Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: dynaman1 on February 11, 2011, 12:07:34 pm
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Yeah, I know there are other DIY forums better suited for this inquiry but I was wondering if anyone is privy to a simple stereo amp design for use with an iPod? I'm looking for something that's relatively simple and can be hand-wired, as opposed to just using the common PCB-based Velleman or Dynaco kit stuff. It doesn't need to have stellar audiophile performance. It's just going to be used as a "shop" stereo. My only requirements are that it use common and readily available tubes, have sufficient gain to be driven by an iPod and possibly gain controls. I'd imagine anything from 5-20W would suffice. Whether it be SE or PP, I'd like to use EL84s or the usual octals in the output.
Any recommendations??
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These were built around the little 6s4 power tube.
http://www.the-planet.org/6S4.html
http://boozhoundlabs.com/6s4hifi/
(http://www.the-planet.org/images/6S4_front.jpg)
(http://www.the-planet.org/images/6S4_final.jpg)
(http://www.the-planet.org/images/6S4_bottom.jpg)
(http://boozhoundlabs.com/images/6s4hifi/6s4-amp.jpg)
(http://boozhoundlabs.com/images/6s4hifi/guts.jpg)
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http://www.schematicsunlimited.com/
have fun! :smiley:
this eico HF20 looks interesting - 12AU7 tubes cost much less than NOS 12AX7 - 6L6GB are still available for respectable $$, and if not in your price range, then the russian mil. 6p3s-e coin base (5881 equiv) are plentiful and for around $6-8 ea. are a bargain.
it's ultralinear and cathode biased. looks like the PT for a super or a bassman would work well for 2 channels - buy it from doug.
:smiley:
--ISO
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http://www.schematicsunlimited.com/
have fun! :smiley:
6L6GB are still available for respectable $$, and if not in your price range, then the russian mil. 6p3s-e coin base (5881 equiv) are plentiful and for around $6-8 ea. are a bargain.
--ISO
6BG6B's are still cheap and are basicaly a 6L6 with a plate cap
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http://www.schematicsunlimited.com/
have fun! :smiley:
6L6GB are still available for respectable $$, and if not in your price range, then the russian mil. 6p3s-e coin base (5881 equiv) are plentiful and for around $6-8 ea. are a bargain.
--ISO
6BG6B's are still cheap and are basicaly a 6L6 with a plate cap
yup - buttery built an amp with those things. i was in on the design, but bailed when the pre-amp became problematic and we discovered the output tubes "sing" under high volume. i turned mine ito a trainwreck with reverb - it ended up being a trainwreck - it was built into a combo. i use it for just for the speaker now. someday i'm going overhaul it into something worthwhile... someday... :undecided: IIRC macintosh used them in one of their early designs.
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Old jukebox amps can be fun to gut and mod into ipod players. My profile pic is one that I did a couple of years ago. Started gutting another one last week. Sometimes they can be had at reasonable prices on ebay. I bought a stack of stereo and mono chassis from a nice old retired jukebox service guy. You get to start with the chassis, transformers and any other parts you can salvage. I usually strip them back to the transformers and start there. Sometimes I can save the tube sockets. Ipods happily play with only one gain stage.
66merc
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6BG6 = the suck
They might be OK in a tame amp but if you overdrive their grids, the bottles sing. This can created a gnarly sound quite similar to a ring modulator. I had super disappointing results. Furthermore, plate caps look cool but are inherently dangerous.
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Thanks for the tips. My eyeballs are burning from skimming schematics but I think I'm gonna start gathering parts for this circuit found at Angela. I've found lots of good feedback about this amp.
http://angela.com/stereosingle-endedel34hi-fiamplifier.aspx