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Hoffman Amps Forum image Author Topic: Stromberg and Carlson ASR-120 - Replacement transformers?  (Read 35424 times)

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Offline txtune

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #100 on: November 07, 2020, 06:11:28 pm »
That's progress.   :thumbsup:

Thanks! It's not pretty.

Offline txtune

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #101 on: November 12, 2020, 06:25:03 pm »
to windy to fly so sketched up a cleaner schematic (CHECK for errors, edit in .sch :)


EDIT missed a resistor  :BangHead:
AND bypass cap
_2 should be correct

Shooter - Coming back around to this. While I still do not fully grasp all of the diagrammatic symbols, I am starting to make some basic sense of it. Starting with the cropped portion of your 'Stromboli' diagram, see attached

I am following power coming in from the wall plug, through the fuse and switch, then it goes through a transformer (I assume the power transformer) and I see the the resistors labeled R58 R459 (I think this is R59) R60 ... in between those resistors are lines with (I assume) voltage labeled 320 300 275 which run down to A B C caps labeled C62 (I think these are C52A B and C from the original schematic)

What happened to C52D? The 50u 25V cap in your schematic? Is it no longer necessary in the new configuration?

What would change for the new JJ cap that I am going to use? 


Offline shooter

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #102 on: November 12, 2020, 06:48:12 pm »
The JJ is a 40 20 20 20
so the 40 become "A", 20 becomes B, 20 becomes C
the "last" 20, i'd leave in case you get a little hum, that cap can be paralleled with A,B, or C to maybe knock down possible hum




Use your "kit's" caps for the PA cathodes, i didn't look at schematic, guessing 1 for each side, so use 2 equal value.
Went Class C for efficiency

Offline txtune

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #103 on: November 12, 2020, 07:01:03 pm »
Ok, I just poured over the photos I have taken and the schematics, side by side, focusing on the connections between the can cap, rectifier tube, power transformer, and all the resistors in that mix... it started making some sense.

When the JJ cap arrives I will keep you posted as it goes together.

Thanks again!



Offline Joel in Texas

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #104 on: November 12, 2020, 07:06:03 pm »
See also Post #61 in the other thread:

"...if you decide to use the JJ cap, note that it has four capacitor sections: 40uf, 20uf, 20uf, and 20uf, all at 500v, right? 

You need three high-voltage caps, with the original being specified as 40uf 450v, 30uf 350v, 15uf 350v. 

There is also a 50uf 25v cap specified on the schematic and parts list - that could be replaced with the Nichicon 47uf 100v mentioned above (from your kit).   

So my recommendation would be to use your new JJ cap in the following way to best meet the need: wire up two of the 20uf sections in parallel. 

This will make your JJ cap have 40uf at 500v (to replace C52A, 40uf 450v on the schematic in the parts list), 20+20 = 40uf at 500v (to replace C52B, 30uf at 350v on the schematic in the parts list), and 20uf at 500v (to replace C52C, 15uf at 350v on the schematic in the parts list).  This will meet or exceed all of the specs of the original power supply filter caps in the can.  Finally, to replace C52D from the parts list, you can use that small Nichicon 47uf 100v, that came in your kit.  That can be handled separately; we can come back to it later.

There are other ways to proceed, but this is my advice right now anyway."

Here is the same recommendation again, in list form:
C52A was originally in the parts list as 40uf 450v --> replace it with 40uf 500v in the JJ can
C52B was originally in the parts list as 30uf at 350v --> replace it with 20+20 wired parallel for 40uf at 500v in the JJ can
C52C was originally in the parts list as 15uf at 350v --> replace it with 20uf in the JJ can
C52D was originally in the parts list as 50uf at 50v --> replace it with that small Nichicon from your kit, 47uf at 100v

If you choose to follow this advice of wiring two of the 20uf can cap sections in parallel, let us know.  We'll tell you how when it arrives and you tell us the letter codes on the terminals.  It only requires a wire connection in the right place.

Offline txtune

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #105 on: November 12, 2020, 07:11:16 pm »
We'll tell you how when it arrives and you tell us the letter codes on the terminals.  It only requires a wire connection in the right place.

Thanks. I just checked the tracking and it still shows postage was printed on the 9th, but it's not in USPS system yet. It was late on Monday when I ordered, plus they were closed on Wed. I bet it gets here next Monday or Tuesday. I will keep this post going with updates when it arrives. Thx

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #106 on: November 13, 2020, 10:54:37 pm »
I did manage to get this old cap can apart and cleaned out, without destroying it completely.

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #107 on: November 16, 2020, 08:09:31 pm »
I enlarged the opening in the chassis where the old cap can was, the JJ is ready to go in. I hope to work on it tomorrow during the day... but that always depends on my regular work load (the kind that pays the bills).

Looking back over both suggestions, from Shooter and Joel, I have a few questions.   

