I am looking at building an amp for my HT. I have looked and searched this forum and come up with this thread
http://www.diyaudio.com/forums/showthread.php?threadid=1713&highlight=theater
which deals with the 6 channel 300W amp for the aussie site. But I believe it has said "coming soon" for a while. Does anyone know when it will be available? Are there any other solutions that are fairly straight-forward? I am thinking roughly 150wpc and 5-7 channels. I am new at this but have done some DIY in the past and feel comfortable that I can do anything I put my mind to.
Thanks for your help.
Craig Carrigan
http://www.diyaudio.com/forums/showthread.php?threadid=1713&highlight=theater
which deals with the 6 channel 300W amp for the aussie site. But I believe it has said "coming soon" for a while. Does anyone know when it will be available? Are there any other solutions that are fairly straight-forward? I am thinking roughly 150wpc and 5-7 channels. I am new at this but have done some DIY in the past and feel comfortable that I can do anything I put my mind to.
Thanks for your help.
Craig Carrigan
I built the Elliot P3A and was very happy with the amps (and Rod's boards)
I think it is harder to build multiple channels because you have to pay a lot more attention to routing power, signal, ground wiring, and probably more compromises are required. Also, if you are like me the design keeps evolving so if you build 3 amps, you have a progression instead of 3 rebuilds of one amp.
Just food for thought.
For home theater a good class AB amp is the way to go. AKSA is well-recieved around here as well.
Rod's site is here: http://sound.westhost.com/index.html
I have some pages as well on my site.
I think it is harder to build multiple channels because you have to pay a lot more attention to routing power, signal, ground wiring, and probably more compromises are required. Also, if you are like me the design keeps evolving so if you build 3 amps, you have a progression instead of 3 rebuilds of one amp.
Just food for thought.For home theater a good class AB amp is the way to go. AKSA is well-recieved around here as well.
Rod's site is here: http://sound.westhost.com/index.html
I have some pages as well on my site.
For the power level specified (150W/ch), the Elliot 3A may fall a little short. I don't know if you are thinking of making your own boards or not.
If you want to buy a board already made or even that plus a package of parts, you might look at www.marchand.com. The form factor is quite compact which is a plus for HT. You will find a couple of possabilities there.
You could also look at www.sealelectronics.com although in my opinion the size and performance of designs may be overkill for HT, especially for surround channels.
If you want to buy a board already made or even that plus a package of parts, you might look at www.marchand.com. The form factor is quite compact which is a plus for HT. You will find a couple of possabilities there.
You could also look at www.sealelectronics.com although in my opinion the size and performance of designs may be overkill for HT, especially for surround channels.
Does anyone have any knowledge of these two?
http://www.marchandelec.com/pm124.htm
or
http://www.marchandelec.com/pm224.htm
I was thinking maybe two seperate amps with three of these inside each. I hope that came across correctly.
Thanks,
Craig
http://www.marchandelec.com/pm124.htm
or
http://www.marchandelec.com/pm224.htm
I was thinking maybe two seperate amps with three of these inside each. I hope that came across correctly.
Thanks,
Craig
sam9 said:
150W vs 100W is only 3.5dB. Thought I'd mention P3A since a lot of new folks seem to consider 100W the point of departure, when the comparison may be to mass-market "100W" amps.
HT is the one place though that more power /might/ be of value for the stereo pair. I can't see it being necessary for most center/surrounds.
power level
You will find that 150 Watts from a good amplifier will be very loud! If you have reasonably efficient speakers you shouldn't rule out the less powerful amps like the P3A or AKSA. Another alternative is the Leach amp. I have heard the Leach and it can get very loud. My HT setup runs at 40W/ch. and it's more than adequate for an average sized room.
I agree with putting 2 channels per chassis as well. My Leach has 3 channels in the chassis, and entirely too much wiring! There are some redesigns of the leach out there with TO3P devices that require much less wiring. If you do go with more than 2 channels in a single chassis, I recommend using these devices. Good luck,
Austin
You will find that 150 Watts from a good amplifier will be very loud! If you have reasonably efficient speakers you shouldn't rule out the less powerful amps like the P3A or AKSA. Another alternative is the Leach amp. I have heard the Leach and it can get very loud. My HT setup runs at 40W/ch. and it's more than adequate for an average sized room.
