Maty,
I think I agree with your distortion comments. High THD, particularly H2/H3/H4, are not good for complex orchestral music. OTOH, such amps, such as SE triodes, are wonderful with simple music, particularly female vocals. Clearly a psychoacoustic issue.
X,
Thank you for putting up all the figures. This is a terrific insight of what sounds good. I do think the holy grail is low THD but descending profile, just as you say. With improving semiconductors and innovation topologies we are slowly achieving this.
Hugh
I think I agree with your distortion comments. High THD, particularly H2/H3/H4, are not good for complex orchestral music. OTOH, such amps, such as SE triodes, are wonderful with simple music, particularly female vocals. Clearly a psychoacoustic issue.
X,
Thank you for putting up all the figures. This is a terrific insight of what sounds good. I do think the holy grail is low THD but descending profile, just as you say. With improving semiconductors and innovation topologies we are slowly achieving this.
Hugh
KEF Q100. With ALL my cheap tweaks they sound much better than new. Tweaked the front bass-reflex too.
True sensitivity is 85 dB/W/m and 4.7 Ohms minimum impedance. And... at -3 dB: 49 Hz. Two first order. The frequency graph is more flat and with fewer oscillations than LS50.
I have a thread in Audiocircle forums:
KEF Q100 for $300
New they sound very bad because the speaker suspension is very good but very rigid. There are not bass the first hours. I think they need about 200 hours! -> for many years they were a failure in sales.
KEF LS50. True sensitivity only 83 dB/W/m and 3.9 Ohms minimum impedance. At -3 dB: 79 Hz. Second order filters. And the furniture has more mass. But they need about 90 cm from rear and the sides too. With German DIY four order crossover -> 80 or 81 dB/W/m.
Q100 and LS50 LOVE watts.
True sensitivity is 85 dB/W/m and 4.7 Ohms minimum impedance. And... at -3 dB: 49 Hz. Two first order. The frequency graph is more flat and with fewer oscillations than LS50.
I have a thread in Audiocircle forums:
KEF Q100 for $300
New they sound very bad because the speaker suspension is very good but very rigid. There are not bass the first hours. I think they need about 200 hours! -> for many years they were a failure in sales.
KEF LS50. True sensitivity only 83 dB/W/m and 3.9 Ohms minimum impedance. At -3 dB: 79 Hz. Second order filters. And the furniture has more mass. But they need about 90 cm from rear and the sides too. With German DIY four order crossover -> 80 or 81 dB/W/m.
Q100 and LS50 LOVE watts.
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To finish the off topic.
Before mass, I had this DSP in foobar2000 (32 bits) and J River MC 24 (64 bits):
KEF-Q100-iZotope-RX-6-De-Hum-21-19550-Suggest-8-mass-added.png
[IMG, only link] http://maty.galeon.com/WP-imagenes/...RX-6-De-Hum-21-19550-Suggest-8-mass-added.png
With more mas over the furniture:
KEF-Q100-iZotope-RX-7-De-Hum-21-22050-Suggest-8-mass-added.png
[IMG, only link] http://maty.galeon.com/WP-imagenes/...RX-7-De-Hum-21-22050-Suggest-8-mass-added.png
Before mass, I had this DSP in foobar2000 (32 bits) and J River MC 24 (64 bits):
KEF-Q100-iZotope-RX-6-De-Hum-21-19550-Suggest-8-mass-added.png
[IMG, only link] http://maty.galeon.com/WP-imagenes/...RX-6-De-Hum-21-19550-Suggest-8-mass-added.png
With more mas over the furniture:
KEF-Q100-iZotope-RX-7-De-Hum-21-22050-Suggest-8-mass-added.png
[IMG, only link] http://maty.galeon.com/WP-imagenes/...RX-7-De-Hum-21-22050-Suggest-8-mass-added.png
Usually the harmonic profile is worse at high power, not so in the Deltic poweramp! It seems that Deltic loves watts.Here is FFT for 2.90vrms into 8ohms showing about 0.033% THD and nice descending profile:
Here is 22.8Vpp into 8ohms or about 8wrms FFT, with same harmonic profile - so sound is very consistent at low or higher power:
I have seen many graphics in which a harmonic profile with everything under 90 dB at 1 watt becomes H3 dominance at maximum power. And they are expensive amps.
