yep, got it in one
That would be most appreciated, thanks!
mlloyd1
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Does anyone know where to buy Renesas higher voltage (>150V) P- and N-Channel laterals active in production?
BR, Toni
What about the Group Buy (Exicon) running now?
You may have missed the deadline for an order.
BTW,
all Laterals appear to be from the same factory, it's just packaging that changes.
http://www.diyaudio.com/forums/grou...20-ecw20p20-mosfet-group-buy.html#post4816881
But that will probably attract triple import duties. Far east to UK, UK to Canada, Canada to Austria.
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Pseudo folded
I do not think this circuit can refer to a folded or cascode configuration at all.
It has been seen without the buffering transistor on John Curl's schematics.
The VAS transistor simply works in differential mode, just as a differential circuit but with very dissimilar input impedances.
Boberly attibutes the circuit with emitter follower buffering to Lender :
http://www.diyaudio.com/forums/soli...age-large-voltage-swings-lenders-circuit.html
http://www.diyaudio.com/forums/soli...age-large-voltage-swings-lenders-circuit.html
The signal path for one half of the output of the IPS is that of a folded cascode, so that is where the reference comes from. Other than that, the whole circuit has little to do with a folded cascode or, for that matter, differential operation, since the contributions from the two outputs of the IPS, though opposite in phase, do not have any where near similar effect on the output current of the VAS transistor.
To the best of my knowledge, the first publication and implementation of an amplifier with an LTP IPS, a current mirror load, and a 2EF VAS was by Bob Widlar back in the 1960's in an early IC op amp.
Cheers,
Bob
Thx, but EXICON's I have enough bought directly from profusionplc. Thats not the question. Bob's mailing has made me thinking that Renesas Laterals are available again ...
I didn't get any response from them at all. The part I ordered was a "Fairchild" 2N5401 shortly after Fairchild stocks disappeared at the major vendors, hoping they had original stock left. What I received wasn't the same shape, size, writing font, lead diameter, or even colour of my remaining stock. The one on the left is an original Fairchild part.
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Hi Jeff,
It certainly does look like a poor fake. There is a Chinese factory making discontinued part numbers, and they are supposed to be the same. They seem to be making North American parts. I don't trust them one little bit.
That should have been disclosed to you before the sale. No response from them looks like further deals are a no-go.
-Chris
It certainly does look like a poor fake. There is a Chinese factory making discontinued part numbers, and they are supposed to be the same. They seem to be making North American parts. I don't trust them one little bit.
That should have been disclosed to you before the sale. No response from them looks like further deals are a no-go.
-Chris
I just threw away 600 pieces of "2SB737" ultra low noise transistors purchased from Chinese sellers on eBay and AliExpress. The real things were discontinued years ago and I thought "what the heck, let's check out the clones / counterfeits from China, they are SO cheap."
They were dreck.
Fortunately, Horowitz and Hill 3rd edition has identified a replacement that is actually BETTER than the original 2SB737, and is currently in production, and is available in thru-hole packaging, and can be purchased from factory authorized distributors. A trustworthy supply chain! Costs more per device than the 600 parts I just threw out but, I'm still happy.
They were dreck.
Fortunately, Horowitz and Hill 3rd edition has identified a replacement that is actually BETTER than the original 2SB737, and is currently in production, and is available in thru-hole packaging, and can be purchased from factory authorized distributors. A trustworthy supply chain! Costs more per device than the 600 parts I just threw out but, I'm still happy.
Would be nice... especially if such info has been made public already by publication.
THx-RNMarsh
Winfield Hill, one of the authors of "The Art of Electronics" 3rd edition, is a member of diyAudio! He occasionally posts messages here; one example is below. I bought a copy of his book and am quite pleased with it; the transistor measurement data is in Chapter 8, with a good summary in Table 8.1a (p.501). I encourage you to read the reviews on Amazon and decide whether or not to buy a copy for yourself. You'd be supporting a fellow member if you did.
I certainly do not think it would be a good idea to PM the author saying "I am too cheap to buy your book so send me a scan of Table 8.1a for free." That wouldn't be neighborly.
I certainly do not think it would be a good idea to PM the author saying "I am too cheap to buy your book so send me a scan of Table 8.1a for free." That wouldn't be neighborly.
I scoured datasheets, and selected and purchased hundreds of low-noise BJT transistor candidates. Paul [Horowitz, the other author -MJ] made a low-noise single-stage transistor amplifier, see AoE III, Figure 8.92, in which we could place our D.U.T. candidates, and he took spectral plots of their noise at different operating currents. I entered the masses of data into Excel, and modeled the e_n, i_n and r_bb' noise components to determine the minimum-possible noise from r_bb' Johnson noise, but at Ic currents low enough not to create base-current i_n * r_bb' noise. Then I made a spreadsheet of about 60 useful transistor candidates, see Table 8.1 on page 501, for y'all to feast on. As a bonus, you also get measured values of the Early voltage V_A, and plots of beta vs current, Figure 8.39 for all the transistors.
We also went through the same exercise for JFETs, and created tables and graphs from our measurements.
This is information I would have died for in years past, that's what motivated me, and now I can go forward on designs using all this grand data. DIY experimenters can too, if they get a copy of our book.
Hi.
Firm JVC used these chips in poweramps JVC AX-50. The idea is to give passive shoulder additional bias equal to the voltage increment of the active of the shoulder. It works.
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With your permission, I will add my two cents. A differential stage without the tracking circuit (boot-strap?) greatly distorts, operating from a signal source with a large output impedance. I solved this problem just two jfet.
Did you buy via Credit Card, or via PayPal?
If so then report them for selling fakes and maybe even for Fraud.
These criminal retailers will only be put out of business if the customers complain to someone who will eventually take action.
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