Amplifier Building vs old and used?

[Whitneyville1]

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?

[jason171717]

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?

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?

[weinstro]

Re: Amplifier Building vs old and used?

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.

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.

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.

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

[jason171717]

Re: Amplifier Building vs old and used?

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?

[weinstro]

Re: Amplifier Building vs old and used?

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.

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.

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.

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/

[Sydney]

Re: Amplifier Building vs old and used?

As a reference: my Hafler 220 amps are from the early 80's ( older than some forum members :D ). Used they sell for the same price paid.
I'd also buy a good used amp vs a cheap kit of questionable quality.

[jason171717]

Re: Amplifier Building vs old and used?

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.



I would use it as a preamp (really just switching and control), assuming it has preamp outputs.



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 developed by Marshall Leach, a professor at Georgia Tech. Cloned multiple times on diyaudio. More info here:
http://users.ece.gatech.edu/mleach/lowtim/

As for the lm chip, is that considered a pure 63 w? Or is that like the yamaha ratings?

I am not sure if i can use the rotel as a pre amp i still can not get rid of the electrical type of ticking noise it produces in anything connected to it when my theater/ game computer is running.

I was just putting that chinese website up here for mostly a shot in the dark ;) all web recommendations for canada will be taken much more seriously!

I will have to look into that leach amp some more it seems pretty popular.

[jason171717]

Re: Amplifier Building vs old and used?

As a reference: my Hafler 220 amps are from the early 80's ( older than some forum members :D ). Used they sell for the same price paid.
I'd also buy a good used amp vs a cheap kit of questionable quality.

Im not calling you old or anything but wow ;) ! What do you recommend a good price point is used?

Im going to this vintage amp guy i know, great guy he fixes up old used amps and sells em cheap, so we will see if by tomorrow i am the owner of a new (old) amp

[Whitneyville1]

Re: Amplifier Building vs old and used?

Try browsing Audiogon.com for good used gear. Throw out the high and low prices and you'll see the "median" prices. Harmon Kardon made some excellent separates (man this sounds awful!) last century.

[dst]

Re: Amplifier Building vs old and used?

Check out DIY with Hypex modules, or from Not cheap but amazing. Or look at Class D Audio's modules. Bang for buck: Emotiva.

[Sydney]

Re: Amplifier Building vs old and used?

Im not calling you old or anything but wow ;) ! What do you recommend a good price point is used?

Im going to this vintage amp guy i know, great guy he fixes up old used amps and sells em cheap, so we will see if by tomorrow i am the owner of a new (old) amp

I yam what I yam .
Don't know the used market in your area, Online prices are usually much higher.
There are so many guys who become DJ's or form garage bands ( who later get out of the biz ), that used gear is easily found.
Some people are real good at finding deals: At a bank sale I saw Crown amps going for $200 :eek:.
That vintage guy sounds like a plan ( avoid Flame-Linear )

[djg]

Re: Amplifier Building vs old and used?

This popped up as a related item with your second link.

http://www.kijiji.ca/v-electronics/c...sor/1093467166

[jason171717]

Re: Amplifier Building vs old and used?

I yam what I yam .
Don't know the used market in your area, Online prices are usually much higher.
There are so many guys who become DJ's or form garage bands ( who later get out of the biz ), that used gear is easily found.
Some people are real good at finding deals: At a bank sale I saw Crown amps going for $200 :eek:.
That vintage guy sounds like a plan ( avoid Flame-Linear )

Thanks for the help Syd!

I have found that online prices are usually pretty high compared to used i have found, not including the rotel for free ;)

[Sydney]

Re: Amplifier Building vs old and used?

Yeah ( 15 years ago ) when I first saw amps sold on the internet, I was shocked and dismayed at the prices.

[Æ]

Re: Amplifier Building vs old and used?

So the boards are a pretty large portion of the consideration?

Not really. Many home made amps have little or no circuit boards with only point to point wiring. What matters much more is the component quality and grading/matching.