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  • weinstro
    replied
    Re: Amplifier Building vs old and used?

    Originally posted by jason171717 View Post
    I was worried that the rotel seemed high at $400.

    As for the speakers they are built of some pretty high efficiency parts by myself, i cannot remember the exact 1w/1m eff but iirc it was 103db
    I don't have statistical knowledge of the market for Rotels, but it just seems high and for $400 there are a lot of other interesting amps to consider.

    Your speaker is probably a good deal less than 103 dB sensitivity, but even if it's 93 dB you can probably get plenty loud with 68 watts - which is the power rating for a properly built LM3886 chip amp.

    Originally posted by jason171717 View Post
    Could I use my rotel ra1312 for spare parts
    I would use it as a preamp (really just switching and control), assuming it has preamp outputs.

    Originally posted by jason171717 View Post
    That link is off a chinese site self found....
    Sigh. Too many things out of your control for my liking. Unless this vendor and design have strong recommendations from users you trust, you would have to worry about counterfeit devices, device matching, equivalent beta/Ids ratings to original design, quality of pcb routing, etc.

    Originally posted by jason171717 View Post
    What is a leach amp?
    Originally developed by Marshall Leach, a professor at Georgia Tech. Cloned multiple times on diyaudio. More info here:
    http://users.ece.gatech.edu/mleach/lowtim/

    Leave a comment:


  • jason171717
    replied
    Re: Amplifier Building vs old and used?

    Originally posted by weinstro View Post
    The Rotel RB-1070 is a solid amp, but $400 seems high.



    The major costs for any home built amplifier will be the power transformer, case, heatsink, and then the actual components and boards. These can quickly exceed your budget. One approach might be kits based on LM3886 chip amps (if your speakers really are 103 dB sensitive, this may be the way to go). Another approach is to use a SMPS - there's a +- 53 Vdc supply available from PE for $20. A third approach is to buy a dead amp (Rotel?) and scavenge the expensive parts. You can buy a dead Hafler DH-200 for $60 often.



    Yes, absolutely. However, it is a system and the power supply and grounding play a role, too.



    Maybe. I'm assuming this is something that originated from diyaudio, but what's the origin of the kit? Is it from the original author or is this a no-name knock off? Are there a bunch of folks that have built it already? At least the output devices are still available from Mouser, Digi-key.

    Another rec would be to build a Leach amp.

    Regards,

    Rob
    I was worried that the rotel seemed high at $400.

    As for the speakers they are built of some pretty high efficiency parts by myself, i cannot remember the exact 1w/1m eff but iirc it was 103db

    I could use my rotel ra1312 for spare parts?

    Its good to know that you need all good quality parts, which i can see the system can only be as quite as its noisiest link ;)

    That link is off a chinese site self found :P i have purchased knock off shoes and clothing from there and one set of real beater ear buds that sounded like they were priced! Other than that nothing really pointed there.

    What is a leach amp?

    Leave a comment:


  • weinstro
    replied
    Re: Amplifier Building vs old and used?

    Originally posted by jason171717 View Post
    I was also looking at this but not sure if it would be worth the extra $ http://www.kijiji.ca/v-electronics/o...ationFlag=true
    The Rotel RB-1070 is a solid amp, but $400 seems high.

    Originally posted by jason171717 View Post
    I have also been looking at for a while now building my own amplifier, my main question is has anyone done it and can it be done for cheaper or better quality around this price range for what is being offered in the above ad.
    The major costs for any home built amplifier will be the power transformer, case, heatsink, and then the actual components and boards. These can quickly exceed your budget. One approach might be kits based on LM3886 chip amps (if your speakers really are 103 dB sensitive, this may be the way to go). Another approach is to use a SMPS - there's a +- 53 Vdc supply available from PE for $20. A third approach is to buy a dead amp (Rotel?) and scavenge the expensive parts. You can buy a dead Hafler DH-200 for $60 often.

    Originally posted by jason171717 View Post
    Do the circuit boards in the power amplifier make a difference in the sound, or is it mostly the transformers? I am pretty new to all of this amplifier building but my research continues
    Yes, absolutely. However, it is a system and the power supply and grounding play a role, too.

