as far as I see , that series is looking good ; no harm in chasing them at your local electro/hardware store
+/-25Vdc is OK , but if you have 18Vac secondaries , you'll get lower DC rails once when PSU is loaded with OS
do not forget to include bleeder resistors in PSU cell itself , to avoid nasty surprises when connecting the same (it's good to have empty caps while doing that) ; 1K/2W resistors will do the job
your sketch is correct
+/-25Vdc is OK , but if you have 18Vac secondaries , you'll get lower DC rails once when PSU is loaded with OS
do not forget to include bleeder resistors in PSU cell itself , to avoid nasty surprises when connecting the same (it's good to have empty caps while doing that) ; 1K/2W resistors will do the job
your sketch is correct
same here
one thing is if they're old , other thing is are they tired and worn and dry
try reforming them
if you have a place in case , connect 50uF motor-run caps as bypass for final caps in filter section , that usually brings some speed and freshness
look at surplus places , sometimes you can find bargains
Hi Zen et al. Looking into adding these motor-run caps after seeing them in a few designs. Can you comment on the 50uf value? Does it matter whether I'm higher (e.g. 75)? Any brand recommendations? I was trying to eyeball what you used in a sissySIT design, but couldn't see any labels...
And to connect as bypass, I just need to flip my ps board and then solder to the leads/traces of the final capacitor on each half?
Thanks.
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I did mention 50uF as lowest value wort having troubles putting in
of course that you can go higher in value
yes - connecting it as bypass to last cap on rail , even if most Kosher variant could be connecting it to channel pcb itself , on power rail pads
tried that, didn't heard difference , doing it in simplest way from then
of course that you can go higher in value
yes - connecting it as bypass to last cap on rail , even if most Kosher variant could be connecting it to channel pcb itself , on power rail pads
tried that, didn't heard difference , doing it in simplest way from then
Just finished the F4 and I am VERY pleased with the sound. Running F4 with B1 Korg and Cornwall speakers (105dB). Compared with M2, Tea-bag style, in above setting the sound becomes more clear, tight and still very easy for the ears. Now I can use the volume knob better. F4 sounds very nice at lowest volume and still could rearrange furniture with highest.
The M2 had a 400VA transformer and the F4 has a dual mono PSU with 2x400VA and Pass general PSU.
Bias is set to 295mV. The build guide says half the trafo-VA but I guessed since I have dual mono PSU heat sinks they sets the threshold. Heat sinks gets to 47°C, (117°F). Heat sinks is 5u 300.
@cal3713, I have not compared without the Ducati motor-run 40uF caps but the sound is addictive so I guess and hope they are doing their job. ZM’s recommendation is at least 50uF(!)
Don’t look at R8. You did, didn’t you? What is a k more or less among friends?
The M2 had a 400VA transformer and the F4 has a dual mono PSU with 2x400VA and Pass general PSU.
Bias is set to 295mV. The build guide says half the trafo-VA but I guessed since I have dual mono PSU heat sinks they sets the threshold. Heat sinks gets to 47°C, (117°F). Heat sinks is 5u 300.
@cal3713, I have not compared without the Ducati motor-run 40uF caps but the sound is addictive so I guess and hope they are doing their job. ZM’s recommendation is at least 50uF(!)
Don’t look at R8. You did, didn’t you? What is a k more or less among friends?
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Additionally try to use fast recovery rectifying diodes instead of typical rectifying blocks.
Also on the F4 input, use THIN wires (eg twisted two wires drawn from LAN twisted pairs) instead of shielded wires.
You may discover more details, speed and freshness too...
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