[Tarzan]

Is The Sensation with batteries 40wpc?

[Randy]

Is The Sensation with batteries 40wpc?

You'd be better off with Seth or Jason replying, but as far as I understand it, that is the case.

[virtue]

Into 8 ohms, yes. 

[Tarzan]

Into 8 ohms, yes.

l know this subject has been covered, what wpc is the 30v/130w PSU into 8ohms.

[srb]

Seth, these are the posted specs for the Sensation M901:
 
Power Supply     RMS Output
Max: 30v           4 ohms, <1% THD
 
24v/65w            30wpc
 
30v/90w            40wpc
 
30v/130w          55wpc
 
30v/300w          87wpc
 
Aren't the 8 ohm specs half of these figures?
 
Steve

[virtue]

At 30v it's half output because it's voltage limited.  At 24v, 8 ohm power remains around 30w since it's current limited.

[bardamu]

Hello,
Sometimes i can get my sensation into clipping in my 2.1 set up. I think the output of my choke input power supply was about 24 volts. If i change the power transformer to one with a higher output voltage( the current rating of the present transformer is BIG) so the output voltage would be closer to 30 volts. Would that be a way to prevent the amp from clipping or reduce it considerably?
Sincere greetings, Edward

[Jason T]

Hello,
Sometimes i can get my sensation into clipping in my 2.1 set up. I think the output of my choke input power supply was about 24 volts. If i change the power transformer to one with a higher output voltage( the current rating of the present transformer is BIG) so the output voltage would be closer to 30 volts. Would that be a way to prevent the amp from clipping or reduce it considerably?
Sincere greetings, Edward

the higher voltage will always help.
whats the current rating on your power supply?

[bardamu]

Hello,
I thought it was close to 9 ampere. I should find the result of my meusurements to see how much i could gain in output voltage by changing the transformer. Maybe it will just be something like 3 or 4 volts maximum.The chokes i use have a 1.3 ampere current rating but i think because of the capacitors the power supply can supply a lot more current. Greetings, Edward

[bardamu]

Hello,
Still thinking about improving my sensation power supply. Right now using a big transformer which is given about 24 volts dc to the circuit. It is a choke input with 2 non swinging choke with moderate induction ( 100mh). One directly behind the rectifier ( making it a choke input) and one between the first and the second capacitor. To keep it functioning like a choke input and to prevent the capacitor getting to much voltage i need a big bleeder. So now i am thinking about using a so called swinging choke with about 5 times higher induction and of course a much bigger induction at lower current ( that is why it is called a swinging choke). So the current needed to go through the bleeder is much smaller so i expect a much better filtering.
In the end i also wanna change the transformer to get some extra volts to get more power.
I will have to make a new power chassis because both the choke and transformer will be bigger. So any suggestions before ordering are welcome.
Sincere greetings, Edward

[Tarzan]

Hi Edward, keep us up to date with your mods and tweaking as they are interesting!

[bardamu]

Hello Tarzan,
It will be quiet a task to start with the new power supply. Apart from the hours i also need to spend a few hundred $ or euros for the choke and the transformer. I have been searching the internet but there isn't a lot of information about solid state designs with choke input power supplies. I have one now but i want top be sure if it can be improved by buying a bigger choke. The power chassis i use now is to small to house this big choke. So have to move everything to a bigger chassis( just a few inches higher will do) but still a big task.
I did forget the ac voltage on my present transformer but like i said before it should preferably be a few volts higher.
I will keep you informed. I don't expect much input here. Diy audio isn't what it used to be.
Kind greetings, Edward

[virtue]

The cheapest way to max Sensation is the Astron power supply. 

This class of linear supply is used for boat and ham radios and tattoo needles.

Surely you can find the equivalent in Europe.

[bardamu]

Hello,
I did find a BIG transformer but it is so big it needs an inrush current limiter.The transformer is not expensive, but it is heavy and i need to collect it with public transport. Not the usual ntc because they can be tricky to apply but there is a company in Germany that did develop a little circuit that will avoid the big current which is caused by the energy that is needed '' to activate'' all the iron in the transformer.
The choke i wanted to use is in the USA but the company still didn't react to my email. It is quiet expensive and transport to Europe wont be cheap either'.
SO i start reading about batteries again. My set up is used every evening about 5/6 hours and in the weekend all day so big AH is an advantage.There are lots of different types available. Usually the better ones with better specs are more expensive. As usual i will make the chassis myself so now i am figuring out how much space i have in my rack. I think about 3 times the seize of my sensation m901 so i am not gonna use 5AH.
Probably 17-24Ah range. Lots of reading and comparing to do.Usually the long life, high discharge types are drawing attention.
We will soon see and hear. Kind greetings, Edward

[virtue]

Lol...  I like "cheap and cheerful" frankly.  5Ah is more than you would listen to in a critical session, even totally disconnected.

[bardamu]

Hello Seth and the others,
In the eighties i did build a French design for a moving coil cartridge amplifier. Power consumption was less than 10 milliampere. There was a commercial version available using an ordinary battery. But for diy folks they also did describe a state of the art version with bigger lead sealed batteries. First using 1AH and then 8 AH. Mine also used to 8Ah or even more .
Their philosophy was that if you need to amplifly very small signals you need to power supply to be extremely stable. They also did make power and pre amplifiers using batteries. They did make some very special devices.
I am sure the sensation will work with 5Ah but batteries aren't that expensive so i will buy bigger ones. I also will buy a ctek charger because using a good charger will keep your batteries in better condition.
Also did read that there are different types of lead sealed batteries for different purposes. Some just buy a general purpose one( the cheaper the better) But there are ones specially developed for standby use( like in a ups) and one for cyclic use ( like in a golf car). I think one designed for cyclic use would be better in an amplifier.
Comparing 3 batteries with the same AH rating: One designed for floating and cycled use and the other designed for cycled use in particular. The same manufacturer, just different series. max discharge current during one minute:  general purpose 48A     general purpose long life 150A    cycled use( also has a longer life) 240A
At a big online electronic company, the 48A is the most expensive and the 2 others just have a difference of 2 $
I guess quality still has a price tag.
http://img411.imageshack.us/img411/5262/h2ultimatetestimplantat.jpg
This is the pre pre built by someone much later after it had been introduced. Try to find the actual circuit LOL
One could copy this post to the dodd battery replacement project as well.
Kind greetings, Edward

[virtue]

Thank you Edward!

[jb26]

Based on the figures for the Battery & various PSUs from Nov 2012 in this thread - am I right at reading that the battery provides the greatest wpc of the available options once they're all converted to the same number of Ohms?

[virtue]

Power output is limited by voltage OR current -- whichever is less.

24v packs tend to start out at 28v, so that is near the max rating.  They do go down to 24v before dying though.

The sensitivity of your speakers will be a much greater determinant of perceived loudness.