    Originally posted by jason171717 View Post
    Would i be safe to buy a cheap board like http://www.aliexpress.com/item/Assem...723120945.html or should i look up the schematics for a good design and make it from scratch?*
    Maybe. I'm assuming this is something that originated from diyaudio, but what's the origin of the kit? Is it from the original author or is this a no-name knock off? Are there a bunch of folks that have built it already? At least the output devices are still available from Mouser, Digi-key.

    Another rec would be to build a Leach amp.

    Regards,

    Rob

    Leave a comment:


  • jason171717
    replied
    Re: Amplifier Building vs old and used?

    Originally posted by Whitneyville1 View Post
    Jason, for the power level you're wanting, I can recommend excellent kit amps from ~$350 to $5000+, the latter being hybrid tube/IC/MONSTER direct coupled tube output amps that are Class A, and sound like they're worth 5 times as much. We all have limits.
    Building a kit amp (like building a good speaker) may not save much money, and can even cost more than an off-the-shelf unit. You decide you want better caps in the power supply, and in the signal path, etc. These are all valid, but add $$$. Russian silver in PCB oil boot-leg audio caps are supposed to "the best" from the guys over on the Vinyl Engine. At a few hundred bucks a piece, they may be.
    I can build a skinny-block 350 Chebby @300HP for $3 grand or $15 grand. The $3 grand will shove your pick-up around for 300,000 miles if you take care of it. The $15,000 will shove your jet drag boat around the lake for a couple of seasons if you stay easy on the nitrous (under 300HP shot above 4000 RPM ONLY!!!). What do you want?
    I guess it is a labor of love :P "kinny-block 350 Chebby" did you mean chevy? But on a more serious note i understand your point and where you are coming from i will save up do my research and when the time comes I would like to build, but for now i will buy a quality used.

    Where do you find these kit amps?

    Leave a comment:


  • Whitneyville1
    replied
    Re: Amplifier Building vs old and used?

    Jason, for the power level you're wanting, I can recommend excellent kit amps from ~$350 to $5000+, the latter being hybrid tube/IC/MONSTER direct coupled tube output amps that are Class A, and sound like they're worth 5 times as much. We all have limits.
    Building a kit amp (like building a good speaker) may not save much money, and can even cost more than an off-the-shelf unit. You decide you want better caps in the power supply, and in the signal path, etc. These are all valid, but add $$$. Russian silver in PCB oil boot-leg audio caps are supposed to "the best" from the guys over on the Vinyl Engine. At a few hundred bucks a piece, they may be.
    I can build a skinny-block 350 Chebby @300HP for $3 grand or $15 grand. The $3 grand will shove your pick-up around for 300,000 miles if you take care of it. The $15,000 will shove your jet drag boat around the lake for a couple of seasons if you stay easy on the nitrous (under 300HP shot above 4000 RPM ONLY!!!). What do you want?

    Leave a comment:


  • jason171717
    replied
    Re: Amplifier Building vs old and used?

    Originally posted by donradick View Post
    A corollary from my original post is:

    You can spend $100-200 and build some nice Class D or even Class A/B amps, and have a lot of
    fun (and some frustration in my case) but in my mind, if
    I'm thinking about spending $350-450 to build a high-end amp, it makes much more sense
    to buy an Emotiva or some other "very stout" amp and be done with it.

    I think you are one the right path with the kijiji link - here in the US, lots of us watch Craigslist for
    similar audio bargains. You just have to know the device reputation, and the expected used price range.

    Hope this helps,
    Thanks for the help. Can you even get emotiva for $400?

    I still have to do some more research to find what the price range is but i am pretty sure, from what i have seen, this is a good deal.

    Leave a comment:


  • jason171717
    replied
    Re: Amplifier Building vs old and used?

    Originally posted by fatmarley View Post
    Hifiwigwam is a good forum.

    Not sure if you can get Cambridge Audio where you are but if you can I think the new amplifiers are excellent value for money. I have a Topaz AM1 that I bought because I blew a channel on my old Onix OA21 (Nice little British 80s amp) and I think it sounds great for the money.
    Yea we get cambridge amps up here none so far on kijiji. Do you know if this is the cap i have to change to fix the emi leak in my old rotel? Click image for larger version

Name:	ImageUploadedByTapatalk1438979924.969483.jpg
Views:	1
Size:	285.3 KB
ID:	1167813

    Leave a comment:


  • donradick
    replied
    Re: Amplifier Building vs old and used?

