Awesome.
Thanks for reporting.
Seeing someone happy, motivates me to help where I can.
Thanks for reporting.
Seeing someone happy, motivates me to help where I can.
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@Tamra,
I think your HS is big enough for higher bias current.
I am currently @1.65A, i love it at 1.8A!
Unfortunately, HS ran too hot, so i need to up size my current heatsinks first.
Enjoy your new F6!
I think your HS is big enough for higher bias current.
I am currently @1.65A, i love it at 1.8A!
Unfortunately, HS ran too hot, so i need to up size my current heatsinks first.
Enjoy your new F6!
I have tried 1.6A still could raise bias current.
Because of summer, I feel comfortable at lower temperature.My room is small.
By the way,I have just tried star ground for RCA -.
The sound have got really glassy now.
Because of summer, I feel comfortable at lower temperature.My room is small.
By the way,I have just tried star ground for RCA -.
The sound have got really glassy now.
Tamra,
Good to know that both channels of your F6 clone is now up and running, and that you are enjoying the music!
Look forward to build updates when you start the Aleph J and BA3 projects. 🙂
Good to know that both channels of your F6 clone is now up and running, and that you are enjoying the music!
Look forward to build updates when you start the Aleph J and BA3 projects. 🙂
Hi Tamra,
I noticed the central ground made up of the joint wire of the SuperThru caps common ground point and now you've moved the input RCA shield from the pcb to this point too?
A small thing but maybe worth considering - if those bridges are simple GB bridges, perhaps you might consider upgrading them to say, Schottky diodes on a scrap of vero-board (perhaps the well tried MSR860, or bigger 1560) or maybe a Shindengen D6SB60 or similar, if you can find them) or even the fairly recent fet rectifiers with the LT4320 chip as per thread here)
It does make quite a difference, with/without the secondary winding snubbers.
I noticed the central ground made up of the joint wire of the SuperThru caps common ground point and now you've moved the input RCA shield from the pcb to this point too?
A small thing but maybe worth considering - if those bridges are simple GB bridges, perhaps you might consider upgrading them to say, Schottky diodes on a scrap of vero-board (perhaps the well tried MSR860, or bigger 1560) or maybe a Shindengen D6SB60 or similar, if you can find them) or even the fairly recent fet rectifiers with the LT4320 chip as per thread here)
It does make quite a difference, with/without the secondary winding snubbers.
Thanks for suggestion Jameshillj.
I have already connected RCA- to star ground then
cut off signal- to PCB.
It was good change.
I was using sic-sbd but heat sink was too small or
10A diode was too small, it get too hot so
I am ordering 20A sic sbd and larger heat sink.
For the CRC filter,Panasonic erx have better bass but I prefer wire wound resistor for high frequency.
So I am considering 2mH air coil 14AWG.
Relay circuit for cl60(PSU) works very good.
Summer in Tokyo is so hot like oven.
I am waiting for autumn to raise the bias...
Winter must be nice.
I have already connected RCA- to star ground then
cut off signal- to PCB.
It was good change.
I was using sic-sbd but heat sink was too small or
10A diode was too small, it get too hot so
I am ordering 20A sic sbd and larger heat sink.
For the CRC filter,Panasonic erx have better bass but I prefer wire wound resistor for high frequency.
So I am considering 2mH air coil 14AWG.
Relay circuit for cl60(PSU) works very good.
Summer in Tokyo is so hot like oven.
I am waiting for autumn to raise the bias...
Winter must be nice.
For a bit of an experiment, try the Isabellenhutte PBH metal foil resistors, from Elfa in Sweden - old stock now, I think as the new versions of these are available from Hifi Collective at a crazy price under the Powertron name. Not sure how significant a difference would be …
I tried those SIC diodes and didn't like the 'edgie' sound - quite noticeable and disappointing - rather expensive too but maybe new ones are now better. Surprisingly, I wasn't all that impressed with the SuperThrough caps and much preferred the Elna for Audio ones - they seemed to produce a more defined sound and definitely clearer bass but that might just be me too!
