Stromberg Carlson ASR-120 console amp questions

Discussion in 'Tube Audio' started by avguytx, Mar 27, 2011.

  1. avguytx

    avguytx AK Subscriber Subscriber

    I PM'd a couple of AK'ers on some information about (finally) rejuvenating my little SC ASR-120 amp and have been searching as best I could thru the AK database about what others have done to this amplifier in their rebuilding. Obviously, it's hard to search via the search function for "ASR-120" on the AK site so I have been teaming that up with Google to help out. I've already installed the IEC power connector, nice RCA jacks and banana style speaker jacks on the back and have wired the speaker and RCA connections already. I've got to find a different power switch than what I was originally going to use and I have the fuse holder already, too. I'm going to incorporate the original power light from the console (which is inside and not trashed...don't worry). My buddy got a wild hair and is cleaning up the chassis today and also picked up 4 feet of 1x3 oak for building a nice frame for it. (I'm stuck at home writing 2 papers for college due this week).

    I'll get pictures of what I've done so far and will post them in this thread as I can, too. I'm wanting to know what you guys have done with yours so far. What caps did you replace and what brands do you prefer? What resistors? What extra little touches or upgrades did you do to take it one step further? I used "orange drop" caps on my Magnavox 9304 EL84 amp and will most likely use them again but am open to other options. Any and all information ad/or opinions are appreciated as I value the technical savvy of you tube guys on here.
  2. spaceman

    spaceman Registered Lunatic

    Sounds like the hard part is done, putting in new RCAs & speaker jacks. This is a really easy amp to recap, even for a dummy like me. I got the can from Jim McShane, since I was placing an order already. The other caps you want to replace are on that little circuit board, essentially under the 7199s. I just used Orange Drops, & it sounds fine, but of course there's room to experiment. Just bend up the little tabs that go through the chassis, & carefully turn the board over, to change the components. It takes a little care, so you don't pull any wires loose, LOL, but it's not too bad, once you size it up. :smoke:
  3. fxer1982

    fxer1982 Member

    i have two of them, first one i had my teck go through it, he had it for a month, i ask him is it ok he says oh yea i just like it so much ive been listening to it at . the only thing i did was to buy RCA 7408 gray plate dual bottom getter tubes and rca 7199 pre amp tubes for it. man is it ever sweet too. i just cant say enough about it. i also purchased some never dull. i little elbow grease and man it looks great, polished up the base and the output transformers so well. im waiting on someone that can fit me with wood side and front for it. i have some old 1/4 sawn oak for the wood. i would like to put on a power lite but other than that it is great. just looks a little raw without wood for now but as far working, i dont know if they all will sound this good but wow. when i get the wood sides and front done i will post photos of it.. i run some 15" altec lansing low freq woofers, magnavox mid horns, pioneer high freq horns, using stromberg carlson three way crossovers, in a altec lansing 420 cabinates..the volume and sound is just remarkable to me. been a tube fan sence the 60's and now im living large with this simple low wattage high feilidty amp.. just truely love it and there is no wonder if i could have more volume. it rocks this home and my niebours too. lucky me...good luck with yours.
  4. Jcricket

    Jcricket not someday, but today Subscriber

  5. avguytx

    avguytx AK Subscriber Subscriber

    Well, my buddy was bored this afternoon so he spent some time cleaning the chassis up on the amplifier and man does it look good! I'm not really sure what the green "stuff" is that he used with it but it's sure going nice so far. He even picked up 4 feet worth of 1 x 3" oak for us to make a new base next weekend. Hmmmm....I think he is wanting to hear this amp on a pair of fresly recapped Heresy II's I have here. :D What a good friend....working on an amplifier while I'm stuck at home writing 2 papers today. :thmbsp:

    You can also see the RCA jacks, speaker connections and IEC power plug we installed last night.

    The cleaning tools of choice he said...

    A couple of test areas



    And the finised cleanup. Suhweet...
  6. fxer1982

    fxer1982 Member

    i got better results with the never dull stuff. much better than the wavey look i see on your amp.. but that is my opition .
  7. avguytx

    avguytx AK Subscriber Subscriber

    Do you have any pictures of your handy work? I haven't seen were you've ever posted any of yours so I can't give my opinion.

    He may have used that on there, too. We tried that last night and it wasn't working quite as well in some spots as there was quite a bit of pitting. I had really good luck with Neverdull on my Magnavox amp, though. These are iPhone pictures so they aren't going to be quite the quality of what my actual digital camera would do.
    Last edited: Mar 27, 2011
  8. fxer1982

    fxer1982 Member

    understood the only camera i have works with other computer that is taken apart. any way what i say will aways be truth. weather you care or not, thats not my issue. we all just chim in with opinions on our progress with different products. i was skeptacal at first but i tried it. very easy to use other than some time and pressure at the fingertips, found it to be a great product that does its job with no abravise scratching. some added wiping with a clean white cloth, but it really did a nice job including the large standing cap...i like it..
    Last edited: Mar 28, 2011
  9. avguytx

    avguytx AK Subscriber Subscriber

    After a 20 month break from working on this little Stromberg, I'm back at it again. I figured it was time to try and complete a few projects over the holidays and this one's card was drawn first. I've still got to order 2 more Orange Drop caps for it as I only had 4 of them that I was going to use on the ASR-110 that I ended up selling off. I'm still in the same boat as I was last year; banana jacks, new RCA's, fuse holder, IEC plug, etc, are all mounted but not completely wired. I'm having to get myself back in the mode of finishing up the power section and remember what went where. I printed out the schematic from Tom Bavis' site so I have that as a reference.

    I also will be ordering the replacement caps that are in the multi-cap can, too. I'm going to leave the can there and relocate them under the chassis. Yesterday, we made a base for it out of Oak that will be sanded and stained today. Well, off to tinker for awhile. I'm hoping I don't let the magic Genie out of it while tinkering with the power wiring. :D
  10. gadget73

    gadget73 AK Subscriber Subscriber

    While you're in there, check the values of the resistors. A fair number of the ones in my ASR-433 were off value by enough to make a difference. Most can be measured in circuit with enough accuracy to tell you if its dead or not. Typically resistors drift high, and any part across it will make the value read lower so if it reads higher than marked value + tolerance in circuit, its probably toast.

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