When you get the second channel completed, drive it with a clean PSU and compare.
Yes, the heatsinks are for processor and they are to small for normal use.This is only for testing ,I will replace it with bigger one.When the second channel is build,then i will try with linear PSU and will see the difference.
regards
zoky2
regards
zoky2
I didn't check - why does one need to check? In case manufacturer mislabeled a SK for SJ and vice versa?
A small 50mm fan running at partial speed should keep it cool if you wish to make it compact like my stereo FX8 setup. A 5R or 10R resistor on 12v fan lead should reduce speed so not noisy. I like the looks of that heatsink though. I have run it with 175mA all the way to 500mA and there wasn't much to be gained running it hot.
Hi Bimo,
I was thinking something along this line and could adapt my current FX8 Bimo mod board to try. I had considered the IRF540 (I have those) but thought the smaller BD139 would react to temperature changes faster. If there was a convenient way to mount an MPSA92 as the Vbe temp compensator that would be even better.
The 2SC1845's are harder to get but ok if patient as 3wks from China is my normal route now for most transistors. I get the IRFP's from Digikey though.
I like your FH9 mod though. Thanks.
I was thinking something along this line and could adapt my current FX8 Bimo mod board to try. I had considered the IRF540 (I have those) but thought the smaller BD139 would react to temperature changes faster. If there was a convenient way to mount an MPSA92 as the Vbe temp compensator that would be even better.
The 2SC1845's are harder to get but ok if patient as 3wks from China is my normal route now for most transistors. I get the IRFP's from Digikey though.
I like your FH9 mod though. Thanks.
I can actually hear the SMPS in the speakers.
Hallo Terry.
I have read time to time these great Mile Apex Thread- so many ideas.
You also has build many different Amps, so you have on Hand Mr. Evils
Cap Multiplier?
I have assembled my own and tested short on Jasons VSSA.
So i think it should also fine work on FX8?
What do you, or other mean?
xrk 971 gives me today a FH9 picture, so i am back here- very interesting,
many good gays sharing knowledge here.
Is there planning organize a group buy for new FH9- nice compact design!?
😱? 😱 ?
Regards Bangla
Hallo Terry.
I have read time to time these great Mile Apex Thread- so many ideas.
You also has build many different Amps, so you have on Hand Mr. Evils
Cap Multiplier?
I have assembled my own and tested short on Jasons VSSA.
So i think it should also fine work on FX8?
What do you, or other mean?
xrk 971 gives me today a FH9 picture, so i am back here- very interesting,
many good gays sharing knowledge here.
Is there planning organize a group buy for new FH9- nice compact design!?
😱? 😱 ?
Regards Bangla
That's why I was asking for FH9 Gerbers from Sonal Kunal (still have not seen the files yet) - to order boards. The boards are so inexpensive (circa $20 to $30 depending on size for 10, and only $10 for qnty 10 x 50mm boards) that group buys are not necessary if you have the Gerbers.
The form factor looks just like a Renesas/Hitachi so it's probably at least a lateral FET of some sort... We will see when I fire up today 😱
What do you guys think of two of these in series with a center tap for a +/-32v 5amp supply?
32V5A power adapter 32V5A switch power supply 32V5A DC stabilized power supply AC adapter-in AC/DC Adapters from Electrical Equipment & Supplies on Aliexpress.com | Alibaba Group
It's not much cheaper than a 200VA 25v toroidal trafo ($32) and diode bridge/caps PSU but is easier as no AC line levels to deal with for a simple (and safe to use) box.
32V5A power adapter 32V5A switch power supply 32V5A DC stabilized power supply AC adapter-in AC/DC Adapters from Electrical Equipment & Supplies on Aliexpress.com | Alibaba Group
It's not much cheaper than a 200VA 25v toroidal trafo ($32) and diode bridge/caps PSU but is easier as no AC line levels to deal with for a simple (and safe to use) box.
Last edited:
Sprint and Gerber files of FH9.
I was busy last few daysthat's why I couldn't finalize and post layout.
Add 100pF from base to colector on VAS transistors BD139/140.
Regards
Revised layout with 100pF added to VAS transistors.
Moderators please delete post #7458.
