Pictures of your diy Pass amplifier

von Ah,

Looks like you are on a roll - congratulations on your successful DIY F5 build!

The build looks really nice in the all black chassis. Heat-sinks at 50 degrees sounds fine. Also good to see another SMPS build. Btw, I checked the MicroAudio website and found SMPS500-CLA - is that the model you are referring to?

Are you using the Castle Micro Towers with the DIY F5?
 
Member
Joined 2008
Paid Member
Thank you, zman!

I started this F5 journey intending to get that SMPS model, but ended up with the SMPS600-CLA after discussions with the owner of MicroAudio. I think it depends on what he has in stock and in development. He is always very helpful and attentive.

Yes, I am using the P7HD microTowers. They agree very well with Pass DIY amps. :yes:
 
F5T for a friend. Teaser

Allmost all mechanical work is done. My hands hurt and its late again. I thought i should share this with you guys.
That is an amp for a friend, his components. Due to lack of time, i offered him to build his F5T Version2 - Well that was fun.
This first image is meant for a teaser, more to come, maybe in seperate thread.
 

Attachments

  • F5T DaEm.jpg
    F5T DaEm.jpg
    834.9 KB · Views: 1,077
Last edited:
My first Amp build. ACA stereo mode, home made enclosure made from old Douglas Fir/Oregon and a smps inside. Will monitor temp but seems to stabilise with heat sinks at 50deg with ambient about 15 deg. Using NAD 7225pe I repaired as preamp. Very happy with sound, its not a fatiging sound and seems to improve the longer its on ?

Cheers
 

Attachments

  • 20210608_172816.jpg
    20210608_172816.jpg
    526 KB · Views: 804
  • 20210608_172755.jpg
    20210608_172755.jpg
    572.7 KB · Views: 795
  • 20210608_172747.jpg
    20210608_172747.jpg
    476.5 KB · Views: 765
weekend

Allmost all mechanical work is done. My hands hurt and its late again. I thought i should share this with you guys.
That is an amp for a friend, his components. Due to lack of time, i offered him to build his F5T Version2 - Well that was fun.
This first image is meant for a teaser, more to come, maybe in seperate thread.
 

Attachments

  • PnN Channel switched.jpg
    PnN Channel switched.jpg
    681.6 KB · Views: 640
Hot

remember the movie "Jaws" ?
Roy Scheiders face... as he realised:
"We need a bigger boat"

thats what i told my friend after some calculations.
But this chassis allready cost a fortune.
He said:
This will be my winter-amp ;)
1 channel 53degree celcius after 45 mins, i hope when the sinks are screwed together with the rest of the aluminium-plates it will idle at55.
 

Attachments

  • IMG_E8737.jpg
    IMG_E8737.jpg
    470.2 KB · Views: 493
Mountingplates

i wish they would me from metal.
The plan was to mount the powermosfets not on bare aluminium, but rather on bare copper. After creating the 3-D models & stl-files in fusion360 they were ready for production, then rona messed with the plan. Running out of time, and since i allready had the stl-files i 3D printed them on copper-PLA - so its "priliminary" and its shiny ;) So here we go...how about "Modding Amplifiers"? Haha;)

The frontend PCB is mounted on a removable socket, (1 position for adjustments... replacing mosfets, and 2nd position for storage)also originally intended to be from solid copper, but i will settle with the copper-PLA. This Copper-filled-PLA is an absolutly amazing plastic. The connectingwires are a tidbit longer as usual.(edit: modified the stl, fets touch now the heatsinks directy)

Having repaired multiple times my own monoamps, i knew my goal in this project was to deliver a modular stereo-poweramp, easy accessibility in a suprisingly smal chassis - internal space=10x14x7inches. So the transformer had to move into a seperate case. There we meet Mr.Elephant 8x4mm² and this huge Speakon-plug - I am still not convinced about this connector.

This image shows the empty chassis just with the rectifiers, that we MUST have 16 of the double diodes ;) mounted under the caps (not shown)
 

Attachments

  • IMG_8584.jpg
    IMG_8584.jpg
    729.5 KB · Views: 527
Last edited:
The specs for this amp are nothing out of the shelf.
A Nelson Pass F5Turbo Version2. Since this amp runs very hot i initially conservatively dialed in 340mA on the 0,5ohms measureing 32,5Volts rails.
The Thoroid Transformer is a 2x115V -4x24Volt @13Amp each secondary, screened.
It boasts 1348VA on the paper... it is humming :-(, thank you audiophonics..2x DIYaudio Filter PCB stuffed with 16 Mundorf 22.000 microfarads 63Volt - You can never have enough.
 
first sonical impressions

A F5T. Typical warm and harmonic also exact reproduction.
I really like the female voices and acoustic instruments rendered here very exquisite. The soundstage is wide and deep.
It sings like an angel. Oh, P3 in middle position.
The chassis is a insulting nice clone.
Preamp is a Linestage replica of this absolutly phantastic Threshold FetOne Series II - The little PCB left of the Whammy with those big 10µF caps.

Thank you Mr. Pass.
 

Attachments

  • IMG_E8745.jpg
    IMG_E8745.jpg
    815.3 KB · Views: 419