100W Ultimate Fidelity Amplifier

[manniraj]

Any good simple CRC PSU gerber files available for Apex amps like FH9HV or AX14? I want to build the PSU in relatively small format and its class AB so do not need huge amount of capacitance and above all I want to build a dual psu hence the form factor being small. I already have Prasi's CRC psu which I have preserved for class A amps 😉

Thanks

 

[prasi]

i think Marc (bandol83) had posted a design of crc (very compact) in Mooly's mosfet amp thread. that should be very suitable.

 

[prasi]

here is a photo... i think you will have to to quasi amplifier thread by ranchu32 for the design files if posted...
My MOSFET amplifier designed for music.

 

[xrk971]

You can also get some premade for quite cheap:

AIYIMA Schottky Rectifier Filter Power Board 63V 10000UF Capacitor Amplifier Rectifier 120A Power Supply Board DIY Speaker Amp|Amplifier| | - AliExpress

or

GHXAMP 50A 1969 Amplifier Rectifier Filter Board Kits 200W Large Current Signal Power Supply 50V 63V Filter Capacitor|Amplifier| | - AliExpress

or

KBPC50 50A 1000V Single double bridge rectifier power supply board without capacitor for TDA7293 LM3886 amplifier kit diy|Amplifier| | - AliExpress

 

[manniraj]

i think Marc (bandol83) had posted a design of crc (very compact) in Mooly's mosfet amp thread. that should be very suitable.

Thanks Prasi, I have built those and used it but wanted to try something else as well.

 

[manniraj]

Thanks X they seem to be good and I can even get this one -

AIYIMA 120A Rectifier Filter Power Supply Board Solder Schottky 35MM Capacitance Rectification Amplifier DIY|amplifier diy|amplifier a|amplifier supply - AliExpress
and use my own capacitors.

 

[clpk]

My AX11 is playing.
44250 thanks for the guidance, I inverted BC517 and installed with the flat part on the heatsink, strange that the layout is with MPSA13 and its flat part on the heatsink. Anyway I must not have observed any information. With 330pf I found a lack of treble, I put 100pf at the entrance, highlighted it a little. What can be done to make the sound a little more "open", to emphasize the highs?
I also replaced the 220r resistor with 180r, so the amplifier worked cooler.
Overall the sound was good, I liked the result.
Follow the result link.

YouTube

 

[channini]

Fh11

my FH11

Youtube

Youtube

 

[xrk971]

Nice work, Channini! FH11 rocks hard with Dire Straights. What kind of voltage are you running on that PSU and what bias current?

 

[channini]

Nice work, Channini! FH11 rocks hard with Dire Straights. What kind of voltage are you running on that PSU and what bias current?

+- 40vdc. And. 3.8v between gate and source

 

[xrk971]

Bias current would be voltage across the big white 0.47R(?) source resistors. Typically 85mA to 125mA or circa 50mV. The test speaker sounds quite good too.

 

[44250]

My AX11 is playing.
44250 thanks for the guidance, I inverted BC517 and installed with the flat part on the heatsink, strange that the layout is with MPSA13 and its flat part on the heatsink. Anyway I must not have observed any information. With 330pf I found a lack of treble, I put 100pf at the entrance, highlighted it a little. What can be done to make the sound a little more "open", to emphasize the highs?
I also replaced the 220r resistor with 180r, so the amplifier worked cooler.
Overall the sound was good, I liked the result.
Follow the result link.

YouTube

glad if I could help...

 

[44250]

my FH11

Youtube

Youtube

I like the way it looks and the way it sounds! could you please point me to the post with files for this amplifier?

 

[xrk971]

Around here:

100W Ultimate Fidelity Amplifier

 

[44250]

thaks a lot!

 

[prasi]

Thanks Prasi, I have built those and used it but wanted to try something else as well.

Something like this?😀...

 

[prasi]

APEX FX-8 BIMO MOD

Meanwhile I am well on the way to building Apex FX-8 Bimo Mod amp. see attached pic from yesterday.
Today I fitted output transistors (2SK and 2SJ) and tested for bias and offset.
All ok...

I am also building a case with upc1237 protect , CRC PSU and VU meter and ESP P88 preamp with volume control. All the pcbs are designed by me.🙂

Because of the lock down in India, I am finally able to complete some of the long pending projects.

PCBs for the Bimo amp are kindly donated by Ivanlukic... Thanks Evan...

regards
prasi

 

[xrk971]

Here is a blast form the past. This was my FX8 Bimo Mod by Prasi that I built maybe 5 years ago. Wow, time flies. I set it up on a plank (as usual for verification builds) and ran as Class AB, although bias is pretty high so it runs quite warm. A few years went by, and I later installed it in a DIYA 4U Dissipante case and ran it at +/-24v and 1.25A bias current in full Class A. It worked well and sounded great. It is a lateral FET amp, so pushing bias into Class A is fine without fear of thermal runaway. Very nice layout by Prasi - awesome amp. Highly recommended.

Here was test on a plank with small temporary heastink in Class AB:

Tiny amp board on large heatsink, but it used it fully as temp was about 47C:

Very quiet amp with PSU based on Pass F6 PSU, I got 0.0mV rms at the amp output:

 

[manniraj]

Something like this?😀...

Thanks Prasi, that cute CRC psu looks cool. Anyway to get boards for this PSU 🙂

 

[prasi]

Thanks Prasi, that cute CRC psu looks cool. Anyway to get boards for this PSU 🙂

Chinese boardhouses are accepting orders but shipping is on hold for India.
Indian ones are all closed..😱
here are gerbers and sch... you could use a small aluminium plate as heatsink ( shown as hatched lines ) for the rectifiers (insulate rectifiers if using such single heatsink).