Power sources and components

i have a similar setup to what you are plannning on ..
except mine is not an APC one. I checked the output on the scope to make sure the output was a sine wave and was pretty satisfied with what i saw.

cost abt 25k too.

Siva also has a similar setup with APC. One good thing about UPS is that you could probably leave the setup ‘on” all the time without worrying about brown-outs, surges etc… SS equipment loves to be “on “ all the time for the best performance.

actually i would like an offline kind of a setup where the feed into the equipment is always from the battery and the charging happens online.(not the kind where power input is from the mains but the switches to the battery only on loss of power.. )

BTW also heard that most Inverters give a chopped sine wave which is almost and equivalent of a square wave... Sachi was that true ?

BTW also heard that most Inverters give a chopped sine wave which is almost and equivalent of a square wave... Sachi was that true ?

That is true for many, so select with care.

Typically the Stepped approximated Sine waves are used for high efficiency.

A true sine wave can be obtained only by actually having a large (audio) power amplifier inside the Inverter. Approx 30% ( my figures are rusty ) of the actual power output delivered at that time, will be heat dissipation, for a pure sine wave UPS !

If an approximated 10 step sine wave ( 5 steps each in the positive and -ve half cycles ) is used, the UPS will have the 50 Hz with 11th Harmonics onwards ie 550 Hz, 600 Hz, 650 Hz etc...

The harmonics are often filtered to levels of below 1% THD ( Total Harmonic Distortion ).

In comparision ( REPORTED Figures - No, not done actual measurements at my stereo ) the mains supply can offer mains power with a THD of 0.5% to approx 10% ).

Like i said i cheked the output on a scope and was satisfied. It was still a stepped sine wave but near close to sine.
I plan to add a power conditioner later which i feel should iron out things.

Hmm. but in the end since the PSU is actually converting the AC to a DC signal, a stepped approximation of sine may be good enough. i anyway doubt if our power in is a sine wave..not to mention the harmonic content.

Amp_nut ji..as usual your "Laymanized" explanation was excellent. THD is perhaps more significant a characeristic to look at.

Siva, i will ping you later for more info as you appear to have done a lot of homework on this

Arj schrieb:

Kind of an offshoot of the thread Replacing Stock Jumpers.., based on B'walla and maneks comment, I was wondering on 1. a separate line into the Audio room Vs 2. having some kind of dedicated Sine Wave power source (eg the 1KVA power inverter from APC) any thoughts on the above ? since my power indraw does no go above 250-300W, the 1KVA should be an enough overkill. Not sure if the pure sinewave for audio will be the equivalent of pure distilled water for drinking ie tasting/sounding insipid ! any thoughts on this ? I think the above APC inverter is around 25K..

Arjun,
I've had limited experience with AC regeneration units & mine has been a very positive one with a PS Audio PS300 unit. It belongs to a friend & I auditioned it in his system in his house.
This unit is exactly what Amp_Nut describes - it has 2 stages of class-AB power amps to generate a pure sine wave output. The output is a pure sine wave with essentially zero harmonics. it is NOT a stepped sine-wave. The power amplifiers are fed from an on-board sine oscillator. The oscillator's freq can be changed from the front panel by the user to tweak the overall sound from your 2-ch/HT setup. In my friend's setup 80Hz worked the best.
However, the PS 300 can supply upto 400VA hence it is recommended for front-end components only.
The bigger unit PS 600 can supply 720VA & is reputed to supply enough power to a mid-sized amp. They state "upto 720W/ch" but I'd easily half that power output & attach no more than a 250W/ch amp to the PS 600.

Arj schrieb:

since my power indraw does no go above 250-300W, the 1KVA should be an enough overkill.

you might have stated the static/idle current draw to us! I bet that when the program material is playing, and you could measure the AC current draw for your amp, you'd find that it draws much more in bursts. The 1KVA might be on the lower side - I'd double that easily. if you constrict the AC power, your system will sound like someone gave it a "wedgie"

bombaywalla schrieb:

[ The 1KVA might be on the lower side - I'd double that easily. if you constrict the AC power, your system will sound like someone gave it a "wedgie" ;)

lol the audiophile wedgie
Mine is a pure class A amp..it draws all it can and keeps the input constant aat that maximum (200W as per the manufacturer for its rated 25W output ). what it can give to the music it gives and the rest it gives out as heat. hence the more dynamic the music the cooler it runs !

since i use 89dB easy to run speakers doubt if the speakers would need to run cool ;). siva has given a good pointer to the APC range..wuill explore more.

I have heard the PS300 too used for the source and pre amp only ..and have heard of it as really good..but it is priced too high

Arj schrieb:

Mine is a pure class A amp..

OK! thanx for the clarification. I didn't realize that you were using a pure class-A amp. I can see that 1KVA might do it for you.
Sounds like a Sugden A21 amp?

Arj schrieb:

what it can give to the music it gives and the rest it gives out as heat. hence the more dynamic the music the cooler it runs !

right you are!

