Hello from Arkansas. For some reason beyond my comprehension, the tube bug bit me. I don't know why, all I know is I'm infected. So being the rational person I am, having never touched anything with a vacuum tube, I bought this:
eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices
I figured "it can't be that hard, it's not a lot of money, and if I can't get it to work I guess it's heavy enough to use as a boat anchor". I know it's a mono 10 watt amp but other than that I have no idea about it. I can't even find a schematic for it. I find the LJ2, 3, and 5, but no LJ4. I'm hoping, if I can get this one up and running, to buy another one and get a pair of Fostex full range speakers and have a nice little hifi rig to play my turntable through in the garage. So that said..hi, I'm Joe, I've never touched a tube amp in my life, and can't find a schematic for the one I just bought. Anyone have anywhere I should look?
eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices
I figured "it can't be that hard, it's not a lot of money, and if I can't get it to work I guess it's heavy enough to use as a boat anchor". I know it's a mono 10 watt amp but other than that I have no idea about it. I can't even find a schematic for it. I find the LJ2, 3, and 5, but no LJ4. I'm hoping, if I can get this one up and running, to buy another one and get a pair of Fostex full range speakers and have a nice little hifi rig to play my turntable through in the garage. So that said..hi, I'm Joe, I've never touched a tube amp in my life, and can't find a schematic for the one I just bought. Anyone have anywhere I should look?
Hello from Little Rock (which is just like Arkansas, but with bad traffic). This little guy isn't complicated enough to need a schematic, but can't hurt if you can find one. I'd recommend getting an RCA tube manual (reprints are common) and getting familiar with the type 5Y3 and 6V6 (probably the octal based tubes missing) and the 9 pin dual triodes like type 12AX7 (probably the other missing tubes).
Before firing it up, you'll want to learn about SAFETY, reforming the electrolytic capacitors, and especially SAFETY.
All good fortune, and write with more questions,
Chris
Before firing it up, you'll want to learn about SAFETY, reforming the electrolytic capacitors, and especially SAFETY.
All good fortune, and write with more questions,
Chris
I already had the tube number written down, but will I have to bias the amplifier when I install the power tubes, or should I be ok as long as I get a matched set? I'm going to replace all the caps in it because I've been reading horror stories about them exploding when they get old. Don't feel like making my wife a widow just yet.
Wow. You've got a golden future in spy satellite analysis. I can't see that to save my life. Very impressed!
Thanks,
Chris
Don't even bother reforming caps. They're gonna go eventually so spend the extra $5 and install new ones. Its not a question of "if" they go bad its "when".LOL, I'm just north of you, I know all about the traffic. I was skimming through the RCA manual in the sticky, but it looks to be a bit too old for the tubes in this amp. Still some good info though. I do have experience with some pretty ancient technology, I'm a crew chief on the C-130 and my first bird was a '62 model. I plan on just replacing all the caps in it, just to be on the safe side. Pretty sure I can get those at Radio Shack, right?
You're a Zoomy! Thank you for your service.
First plane I ever rode in was a C130, and it was old in 1968. We AFROTC kids were riding up to Griffiss AFB for the day, hanging in the straps on the sides. Pilot walks back, says he can't get the blankety-blank landing gear down, we're low on fuel, yada yada. He opens a door in the floor, climbs down, there's a sound of banging, he climbs up, we land. Most fun I had in the 60's.
Thanks,
Chris
I can barely find batteries at Radio Shack....
Doubtful....
The usual US suppliers for electronic components are Digi-Key, Mouser, Alllied and Newark. All online, order with a credit card.
You may get lucky and save some coin over at the ApexJr web site depending on what Steve has in stock.
As probably already mentioned, read the sticky here about tube safety practices, like using clip leads on your meter and never using both hands to probe a live amp.
A couple of other things, replace the two prong power cord with a grounded cord, with the ground wire firmly bonded to the chassis, and do a search here for bringing the amp up with a lightbulb in series with the power cord (assuming that you do not have access to a variac).
Doubtful....
The usual US suppliers for electronic components are Digi-Key, Mouser, Alllied and Newark. All online, order with a credit card.
You may get lucky and save some coin over at the ApexJr web site depending on what Steve has in stock.
As probably already mentioned, read the sticky here about tube safety practices, like using clip leads on your meter and never using both hands to probe a live amp.
A couple of other things, replace the two prong power cord with a grounded cord, with the ground wire firmly bonded to the chassis, and do a search here for bringing the amp up with a lightbulb in series with the power cord (assuming that you do not have access to a variac).
Last edited:
There are also mail order houses that specialize in tube amp supplies like AES:
Antique Electronic Supply
Antique Electronic Supply
Tracing out the schematic is a great way to learn. However, there is an article from AudioCraft at the gromme-precision website. It might help with your investigation.
http://www.grommesprecision.com/grommes/assets/pdf/littlejewelreview.PDF
http://www.grommesprecision.com/grommes/assets/pdf/littlejewelreview.PDF
Thank you. The 130 is an old dirty pig of a bird, but I had a lot of good times flying around the world on it. We always managed to "break" in the good party spots too. Newfoundland, Crete, Germany. It's absolutely amazing how those birds just "knew" we wanted to stay for a couple nights or 30. The only truly scary situations I've been in with the 130 is when we lost #4 engine in flight. And I mean lost as in it fell off the freaking wing shortly after exploding. I had to have my seat cushion surgically removed after that. Other than that we took some enemy fire in afghan land, RPG flew across the nose during climb out. Needless to say, the no smoking on the plane rule went right out the window.
I was in the Air Cadets back in mid 70's and got a 500 mi ride to a base (Shilo) and back down south. I remember it being loud and hard on the ears. Didn't get to fly it but got 15 min. at the controls of a DC-3 on a similar trip to a AFB base now closed , but was big in WW II for training. called Rivers. That DC-3 was still complete from WWII with all the vintage equipment for the paratroopers intact. Nice plane to fly compared to the small ones. If you want to see DC-3's in use there is a CBC show on tonight called Arctic Air. Probably on the net too. They have an unlimited life limit on the airframe, but just keep an eye on the wing bolts and replace them per requirements. Anyway a great plane! I think those C-130's will be around for ever too! I had one fly low over my cabin last summer and realized quickly what it was as it was on a search mission for a lost senior. They have their own distinctive sound! I too worked for the USAF up here though.
Fly safe and have fun with that amp! Good one to learn on and should sound nice!
Randy
Fly safe and have fun with that amp! Good one to learn on and should sound nice!
Randy
Once I get this little sucker working, what would be the best way to connect my turntable to it since it's only a mono amp? And what is a decent high efficiency speaker that's not gonna make my wallet cower in fear that will run well on 10 watts? I was looking at the Fostex speakers but when you factor in the cabinet, they're pretty darn pricey.
RCA Y connector. Speakers, maybe used vintage! For 5.1 you would need 5 tube amps of at least 35W ea for decent sound unless you have pricey big efficient speakers . Tubes do appear to produce more power than SS. Dynaco improved clone of mono version of Mark IV might be lowest cost start and easiest to build, but costs would add up. For preamps simple tube line stage would be best for sonics and cost.
What's your budget?
Randy
What's your budget?
Randy
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.