Yes confirmed M2 amp use opto-couplers that way : base no connected.
That i see on his pcb's. Thanks for response
I'm using a 60v 900va frame transformer for each monoblock.
It's in choke input, with two stages of choke/cap and with a cheat cap of 1uf I'm getting 60v at the load resistor on test.
The first breadboard amp (of two) is under construction, the circuit board (FR-4 with turret tags) is finished and populated.
Just got to finalise wiring up the input transformer (Danbury transformers interstage) and sorting out the in-out sockets, the on-off switch and fitting the bias transformer and module.
One point to make, the mosfet grid stopper resistors should be fitted as close as possible to the mosfet. I was reminded about that by a friend.The positioning of them on my board (as per picture) was changed before everything was soldered up.
PS I used Duncans PSU designer to model the power supply and providing you input accurate data the results are spot on.
The circuit board work in progress.
It's in choke input, with two stages of choke/cap and with a cheat cap of 1uf I'm getting 60v at the load resistor on test.
The first breadboard amp (of two) is under construction, the circuit board (FR-4 with turret tags) is finished and populated.
Just got to finalise wiring up the input transformer (Danbury transformers interstage) and sorting out the in-out sockets, the on-off switch and fitting the bias transformer and module.
One point to make, the mosfet grid stopper resistors should be fitted as close as possible to the mosfet. I was reminded about that by a friend.The positioning of them on my board (as per picture) was changed before everything was soldered up.
PS I used Duncans PSU designer to model the power supply and providing you input accurate data the results are spot on.
The circuit board work in progress.
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Hockey puck's IXFN140N20P stock at Mouser dry bit more today
http://www.mouser.fr/ProductDetail/IXYS/IXFN140N20P/?qs=t7yjd2JO/gTEsrKBTipgAg==
Kindest regards
http://www.mouser.fr/ProductDetail/IXYS/IXFN140N20P/?qs=t7yjd2JO/gTEsrKBTipgAg==
Kindest regards
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What your 4.7 V bias circuit choice could you please write more about ?
Mr. Pass solution ?
Best regards
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I normally build valve (tube) amps, and I had a pair of DIY audio filament modules in my spares box, and also a pair of 6v toroids, so I am using them.
If I was starting from nothing I'm not sure how I would proceed.
I'm in the process of testing my first prototype, but the heatsink is getting to hot and affecting the voltage readings. A household fan is helping to keep it cool at the moment.
If I was starting from nothing I'm not sure how I would proceed.
I'm in the process of testing my first prototype, but the heatsink is getting to hot and affecting the voltage readings. A household fan is helping to keep it cool at the moment.
Oh yes tube filament circuits with modifications can do it.
My start is from potentialy every bias circuit and his psu possible position.
I get by chance some big heatsinks to experiment but it's not that fearless " car style " class A build by great Diyer
My start is from potentialy every bias circuit and his psu possible position.
I get by chance some big heatsinks to experiment but it's not that fearless " car style " class A build by great Diyer
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The heatsinks I am using came from a computer UPS power supply and I thought they would keep the two mosfets cool enough without any fans.
It seems the 10K resistor and 1000uf cap on the bias supply make it very slow to react to changes, so bear that in mind.
Those heatsinks of yours look good, any spares ?
It seems the 10K resistor and 1000uf cap on the bias supply make it very slow to react to changes, so bear that in mind.
Those heatsinks of yours look good, any spares ?
Thanks Pre65
This huge heatsinks was from my city local metal company recycling.
Not for sale on order and is unknow model reference.
Maybe something from England Birmingham few big ones like this :
Heatsinks: 7000 series - 7200HS | BAL Group Ltd
Heatsinks: 5000 Series - 5460HS | BAL Group Ltd
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