Wanted: DIY amplifier builder with experience. I need a 0.7 ohm stable amplifier

[jim_vt]

my Decware Zen will drive a .7 ohm load...doesn't necessarily gain more power over its maximum @ 2 ohms, but it will drive happily into that low impedance load.

 

[Audiophilenoob]

What are the disadvantages of using a resistor solution??????/

I'm sure there's some major ones

 

[Audiophilenoob]

would these metal films work from PE??

http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=005-4

4 of these in parallel??? per tweeter???

 

[Kravchenko_Audio]

yep

Give it a try bud. Time to get your feet wet

Mark

 

[LineSource]

Hi Audiophilenoob,

The main disadvantage of putting a 1 ohm series resistor is the loss of 50% of the amp's power into heat. If you put 10 watts into the ribbon, you also waste 10 watts of heat in the resistor. BUT...many amplifiers sound much better, "sweeter", "warmer" driving a 2 ohm load than a 1 ohm load. My 160lb Krells will easily push 1 ohm, but sound sweeter with a ribbon driving 2 ohm loads. If your current amp will only drive 4 ohms, just increase the resistor to 3 ohms. Just avoid a step-up transformer if you want the best sound.

You can make a non-inductive 1 ohm resistor by contact cementing a sheet of household aluminum foil onto a piece of plexiglass and cutting a serpintine with your Xacto knife.


It will probably cost close to $2K to build the ribbons of your dreams. I would FOCUS on this massive and very dangerous task.

 

[Audiophilenoob]

Hi Audiophilenoob,

The main disadvantage of putting a 1 ohm series resistor is the loss of 50% of the amp's power into heat. If you put 10 watts into the ribbon, you also waste 10 watts of heat in the resistor. BUT...many amplifiers sound much better, "sweeter", "warmer" driving a 2 ohm load than a 1 ohm load. My 160lb Krells will easily push 1 ohm, but sound sweeter with a ribbon driving 2 ohm loads. If your current amp will only drive 4 ohms, just increase the resistor to 3 ohms. Just avoid a step-up transformer if you want the best sound.

You can make a non-inductive 1 ohm resistor by contact cementing a sheet of household aluminum foil onto a piece of plexiglass and cutting a serpintine with your Xacto knife.


It will probably cost close to $2K to build the ribbons of your dreams. I would FOCUS on this massive and very dangerous task.

Right now it looks like it will be around $600 in parts per ribbon.... as long as this india supplier for 5 micron aluminum comes through

well I don't care if I lose half the power... cause the QSC 850 I will use on the tweets is 430 watts at 2 ohms .... so who cares...

 

[Variac]

. cause the QSC 850 I will use on the tweets is 430 watts at 2 ohms

Sounds like a good way to test the tweters until you get them refined, For the final decision and implementation there are probably amps that will sound better. Perhaps when the speakers are finished, you could start on a high end DIY amp project without time pressure-you can listen to your QSC while building its replacement. Lots of newbies making amps around here.

 

[Kravchenko_Audio]

Bingo

Perhaps when the speakers are finished, you could start on a high end DIY amp project without time pressure-you can listen to your QSC while building its replacement. Lots of newbies making amps around here.

If you still need a helping hand then you know where to call

Mark

 

[Audiophilenoob]

Sounds like a good way to test the tweters until you get them refined, For the final decision and implementation there are probably amps that will sound better. Perhaps when the speakers are finished, you could start on a high end DIY amp project without time pressure-you can listen to your QSC while building its replacement. Lots of newbies making amps around here.

sound better???

how so? there doesn't seem to be any difference between the $2000 home amps that I've heard and my proamps...

A tube amplifier solution does interest me though... but from my experience all solid states as long as they're good quality sound the same...

I haven't heard a Class A amp though...

 

[Variac]

I certainly am not going to get into that trap of discussing sound differences between amps but some certainly sound better to me than others. Yes, there is lots of delusion in the audio world but I would suggest trying some high quality amps on your speakers when you are done with them. Some will probably will sound better than others to you.

 

[jacco vermeulen]

FTR: in the stone age a great number of people combined Decca and Technics TH400 ribbon tweeters with class A amplifiers, be it solid state or tube.

The only thing i'd like to discuss is why everytime i see Variac i am thinking grilled piglet, Chinese style, and i start to drool !

 

[Audiophilenoob]

I certainly am not going to get into that trap of discussing sound differences between amps but some certainly sound better to me than others. Yes, there is lots of delusion in the audio world but I would suggest trying some high quality amps on your speakers when you are done with them. Some will probably will sound better than others to you.

I suppose that is true.... amps certainly sound different... but better or not I dunno

I do plan to test some choices out

 

[David Davenport]

Where in NC do you live? There is quite a bit of DIY activity in central NC and even some guys into ribbons that you could discuss your project with.

Dave

 

[Audiophilenoob]

Where in NC do you live? There is quite a bit of DIY activity in central NC and even some guys into ribbons that you could discuss your project with.

Dave

in the fall and spring I'm in Durham

now in the summer I'm in charlotte

 

[David Davenport]

Okay, that is good.

I know a lot of the audio folks in the RTP area but no one in the Charlotte area although I know that there is also quite a bit of activity there and points west. We have meetings in this area from time to time so drop me a note and I'll make sure that you get on the notification list.

Dave