I agree with putting 2 channels per chassis as well. My Leach has 3 channels in the chassis, and entirely too much wiring! There are some redesigns of the leach out there with TO3P devices that require much less wiring. If you do go with more than 2 channels in a single chassis, I recommend using these devices. Good luck,
Austin
My speakers are all B&W 600 series with dipole surrounds. I just wanted to make sure and exceed their power handling because currently with 125w marantz monoblocks I don't seem to get the sound I am looking for. Maybe that will help with the suggestions now that you know my setup a bit more. Also my room size is 12' by 24'
Craig
Craig
Hi,
I had the same idea 2 years ago and started building a 9 channel amp
5x Frontleft, FrontRight, Center, RearLeft, RearRight
2x FronteffectLeft, FrontEffect Right
2x Subchannel.
I've used Elektor designs and changed them (you DON'T want to use them as they are). The designs are:
5x IGBT Power Amplifer
2x HEXFET Amplifier
2x IGBT-sub amp (used in 'Active Subwoofer').
Every amp has it's own supply using a toroid, double bridges, and filtering by tnt-audio.com
The IGBT has 60.000µF buffering, the hexfet 30.000µF and the Sub amp 80.000µF for each.
It will be finished at the end of this year (I only need the frames for the cases, the amps are all finished and tested).
Maybe this is something for you???
Grtz, Joris
I had the same idea 2 years ago and started building a 9 channel amp
5x Frontleft, FrontRight, Center, RearLeft, RearRight
2x FronteffectLeft, FrontEffect Right
2x Subchannel.
I've used Elektor designs and changed them (you DON'T want to use them as they are). The designs are:
5x IGBT Power Amplifer
2x HEXFET Amplifier
2x IGBT-sub amp (used in 'Active Subwoofer').
Every amp has it's own supply using a toroid, double bridges, and filtering by tnt-audio.com
The IGBT has 60.000µF buffering, the hexfet 30.000µF and the Sub amp 80.000µF for each.
It will be finished at the end of this year (I only need the frames for the cases, the amps are all finished and tested).
Maybe this is something for you???
Grtz, Joris
I'm actually building 6 1 channel OPTI-MOS's from Seal Electronics
However, I think the cost of doing this is actually higher than just buying a semi-decent receiver, but then again this should sound better.
However, I think the cost of doing this is actually higher than just buying a semi-decent receiver, but then again this should sound better.
[Not sure if this ought to be new thread, but it's related, so here goes....]
I've been considering something similar, except just for 4 surround channels - I already have a decent power amp for front duty. I'd thought about doing it as a two box solution - power supply in one, amps in another. As this would be a first project, and I don't have a means of producing PCBs, I was intending to use a kit based on the LM1875 which would give me around 25W per channel (+-25V supply). I then got a bit more ambitious, and have started considering a similar kit using the TDA7294 (50W, +-30V supply) to give me a bit more juice, and also mute and standby "out of the box".
My main uncertainty is regarding power supply. I'd like to keep the cost down, so sharing a transformer seems the way forward. Here are a few things I'd like to be confirmed/corrected
1: If I run more amps off one transformer, I need a greater VA rating, but would keep the same voltage output. I should be careful to check what the output of the transformer is UNDER LOAD, as that's what it will deliver in the real world - either that, or I need a slightly higher rated transformer. (Suggestions for what VA rating for the above amps would be appreciated).
2: It's best to have seperate Bridge Rectifiers and Capacitors for each channel on the power supply, although this will up the cost a fair bit. Is if feasible to use the same set to power all channels, or will this degrade things too much?
3: Should I worry about speaker protection circuits, as again this will add to the cost.
Thanks all
I've been considering something similar, except just for 4 surround channels - I already have a decent power amp for front duty. I'd thought about doing it as a two box solution - power supply in one, amps in another. As this would be a first project, and I don't have a means of producing PCBs, I was intending to use a kit based on the LM1875 which would give me around 25W per channel (+-25V supply). I then got a bit more ambitious, and have started considering a similar kit using the TDA7294 (50W, +-30V supply) to give me a bit more juice, and also mute and standby "out of the box".
