Couldn't Help myself bought a restored Motorola SET amp from a console

0 Members and 1 Guest are viewing this topic. Read 3723 times.

Thinker1920

Title pretty much says it all :P :) It was $128 + shipping and the person who had it before me completely went over it and replaced the old caps etc.

Only complaint is that it uses 12au7's and I find that some of the mid's sound muffled, but it puzzles me since I play certain songs through it and they absolutley sparkel, so I'm kinda perplexed. the tubes are NOS Jan philips 5814a (12au7), new JJ el84, and NOS 5Y3GT.


Quiet Earth

  • Full Member
  • Posts: 1788
Sounds like fun. Post a picture when you have time.

If the amp was just restored with new capacitors (and new tubes), give it at least a month of normal use before you make any of the nit picky sound quality judgement calls. In other words, you probably should let it burn in before you start swapping tubes, cables, etc.

IMO, there is nothing wrong with the 12AU7 midrange, especially considering you already have the upgraded 5814. There are other 12au7s to consider such as 6189, but I would get at least 300 hours on that amp before changing a thing. Get to know it first and let the new parts run in.

Just enjoy it for now.  :thumb:

Thinker1920

Ok so I found out that the preamp tubes and the power tubes have 50 hours on them, and I thought I'd try something I put rubber bands on the preamp tubes and I could swear that the treble/mids sound better, is this in my head?  Is it possible that it helped? or am I going nuts? :D

Thinker1920

(I tried to post a pic but the page just hangs or gives me weird html code:-()

medium jim

Sounds like the one Cleby rebuilt/sold.  New tubes take time to burn in before they really start to sound their best.  The rubber bands are acting like quasi tube dampers.  I would recommend that you get real dampers.

Jim

MaxCast


Thinker1920

Ok you have to tell me what I messed up b/c I must have spent at least an hour trying to post that :P :-)

JohnR



They loaded to the server fine but the javascript to insert into your post doesn't work with IE any more. There's an update that fixes all of this coming soon, in the meantime, use Chrome, Firefox, Opera, or Safari.

medium jim

Nothing better than beefy iron to make them glow.  Seriously, I don't understand why anyone would ever want SS amplification.  The only thing I would do is to build a nice wood box/trim for it.
Jim

Thinker1920

Not a bad idea  :thumb:

Quiet Earth

  • Full Member
  • Posts: 1788
I love the CD Walkman and the 3 in 1 oil in that picture!  :thumb:    :D

I think I would remove the rubber bands though,,,   but only because I'm cautious that way.  I would have loved to own something like that when I was a young man. And it would be fun to have it now. Nice score!

Thinker1920

 :icon_lol: I have the 3 in 1 since I like to tinker, comes in handy with one of my favorite "toys" an Emerson 1940's fan I bought when I was 9  :D (at an antique store, I'm not that old  :icon_lol:) If I don't oil it, it gets mad but, she's the best fan I've ever owned and think it's probably going to out live me :P

  My audio dream would be to build a clone of my motorola but with 12ax7's instead, build an active crossover and have the 12ax7 version drive the treble and the 12au7 version run the bass. I think that would probably sound amazing  :D

Thinker1920

After some poking around I think the motorola was designed to be used with 12ax7's since I found a sams photofacts that looks identical to mine and it says its suppose to have 12ax7's but I can't find a model number on mine anywhere, any thoughts? is there a way to look at the circuit/resistors/caps to tell if it's suppose to be a 12ax7 or a 12au7?

Zedguy

  • Jr. Member
  • Posts: 26
Thinker1920,

I have the same amp and it does in fact use 12AX7.  You are correct, it is an excellent sounding amp.

TONEPUB

Nothing better than beefy iron to make them glow.  Seriously, I don't understand why anyone would ever want SS amplification.  The only thing I would do is to build a nice wood box/trim for it.
Jim

I love tubes, but I also love good SS, because you don't have to tube roll and deal with all the problems associated with tubes.  Sometimes it's fun, sometimes it's a pain.  Nice to have a great SS system when I don't feel like putting the wear and tear on the tubes.