Arj schrieb:

I have heard the PS300 too used for the source and pre amp only ..and have heard of it as really good..but it is priced too high :(

yes! that's the only draw-back to these units - their (damn) price!

Like i said i cheked the output on a scope and was satisfied. It was still a stepped sine wave but near close to sine.

If you can Visually observe the waveform as being non-sine, then the distortion is ATLEAST 3% to 5%.

On most days, the mains supply provides lower distortion. However the mains may carry more noise on the line ... that will vary hugely on your electrical neighbours.. Densely packed Indian neighbourhoods, with elevators, airconditioners ....

Ofcourse frequency too varies all over the place on the national grid.

Bombaywalla said :

In my friend's setup 80Hz worked the best.

Bombaywalla, Can you elaborate on how the sound changed with freq ? I have read several reports of persons finalising on a particular freq for their system, but no reports of how the changes manifest themselves, particularly with Non Ideal frequencies ( eg did the sound turn thin ? Sound stage collapsed ? etc )

Thanks

bombaywalla schrieb:

Sounds like a Sugden A21 amp?

Bingo ! as in the proverbial Nail on the Head

Amp_Nut schrieb:

Bombaywalla, Can you elaborate on how the sound changed with freq ? I have read several reports of persons finalising on a particular freq for their system, but no reports of how the changes manifest themselves, particularly with Non Ideal frequencies ( eg did the sound turn thin ? Sound stage collapsed ? etc ) Thanks

Sure, I'll try Amp_Nut. This was a while back so I've to jog my aural memory back!

If I remember correctly, when the freq was set to 80Hz, the bass became fuller & deeper. The sound-stage was wider & more realistic. The tonality of the instruments also sounded right. Overall, I would say that the system sounded more like music that had emotion to it & it drew us in. At other frequencies, the 2-ch sounded like a very good hi-fi system.

I have found getting a seperate power from main distribution board very benificial, seperate earth pits for your hifi also helps in maintaining lower earth potential.

First thing noticed was large improvement is in nuances of music, the little extra that greats like Lathaji, Gulam Aliji and Yesudas can add while singing were clearly heard.

Second one was improved depth of sound stage.

Third reduced noise from phonopreamp, I do use seperate filters for induvidual preamps and source.

That is pretty interesting observation Bombaywalla. What can be the reason/s? Very difficult to experiment unless you have a PS Audio PS3000.

Any idea of an alternative way to experiment with varying freq of supply?

One way I could find was to increase the speed of DG set (250kva, enough power ) engine but the max one can go is only 5-7% of the rated so you end up with only 53.5Hz which did not make any audible difference. My turntable was a different beastie as expected it was running faster without its speedbox.

Thanking you all
Anil

Any idea of an alternative way to experiment with varying freq of supply?

Yes, its possible and quite easy... With a few practical assumptions :

1. The Sound of the sorce ( and maybe pre amp) will be affected the most with Freq changes

2. You have a 50 or 100 Watts per channel, extra amplifier lying around ( may be old, no problem, as long as working.)

3. Download the mp-3 or wav files from the net. The Rives Audio sitre provides a Superb Zipped file of 20 Hz to 100 Hz ( or is it 150 Hz ) test tones, in 1 Hz increments.

( Practical Problem : The duration of each tone is not a very long duration. Even looping the file results in a brief shut down of output )

Run these from your Ipod into the integrated amp / power amp.

You can also generate your own tones using freeware such as Audacity.

4. Connect a suitable Mains Transformer in reverse between the amp fed with 50 Hz test tones and your CD Player Power - 240VAC Input.

Hi AmpNut and others,
Can you advice me on the most economical power conditioner I can get for my system? Right now its plugged into the wall socket, and an extension cord. Its shameful I know, and risky, but money is a major constraint right now. Would it be OK to plug my stuff into an old computer stabilzer that I have lying around. I asked Nova Audio bombay, and they gave me ten grand suggestion. Thats too much for the time being.
Purnendu

Dear Ampnut,
Thanks for the idea . I will look out for a decent remote controled toy

Regards,
Anil

purnendu schrieb:

Hi AmpNut and others, Can you advice me on the most economical power conditioner I can get for my system? Right now its plugged into the wall socket, and an extension cord. Its shameful I know, and risky, but money is a major constraint right now. Would it be OK to plug my stuff into an old computer stabilzer that I have lying around. I asked Nova Audio bombay, and they gave me ten grand suggestion. Thats too much for the time being. Purnendu

If you cannot spend any money on a power conditioner then don't get one!
A bad power conditioner is worse than plugging the equipment into the wall socket. IMHO. FWIW.

Bombaywalla said:

If you cannot spend any money on a power conditioner then don't get one! A bad power conditioner is worse than plugging the equipment into the wall socket.

I agree with you 1000%

OK Thanks,
Which means wait until I can allot ten thousand or so. Its my next on the list anyhow.
Purnendu