My main uncertainty is regarding power supply. I'd like to keep the cost down, so sharing a transformer seems the way forward. Here are a few things I'd like to be confirmed/corrected
1: If I run more amps off one transformer, I need a greater VA rating, but would keep the same voltage output. I should be careful to check what the output of the transformer is UNDER LOAD, as that's what it will deliver in the real world - either that, or I need a slightly higher rated transformer. (Suggestions for what VA rating for the above amps would be appreciated).
2: It's best to have seperate Bridge Rectifiers and Capacitors for each channel on the power supply, although this will up the cost a fair bit. Is if feasible to use the same set to power all channels, or will this degrade things too much?
3: Should I worry about speaker protection circuits, as again this will add to the cost.
Thanks all
ccarrigan said:
I was actually working on a 6 channel leach amp in a single chassis. I would use two 650VA transformers for this. I put this aside, as with my new Thor TL speakers, I don't need more then 60W per channel. I have a leach amp design that minimizes wiring, if you want the gerber files. I am thinking of getting a board order done in january or febuary, after I finish all of my aleph projects and start on getting a home theater setup going.
Here is a picture of my pcb. Like the P3A (which is great if you need less power), it easily mounts on one heatsink with minimal wiring. It appears to be working now from my testing, and I will soon compare it to a channel of the old design on some measurement equipment. I just have been set back by the ideas of the pass labs designs, making me want to get a good 2 channel setup first with my thor tl speakers, then worry about a ht setup for my other room.
Here is a picture of my leach amp pcb:
More pictures (and hi-rez) at:
http://brian.darg.net/leachamppcb
--
Brian
Attachments
Compare this to my original leach amp wiring as Austin mentioned earlier:
Also, I am getting together a 6 channel PGA2310 digital volume control for the large amp, for when I decide to build it.
I am also working on a version of the leach superamp with integrated devices, should you desire 240W+ power into 8 ohms. I am just building it for driving a subwoofer at 500W+
--
Brian
Also, I am getting together a 6 channel PGA2310 digital volume control for the large amp, for when I decide to build it.
I am also working on a version of the leach superamp with integrated devices, should you desire 240W+ power into 8 ohms. I am just building it for driving a subwoofer at 500W+
--
Brian
Attachments
*doh*
Sorry, guess it was a non-sequiter [sp?] I'd followed the link to your photo album and wandered around.
I liked your Aleph heatsinks and the ones on your 'other amplifers; specifically Jen's looked prett nice too.
After looking at your 2nd picture above I think that heatsink wouldn't work well for my Opti-MOS, although that one looks pretty nice too.
I have a hard time finding good heatsinks mail order, although I admit I've never called a distributor, I'm usually too busy in the day to do that.
The Thor's are gluing now .. I routed out the speaker holes and have the flat wire mounted. Gorilla glue is great stuff!
Sorry, guess it was a non-sequiter [sp?] I'd followed the link to your photo album and wandered around.
I liked your Aleph heatsinks and the ones on your 'other amplifers; specifically Jen's looked prett nice too.
After looking at your 2nd picture above I think that heatsink wouldn't work well for my Opti-MOS, although that one looks pretty nice too.
I have a hard time finding good heatsinks mail order, although I admit I've never called a distributor, I'm usually too busy in the day to do that.
The Thor's are gluing now .. I routed out the speaker holes and have the flat wire mounted. Gorilla glue is great stuff!
jgwinner said:
The heatsinks that I have for my aleph chassis, I picked up surplus from a company north of atlanta. They only had a few. I picked up 8 of them for $24 each. Here is the aavid profile for them. They are all 8" extrusions of this:
http://www.aavidthermalloy.com/bin/exdisp.pl?Pnum=65615&LengthUnits=in&ExLength=8&airflow=57.2
I am thinking of ordering the next heatsinks from mmmetals.com next time, as I can't find anymore large heatsinks. Several people have had good luck with them.
I do like how the chassis has come out so far. I am putting a wooden front on the chassis, matching my speakers.
Good luck with your Thor TL speakers. How are you going to finish them?
--
Brian
By finally getting my A** in gear
I'm routing a radius around the front and back sides, and planning on wrapping a thin Walnut laminate around it. I found 36" and 24", so I'll be using two pieces of 24". This wil make a seam, which I'll locate on the side of the speakers and hide with a trim piece.
That's the plan now anyway. The whole family gets here on Tuesday, I have a bad feeling the finish will be MDF
especially considering that Rockler only had ONE 24x96 sheet of Walnut.- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.