Winter here is reasonable so far but we're in a covid lockdown for another month so it's a bit hard to not be a bit depressed
I tried those SIC diodes and didn't like the 'edgie' sound - quite noticeable and disappointing - rather expensive too but maybe new ones are now better. Surprisingly, I wasn't all that impressed with the SuperThrough caps and much preferred the Elna for Audio ones - they seemed to produce a more defined sound and definitely clearer bass but that might just be me too!
Winter here is reasonable so far but we're in a covid lockdown for another month so it's a bit hard to not be a bit depressed
I will check Hifi collective powertron thanks.
About PSU resistor,I believe there are much noise at
my room AC. So I might need more inductance.
Wire wound resistor was no nice but bass get boomy.
Before,I built Hypex UCD180 with linear PSU.
Then tried some caps,diodes, cables etc.
I preferred Rohm sic-sbd and Superthrough.
First time for class A though.
There was a bargain on parts connection for Superthrough cap so I bought 8.
About PSU resistor,I believe there are much noise at
my room AC. So I might need more inductance.
Wire wound resistor was no nice but bass get boomy.
Before,I built Hypex UCD180 with linear PSU.
Then tried some caps,diodes, cables etc.
I preferred Rohm sic-sbd and Superthrough.
First time for class A though.
There was a bargain on parts connection for Superthrough cap so I bought 8.
I would say Panasonic erx is lovely resistor.
I tried mra05,mpc74 and erx for source resistor.
Mra05 0.47 and 0.56 sounds less noise and smooth but
erx are softer and balanced somehow musical to me.
So now I feel lower noise parts is not always best for Pass amp.I will try some more parts for my interest.
I tried mra05,mpc74 and erx for source resistor.
Mra05 0.47 and 0.56 sounds less noise and smooth but
erx are softer and balanced somehow musical to me.
So now I feel lower noise parts is not always best for Pass amp.I will try some more parts for my interest.
ERX are actually low noise parts, at least that is what the measurements I did indicated.
Vishay CPF3 were a little better but ERX are actually good.
The futaba's I measured are no where near as good as ERX or CPF3
Vishay CPF3 were a little better but ERX are actually good.
The futaba's I measured are no where near as good as ERX or CPF3
Those Powertrons are the same as the Isabellenhutte ones (Copper 85%, Manganin 12%, Nickel 3%) - I see some of them are still available at Newark and around $12 ea
The Vishay Dale CPF3 are Nickel Chrome, a rather 'brighter' sound, and the Panasonic ERX are metal oxide, another different sound again - it makes for quite interesting "mix'n'match" options with the different caps
There's a whole world of these "precision resistors" and not generally 'well-used' in audio/hifi circles and they're mostly quite expensive too (like those TC 2575s!)
The Vishay Dale CPF3 are Nickel Chrome, a rather 'brighter' sound, and the Panasonic ERX are metal oxide, another different sound again - it makes for quite interesting "mix'n'match" options with the different caps
There's a whole world of these "precision resistors" and not generally 'well-used' in audio/hifi circles and they're mostly quite expensive too (like those TC 2575s!)
using IXFN140N20P devices in place of the IRFP240
Would using IXFN140N20P devices in place of the IRFP240's work, properly, that is ?
I see the gate charge is 70 nC for the 240's, and 240 nC for the 140N20's.
More gate drive required? Transformer not up to it?
Would using IXFN140N20P devices in place of the IRFP240's work, properly, that is ?
I see the gate charge is 70 nC for the 240's, and 240 nC for the 140N20's.
More gate drive required? Transformer not up to it?
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It would work, but IXTH64N10L2 is better.
You can run the 64N10L2 at 50W each no problem if you have adequate heatsinking.
Yes. I used the FQH44N10 instead of the IRFP240, and have been very happy with the results. The IXTH64N10L2 takes this idea a little further, without being too difficult to drive.
If you are concerned about the drive capability of the front end, you can replace the simple JFet source followers with a diamond buffer. That's what I used in my F6.
If you are concerned about the drive capability of the front end, you can replace the simple JFet source followers with a diamond buffer. That's what I used in my F6.