The JJ is a 40 20 20 20
so the 40 become "A", 20 becomes B, 20 becomes C
the "last" 20, i'd leave in case you get a little hum, that cap can be paralleled with A,B, or C to maybe knock down possible hum

This would give me the following, correct?
C52A - 40uf at 500v in the (JJ can)
C52B - 20uf at 500v in the (JJ can)
C52C - 20uf at 500v in the (JJ can)
C52D - Save in case needed

Can I parallel the "last" 20 with any of the taps? Or just with one of the other two 20s?


C52A was originally in the parts list as 40uf 450v --> replace it with 40uf 500v in the JJ can
C52B was originally in the parts list as 30uf at 350v --> replace it with 20+20 wired parallel for 40uf at 500v in the JJ can
C52C was originally in the parts list as 15uf at 350v --> replace it with 20uf in the JJ can
C52D was originally in the parts list as 50uf at 50v --> replace it with that small Nichicon from your kit, 47uf at 100v

Would this give me the following?
C52A - 40uf at 500v in the (JJ can)
C52B - 40uf at 500v in the (JJ can)
C52C - 20uf at 500v in the (JJ can)
C52D - 47uf at 100v (Nichicon)

Shooter and Joel, I really appreciate you guys helping out, and Sluckey too!



Offline txtune

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #108 on: November 17, 2020, 09:26:20 am »
Before I go any further I have a question about grounding this cap. The old can had tabs on it that were soldered to the chassis. This one is setup a little different. Should I run a wire between the chassis ground and the negative? Or from the chassis ground to an empty terminal strip tab, then connect the cap ground to that, as well as anything else that needs a ground connection?

Offline sluckey

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #109 on: November 17, 2020, 09:42:45 am »
Connect the red/yellow wire from the PT to the cap can negative terminal. Also connect the negative terminal to chassis ground using a short wire with a ring lug. Secure the ring lug to chassis using one of the cap bracket screws.

It's OK to rotate the cap for a more convenient connection of the wires and components if needed. Looks like that big resistor was originally connected to one of the cap can mounting lugs, but it can connect to any chassis ground if more convenient. Or just connect it to the new can negative terminal along with the two wires installed above.
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #110 on: November 17, 2020, 10:23:28 am »
Quote
Would this give me the following?
:thumbsup:

Went Class C for efficiency

Offline txtune

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #111 on: November 17, 2020, 12:25:43 pm »
Connect the...

How does this look before I solder it?

Also, the resistor you were talking about is the 150ohm 10W, correct? Would the new resistor (pictured below) be a suitable replacement?

Thanks

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #112 on: November 17, 2020, 12:47:43 pm »
Get rid of those loops on the green wire. Probably only needs to be about 1" to 1.5" long. Also use a kep nut or at least a star lock washer. That green wire needs a really secure connection to the chassis.

The resistor is the same. Probably nothing wrong with the original. I'd probably just solder an extension lead onto the original. You might even consider another ring lug for the resistor, rather than soldering it directly to the cap negative terminal. Flip a coin.
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #113 on: November 17, 2020, 01:13:36 pm »
Get rid of those loops on the green wire. Probably only needs to be about 1" to 1.5" long. Also use a kep nut or at least a star lock washer. That green wire needs a really secure connection to the chassis.

The resistor is the same. Probably nothing wrong with the original. I'd probably just solder an extension lead onto the original. You might even consider another ring lug for the resistor, rather than soldering it directly to the cap negative terminal. Flip a coin.

I will get a k-nut and shorten the green wire.

Could I solder the green wire on that lug, then run the green back to an empty on the terminal strip? If so, I could land the resistor and the black/yellow on the terminal strip as well.

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #114 on: November 17, 2020, 01:28:50 pm »
There are lots of ways you can do it but when you're done, the cap can negative terminal, red/yellow PT wire, and that 150Ω resistor must all have good electrical/mechanical contact with the chassis, preferably all at the same chassis point.
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #115 on: November 18, 2020, 01:51:24 pm »
...good electrical/mechanical contact with the chassis, preferably all at the same chassis point.

That makes sense, more connections is more potential failure points.

I may attach the red/yellow on the negative terminal... I was hoping the new 150ohm resistor would reach the terminal strip, no joy on that.  Or perhaps wait another day (or two) for the terminal strips to show up in the mail and install a new one. That would help unclutter the area a bit.

Speaking of the existing terminal strip...

The two yellow wires and one red/black wire used to connect to the tuner chassis plug, which I removed.

How would you deal with wires, coming from the PT, which are no longer being used? 

Also, is the circular resistor in the center of the terminal strip C63A/B?

Is that a left over component from the wall plug/fuse setup that is no longer in use?

The last attachment is an earlier photo that I marked up for reference to this post.

Thanks

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #116 on: November 18, 2020, 02:28:05 pm »
Don't mess with anything that you don't have to. Those unused PT wires ain't hurtin' anything.
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #117 on: November 18, 2020, 02:30:33 pm »
Don't mess with anything that you don't have to. Those unused PT wires ain't hurtin' anything.

