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).