Can I use a preamp with the sensation m901?

Nocturne79 · « **on:** 8 Dec 2012, 12:51 pm »

Hey all I was wondering if I can use a preamp in the chain with the sensation m901?

Thanks and happy holiday

Nocturne79

Jason T · « **Reply #1 on:** 8 Dec 2012, 05:07 pm »

Quote from: Nocturne79 on 8 Dec 2012, 12:51 pm

Hey all I was wondering if I can use a preamp in the chain with the sensation m901?

Thanks and happy holiday

Nocturne79

absolutely I've done it plenty.
simply turn the volume knob on the sensation up all the way and go for it!

Tarzan · « **Reply #2 on:** 9 Dec 2012, 11:32 am »

Sensation is mental as a pre-amp

abernardi · « **Reply #3 on:** 10 Dec 2012, 05:48 am »

I've been using an Axiom passive preamp with the 901 and I think it sounds a little better. It seems to clean up the frequencies around the ssss's.

bardamu · « **Reply #4 on:** 17 May 2014, 08:38 am »

Hello,
I have just one m901 used 80 hertz and up.
I have altec VOT with 16 ohm 515 speakers. High effieciency so should be easy to get some SPL. But these little monsters have a rather peculiar impedance curve. There is a peak close to 70 ohm. Most good amps dont care if it gets low or even lower but this high. The famous Hiraga amps didn't mind so did some otl designs.
But because my M901 sounds so gorgeous in my '' cheap '' set it seems tempting to give it a try. A pity the 2.2 cap has been removed ( to be able to compare the original 100nf to another one. ( which was better for sure).
The big set uses a Rega appolo transport and a curcio dac ( 4.4 volts output all bits on) and tube line amp with symmetrical output . So maybe just use the dac and make the m901 function like an integrated amp. IF it works well i wanna get another one with a tube buffer which will increase input impedance which would be an advantage for my line level filter between pre amp and power amps.
Can the m901 cope with high output of the dac?
It will be a real load of work trying my present m901 in the other set. Changing the cap, disconnect and connect everything, having a tv set-up with no sound.
I guess no one did try virue with altec? I remember someone with other horns. Have to read again.
I know the virue crowd isn't a typical diy crowd. i did ask around in France but there they don't know the virtue devices.
Any ideas or suggestions are welcome, the best one will get a set russian paper in oil or teflon caps lol, Sincere greetings, Edward

bardamu · « **Reply #5 on:** 25 May 2014, 07:44 am »

Hello,
After some Emails with Gary Dodd i did accept his offer to make a variable gain preamp with the 6085/e80cc for me. Why not the Russian tube everybody raves about? well i think the price of this tube has been going up to much. The 6085 is expensive as well but i got at least 50 in stock. They last a long long time and i like the way they sound. By not buying the russian tubes i will save some money that can be spend on the output cap. First find out about the '' sonic character '' of this new device and then see if i can improve it with adding a 200$ ?cap ?
A pity you cannot send these caps back if you dont like them. Lots of stories about caps on the internet but what could be heaven in one device could be a disaster in the other.
Brands talking about mix of gold silver oil sound more like pure marketing techniques to me.
I really like paper in oil caps from philips, sic safco and i love the k75-10 from Russia too. Yes did try the mit, the wondercap, the csi, scr, solen. Not my style.
Sincere greatings, Edward
P.s now let those readers start typing!!!

virtue · « **Reply #6 on:** 27 May 2014, 05:11 am »

Wow, that's great. It's nice of you to give Gary work. Perhaps he's the only guy who can build to your specs, Edward!

bardamu · « **Reply #7 on:** 27 May 2014, 10:48 am »

Hello Seth, my specs arent that peculiar if you understand what i wanna have.
Of course there are not a lot of people who do wanna bi amp the way i do.
Probably will also connect an antimode device to correct my pair of subwoofers. Input impedance of thecantimode is 10kohm but the designer from that device did tell me they can make one with a higher input impedance.
We will see, sincere greetings, edward

virtue · « **Reply #8 on:** 28 May 2014, 04:19 am »

I just posted a DIY price of $200 for the ONE.3 board set with cables.

http://store.virtueaudio.com/product-p/vrtu-ia-vaone.3-pcb-1.htm

The full upgrade including labor will be $250.

http://store.virtueaudio.com/product-p/vrtu-ia-vaone.3-upgrade-1.htm

Seth

bardamu · « **Reply #9 on:** 5 Jul 2014, 12:23 pm »