    Originally posted by jason171717 View Post
    All of these things to consider buying is looking more my speed, for now :P
    A corollary from my original post is:

    You can spend $100-200 and build some nice Class D or even Class A/B amps, and have a lot of
    fun (and some frustration in my case) but in my mind, if
    I'm thinking about spending $350-450 to build a high-end amp, it makes much more sense
    to buy an Emotiva or some other "very stout" amp and be done with it.

    I think you are one the right path with the kijiji link - here in the US, lots of us watch Craigslist for
    similar audio bargains. You just have to know the device reputation, and the expected used price range.

    Hope this helps,

    Leave a comment:


  • fatmarley
    replied
    Re: Amplifier Building vs old and used?

    Originally posted by jason171717 View Post
    I will find and ask on a hifi forum as well but so far some good info is coming up here, any forums you recommend including pinkfishmedia.

    I am a little more limited in my choices for now in this part of the world :P

    I will watch for an NAD silverline s300 as well thanks.
    Hifiwigwam is a good forum.

    Not sure if you can get Cambridge Audio where you are but if you can I think the new amplifiers are excellent value for money. I have a Topaz AM1 that I bought because I blew a channel on my old Onix OA21 (Nice little British 80s amp) and I think it sounds great for the money.

    Leave a comment:


  • jason171717
    replied
    Re: Amplifier Building vs old and used?

    Originally posted by Sydney View Post
    Jason: Craig is an EE and as you stated:

    Just something to consider
    All of these things to consider buying is looking more my speed, for now :P

    Leave a comment:


  • Sydney
    replied
    Re: Amplifier Building vs old and used?

    Jason: Craig is an EE and as you stated:
    I am pretty new to all of this amplifier building
    Just something to consider

    Leave a comment:


  • jason171717
    replied
    Re: Amplifier Building vs old and used?

    Originally posted by PWR RYD View Post
    I've built lots of amplifiers. Class A, AB, D, tubes, chips, descrete transistors, etc. I always build them because I find it fun and rewarding. But I don't build them to save money ;)
    I see :P well be in touch when its time to build !

    Leave a comment:


  • PWR RYD
    replied
    Re: Amplifier Building vs old and used?

    I've built lots of amplifiers. Class A, AB, D, tubes, chips, descrete transistors, etc. I always build them because I find it fun and rewarding. But I don't build them to save money ;)

    Leave a comment:


  • jason171717
    replied
    Re: Amplifier Building vs old and used?

    Originally posted by donradick View Post
    Man, those Rotels look nice!
    I'd buy the complete setup for $200, you'll need or want it sooner or later.

    You can build your own amps, but it's going to cost you a lot more than it seems at first.
    You can Google these if you wish:
    You can get an Abletec SMPS (500 W or so) here at PE for $20, and 2 IRS2092 LJM boards
    (300 W each into 4 ohms) for about $25 each. So that's about $70 so far - but the case,
    switches, connectors, wire, will run you at least $100. So now you're looking at about $200 or
    more for a nice Class D powerful, clean amp.
    The DIY Gainclone LM3886 amps have a similar cost basis, but sound very good.
    Trouble is, many people will say that they prefer Class A/B or even Class A amps.

    I used to think that all amps sounded the same, but actually they really sound different.

    So I'd buy that 60 W/ch Rotel setup, and I'd suggest looking at Ebay (or equivalent) for
    a used Adcom GFA 535 or 565 (IIRC). Lots of people love their Class A/B sound.

    Hope this helps.
    As for the rotels i think i will jump on them, the soonest i can go hear them is next week, sellers orders ;) , so i will post up here how it goes!

    All of your info on building amps is going to help a lot, thanks. I think ypu are right i will buy these rotels for the time being and then do some more research and look into building an amp.

    Leave a comment:


  • jason171717
    replied
    Re: Amplifier Building vs old and used?

    Originally posted by fatmarley View Post
    If I were you I'd ask on a hifi forum.

    Over in this part of the world, old JVC amps are starting to get popular - LINK

    Iirc the Nad Silverline S300 is class A and sounds great.
    I will find and ask on a hifi forum as well but so far some good info is coming up here, any forums you recommend including pinkfishmedia.

    I am a little more limited in my choices for now in this part of the world :P

    I will watch for an NAD silverline s300 as well thanks.

    Leave a comment:

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