Two Audio Grade Semisouth SIC JFets

[vdi_nenna]

I'm sure all you guys know about these jfets already, but I haven't seen much regarding the SJEP120R100A and SJEP120R063A on this forum.

I thought you guys would be a bit more excited about these, since they are audio grade. My apologies if this was discussed somewhere else.

http://semisouth.com/wp-content/uploads/2011/05/DS_SJEP120R100A_rev1.1.pdf

http://semisouth.com/wp-content/uploads/2011/05/DS_SJEP120R063A_rev1.1.pdf

R100A is $23 each at Newark/Element14, with discounts at 25, 50 and 100 count.
US - Electronic Components Distributor | Newark.com


R063A is $45 each
US - Electronic Components Distributor | Newark.com

Does look like they ship from Farnell UK and there is a 135 day lead time.
Is this what's slowing you down?

 

[wrenchone]

I'm far more interested in the depletion mode 085 fet from Semisouth, whether or not it's called an "Audio" device.

 

[vdi_nenna]

I think the r063 is depletion mode.

 

[ra7]

Thanks for sharing! It's all moot right now, because they are all unavailable.

 

[wrenchone]

Nope - the R063 says right at the top of the data sheet that it's normally off...

 

[vdi_nenna]

You are correct, Sir!

 

[Zen Mod]

in those Semisouth names :

letter E in name means enhanced
letter D in name means depletion

depletion means normally ON
enhanced means normally Off

( even Mighty ZM found a way to remember that .... so - anyone can )

 

[vdi_nenna]

I associated depletion with "Off"; enchancement with "On".

 

[qusp]

so are we to take it that the 'audio grade' devices are simply ones that didnt quite make the normal specifications, but are still useable for comparatively less demanding audio designs?

 

[Tea-Bag]

so are we to take it that the 'audio grade' devices are simply ones that didnt quite make the normal specifications, but are still useable for comparatively less demanding audio designs?

I've wondered the same thing, but I can't imagine they really test them and label afterwards.
Maybe they make these in a different factory, or with some different quality controls afterwards.
The lower lead times (confirmed directly with them) suggest a different process going on. Previous lead times have been 3-4 months.
My contact there is in sales, so I have not gotten a specific answer to differences. Generally you get what you pay for, but it's very likely us in audio don't need the same tolerances as the other power equipment they were designed to go into. It's a compelling price difference, but at my cost, I am not sure I can compete with the channels. It then becomes a question of premium of matching.

 

[Nelson Pass]

R063 is a fatter version of the R100, but it of course comes with more
capacitance.

I'm really pleased to see the reasonable pricing. I understood that Farnums
is Australia was charging more than $50. You have to buy a lot of these as
an OEM to do much better.

I hope they will also make the depletion mode parts available as well,
although I don't expect them to be more popular.

😎

Scanning the spec sheets, I see that the R100 has a -15V rating for Vgs and
the R100A is -10V. This is never going to be an issue for audio guys.

 

[vdi_nenna]

From SemiSouth

Hi Vince,

We appreciate your interest in our products. It is my understanding that you may order direct from Newark (US) instead of UK Farnell; therefore, avoiding a loop. I am sorry for this inconvenience and I will check on this matter.



You may order direct from us – I need some information for the quote :

Company Name

Application

Quantity


Thanks,

Brenda

Brenda J. Temple

Director of Inside Sales and Contracts

SemiSouth Laboratories, Inc.


Now what? Group buy?

😉

 

[ra7]

why don't you ask Brenda to give you a quote for 100 parts?

 

[Zen Mod]

I'm not so sure that you can expect much lower prices than from Zhou , even in case of massive GB

 

[vdi_nenna]

why don't you ask Brenda to give you a quote for 100 parts?

I just did....😉

I'm not so sure that you can expect much lower prices than from Zhou , even in case of massive GB

I think it's importamt to start establishing something with SemiSouth from inside the US.

Also, maybe we should wait until Tea-Bag has sold out.

 

[Nelson Pass]

why don't you ask Brenda to give you a quote for 100 parts?

Go with Newark. The price is good.

😎

 

[simon7000]

Go with Newark. The price is good.

😎

You might just want to check the Farnell export site they seem to be about 10% lower and quote the SJEP120R100A 1000 pc.s @ 9.02 euro or $12.30! ($17.06/100)

 

[Skorpio]

R063 is a fatter version of the R100, but it of course comes with more
capacitance.

I'm really pleased to see the reasonable pricing. I understood that Farnums
is Australia was charging more than $50. You have to buy a lot of these as
an OEM to do much better.

I hope they will also make the depletion mode parts available as well,
although I don't expect them to be more popular.

😎

Scanning the spec sheets, I see that the R100 has a -15V rating for Vgs and
the R100A is -10V. This is never going to be an issue for audio guys.

Is this device (SJEP120R100A) a direct replacement for IRFP240 in ZEN4 as gain device? It would be convinient as housing and pin numbers match...
🙂

 

[Nelson Pass]

You would have to adjust the bias network for a lower voltage, the Vgs
being about 1.7 volts IIRC.

😎

 

[Skorpio]

You would have to adjust the bias network for a lower voltage, the Vgs
being about 1.7 volts IIRC.

😎

Nice, this should be within range of R4 🙂

Could the distortion decrease seen on the F2 versus F2J be expected on the ZEN4 also? This would be some upgrade...

And what about the general impedance reduction used on F2J, is that due to gate leakage? Would this be an issue on ZEN4?