Hello Virtue crowd,
I just did buy a secondhand sensation with a Dodd tube buffer to use as a power amp in my big system.
First i will just use it as an integrated amp because my present pre amp has balanced outputs. Will use it with the 100nf cap and add my present SVS subwoofer ( will buy a second one after my new Gary Dodd pre amp has arrived)
With the new pre amp there will be a 12db filter at 600 hertz consisting of a little coil a 40nf cap and a pot for adjusting the volume.
Adding all this , a decent input for the battery power supply ( probably speak on) and another power switch because the old one needs to move because of the seize of the speak on will force to make a new bottom/rear panel just like i did for my other sensation.
Eventually i will just need one set of inputs, the switch, the binding posts, the speak on and some holes to mount the set of pots and the set of coils.
In my other set i did switch to virtue cables for modulation and speakers. REALLY nice!!! Because i have to solder any way i might as well skip the cinch, just mount a decent strain relief and connect the coil directly to the cable. Buy some virtue cable of the roll and have the same brand of plug on the other end to have a perfect '' match '' with the Cardas ( if i am right Gary is using on my pre amp).
I need some space on the rear side so i want to '' abort '' the connectors not in use ( 2 sets of input, 1 set output and the subwoofer out) Can i just pull them out off the small board connectors? Dont want to have them lying around on the inside. Do i need to short them like you can do with shorting plugs. There are coils at the input do they need to be used when you short the inputs?
I will you keep you informed. Will have to wait untill it is here and wait for your thoughts to in order to be able to make the right metalwork.
Big batteries will take about a week to arrive. Sensation is allready in transit so i guess that will take about a week too.
YES, the batteries will be a bit bigger than my other ones because i once did say that space was a limit in the other set. Here is also a space limit but there is more space. Will put the batteries hanging right under the sensation supporting '' level '' in my rack. From battery pack to rear side power entrance will be one foot maximum. Will have to do some metal work to make it sturdy and safe. Each battery is just above 60lbs. Yes it has to feed the tube buffer as well.
Sincere greetings, Edward

Tarzan · « **Reply #10 on:** 6 Jul 2014, 10:36 pm »

Do let us know you get on Edward, sounds interesting, l myself use one of my Sensations as a pre- amp to good effect.

bardamu · « **Reply #11 on:** 7 Jul 2014, 05:21 pm »

Hello Tarzan,
Because i have lack of space on the rear side i need to '' abort '' some inputs which will not be used.
The technical support on this website is far below average so i will just do what seems logic to me. I hope the SVS subwoofer ( S will get a second one after my Dodd pre amp has arrived) can match well with the altec horns. So i can replace both caps in my sensation with a 100nf one. My replacement already was way better than the original one. Have some candidates.

I think the best part of the sensation is the power amp. After all the pre amp part has no gain. That is why i did hunt down with a tube buffer. Also no gain but must be better than a silicon one.
The big changes with the virtue gear are in the powerr supplies. I will send you a personal message when i am done,
Sincere greetings, Edward

Tarzan · « **Reply #12 on:** 10 Jul 2014, 12:23 pm »

Ok thanks Edward.

bardamu · « **Reply #13 on:** 20 Jul 2014, 05:52 pm »

Hello tarzan,
Just a small update.i dud start with the metalwork for my new sensation. The last one seems to have come from a different production run or someone who did do the metal work needs new glasses or a better machine. Some things didnt fit 100% And i had to do some afjustments. I just did copy the spare part i did do myself and added a few holes.
There will only be one set of xlr input, there will bea lundahl transformer who will change the balanced output from my pre amp to an unbalanced one. There will be at 600hertz filter with 12 db slope.
The speaker connectors will be on top.
I did put a decent power switch and high amp rating connector.
Have to find a solution to mount the tube buffer black box. It was glued but did come loose during transport.
The stand offs i did use for the print are just 2 mm higher than the original and now the buffer dont fit. Anyway it was mounted in such a way that i did decide to change it anyway. You need to do a lot of cursing to get it out especiallywith all the wires and the bigger caps.
Ooh yeah the caps the caos will be changed too.
Greetings edward

bardamu · « **Reply #14 on:** 20 Jul 2014, 05:56 pm »

virtue · « **Reply #15 on:** 20 Jul 2014, 07:33 pm »

Edward,

If you can get the top back on Sensation I may forgive you for destroying it. Those blue ones are my favorite - so gorgeous.

Hugs,

Seth

bardamu · « **Reply #16 on:** 20 Jul 2014, 08:57 pm »

Hello Seth,
As you can see i did create some xtra depth by turning the aluminum piece that holds the back panel 180 degrees and also did create some extra height by omitting the sliding top panel. The top panel is nearly invisible in my set up so i dont mind.
Need the extra height too to mount the black box from the notorious gary in a decent way.
If it sounds allright next week i will be happy.
I needed the space too for a better connector and power switch. I would rather have good connectors on the print and pay more and have columns and a fancy colour.
wait untill you see my batteries. they will arrive tomorrow at work .
sincere greetings, Edward

Tarzan · « **Reply #17 on:** 21 Jul 2014, 09:44 am »

Nice work Edward

bardamu · « **Reply #18 on:** 21 Jul 2014, 10:56 am »

Hello,
Today after work i will install a Russian oil cap 100nf and a 100nf Russian teflon or a French polystyrene( the one i am using in my other sensation). So i can switch between the 2 after a few weeks the 600 hertz will be used too. So it will be used between 100 and 600 hertz. IMportant frequency part so cannot use crap cap like soniccap lol.
Sincere greetings, edward

bardamu · « **Reply #19 on:** 22 Jul 2014, 05:59 pm »

Hello,
Installing the caps i will need daylight. The person who did install the sonicaps must have bad light because the soldering doesnt look to well. Might even be a cold joint. So i will do it friday afternoon and take a half day off at work and use my special electronic light which is at the kitchen table now. But that one cannot be used for electronics all the time.
I did get the batteries, they are heavy and big. If you see them you know it would be nice to change the connector and the power switch too.
This was the biggest battery that i could install into my rack with just some minor changes. Batteries usually have a position that will make them work better and last longer than in other postions. Especially charging is best done with the connectors facing upwards.
There will be another panel mounted on top of thepanel with the big holes in suchs way that i cannot be moved and kind of locked by the 9 hexagonal.........
connections between battery terminal and power connector at the back of the sensation will be maximium

one foot