Thanks a lot Tony. I know the Fostex drivers needs a long breake in time. Mine are probably not fully broken in yet, but I felt it was fair enough to compare amps on them, nonetheless? Here is another shot from the Azorer's.apassgear said:
Wait and see to when those Fostex are really broken in.
Good to see you back after some nice vacations…
Cheers
Steen
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Steen,
Don't feel bad about the quote thing. It's counter-intuitive. You'd think you'd be able to choose from the Reply screen, since that's what you're doing. Nope, gotta choose before you go in, Oh, well.
Caps: People fixate on the rolloff frequency as though it's a brick wall filter. Ain't so. A 6 dB/oct filter starts rolling off ages before the formal -3dB point, And then there's the phase shift to worry about.
Or you could peek in Nelson's stock room and note that he buys 220uF caps by the metric ton. If it's handy, sometimes that's the part you use.
Grey
Don't feel bad about the quote thing. It's counter-intuitive. You'd think you'd be able to choose from the Reply screen, since that's what you're doing. Nope, gotta choose before you go in, Oh, well.
Caps: People fixate on the rolloff frequency as though it's a brick wall filter. Ain't so. A 6 dB/oct filter starts rolling off ages before the formal -3dB point, And then there's the phase shift to worry about.
Or you could peek in Nelson's stock room and note that he buys 220uF caps by the metric ton. If it's handy, sometimes that's the part you use.
Grey
Steen did you get any fish at azorerne.
Got three yesterday in Mariager.
22 uf would make it feasible to use some better Caps. After all they are in the signal path.
I know from experience what is does in loudspeaker design to go from EL.caps to film types. Even if it's costly for larger values for midrange filterening.
Got three yesterday in Mariager.
22 uf would make it feasible to use some better Caps. After all they are in the signal path.
I know from experience what is does in loudspeaker design to go from EL.caps to film types. Even if it's costly for larger values for midrange filterening.
About coupling caps, any suggestion for a specific brand/type?
Maybe a NP cap could be a good choice, such as the N or Nx series from Black Gate.....
Or the ubiquitous Panasonic FC or the new FM?
BTW, does anybody know that Panasonic released a new series "for Audio" available from Farnell?
Maybe a NP cap could be a good choice, such as the N or Nx series from Black Gate.....
Or the ubiquitous Panasonic FC or the new FM?
BTW, does anybody know that Panasonic released a new series "for Audio" available from Farnell?
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massimo said:
You can’t go wrong with FC but it’s a good idea to test BG standard or the more pricy N’s.
I’ve heard mix reactions to FM’s as coupling caps, thou it’s an excellent spec lytic.
But in the end it’s a personal thing or taste and will also depend on the other components your system has, so let your ears be the judge.
Nelson Pass said:
The larger the caps, the longer the delay for turn-on thump.
The F4 behaves very civilized on turn-on
Regarding the cap's; I used Panasonic FC's in the F4 with good results (as you figured out by now
) I am not sure if there is a lot to be gained from using more expensive caps. When restoring the NS10 preamp, I used only BG N's in the signal path. I am sure that was a good choice, since it sounds like mountainair in an early morning Just like Keb' Mo's voice, if you know what I am talking about Blues does Vix, sorting out the 600+ pictures makes me want to go back to Sao Miguel. Unfortunately it was too windy to go fishing, so I didnt catch any Marlin this time. Next time I will!
MiiB, is Mariager Fjord your homewater? Its one of the most beautyful places in DK.
Steen
Steenoe, as you're one of the few who already have built an F4, what do you thnk if I send you (for free, of course) 4 pcs new Pana "for Audio" 220uF/35V ?
Do you have time to try them and report us how they do sound?
They are quit small and I'm pretty sure they fit in any pcb.
If you accept, drop me a mail with you complete address.
I'm just curious about them and I don't any audio gear using EL caps as coupling caps where to test them by my own.
Do you have time to try them and report us how they do sound?
They are quit small and I'm pretty sure they fit in any pcb.
If you accept, drop me a mail with you complete address.
I'm just curious about them and I don't any audio gear using EL caps as coupling caps where to test them by my own.
Wow, nice holiday pictures steen. Welcome back!!
I'm very interested in how the consumers react to this amp too - and I don't even have money evolved...
