Roender,
I have just looked at the Tibi project. It's bass control is not from a much more powerful amp to?
I think that hard to drive speakers are better served by more power, and these mosfet amp have a facility to push amps.
My FC-100 is driving my new B&W 804 for the first time today.
Denis
I have just looked at the Tibi project. It's bass control is not from a much more powerful amp to?
I think that hard to drive speakers are better served by more power, and these mosfet amp have a facility to push amps.
My FC-100 is driving my new B&W 804 for the first time today.
Denis
DRZ1 said:
At almost twice the voltage, the power difference is meaningful. That would be my guess for the difference in bass perception. More power or, better yet, more efficient bass drivers. Those may be very nice speakers, but there is no replacement for displacement when it comes to bass, unless you have a big giant horn (which is another form of displacement).
Sheldon
DRZ1 said:
Well, in my opinion, I think this is a misconception.
You not need more power (voltage) from an amplifier to drive a difficult speaker. Instead, he must deliver current without sagging rails, and Zout must remain constant when speaker impedance sag at half or less than nominal.
ttan98 said:
I don't know ... never tried without enough matched (5% class at idle working current) complementary transistors, in both hfe and Vbe.
maxlorenz said:
Not yet, and I don't know if is necessary in power amplifiers which use r-core in PSU.
fab said:
Fab,
Please don't twist my words ... I well remember what I said, that I was unable to make an amplifier with good enough bass using laterals, not they are unable to perform well at LF 😉
Cheers,
M
could this be linked to the space available on the PCB for smoothing caps, or is it down to the quality/size of decoupling caps or something else?roender said:
AndrewT said:
I think is related with the current capability of capacitors bank, how do they respond to transients, electrically and not in the last mechanically. In other words, the quality of the caps.
We definitely need some snake oil here
Fab I too think mosfets arent as good as BJTs in bass, to get good bass from them I now use totem pole drive but what works good and lets them rip out bass notes like bjts is by driving them with diamond buffers. 🙂
Hello Roender
First and foremost Thank You! for an excellent project - first rate
even J. Carr thought so, high praise indeed!
Post #589
I'm almost ready with a full classA version named RMI-FC25. 2x25W RMS per channel.
How are you progressing with the class A version?
I have 8 ot the Ernst Meiss pcbs but will almost certainly prefer to
the build the class A version when it becomes available - I will
either build these for a friend and relatives or SELL the boards haven't really decided one way or the other.
EPCOS SIKOREL is what I intend to use I have bought about
140 of them from a thorough gentleman Rolandas who is a DiyAudio
member namely "elviukai" - they are quite 'pricey' but have an
impeccable reputation and credentials.
Yours Sincerely
John
First and foremost Thank You! for an excellent project - first rate
even J. Carr thought so, high praise indeed!
Post #589
I'm almost ready with a full classA version named RMI-FC25. 2x25W RMS per channel.
How are you progressing with the class A version?
I have 8 ot the Ernst Meiss pcbs but will almost certainly prefer to
the build the class A version when it becomes available - I will
either build these for a friend and relatives or SELL the boards haven't really decided one way or the other.
EPCOS SIKOREL is what I intend to use I have bought about
140 of them from a thorough gentleman Rolandas who is a DiyAudio
member namely "elviukai" - they are quite 'pricey' but have an
impeccable reputation and credentials.
Yours Sincerely
John
johnYks said:
John,
The 2x25W full A class amplifier was a little overrated for the heat sink I had. It was converted to a better RMI-FC100 with R-core and external PSU, not on the amp PCB, based on Muse KG.
I've heard that Sikorel is a fantastic capacitor.
Cheers,
Mihai
roender said:
I agree with you , but i think that a higher power amp have more facility to deliver more amps when they are necessary, that's my simple conclusion.
I have seen this many time, and speakers manufacturer seems to go in the same way. But like you say, it's not 100% the reason, and the quality of the amp to drive current is the first place to search a solution, with damping factor and output impedance. By the way that's the first reason i decided to build your FC-100....