Btw, the 60 Hz peak is very low too!
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Hi Maty,
The DELTIC has a very consistent sound over a wide range of playing levels. Having the same profile and same THD at both 1w and 8w is a pretty neat trick. I think it continues even higher. This has all to do with the topology that Hugh designed. The PSU is very simple CRC with about 10mF // 0.22R // 10mF. It’s all located right next to the outputs with thick double traces with via stitching for an ultra low impedance path for super bass authority and and to not degrade the DF to the extent possible.
The DELTIC has a very consistent sound over a wide range of playing levels. Having the same profile and same THD at both 1w and 8w is a pretty neat trick. I think it continues even higher. This has all to do with the topology that Hugh designed. The PSU is very simple CRC with about 10mF // 0.22R // 10mF. It’s all located right next to the outputs with thick double traces with via stitching for an ultra low impedance path for super bass authority and and to not degrade the DF to the extent possible.
I reconnected the Alpha BB after a 4 month hiatus after the basement flood. Listening for past hour and man, it sounds so good. Love the natural smoothness and bass authority. It drives my 82.4dB speakers without hesitation. It is so smooth and the headroom is just incredible.
I really could be happy if I only had this amp.
I really could be happy if I only had this amp.
Attachments
But you do not live on the Mediterranean coast like me: hot and humid summer in the first Roman capital of Hispania, Tarraco.
Tarraco - Wikipedia
My cheap and tweaked second system has very good sound since I solved my serious problems with the incredible noisy electrical grid.
Some hours ago I listened one of the best records I have. It seemed that the cantaora and the guitars were in the room. A treasure.
Lole y Manuel - Nuevo Día (1975), Vinyl, Movieplay, Spain
I believe what he wrote even if the fan blows away that heat the heat is still a problem because of the warm weather. He will need to use an AC to cool down the room. When is warm at summer I use 2 or 3 fans and almost makes no difference in the room or apartment temp. I still suffer from the heat. Here in Toronto for 6-8 months is OK to use high-Class A amps, even a 120W type like my Aleph X if the power consumption, not a problem, you know financially. That is why I will never go over 50W type in Class A as an SS amp. Even a 30W amp would do the job with general 87-88db sensitive speakers. Yes, you have there a great and lovely amplifier!
X,
Many years ago I built a Zen, the very first DIY Pass amp in the early 90s. I cooled it with water, using a discarded dishwater shaded pole pump, metres of 10mm ID plastic pipe, and passed it through the wall and down into the soil under the home. I had a water level sender made from a copper wire and an IC at low voltage driving an AC solenoid valve from the mains off a dish washer. If the water fell, the mains topped it up automatically. It was silent, except for the bath time gurgles when an air bubble came to the Al welded heatsink. Of course it had a wonderful, liquid sound, and the sonics were good too.....
I loved that 10W amp, it had huge THD but man, did it sound good.......
Hugh
Many years ago I built a Zen, the very first DIY Pass amp in the early 90s. I cooled it with water, using a discarded dishwater shaded pole pump, metres of 10mm ID plastic pipe, and passed it through the wall and down into the soil under the home. I had a water level sender made from a copper wire and an IC at low voltage driving an AC solenoid valve from the mains off a dish washer. If the water fell, the mains topped it up automatically. It was silent, except for the bath time gurgles when an air bubble came to the Al welded heatsink. Of course it had a wonderful, liquid sound, and the sonics were good too.....
I loved that 10W amp, it had huge THD but man, did it sound good.......
Hugh
Class A with 50 watts at 8 Ohms.
