i am strange with age of 52...i need to know....then it is stored in my brain 😉
and minek is a nice guy...look at his project
and minek is a nice guy...look at his project
Yesterday compare test of my both FX8:
FX8 amp1 now with Wima 22µF at input cap and new PSU (2x33mF cap bank , no CRC) by Q17 project.
C4 is a big Epcos (orange) 1000µF/16V
FX8 amp2_ "muse edition" - instead of rail caps Panasonic 680µF/50V i use UKZ 470µF. C4 is a220µF 25V ukz
gain is at both amps at 26,5dB
bias is Class Ab = 750mA with rail about 31V
sound is very similar with a small advantage of darkness of the muse amp. the clearness and texture is for me the same. (MKS24 Wima 22µF kost about 7 euros-good cap- it is my first MKS film cap as input cap)
with the muse amp sounds more powerful with a bit more punch and deeper bass and it has 0,5m deeper stage. not much but you notice in the comparison.
next will be to enjoy then test around with more power-->
enjoy
FX8 amp1 now with Wima 22µF at input cap and new PSU (2x33mF cap bank , no CRC) by Q17 project.
C4 is a big Epcos (orange) 1000µF/16V
FX8 amp2_ "muse edition" - instead of rail caps Panasonic 680µF/50V i use UKZ 470µF. C4 is a220µF 25V ukz
gain is at both amps at 26,5dB
bias is Class Ab = 750mA with rail about 31V
sound is very similar with a small advantage of darkness of the muse amp. the clearness and texture is for me the same. (MKS24 Wima 22µF kost about 7 euros-good cap- it is my first MKS film cap as input cap)
with the muse amp sounds more powerful with a bit more punch and deeper bass and it has 0,5m deeper stage. not much but you notice in the comparison.
next will be to enjoy then test around with more power-->
enjoy
Nice to read about. I think you will prefer your Muse Edition ?
500 Watt Connex was delivered 🙂 I ordered a +- 35 Volt Type. In the past there was a pot on board, +- 5 % voltage adjust. Gone... the voltage is fixed on this SMPS.
After 2 hours i adjustet the bias to 300 mA. The heatsinks keeping relative cool....but not my testing resistors. 10 ohm 5 watt are to small, i need bigger 10 ohm resistors. I'm tired of buying someting... 🙁
Dc offset is -1,9/+2,2 mv at the two amps. With some thermal adhesiv i made the heatsinks of the SMPS larger.
Tomorrow i can listen for the first time. Perhaps 300 mA bias is enough.
Greetings Pedda
500 Watt Connex was delivered 🙂 I ordered a +- 35 Volt Type. In the past there was a pot on board, +- 5 % voltage adjust. Gone... the voltage is fixed on this SMPS.
After 2 hours i adjustet the bias to 300 mA. The heatsinks keeping relative cool....but not my testing resistors. 10 ohm 5 watt are to small, i need bigger 10 ohm resistors. I'm tired of buying someting... 🙁
Dc offset is -1,9/+2,2 mv at the two amps. With some thermal adhesiv i made the heatsinks of the SMPS larger.
Tomorrow i can listen for the first time. Perhaps 300 mA bias is enough.
Greetings Pedda
Attachments
![IMG_20231214_170442[1].jpg](/community/data/attachments/1154/1154464-a448af9e83b8e14da2dcfca2796bfc6c.jpg?hash=pEivnoO44U)
I ordered 4 pieces 10 ohm 50 watt in China now. They are rearly cheap. After 14 days they will arrive. In germany all people are building amps, i think...all resistors with 10 ohm are gone ore to expensive.. 😉
Testing the Amp with music, a cd of Marla Glen. Sounds very well on this amp. A feeling of controll in all ways. After the CD was finished i got a temperatur of 34 degrees on the heatsink. A higher adjust as 300 mA seems to be not possible without greater heatsinks. No hiss no hum...silence. I first try it with headphones. I wont destroy my speakers...🙂
You are right Chris, sounds powerful. May be thinking about a greater amp with more power 🙂
Im glad to built....many thanks to Apex, Bimo, Prasi and so on for this beautiful little amp....
The next one please 🙂
Greets
Pedda
You are right Chris, sounds powerful. May be thinking about a greater amp with more power 🙂
Im glad to built....many thanks to Apex, Bimo, Prasi and so on for this beautiful little amp....