😀
But in the bass music program, it's very easy to reach the rail voltage, even with relatively normal listening level. It's the reason why i use 60,000uF on each channel in my FC-100. Did you try to use bigger and better caps near the collectors ?
maxlorenz said:
I use big R-cores with double secondaries and schottky rectifiers for each channel of the Connoisseur 4-series preamps, and the improvement was evident😀.
regards, jonathan carr
Admittedly, my PS topology is a bit different from what Max uses 😀.
If you were to not bother to develop new topologies, but remain with circuits that have already been posted, I would suggest something along the lines of a stacked version of
jonathan carr
If you were to not bother to develop new topologies, but remain with circuits that have already been posted, I would suggest something along the lines of a stacked version of
jonathan carr
Thanks JCarr,
I am about to try that floating PS as I have some Power Darlingtons here. We will see if topology is more important than the active unit used 😀
Sorry, I meant that even after the improvement made by the R/core, the charge transfer supply made and evident increase in transparency, etc...
About Sikorels, I use them in a pair of amps and they are surely very good, but I would not say that they have super bass...in reality they are more transparent and detailed than BHC AL41 (I don-t have experience with 4 pole) for example, but the perception is than they sound clearer and thiner than the former, though the bass is more controlled. This is a frequent observation in my experience> whenever there is an increase in transparency, the extremes may extend but the sound gets thiner (less noise on the bass perhaps) even though the bass gets more controlled and harmonics get richer...I do not know if I explain myself...
I mean, as I like classical music, I am OK with Sikorels, but were I a rock fan I would prefer BHC.
Edit> the charge transfer PS could make the purchase of super capacitors unworthy> this is an hypothesis...
Cheers,
M
I am about to try that floating PS as I have some Power Darlingtons here. We will see if topology is more important than the active unit used 😀
Sorry, I meant that even after the improvement made by the R/core, the charge transfer supply made and evident increase in transparency, etc...
About Sikorels, I use them in a pair of amps and they are surely very good, but I would not say that they have super bass...in reality they are more transparent and detailed than BHC AL41 (I don-t have experience with 4 pole) for example, but the perception is than they sound clearer and thiner than the former, though the bass is more controlled. This is a frequent observation in my experience> whenever there is an increase in transparency, the extremes may extend but the sound gets thiner (less noise on the bass perhaps) even though the bass gets more controlled and harmonics get richer...I do not know if I explain myself...
I mean, as I like classical music, I am OK with Sikorels, but were I a rock fan I would prefer BHC.
Edit> the charge transfer PS could make the purchase of super capacitors unworthy> this is an hypothesis...
Cheers,
M
maxlorenz said:
It is 🙂. But I'd also include construction.
Don't worry, I understood exactly what you meant. That's why I borrowed your phrasing for my first post 😉.
And expensive power cables 😀. A major reason why power filter caps can have such an effect on the sound is that on one hand they must deal with charging pulses and on the other hand they need to handle whatever signal current travels backward from the amplifier circuits (you can measure this and see how the music signal and charging pulses superimpose). Also the power filter caps are connected to the component's ground, which then gets connected to every other component in your system via the interconnects.
Keep the charging pulses away from the signal currents and grounds and the "sound" of the filter supply cap becomes much harder to detect.
I will add that with a normal power supply, connecting a common-mode choke between power transformer secondaries and rectifiers can reduce the superimposition of signal current and charging pulses. Not a total solution, but still a step in the right direction.
regards, jonathan carr
Grounding
Hi Mihai
I have just finished building the first mono block and am just checking the wiring before I create the next "big bang"!
In you photos it looks like you have a ground wire from the front end PSU to the FC100 ground pin and also a ground wire from the power amp supply to the mid point on the 4*10,000uF capacitor bank.
I can see the 0 volts for the speaker is taken from the ground point where the front end PSU feeds in.
Is this correct?
Thanks
Hi Mihai
I have just finished building the first mono block and am just checking the wiring before I create the next "big bang"!
In you photos it looks like you have a ground wire from the front end PSU to the FC100 ground pin and also a ground wire from the power amp supply to the mid point on the 4*10,000uF capacitor bank.
I can see the 0 volts for the speaker is taken from the ground point where the front end PSU feeds in.
Is this correct?
Thanks