[Bob in St. Louis]

Hey guys!

A fellow forum member and (relatively) local chap loaned me a tube amp to play with for a while. That's all fine and dandy, I'm gradually coming over to "your side" of the fence.

But there's a problem with the amp.

Twice now since he brought it over (Friday) when I turn it on, the left channel tube doesn't glow, and no output from the left speaker. I've swapped output tubes from right to left and still have the same problem.
I've used it everyday, and when it's working, it sounds very good. No signs of any problems.
Trying to let it warm up for 15-30 minutes had no effect. Usually, after turning it on the tubes are glowing after several seconds.
I've not opened it up to see what's going on inside, mainly since I wouldn't be able to diagnose anything other than a visual loose wire. I know of the danger potential with the caps, but am willing to "dig in" and find out what the problem is with some assistance from somebody that knows tube amps.

In case it might be helpful, here's a 6moons article with a few specs on the unit:
http://www.6moons.com/audioreviews/almarro/a205a.html

Any ideas guys? 
Bob

[Bill Baker]

Hello Bob,
 I have had this happen in the past with this unit. Open it up and look at the connections at the tube sockets for both the input tube and the power tube of the effected channel. If you look close, you may find a miss solder joint. Look for a resistors or wire that is connected to the tube socket but no solder.

 Another option to look at is the tube socket itself. There could be a loose connection at the pin of the tube(s). Try taking a small needle or pick and tightening up the small metal sleeves inside the tube socket. Obviously, unplug the amp first.


 These issues were only experienced on some of the older pieces. I have never had any problems with current production pieces so far.

[Bob in St. Louis]

Bill Thank you for the reply.
Should I discharge the caps first, or does it matter?

Bob

[Bill Baker]

Hello Bob,
 The piece you have is one of the original designs. I don't remember if they have resistors on the filter caps to discharge the power supply or not. It wouldn't be a bad idea to go ahead and discharge the caps first if you actually have to perform any soldering.

[Bob in St. Louis]

OK Bill, good deal. I'll give that a try (probably this weekend).
If you guys never hear from me again, I failed at my first attempt draining caps!

Thanks again Bill, I owe you one. 

Bob

p.s. Would it hurt the unit if I continue to use it until it's repaired? Or should I stop all together?

[gooberdude]

Bob, what the hell are you doing?  tubes are gonna lead to nothing more than more satisfaction with your already smitten self.     

we don't want that!  there's not enough Emoticons...


i just bought the modd'd ASL Wave 8 monoblocks from another member, should arrive by Friday.  the SI's drive a person to do such things i think.

its tube time...

your cd just got dropped in the mail today (sorry)...i'm a slow poke at times.

You should link up with some GAS regulars, seems like they know a thing or 2 about tubes   


matt

[Bob in St. Louis]

Yea, I know Matt. I couldn't resist. I've been hearing how good tubes are for quite some time now.
Have had the opportunity to hear tubes at Steve Deckert's place and some of the local GAS guys houses. They all sounded good (of course), but still had this little voice (way back) in my head that was telling me I needed to hear them in MY room with MY toys. Lin, Dennis (Decware member) and I have been trying to get together for several months to have a little "mini get to-gether" at my house. The planets finally lined up the other day. Lin drove a total of SEVEN hours round trip to come to my place to loan me an amp. I thought if a guy is willing to do that, then tubes must truly be something I need to give an honest audition.
....and yes, the GAS guys know a thing or two about tubes.  {understatement of the decade!!}

Thanks for the CD Matt! 

Bob

[Bob in St. Louis]

Well I finally popped the hood with the intention of a repair.
Nothing visually out of the ordinary.

Bill, you said the heater circuit wire. I found what I would assume is that circuit, a large gauge white wire that runs from the left channel socket straight over to the right channel socket. It looked reasonable that it was for a heater since they're no other reason to have a wire connecting two separate channels. Anyway, I liquefied the solder and added a very small amount. Still no go. That wasn't it. It the type of solder used in here something special? I don't want to dilute it with my typical lead solder if I continue on this path.

Thanks Guys
Bob

[Scott F.]

Hey Bob,

If you want to bring it out today (assuming you are free), I'll have one of my pre's up on the workbench trying to get it going again. Since I'll have the soldering iron heated up, we can have a look at the Almarro and see if we can't get it going again.

If you want, give me a buzz, I'm in the book.

