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class a

  1. F

    Inconsistent Vgs when matching output MOSFETs (Class A amp repair)

    Hi all, I’m repairing a Class A MOSFET amplifier with a blown channel. One N-channel output MOSFET was found shorted. Each channel uses three N-channel and three P-channel MOSFETs. I initially replaced the failed device, but when checking the channel with thermal imaging, I noticed that one...
  2. wmac

    Luxman L-560

    Hi, I am restoring a Luxman L560, and I need to find a power switch. Please get in touch with me if you know where to find it. Also, I need to find a service manual
  3. maskof

    Looking for Luxman M-07 service manual and schematics.

    Hello everyone , I found this Luxman set, which includes: LUXMAN M-07: Stereo power amplifier LUXMAN DA-07: D/A converter LUXMAN C-06: Control amplifier However, my concern is that I couldn’t find any manuals for them, especially for the LUXMAN M-07. Does anyone here have the service manual...
  4. mosfets

    Building the John Linsley Hood JLH 1969 Class A audio amplifier

    There is a channel on YouTube called Steve's Trivia by an interesting old fella named Steve Wagner. He did a video series on the JLH 1969 amplifier. I thought to email him and ask for a trade and see if he was interested in making a few videos on the Mike Bitner amplifier called Symasym. Wagner...
  5. Luxman M05/C05 : "Lily was here" - YouTube

    Luxman M05/C05 : "Lily was here" - YouTube

    Luxman M05 & C05 Bowers and Wilkins 801 S1
  6. goldswimmerb

    M-60 Class A Bias Question

    Hey, just a simple question here, is the 110mv +- 10 number given in the SM correct for class A bias on the M-60? I've noticed, of the several I've seen, they always seem to top out around 85-90mv. Hoping someone with a bit more engineering knowledge may be able to weigh in...
  7. H

    4 Transformers in a 2 Channel Amp?

    Does anyone know why a 2 channel amp would have 4 transformers in it rather than just 2 or 1? I'm going to try and attach a screenshot I took from Bedini's webpage that shows the internals of their Dual Mono 100/100. Usually I only ever see 1 or 2 transformers in a 2 Channel amp. I have a...
  8. AlexHempel

    Pioneer M-22; Worth a Repair Attempt?

    Greetings AK denizens, I recently purchased a Pioneer M-22 on Ebay and am in a bit of a quandry. The first few times I flipped the switch it refused to turn on (no LED, no relay clicking, and no output on the terminals). I then plugged the cord into a different outlet and it powered up. In...
  9. RogerMod

    Burning Amp 2018, Fort Mason, CA

    We had a nice turnout this October in San Francisco. Thanks to all the DIYers who brought their work to show off. Thanks to Linear Systems, makers of really low noise FETs and other SS devices, for hosting the event. Here is a link to their site. All the presentations can be seen there. See...
  10. Soun!

    Cool-running Krell - Oxymoron?

    Dear experts: Are there any cool-running natural convection-cooled Krells providing up to 50 W/ch in class-A?;) Let us define "cool-running" at about 45 °C (113 °F) heatsink temperature, which is pretty warm.:rolleyes: Please chime in!:)
  11. destroyerzx1

    Forte or threshold?

    There are a few amps locally for sale but i dont know what the best option is or what is a good price. Which should i pickup ? Or should I wait if the prices are too jacked ? Threshold s150 class a/b $750 Threshold s150 class a $1200 Forte 1a $900 Or a Yamaha b2 for $950
  12. Kreshna

    What is "Pass A30?" Is it genuine?

    I found this monoblock amp on Ebay. The description says "Finished Pass A30 Mos Single-ended Class A Power Amplifier Mono 30W HiFi Amp". So, is that a true DIY version of Pass Labs XA30.5? Or is that just a crappy Chinese amp with the name "Pass" and "A30" slapped in to fool people? As far as I...
  13. J

    Yamaha CA-800 - restoration - few questions

    Hi, I got this Yamaha. Decided to do basically full restoration. Now I read that the two microswitches for ClassA/Normal operation are a weak point and it's a good idea to change them. What exactly do they do? I can see red and orange cable coming from the transformer. Red brings 30V, Orange...
  14. noobist

    Luxman C-02 M-02; quality, classes and heat.

    G'day all, First off, I have chosen my name with care, which gives you an idea of my technical knowledge. I currently have a Luxman C-02 pre-amp (class A) combined with a Rotel RB 971 Mk II (class A/B) poweramp. A while back I was thinking about switching the Rotel for the Luxman M-02 thinking...
  15. davstev

    Considering the Threshold 400A...

    Hi all, I am currently running a Kenwood 700M into a pair of Tannoy 12" Golds, which I am happy with. I've encountered a Threshold 400A, a class A amplifier that I am considering, simply because people seem to rave about it. Somehow, this feels like a big leap to consider. 400A receives huge...
  16. skrodahl

    The BSTRD - Class A Tube Pre and PSU, with Eagle Project Files

    There was a strange little thing that appeared in Danish magazine Ny Elektronik (New Electronics) in 1989. A very simple preamplifier that used two L63 tubes in Class A with no feedback and it operated pretty much badly out of spec. (It was supposed to though, that was the whole angle of the...
  17. destroyerzx1

    need recommendations for "Best" Stereo amp under $2000

    current system: JBL Apollo C51 Emotiva UMC-200 XIANGSHENG 728A HK citation 22 Borrowed emotiva xpa-2 setup is a bit wonky but it goes from my computer to the umc-200 and from there goes into the 728A down to whatever amp is hooked up. I have been tube rolling with the ( feels kinda silly have...
  18. TellMeWhy

    Best power amp for under $250 used?

    Top choices, vintage or otherwise, excelling at low volume clarity and soundstage and able to drive current demanding relatively inefficient speakers (Kef 103.2 Reference, 8 ohm, 86 dB/1m). 60 watts and above preferred. Am planning to use a recapped Marantz 2230 as a pre. Class A? Mosfet? Thanks...
  19. G

    BC Acoustique 80w pure class A...anyone?

    http://www.bc-acoustique.com/en/index.php?page=shop.product_details&flypage=flypage.tpl&product_id=95&category_id=7&option=com_virtuemart&Itemid=40 I searched for it on this website and received....5 hits.... Looking for an amp for my totem forests. Was leaning towards a peachtree nova 220se...
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