45’d the 2a3 Stereomour

ALL212
ALL212 Posts: 1,577
in DIY, Mods & Tweaks
Temptation finally overcame me and I did the 45 mod on the Bottlehead Stereomour. Power is now at or just under 2w class A.

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Aaron
Enabler Extraordinaire
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Comments

  • ZLTFUL
    ZLTFUL Posts: 5,651
    If you need someone to do some A/B testing for you, just box it up and send it my way.
    o:)

    Gorgeous looking piece man.
    "Some people find it easier to be conceited rather than correct."

    "Unwad those panties and have a good time man. We're all here to help each other, no matter how it might appear." DSkip
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  • lightman1
    lightman1 Posts: 10,789
    I'll give it a listen if it winds up at Ryan's.
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  • mhardy6647
    mhardy6647 Posts: 33,894
    edited June 2018
    Nice. 45s are magical -- and prices reflect that magic ;)

    Ever think about -- the 46? ;)

    http://vinylsavor.blogspot.com/2011/05/tube-of-month-46.html

    zenfcjfagkyu.png


    There were globe 46s too -- they're 'spensiver than the ST shaped 46, but cheaper than globe 45s :)

    5 pin sockets required, tho' :p


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  • ALL212
    ALL212 Posts: 1,577
    46's!!?? Really don't want to mess with the sockets. I think I can run the 2a3's back in here but at less power and I need to do more comparison. But...DAMN!!!

    I've built an adapter that allows me to use headphones right off of speaker terminals. I've used it to adjust the hum pots on this amp. With the 2a3's you really couldn't use them to listen to headphones, just a bit too much noise. With the 45's in here the noise is detectable - the background isn't pure black - but the level is so low that it's doable and very pleasant also.

    45's have a bunch of direct replacements that I need to research including globe versions. The ones in the amp are from Brent Jesse and are a matched pair of RCA's - electronically and physically matched. The 45 family is a bit less money than 2a3's - one of my reasons to do this but I could find no articles out there that dis'd the 45's in any way and most mentioned "magic". I likes me some magic! B)

    Speakers are rebuilt Boston Acoustic A60 series I's. Source is Squeezebox Duo running through the modded Music Hall 25.3 DAC.

    The mod involved clipping four resistors out and moving two wires. Took longer to heat up the iron than it did to do the mod.

    I doubt very much I'll be going back to the 2a3's. I'm not sure if I can describe that magic yet but it's there.
    Aaron
    Enabler Extraordinaire
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  • SCompRacer
    SCompRacer Posts: 8,504
    edited June 2018
    I wish I could been there supporting your upgrade... >:):D


    Nice work!
    Salk SoundScape 8's * Audio Research Reference 3 * Bottlehead Eros Phono * Park's Audio Budgie SUT * Krell KSA-250 * Harmonic Technology Pro 9+ * Signature Series Sonore Music Server w/Deux PS * Roon * Gustard R26 DAC / Singxer SU-6 DDC * Heavy Plinth Lenco L75 Idler Drive * AA MG-1 Linear Air Bearing Arm * AT33PTG/II & Denon 103R * Richard Gray 600S * NHT B-12d subs * GIK Acoustic Treatments * Sennheiser HD650 *
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  • mhardy6647
    mhardy6647 Posts: 33,894
    ... just hope you never hear an SE amplifier running the 50 DHT as outputs*.
    Then you'll want to be selling a kidney.

    :|

    ______________
    * I heard Dave Slagle's SE 50 amplifier at a shindig some years back. Still looking into who pays the best for a used, nearly sixty year old kidney...



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  • ALL212
    ALL212 Posts: 1,577
    SCompRacer wrote: »
    I wish I could been there supporting your upgrade... >:):D
    Nice work!

    I did need help on determining which end of the iron is hot. That really pisses me off when I get that wrong!
    Aaron
    Enabler Extraordinaire
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