Solid-State Power Amp Adventures

Discussion in 'Power Amps' started by purr1n, Jan 24, 2017.

  1. Sylafari

    Sylafari Acquaintance

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    What I meant by my comment about speaker amplifier prices is sure they might have a bigger box and a few more parts but, the price difference from cheap speaker amplifiers to high end "audiophile" speaker amplifiers differs by literally orders of magnitudes when compared to headphone amplifiers. I also happen to have a BS in Electrical Engineering and although I don't know how everything inside a speaker amplifier vs a headphone amplifier works, I don't see an order of magnitude difference in cost from just a simple look at the circuit board and parts alone of various "audiophile" speaker amplifiers. In fact there are very complex high end headphone amplifiers as well but price discrepancy between them isn't as crazy as I see in speaker amplifiers (was looking into recommendations for just good speaker amplifiers on the internet and I see tons of them in thousands of dollars range to even tens of thousands of dollars, the Schiit Vidar is one of the very few I see that is a good speaker amplifier that costs under $1k).

    As for the speakers, I am going to test the Ascend Acoustics Sierra Luna, KEF Q100s, KEF LS50 (I bought the KEF LS50W and returned it so probably not going to like them again), Amphion One15, and maybe compare them to a few active monitors (JBL 705P, Genelecs). I'll just pick what I like at the end of the day and roll with that.
     
  2. dmckean44

    dmckean44 In a Sherwood S6040CP relationship

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    So basically, 2-channel stereos used to be in every home and were a mass market item. By the early 80s the Japanese completely dominated this market and produced in such quanities that very high end amplifiers by even today's standards could be had for roughly $400-$500 in 1985 dollars. The American companies that carved out a niche and still competed mostly focused on the high end of the market with overbuilt equipment.

    When the market started to bottom out in the early 90s and home theater hit, the American companies still producing amplifiers raised their prices and produced in lower volume. Over time asthetics became more important to their clientele and dollars started getting poured into things like larged milled aluminum chassis, 4 watt resistors, giant film capacitors and toroidal transformers.

    The audiophile press ate it all up and even though budget gear often still gets great reviews they leave it off of all their best of lists (or put it at the bottom) and it gets forgotten about after a year or two. New people coming into the hobby either end up spending a ton of money needlessly, get frustrated and leave or get into the vintage side of the hobby where attitudes are more reasonable.
     
  3. Hrodulf

    Hrodulf Prohibited from acting as an MOT until year 2050

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    In most stereo amps I've seen 60 - 80% of the BOM price goes to chassis/trannies/PSU caps. I'd imagine that in higher tier class-AB transistor matching can become an issue. Overall the BOM will make up around 20 - 30% of retail price in traditional distribution schemes for low volume items. Selling direct can shave a good portion off of that.
     
  4. Priidik

    Priidik MOT: Estelon

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    Speaker guys are richer, and the ceiling thus higher.
    Remember there was the Apex Pinnacle, the Viva amps etc, easily comparable in price to high end speaker amps.
    Don't even look at high end stat amps. Wait another decade, and you'll see hp amps costing 10k+ again.
    It's blasphemy to insert your Focals or Audeze into a Magni. The amp must cost at least as much as the cans!!!

    Ok then, put together BOM for a simple stereo 100W to 8 ohms class A amp.
    Heatsinks alone for such a thing cost (at least 100$ a pop in large quantities) more than most complete headphone amplifier's full BOM.
    It might come as surprise that modern high quality power transistor can be more expensive than audiophool approved opamp.

    What's inside a typical solid state hp amp? Couple of tiny transformers, at best (cheap), low voltage small capacitors (cheap), usually no dedicated heatsinking (no added cost), tiny pcb, handful of tiny transistors or worse a few opamps and a pot.
    Such a thing shouldn't cost more than 500 $.

    Dang, @Hrodulf beat me to it.
     
    Last edited: Dec 8, 2017
  5. Sylafari

    Sylafari Acquaintance

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    I'll agree a simple stereo 100W Class A amplifier would be a bit expensive but isn't it much cheaper if I made it Class AB or even D (still see some Class AB amps or even D go for really expensive amounts of money)? Also it is only a BS in EE, it is not like if you have a BS suddenly you can understand everything about audio amplifier schematics (it is shocking to me a bit how little I actually understand certain things) or cost of parts (didn't realize certain audio parts cost so much, when I was in college mainly dealt with only cheap parts in circuit labs).

    Anyways this is just my first foray into speaker and speaker amplifiers so I was just surprised by the price jump compared to the only thing I knew before which was headphones and headphone amplifiers.
     
  6. Hrodulf

    Hrodulf Prohibited from acting as an MOT until year 2050

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    For higher power designs thermal design for chassis also becomes an issue. 100W class A actually is a lot and for that one needs Krell KSA-100 type heatsinking, where chassis cost + trannies will be positively insane. And for every extra pound your amps gains, logistics costs go up as well.

    Then there's the thing called marketing. For luxury items that also eats up a friggin lot. And don't even try to give me any of that "good stuff sells itself" crap.
     
  7. Priidik

    Priidik MOT: Estelon

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    Class D amps costing more than 2k$ is very wrong indeed, at least compared to honest brute force A and AB amps.
    In class A-B transistor amps, where double or more transistors are needed, matching is preferred, usually mandatory in case of mosfets;
    although one can get away with fewer of those.
    Any sort of extra mile in psu costs dearly in higher power applications.
    Inductors, oversized trafo, extra capacitance, regulation.
    Vidar and the JOB/NuForce seem rather minimal in this part.
    Very generally, as many times it weighs more, the many times it deserves to be more expensive,
    as this usually results directly in sound quality.
     
  8. Metro

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    Very interested in hearing about the Luna, which hasn't been written about much. It had a very small initial production run and just now coming into general availability. It hasn't even been officially launched on their website yet.
    http://forum.ascendacoustics.com/sh...cing-the-Luna-Mini-Monitor!&p=58179#post58179
     
  9. Peter

    Peter New

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    I have the top off my Chi fi amp and took some photos:

    [​IMG]

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    [​IMG]
     
  10. murphythecat

    murphythecat GRU-powered uniformed trumpkin

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    yeah exactly. between 1979 to about 89', the japanese major companies poured huge amount of money into audio R&D. getting a good amp from that era, restauring it, will give you something that blow away any cheap under 2k amp on the market today. in many ways, its as good as SS can get and not far from what pass is doing even today. trick is to find out which amp to buy from the japanese majors. need to look at the schematic, ect.

    j-fet input, mosfet voltage amp and mosfet output stages (lateral mosfet) with overbuilt PSU is not something you can find today under even 3k because it actually cost a lot of money to build. you can buy a 500$ vintage amp, restaure it and get hifidelity.
    at the same time, im just blown away by what a damn lm3875 gaincard with TKD pots can do really.

    all i know is class d is not the answer to my ears. and cheap class a/b either. they sound just very ordinary compared to good SS.
     
    Last edited: Dec 11, 2017
  11. dmckean44

    dmckean44 In a Sherwood S6040CP relationship

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    Some of the better vintage Japanese MOSFET amps have become collectable and demand too much money but some are completely under the radar and cheap. The Sherwood S-6040CP I'm having restored (cleaning, recap, deoxiting the switches, polishing chassis, replacement of the trimmer pots, replacing the speaker relay, replacing the heat sink grease and then adjusting everything to spec.) cost me $40, parts cost were $90 (mostly for the big filter caps) and another $200 labor, so $330 all in. I'm sure it will run great for another 35 years after this.
     
  12. Forza AudioWorks

    Forza AudioWorks MOT: Forza AudioWorks

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    The question is this: how good is it in comparison to the latest stuff in similar price range?
     
  13. msommers

    msommers High on Epipens

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    A comparison between the latest M-22 et al. vs Pass Labs First Watt or older Aleph stuff would be cool, since they're all roughly in a similar price bracket. I'd love to hear more SS but having had class A for the last while, it's made really cautious of trying anything SS that isn't also Class A. Don't think I could go back...

    Having to use a high quality transformer is an additional expense for some of these things. But for that Sherwood at $330, that seems worth playing around with!
     
  14. Forza AudioWorks

    Forza AudioWorks MOT: Forza AudioWorks

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    I can only say that FirstWatt F7 is stupidly, mind-bendingly good for the price. This is a rare example of not quantity but quality watts and as such is realistically the only thing I need when easy loads arrive to my place. It was able to satisfy my needs to a point where I'm not in search of something similar, I gave up on tubed stereo power amps a good while ago because of this machine. Beautiful amplifier.

    If there's no need to go after lots of watts, I'd stick to what Papa Pass does. Though I have to say that $330 for vintage 100WPC looks good, I probably wouldn't say 'no' to that, but at the same time I'd be cautiously optimistic about the whole thing. Vintage stuff is, err, vintage. One never knows, right?
     
  15. murphythecat

    murphythecat GRU-powered uniformed trumpkin

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    lol, a sony ta 707 restaured will destroy any 500$ amp of today thats for sure! hell, id put it against a 5k luxman or 10k accuphase. i should do this soon btw as im just too curious

    amps are no some esoteric stuff, the tube amp and SS done well (ie: no compromises) in the 80's is still pretty much what we know about amplification. in the under 3k market today, its all very compromised design that you will find today apart from some very boutique stuff that are actually doing something hifi.

    dac and to some extent speaker desing have done a good leap forward since then, but not amps.
     
  16. Metro

    Metro Friend

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    Where do you go for this type of service?
     
  17. msommers

    msommers High on Epipens

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    My thoughts exactly. It'd be nice to be wrong here!...but would more of a pleasant surprise than anything.
     
  18. Forza AudioWorks

    Forza AudioWorks MOT: Forza AudioWorks

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    Fair points, yet when I see Goldmund's god tier (apologies, I couldn't help it) circuitry inside of a $499 deck, I somehow doubt that. So let's make it 'any' without this one example of fine engineering and we're good :eek:

    Fair enough:D?
     
  19. Forza AudioWorks

    Forza AudioWorks MOT: Forza AudioWorks

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    ...and inner minimalist in me likes the looks of new stuff more, but for several hundred bucks one can't have everything.
     
  20. dmckean44

    dmckean44 In a Sherwood S6040CP relationship

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    Even completely unrestored it sounded better than most things under $2k. It simply costs a lot in 2017 to make a giant 35lb dual transformer MOSFET amplifier.

    I found another hobbyist that was local to me that restores his own stuff on Audiokarma, I asked him where to go locally and he offered to do it.
     

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