The diyAudio Firstwatt F6

6L6

Moderator
Joined 2010
Paid Member
1) There are nice ones that fit from parts-express, but their new website is unnavigable and I can’t find the link. :(

2) You’re not missing anything. The big diodes on the PCB are faster and possibly quieter, but I’ve built many of these with both configurations and they all work well.

3) Get a 300VA with shield, and 15000uf-18000if caps for the board

4) L brackets are nice. Frees up a lot of room.

5) Probably, but it not sure where exactly. BOM go stale very quickly, where the schematic is always right. Order the PCBs so you can see lead spacing and the like and choose the parts you want to use. Or, the store has PCBs with transformers and also transformers + the rest of the parts except Jfets. It’s going to be difficult to order one amp’s worth of parts for cheaper than the bundle’s value.
 
Thanks 6L6! I was reading your replies in the PSU thread all day.

No harm in going with four 22KuF caps (per channel) for the PSU is there?
Was going to go with these ones: https://www.mouser.ca/ProductDetail...zwsWlqlEZtJilWq73OxyRWUaZtvAjq8MjYOb1XBEoUwqG

Similarly this bridge rectifier should be good, yeah?
https://www.mouser.ca/ProductDetail...r/GBPC3502-E4-51/?qs=AvlKB63p5SnGQb0LYrYn6w==


Hmm can't find a L bracket for the Antek AS-3218 - 300VA 18V Transformer
AS-3218. Will have to keep looking.
 
Member
Joined 2012
Paid Member
Simpson Strong Tie A24 as L bracket, with Antek AS-3430:

914512d1611436534-25w-single-hammond-193v-choke-loaded-2sk180-lamp-simpson-strongtie-a24-transformer-bracket-jpg


https://www.homedepot.ca/product/si...x-2-1-2-inch-zmax-galvanized-angle/1000170464
 

6L6

Moderator
Joined 2010
Paid Member
Yes, those are the ones!

Thank you Dennis!! :yes:

The brackets Ben suggests would work beautifully. :D I’d try to get that if you have a home depot nearby. There’s no need for a dedicated, transformer-specific bracket, it’s literally an L of metal.

If you need to order, Toroid of Maryland makes a bracket, the L-300 is the one you want. L-Bracket – Toroid
 
Today, I remounted the boards . . .
Now Mosfets are firmly attached but left channel offset fluctuation still exists but smaller degree than before.
Hakan

I have this type of problem too; first had it in my F5 and later in my ACA. One channel can be silent for a minute while cold then starts to give noise. I figured out it comes because of a loose soldering of a part that heats up, to find out in the F5 after a long time found a wire connection to my off-board TO-3 format FETs; the wire had to be scraped again and resoldered, I was surprised a joint can get hot too.
Now in the ACA one channel is silent for a minute then starts to give noise and flutter with spurious offset fluctuations. Resoldered many parts, tried to move parts by hand, sometimes this solves it for a short time; resoldering that part did not yet give reults. But I am on my way.

So I see a tedious task ahead of you .:scratch:
 
So when I decided finally to take the plunge, I planned to build the F6, thinking that with few components it'd be a better choice for a complete newbie like myself. However, if you haven't seen the Aleph J Newbie thread and blog, check it out; as it includes a BOM for the PSU- and an Aleph J. It's quite organized; each component is marked to match the schematic, and whether it's the amp board or the PSU. So I would find it useful for most of the FW clone designs.


Aleph J build guide for noobs


As for transformer mounting gear, I got the omega bracket from here:
Mounting & Hardware – Toroid


Nice selection, decent prices but really expensive shipping, IMO.



Thanks 6L6! I was reading your replies in the PSU thread all day.

No harm in going with four 22KuF caps (per channel) for the PSU is there?
Was going to go with these ones: https://www.mouser.ca/ProductDetail...zwsWlqlEZtJilWq73OxyRWUaZtvAjq8MjYOb1XBEoUwqG

Similarly this bridge rectifier should be good, yeah?
https://www.mouser.ca/ProductDetail...r/GBPC3502-E4-51/?qs=AvlKB63p5SnGQb0LYrYn6w==


Hmm can't find a L bracket for the Antek AS-3218 - 300VA 18V Transformer
AS-3218. Will have to keep looking.
 
So I see a tedious task ahead of you .:scratch:

Sorry for your long and tedious work, but if it's any consolation, many times this kind of hard work makes us to learn more.

I also replaced the zener which seemed to be faulty (as Dennis predicted) and now everything is working perfectly, best of it amplifier sounds really beautiful from start and even improving daily :)

As Bare mentioned, I also always use old school leaded eutectic 63/37 solder and never had any problem with soldering.

Regards,
Hakan
 
I was looking at the site, Antek seems less expensive (at least for the items I was interested in), Anteks site was easier to navigate, cleaner, just an opinion. It's nice to know that there are parts being made domestically, that not everything has to have an Asian origin.
 
Last edited: