AliExpress / eBay JL Hood 1969 Class A Amp

Discussion in 'Power Amps' started by purr1n, Apr 25, 2017.

  1. philipmorgan

    philipmorgan Member of the month

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    > Are the cap values too large to be replaced with the big soup can film caps?

    No
     
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  2. purr1n

    purr1n Finding his inner redneck

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    The issue with big caps is real estate. You can always cut holes in the chassis to make smoke stakes.
     
  3. ohshitgorillas

    ohshitgorillas Almost "Made"

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    I can kinda see what you mean looking at the pictures more closely. If I took the pot out and used my Saga as a preamp, it looks like there might be a little bit of room in the front. I'm sure I'd figure something out in any case. I'll snag one next payday, still sounds like a good time to me
     
  4. Priidik

    Priidik Friend

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    You'd need another chassis for this.
    Given the effort and the potential payoff it's very likely not worth it.
     
  5. Wushuliu

    Wushuliu Acquaintance

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    For the curious, there is also a much smaller Chi-fi JLH-based headphone amplifier, the L1969Phone SE, on ebay for $38 here. $18 without the case. It's what I use (albeit modded). As I am (relatively) new to the headamp side of things and diy-adjacent I can only compare it to a Tangentsoft MINT, to which I find it superior. Less power than the larger amps of course but IIRC from a diyaudio thread, having a single rail power supply minimizes the hum the larger dual rail versions tend to suffer from.

    I may get a Vali 2 or Magni 3 so I can have another reference point.
     
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  6. ohshitgorillas

    ohshitgorillas Almost "Made"

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    Thanks to @dmckean44 I now have a Nobsound version of one of these sitting on my shelf. It's warming up nicely, tracking the heatsink temp with an IR thermometer, it's at about 121F and has been on for about an hour and a half. I think it really hit its stride around 40 minutes. I'm upgrading from a Topping TP60 which was actually surprisingly good imho, but this thing has a meatier sound, or perhaps is just letting the meatiness of the Bifrost Multibit shine through more. I will keep listening and return with impressions once I feel I've really gotten to know the thing. I will say, even with 98 dB speakers, I was a little worried that this thing wouldn't be enough for my TV's relatively low gain digital output, but it's perfectly sufficient to get absurdly loud.
     
  7. ohshitgorillas

    ohshitgorillas Almost "Made"

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    So, in terms of the JLH '69 vs the Topping TP60, I don't think there's a huge amount of difference. They have about the same level of detail retrieval and dynamics, but the JLH definitely has better soundstage/imaging and gives a more solid sense of a performance in the room. I think there also might be a slight veil, but I'm sure that will be reduced with the addition of some film cap bypasses.

    One small concern, are my speakers supposed to make a thump after the thing turns off?
     
  8. crazychile

    crazychile Eastern Iowa's Spiciest Pepper

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    Turn off thump may not be so common these days, but it wasn’t uncommon 30 years ago. Some of the big Adcom and NAD amps did it. As long as it isn’t too loud it isn’t an issue.
     
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  9. ohshitgorillas

    ohshitgorillas Almost "Made"

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    [​IMG]

    Finally got around to putting in two 30uF paper in oil caps, NOS Russian military. They fit really well, although I haven't bothered to mount them in there properly. I also replaced the output wiring.

    Sonically we're still in the first hour of playtime, but it's definitely painting with a finer brush, so to speak. Faster, more precise, more dynamic. Very nice.

    Eventually planning on replacing all the signal wiring with Mogami two-core shielded wire (input) and Neotech solid core or Cardas litz 16 or 18 awg UPOCC. This amp is really nice, I'm really glad I came across this thread.
     
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