I put a fan close by the heatsinks, and its been playing just fine. I do not like to run things too hot. chicken
what's the best position for p2 without distortion measurement?
what's the best position for p2 without distortion measurement?
mid position is probably position inducing least thinking aboout
P2 maxed - least Aleph CCS modulation - acting more like pure CCS
P2 minimized, highest Aleph CCS modulation
you can do without distortion measurements , that involving precise counting of turns , listening and writing impressions ........ in incremental steps
btw. P2 is having nothing with DC settings - one end of it being AC coupled to rest of the world
P2 maxed - least Aleph CCS modulation - acting more like pure CCS
P2 minimized, highest Aleph CCS modulation
you can do without distortion measurements , that involving precise counting of turns , listening and writing impressions ........ in incremental steps
btw. P2 is having nothing with DC settings - one end of it being AC coupled to rest of the world
Thanks ZM, all good info.
Yes, p2 is cap separated, no affect on dc. I had wrong instructions.
If you can affect the sound of an amp this much with just one trimmer/pot, it could be useful to have few settings marked, and instead of multiturn use normal pot, stick it on the front and allow the listener to select.
From dark and soft to bright and sparkly. And all in between.
Fun stuff.
Yes, p2 is cap separated, no affect on dc. I had wrong instructions.
If you can affect the sound of an amp this much with just one trimmer/pot, it could be useful to have few settings marked, and instead of multiturn use normal pot, stick it on the front and allow the listener to select.
From dark and soft to bright and sparkly. And all in between.
Fun stuff.
that would be too easy
and it was never good to make level of lazy idiocy even higher
well, that's internet .........
standard keratherm from diystore
torque unknown
I am considering changing just q2 for mica
aaah, I did not measure heatsink temp, but it was just warm to touch, not hot
other question, what do people prefer, monoblocks, or single chassis
I can make two separate power supplies, that way diode bridges do not get too hot
how about switching power supplies? anyone tried?
torque unknown
I am considering changing just q2 for mica
aaah, I did not measure heatsink temp, but it was just warm to touch, not hot
other question, what do people prefer, monoblocks, or single chassis
I can make two separate power supplies, that way diode bridges do not get too hot
how about switching power supplies? anyone tried?
Over the weekend, I replaced keratherm insulator on Q2 with mica. Temperature of Q2 dropped ~15 degC, now its just a little over 50. All good here.
Now to finish it so its movable to downstairs and compare the sound to F1J and M2.
Now to finish it so its movable to downstairs and compare the sound to F1J and M2.
What power transformer are people using for their F3's? I see that Antek has the AS-4435 and AS-3435 as options, but wanted to see if there were other options that I could be missing.
I used 2x Antek AS-2218 with the dual 18V outputs of each transformer wired in series for my F3. This leaves the option open to wire the outputs in parallel for the lower voltage Firstwatt amps.
Chas,
That’s a great idea. I never thought of wiring the transformer that way. I’m repurposing one of my amps for the F3, and this will save me money and time since it has 2 AS-3218 transformers in it.
I have already order the parts for it. Can’t wait to get it running.
That’s a great idea. I never thought of wiring the transformer that way. I’m repurposing one of my amps for the F3, and this will save me money and time since it has 2 AS-3218 transformers in it.
I have already order the parts for it. Can’t wait to get it running.
page 2 and last page of F3 service manual is showing that
you think that Pa was going to buy 36Vac Donuts, while having zillion 2x18Vac already?
he even did use same cap bank pcbs, two rails connected in series....... at least that's shown in mentioned file
I'm 100% sure it was published here, not originated from my personal Spy in FW/PL
you think that Pa was going to buy 36Vac Donuts, while having zillion 2x18Vac already?
he even did use same cap bank pcbs, two rails connected in series....... at least that's shown in mentioned file
I'm 100% sure it was published here, not originated from my personal Spy in FW/PL
The information that I could find from Firstwatt on the F3 is below. Please note this is not the same as the dual mono power supply used on F1 or F2 and that was supplied in the latest F3 Group Buy. See post 120 of the F3 Clone Board Set Group Buy thread for the schematic of the boards in the group buy.
I used a 500VA Toroidy 2 x 36V with a dual-mono supply.
(Note: don't treat this as a datapoint on the subject of "how large?". I got a 500VA so the transformer would cost more than the shipping. There's just something galling about it being the other way around to get a 300VA to my doorstep.)
(Note: don't treat this as a datapoint on the subject of "how large?". I got a 500VA so the transformer would cost more than the shipping. There's just something galling about it being the other way around to get a 300VA to my doorstep.)
Thanks for the information. As I think through repurposing one of my amps for the F3 I could actually keep the current power supply.
I would just take the negative rail of the existing +/-24v power supply to the ground on the F3 board and the ground on the power supply goes to the chassis ground through a thermistor.
Well at least now have large caps for a Singing Bush or Lazy Singing Bush.
By the way I have been in situations where I need a 12 cent resistor and the shipping is $15. I start thinking about what else I need so it makes sense to place the order.
I would just take the negative rail of the existing +/-24v power supply to the ground on the F3 board and the ground on the power supply goes to the chassis ground through a thermistor.
Well at least now have large caps for a Singing Bush or Lazy Singing Bush.
By the way I have been in situations where I need a 12 cent resistor and the shipping is $15. I start thinking about what else I need so it makes sense to place the order.