I am not much of a power amp designer but i have helpers.
The Opal is build for me.
Then we have the Frans deWit Signature One.
For DIY there is the Nobrainer, designed by Frans and me.
There is also a thread about it.
The Opal is build for me.
Then we have the Frans deWit Signature One.
For DIY there is the Nobrainer, designed by Frans and me.
There is also a thread about it.
Yesterday it reached a new milestone, the 4AmpT net fuses where blown (several times). Extensive measuring and testing found nothing wrong, the amp was consuming 900Watt per channel and delivering (about) 600Watts per channel to the 'Carver Amazing, Platinum Edition's (loudspeaker panels), it was party time 🙂
Thanks, will check out the Nobrainer. I had this vision in my head of a BF862 JG Buffer front-end, mosfet VAS and lateral outputs. It's the direction i want to try taking my Fetzilla, make it more "Gerhardesque" 🙂
Wow, you are an inventor of words. Modulating into the darkness.https://ia801702.us.archive.org/15/...s and Low-Pass Amplifier Design (1968)-RR.pdf
This looks like a fun project :http://www.audiodesignguide.com/full/conus1.html
I ones had a pair of Ohm F.
They where eating power like crazy and sounded a bit dark.
But the bass and 3D space where amazing.
I ones had a pair of Ohm F.
They where eating power like crazy and sounded a bit dark.
But the bass and 3D space where amazing.
Due to a unfortunate event some days ago involving my bicycle and a dog I'm more or less immobilized and have bitten my way through this whole thread from where I once left it.
Wow!
The SE-Fet/folded-cascode input has been discussed ten years ago around here.
The second stage was with opamps, though. I build a few versions, it sounds promising, albeit I did not manage to get stable DC-conditions (this with a 9V-Block and a psu for the opamp-part). If I would do it again, I'd feed a CCS for the cascode-Q with a separate negative supply.
Or, if I'd been into tubes, build it with a p-fet input and fold-cascode it with a tube. This would give me some voltage swing to burn in a shunt riaa network.
Maybe, if my immobilization persists during next week my bench finds me sitting at it since a long time... (I can sit well, but not stand up (ough) or walk around (ooough))
Rüdiger
Wow!
The SE-Fet/folded-cascode input has been discussed ten years ago around here.
The second stage was with opamps, though. I build a few versions, it sounds promising, albeit I did not manage to get stable DC-conditions (this with a 9V-Block and a psu for the opamp-part). If I would do it again, I'd feed a CCS for the cascode-Q with a separate negative supply.
Or, if I'd been into tubes, build it with a p-fet input and fold-cascode it with a tube. This would give me some voltage swing to burn in a shunt riaa network.
Maybe, if my immobilization persists during next week my bench finds me sitting at it since a long time... (I can sit well, but not stand up (ough) or walk around (ooough))
Rüdiger
Have you seen the circuit that the always interesting JC Morrison published on his blog a few years ago hybrid folded cascode Gm amp | lab jc.
It sounds almost exactly like what you're describing. I attached a copy of the circuit to make viewing it a bit simpler. I haven't built it but it looks very interesting.
---Gary
Attachments
Luckily the output is marked 120V you are warned (that what you get when SDI is scraped and these 'engineers' get a new job). 🙂
https://www.google.com/search?q=sdi...CLyQOF1oD4BA&ved=0CAgQ_AUoAw&biw=1496&bih=925
p.s. I see 16mA is also marked, this most be a killer app. 🙂
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Come on, it's a conceptual sketch! 😉
thanks for the link, Gary, yes, that's what I meant!
Now to find a realistic spice model of a D3a, or, better yet, some unknown russian tube that sells for a few pennies...
Rüdiger
thanks for the link, Gary, yes, that's what I meant!
Now to find a realistic spice model of a D3a, or, better yet, some unknown russian tube that sells for a few pennies...
Rüdiger
Ale (mogliaa on this site) has done a nice comparison of quite a few Russian tubes to the D3A. Take a look here: http://www.bartola.co.uk/valves/2013/02/23/russian-pentodes-in-triode-mode/
---Gary
