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Old 27th April 2013, 09:05 PM   #1041
TMM is offline TMM  Australia
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Quote:
Originally Posted by whip View Post
That is true in some cases, but I was being more concerned with electronics, Technology has moved on and what it took to make an amplifier in the old days was large 5 and 10 % tolerance through mounted components ie. resistors, capacitors, ect.
Now days many high tech companies are using surface mount 0% tolerance components which are smaller and only use one side of the circuit board and the other side free for more stuff. That alone reduces costs and improves consistency.
I am not an engineer but I am sure one could tell you many ways that technology has improved and cost less. Not to mention that labor cost in Asia are far less then in North America. Sad as it is most of the Amplifiers are made in Asia , the companies had no choice in order to be price competitive. Designed here and built there and quality controlled here. That is the formula for todays Car Audio. Mostly.
Components are not 0%... in most cases, even in high end gear you will find that resistors are 1% or 5% tolerance and capacitors are 20% tolerance. There is no real need for anything better because we design to not rely on the tolerance of non-linear components (capacitors, inductors) where possible, or use feedback to cancel out the distortion that is unavoidable (e.g. from transistors). Tolerance of linear components will usually just cause the volume of the output to be slightly out (fractions of a dB) and often the manufacturer will use an adjustable pot for passive components that adjust things like DC offset of an amp - so tolerance there doesn't really matter either. If a component doesn't need to be a low tolerance, they will use a higher tolerance component to save $ - for instance it's probably not going to matter if the turn-on delay of an amp is 7 seconds instead of 5 seconds due to the tolerance of a capacitor in the delay circuit, and the ESR of that cap isn't going to affect the sound quality of the amp so they will just use the cheapest nastiest cap that they can *

Surface mount boards are cheaper to manufacture because the boards, components are cheaper to make (cheaper/faster not to drill so many holes in the board, the leads on a through-hole component cost extra, it all adds up!) and surface mount parts can be placed by machine. Through hole requires a human to place the components - Chinese labour is pretty cheap but not cheaper than a surface mount pick and place machine! It's still cheaper to get a Chinese person to operate said pick and place machine than an American though

*Interestingly, it can also be cheaper just to use exactly the same component over and over again on your board (requires less reels of components to be loaded into the pick and place machine) so they might engineer the delay circuit to use the same components that are used in part of the amplifier or something like that, even if they are complete overkill for the job.

Last edited by TMM; 27th April 2013 at 09:20 PM.
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Old 29th April 2013, 10:24 PM   #1042
Tadream is offline Tadream  United States
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Seen plenty of through-hole components machine assembled on factory tours - and then wave-soldered. Most of the difference IS in the lack of need to drill and the surface-mount stuff being cheaper and smaller. Even a few pennies per component add up on mass-produced stuff.
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Old 29th April 2013, 11:00 PM   #1043
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It's not the best comparison, but I purchased a newish class-D Alpine MRX-F30 amplifier about a month ago. A week later, I picked up a Jensen KA3 from the late 1990's for $25. The older Jensen is a class AB and can drive a subwoofer at 1 ohm but otherwise, I cannot hear any difference in sound quality. The Jensen just runs hotter lol. Popping open the unit revealed a standard selection of output transistors (enough for 1-2 ohm operation) mounted to a beefy heatsink. Opamps were of the cheap, nasty 4558 kind.

I've heard that this is a rather nice Jensen, not like one of the nasty poor-quality amplifiers they make now. When I bought it, the unit looked like it had been used in the jungles of Vietnam for a decade but it still works like new haha. The bottom line though is that the new F30 produces the same amount of power while running cooler and more efficiently.
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Old 3rd May 2013, 05:22 PM   #1044
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Default 1986 Kenwood Amps

Simply looking for opinions whether or not I should continue on plans to use two Kenwood amps (KAC-720 and KAC-8020) that I've owned since new and never used (long story) in my '78 VW bus.

So far my expenses are limited to buying the service manuals to give to an electronics guy (cause I am not one - lol) to build new din pin / RCA cords (to run to speakers which have been lost and one new power cord (for the 8020) that was lost.

Given I will have to pay someone to build these (trust me I've been all over then net searching for them and all or discontinued) just in order to install / use them, in your opinion(s) should I continue with the project?

TIA.

wb
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Old 27th June 2013, 12:14 AM   #1045
ppia600 is offline ppia600  United States
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Here is an oldie I just found, REALLY basic amp by pyramid...and made in USA. Pretty dirty and assembled with rivets. I had to drill a few out to see what makes it tick. Looks like the push-pull early design with only two transistors per channel. I still haven't attempted to power it up.

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Old 27th June 2013, 12:16 AM   #1046
Robcrx is offline Robcrx  Canada
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^^ RARE, one of Pyramids first amps ?
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Old 27th June 2013, 12:19 AM   #1047
ppia600 is offline ppia600  United States
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Possibly, maybe before they sold out? I remember having a cheapo amp in the 80's and it used this same design but with more transistors and an actual board. This little amp is pretty heavy with four transformers. It also says "Elite Mobile Sound Devices" on the sides. The bottom slides out of the main heat sink and it and both ends are aluminum. I did a little searching on the company name and the model number but couldn't find anything solid.
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Last edited by ppia600; 27th June 2013 at 12:22 AM.
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Old 21st July 2013, 01:12 AM   #1048
Gioba is offline Gioba  Italy
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Quote:
Originally Posted by Perry Babin View Post
IMO, amps using SMD parts wouldn't be old school.

I don't think made in the USA would be a requirement but most OS amps would have been made in the US. Amps like the Kenwood KAC-1020 and the Alpine 3521 would be OS.

Of course, this is my opinion. It's all relative. I was reading on some forum where they were talking about old school Audiobahn amps.
Mostly old school amps are Made in USA, absolutely.
It isn't a building factor only, but sound's quality, with dynamic thrust and great control of response.
Bass range control has the best..
For sound quality and life's product, american OS is unsurpassed!

Last edited by Gioba; 21st July 2013 at 01:34 AM.
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Old 21st July 2013, 04:53 PM   #1049
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Default LOW distortion

Certain Old amps are desireable because they can give High output @ very low distortion (.05% THD) at rated output.

Most current amps (Yamaha) rate their output power @ 10% Distortion (Music Power). Am I the only one who knows how to convert "Music Power" to RMS?

Clean amps will Always be desireable over 10% Distortion, Multi-amp, abortions!!!


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Old 22nd July 2013, 10:22 PM   #1050
Gioba is offline Gioba  Italy
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Quote:
Originally Posted by regal View Post
For old school amps I really like the Harman Kardons, I have the 40 watter its a CA240 sitting in a closet, just a beautiful heavy design. I swear it has more power than modern 100 watt amps. Anyway am I the only H/K amp-o-phile or are there others out there?
The Otala's sons?
More beautiful amps i ever seen, great construction.
And very musical sound!

I will never sell those.
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