hand built guitars?

Agree Agree so I guess we just disagree on the importance of consistency then. Since acoustical instruments have their fundamentals associated with some complex mix of harmonics I'd say it is important to treat all those with consistency. There might be more to it though, as I didn't really hear much of a difference in my Carbon as I did on my BH ... Some might also remember the difference stated between KGSShv IXYS/fet) and Sanyo(bjt) ... most prefer the latter for some reason ...

the fet (cascoded or not) will deteriorate across the audio region where as most bjt CCS does not. If you just want high numbers, fets seems to be the answer. If one want linearity bjt seems to be a better option.

...and how does the numbers look like at, lets say 4kHz?

probably because Joamat is not using his T2 at full blast, thus the 10m90 will see less than1kV

how do you figur that from the pics in this thread?

60ohm -> RN60D or similar If you bought the mosfet Kevin mentioned you need to flip source/drain, as it is an n-channel Also it has exposed drain on the backside - ceramic isolation and washers that goes all the way through is needed

Well, that is a good point - after reading you post, I did sim the T2 CSS against the 10m90/DN2540 depletion, and although the T2 comes out with a lower impedance in comparison, it maintains it well above 20kHz as oppose to the depletion cascode ...I assume it is not only a question about doing well at DC, but also how well across the entire range

I guess Jung is aware of the limitations of his test setup. Anyways, you brought up the results to support your claim - which it really doesn't. Well, the Pimm web-site isn't up anymore, so it is kind of hard to discuss. never said you did. Agree. Don't consider it a downside as such. I guess it depends on what ever you consider "good", "best" or "ultimate" ... as far as I have experience the various CSS all deteriorates at some point, some earlier(lower frequency) than others. I guess that is caused by the output capacity of the device(s) used. In that area the fet's doesn't really excel.

I am not aquinted with the work of Gary Pimm, and as you stated, his website is no longer up. Not really, Jungs measurement shows deterioation above 1kHz - Jung even mention this in his text. Still, the cascoded fets demonstrate higher impedance in comparison to their bjt counterparts. - but seems to lack in linearity.

is it a description of what you needed to repair after the amp blew up the last time? I guess before you replaced the ½W with something more bold?

Cascoded bjt's CSS are linear throughout the audio region. In comparison the cascoded fet's demonstrate impressive results at DC but drops through out the audio region, and 'meets' the cascoded fet CSS around 3kHz.. I use a T2 CSS in my Blue Hawaii. Don't use the T2 CSS in my Carbon anymore.

There are a top cover, just waiting for the rings to arrive in order to finish it.

are the 10m90 at the BIAS/PSU mounted using insulation washers - doesn't look like ? Can see you are using nylon for those at the amp board ;o)

Can you shrink yourself into a three-layer pilot and fly one of those?

Neat implementation...2x 9360 + 3x c4686? ...is the other CSS on the bottom side?