Andrzej Sochon said:
Nice idea on the stickers - they look so similar otherwise.
The boards are soldered except the Fets and I won't be completing them until few months later because I need to return back to my home country before sourcing and integrating the circuit into the heat sink chassis. Not really keen to lug back 20kg of chassis on a plane.
her shann
Ear trouble and bipass cap
Andrzej,
Sorry to hear about the ear problems - not pleasant - most of us take good hearing for granted, unfortunately.
Now, for the Nicki KZ and FGs (not the same sound), I use the Wima mkp-10 150nF/50v bipass cap + series 0.165 ohm [0.15 + 0.165R] for the C1,2 (220uF), C3,4 (470uF), and [2 //47nF + series 0.1R] for C5,6 (100uF) - this is for Transistor (not Fet) Cmultiplier in P/S. - may be different with CRC, etc P/S.
The series resistor gives more flexible and better results - known as a generic "snubber", as mentioned before - thank you.
Not sure if Wima mkp = Vishays mkp (Roedestein? 1832?)
If you want to do a "real number" on this rather simple amp, suggest you look up the "Promitheus DIY Audio" website and check out the "Tuning power transformers" in the article section. Not an easy thing, this, but with patience = amazing results! Works with all p/supplies - even the CD player lazer supply! (not switch-mode supplies)
I use the F3 amp on my setup and no big surprise, the same [C + R] bipass technique works here, also!
My F3 now has a rather different sound to the factory original and is also very different to my F4 which needs a pumpkin, I think!
Cheers .. jh
Andrzej,
Sorry to hear about the ear problems - not pleasant - most of us take good hearing for granted, unfortunately.
Now, for the Nicki KZ and FGs (not the same sound), I use the Wima mkp-10 150nF/50v bipass cap + series 0.165 ohm [0.15 + 0.165R] for the C1,2 (220uF), C3,4 (470uF), and [2 //47nF + series 0.1R] for C5,6 (100uF) - this is for Transistor (not Fet) Cmultiplier in P/S. - may be different with CRC, etc P/S.
The series resistor gives more flexible and better results - known as a generic "snubber", as mentioned before - thank you.
Not sure if Wima mkp = Vishays mkp (Roedestein? 1832?)
If you want to do a "real number" on this rather simple amp, suggest you look up the "Promitheus DIY Audio" website and check out the "Tuning power transformers" in the article section. Not an easy thing, this, but with patience = amazing results! Works with all p/supplies - even the CD player lazer supply! (not switch-mode supplies)
I use the F3 amp on my setup and no big surprise, the same [C + R] bipass technique works here, also!
My F3 now has a rather different sound to the factory original and is also very different to my F4 which needs a pumpkin, I think!
Cheers .. jh
"forming " caps
Forgot to add that even driving the F4 quite hard with a 10 volts radio signal into 4R dummy load (power Rs), it still took about 5 days (cont) for the Nichicons to produce 'good' base.
When replaced C1,2 with 330uF Rubicon ZLs, it took over two weeks to come good - nearly gave up on them - added "Eromak-1" FKF bipass [0.12uF + 0.1R]. Rather smooth, effortless sound and quite detailed, but no Ferrari.
Tried Rifa 216 Styrene bipass [36nF + 0.15R] - woke it up a lot!
Havin' some fun with these amps.
Forgot to add that even driving the F4 quite hard with a 10 volts radio signal into 4R dummy load (power Rs), it still took about 5 days (cont) for the Nichicons to produce 'good' base.
When replaced C1,2 with 330uF Rubicon ZLs, it took over two weeks to come good - nearly gave up on them - added "Eromak-1" FKF bipass [0.12uF + 0.1R]. Rather smooth, effortless sound and quite detailed, but no Ferrari.
Tried Rifa 216 Styrene bipass [36nF + 0.15R] - woke it up a lot!
Havin' some fun with these amps.
Re: "forming " caps
I respect your receptions and have interest in them.
Nevertheless, I feel somewhat strange. With my F4, I used unknown Chinese 220uF electrolytic caps for C1 and C2. Listening to Leonard Cohen, By The Rivers Dark, I don't miss any deep and clear bass. When he tries to raise his low voice, the deep bass grabs him and pulls him down back . . .
According to my impression, C1 and C2 has no time to charge and discharge along the music signals . . . even the slow and deep bass . . .
jameshillj said:
I respect your receptions and have interest in them.
Nevertheless, I feel somewhat strange. With my F4, I used unknown Chinese 220uF electrolytic caps for C1 and C2. Listening to Leonard Cohen, By The Rivers Dark, I don't miss any deep and clear bass. When he tries to raise his low voice, the deep bass grabs him and pulls him down back . . .
According to my impression, C1 and C2 has no time to charge and discharge along the music signals . . . even the slow and deep bass . . .
I remember when we first heard about the "silks" Lots of derision because it seemed like a case of "if silver is good, gold must be better" type marketing. Now it turns out that a level headed guy like Nelson 
finds them to be superior. That's what's fun about this field- ya just never know....
finds them to be superior. That's what's fun about this field- ya just never know....
Just for the drill of it ..I just bought a bunch of the "Silks" from www.banzaieffect.com. They have a very good selection.
cviller said:
regarding this thread, starting a F4 wiki wouldn't be a bad idea
Nelson Pass said:
The signal path of my set-up consists off prp, holco, blackgate and mundorf.. using panasonic fc's is the final stage makes me wonder if these caps aren't the "weakest link"...
Think I'll try the elna's in my second F4, cheaper and easier to find here in Holland. Will be nice to compare wit the Panasonic's
Heat sinks
Hello Group:
For those in the process of making a F4. I thought it would be good to let you know there is a group buy getting started for heat sinks. The sinks being bought are Conrad heat sinks from Austrailia. The model being bought is perfect for the F4.
Check it out it will be a good value
Hello Group:
For those in the process of making a F4. I thought it would be good to let you know there is a group buy getting started for heat sinks. The sinks being bought are Conrad heat sinks from Austrailia. The model being bought is perfect for the F4.
Check it out it will be a good value