The next one please 🙂
Greets
Pedda
@Kleinhorn
I like your cabling. It is very clean.
I recommend to use thermal paste, this is important to reduce thermal coupling. E.g. 10-16 Kelvin w or W/o thermal paste.
I like your cabling. It is very clean.
I recommend to use thermal paste, this is important to reduce thermal coupling. E.g. 10-16 Kelvin w or W/o thermal paste.
Hi...
You can get the binding posts here https://de.aliexpress.com/item/4001126946638.html?spm=a2g0o.productlist.main.53.681ff28cmMcoXj&algo_pvid=0904b859-ea3b-44e6-9765-168dec425867&algo_exp_id=0904b859-ea3b-44e6-9765-168dec425867-26&pdp_npi=4@dis!EUR!15.26!7.7!!!16.37!!@2103956a17026514320523671e5dc5!10000014631083203!sea!DE!0!AB&curPageLogUid=MRq7jAtc0OT4
I think its a good connection. Not so expensive as in germany.
Peter
You can get the binding posts here https://de.aliexpress.com/item/4001126946638.html?spm=a2g0o.productlist.main.53.681ff28cmMcoXj&algo_pvid=0904b859-ea3b-44e6-9765-168dec425867&algo_exp_id=0904b859-ea3b-44e6-9765-168dec425867-26&pdp_npi=4@dis!EUR!15.26!7.7!!!16.37!!@2103956a17026514320523671e5dc5!10000014631083203!sea!DE!0!AB&curPageLogUid=MRq7jAtc0OT4
I think its a good connection. Not so expensive as in germany.
Peter
I am waiting for the test resistors i ordered...then i will have another try to adjust a little bit more bias....
In the Moment i have trouble with the FH9 boards. Both not working. At the first board i cant make any bias adjusting, the second board has over 20 volt on the output. I soldered the IRF240/IRF9140 in. The next try with the IRF240/IRF9240. Something wents wrong, but at the first look i cant see any mistake. All capacitors have the right polarity, diodes have the right direction....mhmmm. I have to search...test the transistors...💩
Peter
In the Moment i have trouble with the FH9 boards. Both not working. At the first board i cant make any bias adjusting, the second board has over 20 volt on the output. I soldered the IRF240/IRF9140 in. The next try with the IRF240/IRF9240. Something wents wrong, but at the first look i cant see any mistake. All capacitors have the right polarity, diodes have the right direction....mhmmm. I have to search...test the transistors...💩
Peter
Hi Chris.
i will check T4, BD139 and the others. T4 is mounted on the heatsink with isolation. I have measured the isolation to the pins. VR1 i can measure, seems to be ok on both boards. I dont rearly know...
I have tested one IRF9140 with my atlas...completly dead....in all directions...whats that ?....dont know. I will check all transistors tomorrow . Its to late now...
God night..thanks for your tip...
Peter
i will check T4, BD139 and the others. T4 is mounted on the heatsink with isolation. I have measured the isolation to the pins. VR1 i can measure, seems to be ok on both boards. I dont rearly know...
I have tested one IRF9140 with my atlas...completly dead....in all directions...whats that ?....dont know. I will check all transistors tomorrow . Its to late now...
God night..thanks for your tip...
Peter
Good Morning
Strange...i never had defect IRF...as Zen mod wrote years ago. nobody is cloning the dirty cheap IRFP240 because the are sooo cheap.
connect gate with source with a short wire to discharge the gate...then the MOSFEt should be off! remove the wire then try again.
Strange...i never had defect IRF...as Zen mod wrote years ago. nobody is cloning the dirty cheap IRFP240 because the are sooo cheap.
connect gate with source with a short wire to discharge the gate...then the MOSFEt should be off! remove the wire then try again.
Yes the Print Labels of the to 126 ( Bd 140 or similar) are mirrored. I Had this at the AA14 Amp too.
Finde that finally the Amp ist Wirkung. Congrats
I really think to open a new thread for fh9 and ASK an admin to help and copy the posts...
Finde that finally the Amp ist Wirkung. Congrats
I really think to open a new thread for fh9 and ASK an admin to help and copy the posts...