So cviller added the cascode option to the board (I couldn't remember what happened about that)?
Where did you get those washers on the mosfets from?
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I like it.
I used to have a huge jar of 1c and 2c coins (copper). There must have been over 500 coins in that jar. Unfortunately I don't know where it went.
I used to have a huge jar of 1c and 2c coins (copper). There must have been over 500 coins in that jar. Unfortunately I don't know where it went.
Just one comment.
I am pretty sure you could use a shunt regulator on the first two stages and use crc for power buffer output stage.
Has anyone tried it?
I am pretty sure you could use a shunt regulator on the first two stages and use crc for power buffer output stage.
Has anyone tried it?
Look no further than Salas' shunt regulator. You could also check out Erno Borbely's shunt regulator and I am certain Nelson also published a very simple design.
Its been a while since I built an amp, just ordered the boards from the store. Last time I built and amp was back in like 2001. Had to take a DIY audio break, as 3 kids consumed all extra time and $resources$. Looking forward to building a new heater for my listening room, wait I live in Florida, Nelson could you make amp that sucks heat out the air please. I find myself loosing sleep again at night thinking of different circuits and mods. Time pull the heatsink extrusions (those chunks of metal) as my wife calls em out of the corner of the garage.
Now to find, beg borrow or steal a some elusive Toshiba 2SJ109. Any one have some laying around that aren't needed?
Chad
Now to find, beg borrow or steal a some elusive Toshiba 2SJ109. Any one have some laying around that aren't needed?
Chad
I'm going to use two 2SJ74.s to replace the one 2SJ109. I found some 2SJ74's at MCM Electronics they are GR classification with IDSS of -2.6 to -6.5ma but they should work in this application.
The input JFET pair should be matched. Maybe not an exact, very close match but, not just purchasing 2 (per channel) off the shelf devices. I would suggest chasing down Blues or someone with a copuple matched devices for sale at a reasonable $$$ for a good start on your amp. it's a good place to spend a few extra bucks 
Yeah, tracking down the 2SJ109 is really tough. We assumed that most people will use two discrete JFETS. They should work..
I was just wondering if Nelson classifies this amp as a two gain stage or three gain stage amp.
Yes I understand you need matched pairs thats why I ordered 25 of the devices while they had them in stock. Hopefully I can find 2 pair that are matched close enough. thanks for the reply.
Well obviously I'm not Nelson but, there are 3 distinct stages of gain here. The input stage consisting of the JFET diff amp providing some voltage gain and taking feedback from the next stage. It drives the single N MOSFET common source "VAS" second stage for most of the voltage gain and enough current to drive the third, output stage. The output of this stage is also fed back to the diff pair. The output follower stage only provides currnet gain to drive your low impeadance speakers. 3
Variac,
Thanks for the quick shipment. Got my set of boards today.
Has anyone put a BOM together for the BA2 or do I have do it the old fashion way? (Didn't find one doing forum search)
Nelson,
Would you like to donate a set of 109's to good home since it looks like all the Burning Amps that you donated where not put to use with the input board you designed? (you don't know unless you ask, plus you would be able tell people William Shakespeare listened to your amps) On another note Nelson I just wanted to say thanks for your sharing of info with all us diyers. I've been member here since 2001 and you have shared lots of your intellectual property since then and I look forward to future projects. ie. The DAC.
Since I know the above is a very very longshot, where is the best place to source the 74BL's from? Any body use the guys on Ebay that claim to be matched pieces?
Thanks in advance,
Chad
Thanks for the quick shipment. Got my set of boards today.
Has anyone put a BOM together for the BA2 or do I have do it the old fashion way? (Didn't find one doing forum search)
Nelson,
Would you like to donate a set of 109's to good home since it looks like all the Burning Amps that you donated where not put to use with the input board you designed? (you don't know unless you ask, plus you would be able tell people William Shakespeare listened to your amps) On another note Nelson I just wanted to say thanks for your sharing of info with all us diyers. I've been member here since 2001 and you have shared lots of your intellectual property since then and I look forward to future projects. ie. The DAC.
Since I know the above is a very very longshot, where is the best place to source the 74BL's from? Any body use the guys on Ebay that claim to be matched pieces?
Thanks in advance,
Chad
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