Newbi wants to pick your brain

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Hello, I am new here but wanted to ask everyones opinion on a few things. I have been into audio most of my life. I am looking to get into some higher end equipment. I currently have all Pioneer Elite components and Definitive Technology speakers, the mains being BP8Bs and subs being a PF 1500TL. I actaully really like these speakers but think I could get more out of then with a better amp. I have used a few commercial units, older ones, like an Adcom GFA-2 and Nikko Alpha 130, 220, 230 and even the huge 450. I know these are not anything high end but still fun (and easy) to listen to and pick apart.

While I was shopping for my equipment I ended up making friends with the owner of the store I ended up going with. They also sold some very high end stuff, one being Pass and at the time Genisis speakers. I used to go by on the launch and sit there just listening to that wonderfully delightful combo. From then on I was hooked on Pass amps but knowing it would be a long long time before I could afford them.

I have been looking at the pass DIY site for years now but have not acted on my want for something better. Also my trusty old Nikko 450 has finally past on and I was think about seeing if I could use that case/ heatsinks/ transformer so one of Nelsons wonderful designs. I am looking for something that will work well with my speakers as they are rated by Def Tech at 91db even though I think that is a little high. I listen to a wide range of music but with a nice class A amp I think I would only use it for 2 channel "quality" sit down and loose yourself music. I was thinking I could make a fairly simple relay box that I could use to switch from my receiver for HT and then to this amp for 2 channel duty.

I guess what I am asking is that the wattages are of the different Pass DIY amps, how much wattage they disapate so I can see if the heatsinks in that amp are going to be big enough, cost of biulding and lastly the skill that will be needed. I am an electronics repair tech by trade so the soldering and the like is not an issue, just when it come to custom amp designs I an just learning ( but watch out if I get all figured out;) ).

Any help hear would be great. Sorry to be so basic but hopefully over time I will learn all I can. I will post pics of the parts I am looking to use probably tom. Just wanted to get a head start. I really have an itch to do this.

THanks agian

Rick
 
1. - Sorry, I seened to have missed that page on my many trips through the Pass site. Thanks. Its been a joy reading that info.

2. - After looking on there I think either the Alphe 2 or Alpha 4 are looking like something I am wanting. HereHere is a link to pictures of the amp I am looking to use. DO you think I will have enough heatsink for either one of these.

3. - If I were to go with the Alpha 4 for now, can you and how hard is it to bridge in the future if I ever desided I needed and wanted more power.

4. - Can anyone help me find more info on that tranny. Sure wouldbe nice if I could use it for this project.

Thanks for your help

RICK
 
Maybe in a gale force wind. Check out some of the heat sink makers like Aavid Thermalloy and check their themal resistance/surface area numbers for sinks with simular fin spacing and make a educated guess about their thermal resistance. I would think you could get maybe 50 watts per sink. (That's dissapation, not output)

Better Idea would be mount a few of those aluminum power resistor on a sink, mounted in the chassis and feed them maybe 50 Watts total and see what the final temp is. You want to keep the sinks below 60deg C.


There's a lot of work ahead, but it is very rewarding.

PS it's Aleph

Also read up in this forum. There's a ton of usefull info on the Aleph line of amps. The low part count is what first lured me in, then I read about how great these amps sounded. I believe in all of the philosophy behind them and couldn't care less about my electric bill or the global warming BS.

Enjoy
 
Only that much. WOW. I would have guessed more. The amp was rated at 220w/ch at 8ohms in its past life. I am going to look tom. and see if I can find anything close to that design as to get a better idea as to its thermal resistance.

The power resistor is a good idea. I might have to try that one next weekend.

What got my attention about the Pass amps had everything to do with the huge smile I got when I first heard a pair. I had no idea then that they actually used so few parts. Fancy parts, good specs and the like are all well and good but my ears tell me this is what I want. So let the adventure begin. I am loving all the reading on the forum. Some can be alittle overwelling but I am sure with time I will learn it.

Thanks again and any more thoughts would be great.

Rick
 
Turboegt said:
Only that much. WOW. I would have guessed more. The amp was rated at 220w/ch at 8ohms in its past life.

My guess is that your original amplifier was a fairly efficient class AB amplifier where most of the power was transferred to the load, leaving a small portion to be dissipated as heat, hence the smallish heatsinks. The Aleph is a class A amplifer that is very inefficient. A much smaller portion of the power is transferred to the load and most is dissipated as heat which makes the requirement for much, much larger heatsinks.
 
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Turboegt said:
Only that much. WOW. I would have guessed more. The amp was rated at 220w/ch at 8ohms in its past life. I am going to look tom. and see if I can find anything close to that design as to get a better idea as to its thermal resistance.

The power resistor is a good idea. I might have to try that one next weekend.

What got my attention about the Pass amps had everything to do with the huge smile I got when I first heard a pair. I had no idea then that they actually used so few parts. Fancy parts, good specs and the like are all well and good but my ears tell me this is what I want. So let the adventure begin. I am loving all the reading on the forum. Some can be alittle overwelling but I am sure with time I will learn it.

Thanks again and any more thoughts would be great.

Rick
Turbo,

Have a read through some of these Pass articles (starting from the bottom of the page). It will take you through a 25 year trip that some of us have already experience.
http://passdiy.com/legacy.htm

Have Fun,
 
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