It is more like a building block than an actual power amp. Everytime I plug it into my system I'm startled on how wonderful it sounds and when I get all excited and want to turn up the volume, I get disappointed cos it won't go any higher. (well I just have to build myself a preamp)
It has been very hard for me to explain to family and friends that this amp has no voltage gain - it just seem too abstract for non-techies. But I guess firstwatt's audience are very competent buyers who know how to interpret specifications and look at the nice illustrations in the manual.
It would probably be a bad call to put in a full page advert in stereophile along with a review - sure you'll sell amps, but I'm afraid that would attract buyers that don't understand what they have bought.
NP said:
I'm very interested in how the consumers react to this amp too - and I don't even have money evolved...
It is more like a building block than an actual power amp. Everytime I plug it into my system I'm startled on how wonderful it sounds and when I get all excited and want to turn up the volume, I get disappointed cos it won't go any higher.
(well I just have to build myself a preamp)It has been very hard for me to explain to family and friends that this amp has no voltage gain - it just seem too abstract for non-techies. But I guess firstwatt's audience are very competent buyers who know how to interpret specifications and look at the nice illustrations in the manual.
It would probably be a bad call to put in a full page advert in stereophile along with a review - sure you'll sell amps, but I'm afraid that would attract buyers that don't understand what they have bought.
cviller said:Everytime I plug it into my system I'm startled on how wonderful it sounds and when I get all excited and want to turn up the volume, I get disappointed cos it won't go any higher.
Christian,
I completely agree with you - it´s really a wonderful sounding amp. Compared to the Babbelfish (which is the best amp I have had until now) it sounds "less romantic", more refined and has a firmer bottom end. Regarding the volume, although, I don´t share your doubts. I´m using an Aleph P with two monoblock F4 amps in balanced mode to drive my Tannoy HPD 315s. Believe me - this goes really loud. The best is, its not only loud, it still sounds absolutely clean. There is absolutely no sign of stress or loss of details and control. Perhaps you should invest into another F4. You know: 2 amps play twice as loud as one amp
Thanks a lot to Mr. Pass, Veteran and of course you for sharing the schematics and PCBs of this amazing amp.
schuhbu said:
Great, the European diy community is leading...
Do you have pictures of your new amps?
I have no doubts at all about the capability of F4 - it has enough power for me at least. My only doubts concern how consumers react to this new kid on the block.
Well, about my lacking volume - I have been trying to keep this a secret... I currently use a nad302 as preamp, which is why I cannot drive the voltage higher than line-level.
My speakers are also ordinary inefficient speakers, but still I get just about the volume I need.
I plan to use this attenuator: (I have calculated and bought resistors for a 48k load)
http://www.diyaudio.com/forums/showthread.php?s=&threadid=21198&perpage=10
Now I just need to decide on the gain stage and find the time to build it.
veteran said:Great work (like always) Mr Pass
Modifications added - I almost redesigned PCB. I will probably place sources in PDF format for a minute.
schematic f4_r0
Hi Veteran,
Great design. Are you going to offer boards?
Thanks!
cviller said:
Great, the European diy community is leading...
Do you have pictures of your new amps?
They are not yet completed and are still in their "skeleton phase". Still looks a bit like a spaghetti incident.
Next week I´m going to complete the cabinets (I hope, I do so - my Aleph P looks this way since half a year now).
I used Veteran´s pdf for the boards. The transformer is 330VA, caps are Evox-Rifa and Sikorel, 152.000uF/amp.
Heatsinks are 325mm x 160mm x 40mm and get quite warm now, but I think they don´t get too hot. I can still touch them for several seconds without getting blisters.
The enclosure will be made of 8mm aluminum, the front panel of 15 mm aluminum silver anodised.
cviller said:
I hope you can read Cyrillic
I´m using the Relvol of Dantimax. It works just fine for me.
Cheers
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schuhbu said:
Looks really good, nice and solid! I think you have enough capacitance in your psu..
Are your heatsinks made of two square pieces? If so, you'll get better performance from them by rotating them so cold air can be "sucked" in in the bottom an blown out in the top. Placed horizontally makes them less efficient because the hot air cannot easily escape the fins.
Banned
Joined 2002
ipolyakov said:
We are offering boards here >> http://www.diyaudio.com/forums/showthread.php?s=&postid=1189280#post1189280