Efficieny about 20% -> 250 watts... by channel! Almost becoming to heat, how much? I do not know, but sure you have a stove of at least 450 watts in the room I suppose. Too much in the Tarraconensis summer.
Class AB has about 65-70% efficiency and does not work always at max power like class A.
Efficieny about 20% -> 250 watts... by channel! Almost becoming to heat, how much? I do not know, but sure you have a stove of at least 450 watts in the room I suppose. Too much in the Tarraconensis summer.
Class AB has about 65-70% efficiency and does not work always at max power like class A.
i am using water cooling for my ozone generator machines . each module is 1000 watts and in one cooling block (aluminium) we attach two boards on each sides . we use cooling tower / chiller / heat exchanger for cooling the block.
Attachments
Gee Raj,
That is well designed, beautiful pcb, and very high energy density!
Somewhere in my garage I have a 15KV Tesla coil but I have never used it....... given to me by a young engineer who built it about 25 years ago and then cleaned out his home when he went to work in Switzerland.
I really love audio, that is the problem........
Hugh
That is well designed, beautiful pcb, and very high energy density!
Somewhere in my garage I have a 15KV Tesla coil but I have never used it....... given to me by a young engineer who built it about 25 years ago and then cleaned out his home when he went to work in Switzerland.
I really love audio, that is the problem........
Hugh
Hi hugh , Xrk sorry for the off topic . it may be useful for some one trying to build high power class A.
have to congratulate both Hugh and Xrk for their extraordinary contribution in this forum.
you people are doing tremendous work. i too love audio hugh. but i i have time only to
lurk here and there in the forum.
have to congratulate both Hugh and Xrk for their extraordinary contribution in this forum.
you people are doing tremendous work. i too love audio hugh. but i i have time only to
lurk here and there in the forum.
New thread for self-contained Aksa Lender pre-amp module, called The Melbourne. Turns out to sound great as a headphone amp as well. Bipolar power supply, DC coupled output, superb harmonic profile.
The Melbourne Class A Headphone Amp and Pre-amp
2Vpp into 519R load:
The Melbourne Class A Headphone Amp and Pre-amp
2Vpp into 519R load:
Hi
I completed alpha20 with respect to 4ohm version and facing the problem
The DC offset is 22v
These are the voltage ratings across the transistors with respect to ground
V131
S 22
D. 26.5
G. 26.3
V132
S. 22
D. -26.57
G. 19.7
Bc547c
C 27.35
B 23
E 23
V103
E -26.75
C 20.6
B -26.14
V101
E 0.75
C -26.3
B 143.9
V102
E 0.75
C -26.7
B 9.94
Please assist me to solve the issue
Followed below values c105 and c113 are used 220pf
R128 is 863
I completed alpha20 with respect to 4ohm version and facing the problem
The DC offset is 22v
These are the voltage ratings across the transistors with respect to ground
V131
S 22
D. 26.5
G. 26.3
V132
S. 22
D. -26.57
G. 19.7
Bc547c
C 27.35
B 23
E 23
V103
E -26.75
C 20.6
B -26.14
V101
E 0.75
C -26.3
B 143.9
V102
E 0.75
C -26.7
B 9.94
Please assist me to solve the issue
Followed below values c105 and c113 are used 220pf
R128 is 863
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Can you clarify what is B of V101 again? 143.9 is not right.
Hi Cl00sed,
Also, if you can take the time to hand write or use paint program to enter values above into actual schematic it will save us from having to do that ourselves. The visual image of the whole amp with DC setpoints is what we need to see the problem. I can see that gate voltage on V131 appears to be too small. There is thus no current supplied by the Aleph CCS.
Thanks,
X
Hi Cl00sed,
Also, if you can take the time to hand write or use paint program to enter values above into actual schematic it will save us from having to do that ourselves. The visual image of the whole amp with DC setpoints is what we need to see the problem. I can see that gate voltage on V131 appears to be too small. There is thus no current supplied by the Aleph CCS.
Thanks,
X