Pass F5m

[Russellc]

The AR was one of the best examples of an affordable spring suspension turntable back when the Linn was the main and much more expensive alternative. Perfect for a second system. I was thinking of setting up the AR in my office, but needed to install a Rega wall mount shelf to make that happen.

The Sorbothane puck supports in the VPI Jr were a step back, but the acrylic platter was an improvement, so kind of a wash overall relative to the AR. The VPI really needed the spring suspension upgrade, and the Ittok arm handles a wide range of cartridges. I could build a second VPI Jr from remaining parts if I wanted to, but that’s not an interesting option now that I have the Rega as a second table in my main system.

I use a wall mount shelf, ever since the first time I used it. Mount to load bearing wall and you can jump up and down. Large unexpected improvement!

Russellc

 

[Russellc]

My first high end turntable was the AR.

😍

Not counting some Connosseur BD1 kit long ago mine too, this very one in fact.. Hardly high end.... the BD1 that is. The Shure cart sounds quite good all thing considered, glad to get it back in rotation. Also have an Ortofon on Super OM 30 that works very well with the Infinity arm.

 

[Russellc]

My Fm5 chassis ( 3U ) arrived from Modushop, along with black knobs for the Zenmod addition Iron Pre case. I've gotten spoiled with the "Deluxe" versions, forgot to get the perforated floor piece, will have to drill back panel and drill and tap heatsinks. I did get the extra long 400 mm version. No biggie, just a touch more time.

 

[Russellc]

First time I ordered knobs from Modushop. Very nice quality and darn fair price for what you get. They came along with chassis for Fm5, I swear
it takes no longer from Italy. Very fast delivery!

 

[Toys4Boys]

Mount to load bearing wall

Another trick, if your ttbl is on a freestanding rack, you can insert a piece of wood, or other, between the top of the rack and the wall. It must be slightly longer than the distance to the wall in order to partial coupe the stand to the wall.

 

[Aleph5]

My special chassis just arrived! (Maybe there's a dedicated thread for it that I can't find now.)

Many thanks, Gianluca!

 

[DCE1198]

Said thread would be here:

https://www.diyaudio.com/community/...ime-only-pre-order.411348/page-4#post-7735625

Dan

 

[Aleph5]

Thanks, Dan. I'd move it if I could. Moderators may wish to. (I don't normally do surfing around other forums. 😏 )

 

[N Brock]

Very cool! I'm working on a similar ACA Mini concept. Do you have a BOm yet?

Yes, though I've revised the design to keep things a bit simpler. Instead of the tach controlled switch, I'll use a thermal switch on the heatsink to protect against fan failure. New boards are in the works with that change, but here are some pics of the reworked prototype using the Rev 0 board. Biased at 1.4A the heatsink reaches about 10°C above ambient temp . I used what I had on hand for the power rail FETs and the IRF9520 is getting toasty, so no serious testing until I can swap both to low R_ds on parts.

The BOM for one channel is attached (it's a .csv but saved as .txt for forum upload).

Do you have more info on your ACA Mini project somewhere?

 

[birdbox]

Now that's cool! My mind immediately goes to a 3D printed enclosure to maximize the fan cooling effects (drive air to bottom before exit allowed).

Me likee...me wantee 😉

 

[audiosteve]

Yes, though I've revised the design to keep things a bit simpler. Instead of the tach controlled switch, I'll use a thermal switch on the heatsink to protect against fan failure. New boards are in the works with that change, but here are some pics of the reworked prototype using the Rev 0 board. Biased at 1.4A the heatsink reaches about 10°C above ambient temp . I used what I had on hand for the power rail FETs and the IRF9520 is getting toasty, so no serious testing until I can swap both to low R_ds on parts.

The BOM for one channel is attached (it's a .csv but saved as .txt for forum upload).

Do you have more info on your ACA Mini project somewhere?

I built the first rev and blew a cap. Rev 2 is not built yet. But soon. I'm send you a schematic and a board pic. Not willing to share widely yet. It's not as ambitious as yours

 

[Hylle]

For F5m is it ok to use a 2x24VAC transformer? Maybe bias needs to be lowered ?

 

[Nelson Pass]

Or heat sinking increased?

There is also some margin for a higher temperature.

 

[Hylle]

Sound like it is not impossible to use the transformer I already have, Thanks Nelson, I have already ordered the Kit...

 

[Monk55]

Burning in.
Running at 22.7vdc
1.4a bias
Unloaded ps 25.6vdc
2x18 tranny

 

[6L6]

Looks great!!

 

[e_fortier]

Great work! I’ve never seen that CRC PSU, is this your creation?

 

[Monk55]

Might’s HA boards. Decided to separate completely. Have yet to listen.
800v, 35 amp rectifiers.
Still setting bias.

 

[Monk55]

On the eve of BA24, what can I say…tip O the cap to Mr Pass!
Ended up with 1.6A but it’s sounding very full & running cool. Great separation & depth. I listened to my F6 just prior & the F5M, seems different…ya I know…it’s very balanced & a bit more bass. Just cleaner sounding. Keeping all other pieces the same. Did I mention dead silent!
I did take a while to settle bias/offset. One chnl a bit more finicky.
Thanks to Gianluca for the great case!

 

[zman01]

Monk55,

Well executed build, kudos!

You used the stock MOSFETs?