If the answers above still leave doubt, I used the 200VA Antek and I feel my unit works fine. I had 24V rails unloaded, and only checked them again after it was running for several days, and remember being surprised that they measured lower when loaded. I think between 21-22Vdc, and I can't check now as I am traveling. And as mentioned above, there is the benefit of the bias current running higher for a given dissipation.
Also remember that Nelson approved of the 200VA 18V Antek in his write up. So there isn't any question that the F5m will work well with it.
My assumption is that when @WBS says (emphasis mine) "Thermistors will be Ametherm 10 Ω 8A 22mm", they mean all of them. I'm hanging a lot on pluralisation there, though.
New (nice) photos take several weeks to organize, and we know you'd rather not wait 🙂 Moving forward, for the first few batches of any new kits we will likely be moving towards not-so-nice but more up-to-date photos. Or a note of "Photo is of R1" and the description details that the kit being sold currently is R2, etc. This is also an issue in regards to build guide photos with parts changing from batch to batch based on availability.
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Mr. Pass mentions 1.1A max bias for use with a 2U heat-sink; a 200VA power transformer would be sufficient for the amplifier running at 1.1A bias.
Dropping ~2V on the rails is common when operating under load for a Class A amplifier.
Those are 1.181" Dia (30.00mm) while the 4700uF Epcos are 1.000" Dia (25.40mm).
Do the 10000uF fit on the pcb?
Theses might be better:
https://www.digikey.de/en/products/...05?s=N4IgTCBcDaIEIBYCMYDMSCCB2JAGAnALIgC6AvkA
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Regarding 1k pot. Why not coose this one:
https://www.digikey.de/en/products/...konjVXvok364ydPwjigcngxTFYF-kgqEKw-XrJXVNqDbs
more precise and better protected against dust
https://www.digikey.de/en/products/...konjVXvok364ydPwjigcngxTFYF-kgqEKw-XrJXVNqDbs
more precise and better protected against dust
My guess would be price - I think those are about 3 times the price of the 1 turns in the BOM. I'm planning on grabbing a 4 turn myself, which is even more expensive, but I think it'll be the sweet spot between my neuroticism and my impatience. 😁
Prolific DIY builders might want to consider buying 10 turn trimpots for USD 0.23 per piece, in assortments like (this one) .
@Mark Johnson I assume the ones linked to are a good option, for the majority of projects here what value R is used?
These are Bourns “like” trimpots.
I would be cautious using Bochen trimpots in any project, especially if using any obsolete or difficult to replace transistors.
I would be cautious using Bochen trimpots in any project, especially if using any obsolete or difficult to replace transistors.
For folks looking for a deal on a 200VA, I recently bought the following transformer for another project. I offered the seller $30 and he accepted it.
200VA eBay
Well F5m sold out and instead of 36 minutes, it was over 36 hours! That was a good run this time around. I hope to see Greedy Boyz builds from all over the world soon on this thread. Glorious music for all.
I'll also add a big Thank You to all the folks who make these awesome projects possible; Papa, WBS, Jason, Elena, and the rest of the DIY Audio team!!!!
I'll also add a big Thank You to all the folks who make these awesome projects possible; Papa, WBS, Jason, Elena, and the rest of the DIY Audio team!!!!
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The unsung hero of the store with fast and courteous help when needed and never acknowledged must go to Elena.
Forum needs a standing ovation icon btw.
I bought a bunch of bourns knockoff 25 turn pots from Tayda and they seem to measure fine, but haven't put any into an amp yet. "Baoter" and "Bonens" @ something like 25 cents ea... they are cermet. I'll cross my fingers and give em a go on the next couple of channels
nothing wrong with them, nowadays
put them in gizmo tester and twiddle, you'll find nothing wrong
put them in gizmo tester and twiddle, you'll find nothing wrong