[Bob in St. Louis]

Oh Scott, that'd be super SUPER cool.
  But I'm in the middle of cooking a tasty lunch for some company that will be here at noon.  Some of the food's already on the grill, thought I'd check my messages real quick.
It's my Mother and Nephew, they usually don't stay but a couple hours. Maybe this afternoon, after they leave if it's not too late. I personally like to "chill out" for awhile the evening before having to go back to work. Especially after a long weekend. In order to be courteous, I'd assume you're the same way.

Scott, let me know how late you're willing for me to come over. I'd really like to do this, but I don't want to monopolize your last evening before work tomorrow (or mine either).

Thanks Scott, 
Bob

[Jon L]

I also suspect the tube sockets/pins, perhaps a loose pin contact somewhere.  I would just go in and use a thin pin/needle to bring out all the contacts closer to the outside.

Anyway, if you do keep the Almarro (MkI or II), do make sure to try some Russian 6Pi14Pi-EB and Sovtek 12AX7LPS in this thing.  Out of this world. 

[Scott F.]

Oh Scott, that'd be super SUPER cool.

Scott, let me know how late you're willing for me to come over. I'd really like to do this, but I don't want to monopolize your last evening before work tomorrow (or mine either).

No worries 

I'm just down the basement cleaning, reorganizing and doing stuff (piddling). So, nothing major at all. I'll be around all afternoon with the exception of heading out to pick up a new toy    I should be back by 3pm or so.

[Sarmck]

Off topic, but:

OK Scott, I'm curious.  What "new toy" did you get?  Are we gonna' have to wait until the '07 Christmas Bash?

Ron

[Scott F.]

I bit the bullet and bought a new Digital Camera. That old Sony I was using, though good enough to get a number of shots published, just doesn't have the horsepower the new ones have. After doing a bunch of reading, I decided to go for the Canon 30D. One of the big reasons (besides the quality) is that I've got a number of Canon EF, auto focus lenses that I can mount on this body.

I thought about the Rebel XTi but it has a smaller, plastic body. The 30D has some substance to it, it feels like a real camera (actually it reminds me of my old dinosaur TX and EOS 35's).

So the learning curve starts all over again    Should be fun though.

[Sarmck]

Good deal Scott on the 30D.      I have the 35 mm film and a digital version of the early Canon EOS Rebel.  Also have lenses that fit either camera , but the film version of the camera is only collecting dust now.

Have fun with the new purchase and I'll look for MORE shots from you in the gallery now.   

Ron

[Bob in St. Louis]

Jon - Thanks for the suggestion. If I keep the unit, I'll remeber this thread, and that you're the first one to get me started tube rolling! 
Not sure about the "MkI or II"?? 

Scott - About 6:00 now, Mom really stayed late! Too late for us today.  I think the wife has plans on a Sunday in the next week or two. (Plans without me! ) Does that sound good? Regarding you cleaning your basement: Don't throw anything away! I'm sure your "trash" is more useful that a lot of folks "treasure"! 

Thanks again for the offer Scott.
Bob

[Scott F.]

Thanks Ron,

Just sitting here trying to remember how to shoot in fully manual  It's been....like....forever since I've done that....all the way back in my film days.

Oh, I think I gave one of the Gasser's my old 35mm EOS 650 body (I forget who), otherwise it would be gathering dust too. 

Man, this thing has boatload custom settings. WAY more than that little Sony 



Bob,

No problem. After you tinker a bit and if you can't get it up and running, just give me a buzz. I'm home almost all evenings and weekends.

[opnly bafld]

Not sure about the "MkI or II"?? 

It is an original.

[Bob in St. Louis]

Thanks Scott, I got your PM and will let you know when Mommy will let me come out to play. Probably on a weekend if you don't mind.

Lin, thanks for the clarification!
You know Lin, You really blabber a lot.   Your posts are unnecessarily lengthy.
Good to see you again Sir, You haven't been posting much recently. Everything OK?

Bob

[Bob in St. Louis]

Well it's been a few weeks now since Scott sprinkled some of his magic tube dust on the amp. Seems to be working perfectly.
Seems to have been the heater circuit that I mistakenly identified. I was one the big fat white wire (seemed logical, the largest gauge wire being a high amp heater circuit), but Scott had all the fancy tube books with schematics and diagrams. Turned out to be a small gauge twisted pair.

Scott, Thank you very much. 

Bob