Ok, I will leave them where they are. Can I remove the disk shaped cap in the middle?

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #118 on: November 18, 2020, 02:42:47 pm »
Are you asking for my permission?
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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #119 on: November 18, 2020, 02:49:30 pm »
Are you asking for my permission?

hahaha ... no, more like your opinion, both would be nice!  :icon_biggrin:   

Two posts back I asked about the circular resistor in the center of the terminal strip. Is it C63 from schematic? Is it left over component from the wall plug/fuse setup that is no longer in use?

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #120 on: November 18, 2020, 04:31:59 pm »
I believe it's already out of the circuit since you changed the AC primary side.  It "didn't" fail when we did initial 2 prong tests so for now just leave it.  once you're jamin to the stereo, then you can decide how to clean up the leftovers
Went Class C for efficiency

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #121 on: November 18, 2020, 04:53:24 pm »
Sounds good. I will remove the green wire 'jumper'  between the cap can and terminal strip and connect the red/yellow to the cap can along with the 150ohm resistor and chassis ground. If that is all I need connected to the negative terminal on the can, I believe it is, then I will solder it and start figuring out how to connect the rest of the wires/caps/resistors back into place.

Offline PRR

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #122 on: November 18, 2020, 06:07:22 pm »
.......Can I remove the disk shaped cap in the middle?

Muntzing

Reach into a live TV chassis, snip out a part. If the TV keeps working, you did not need that part, and you can scold the designer who drew it in.

https://www.electronicdesign.com/technologies/boards/article/21771148/whats-all-this-muntzing-stuff-anyhow


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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #123 on: November 18, 2020, 06:49:08 pm »
Muntzing... Hahaha! Thanks for the memory.
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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #124 on: November 19, 2020, 06:03:32 pm »
Muntzing

Thanks for sharing, I love history nuggets! I was rooting for him until I read the line " The repairmen were happy to get all this repeat business, but eventually the customers figured out that a low initial cost was not necessarily the best investment ..."   Does that mean he was snipping a bunch of non-frivolous parts?


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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #125 on: November 19, 2020, 06:17:42 pm »
I did not get a chance to finish up today. The pictures below is where I left off.

The marked up photo depicts where I believe the 2200ohm 5W resistor should be placed and where I believe the 100ohm 10W should be reconnected.

The circle around the wire and two resistors is where I am a bit confused. They had been connected to the cap can at 'C52D' which was 50u | 25v.

ETA: The line from the 100ohm should be coming from the other side of the resistor...

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #126 on: November 19, 2020, 06:46:32 pm »
time to learn schematics!


make your pics match up with these pics.


your blue line points to where the R was originally, and still is, soldered, are you wanting to unsolder and move to cap?

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #127 on: November 19, 2020, 06:50:29 pm »
Just connect the two 47Ω resistors and the yellow wire to an unused lug on that empty terminal strip. You should have a single cap that needs to connect parallel with that big brown 150Ω resistor. Negative lead goes to chassis ground.
« Last Edit: November 19, 2020, 07:04:11 pm by sluckey »
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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #128 on: November 19, 2020, 07:33:10 pm »
your blue line points to where the R was originally, and still is, soldered, are you wanting to unsolder and move to cap?

No, my bad. See attached, this is where I believe the 100ohm R should connect.

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #129 on: November 19, 2020, 07:50:19 pm »
No, my bad. See attached, this is where I believe the 100ohm R should connect.
No it doesn't. You better study your pics and get it right. Otherwise, you may just blow up something. You are missing a big 2.2K/5W resistor. Where is it?
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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #130 on: November 19, 2020, 07:57:40 pm »
No it doesn't. You better study your pics and get it right. Otherwise, you may just blow up something. You are missing a big 2.2K/5W resistor. Where is it?

I drew it into the last picture attached to post #125.

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #131 on: November 19, 2020, 08:04:11 pm »
OK. Now see the cap terminal with the two red transformer wires on it? The free end of that 100Ω/10W has to connect to the same terminal.
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #132 on: November 19, 2020, 08:15:27 pm »
OK. Now see the cap terminal with the two red transformer wires on it? The free end of that 100Ω/10W has to connect to the same terminal.

Like this? With the blue being the 2.2k 5W

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #133 on: November 19, 2020, 08:40:15 pm »
yes
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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #134 on: November 19, 2020, 08:42:23 pm »
yes

Thanks. I will post a photo tomorrow when I get it all connected, but before I solder any of it together.

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #135 on: November 20, 2020, 08:24:50 am »
something seems off
the 2 OT CT (reds) should be at the same point as the 100,  2.2k, and cap  :dontknow:
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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #136 on: November 20, 2020, 09:05:05 am »
something seems off
the 2 OT CT (reds) should be at the same point as the 100,  2.2k, and cap  :dontknow:
Yes, that's what he is showing. His blue blob is a 2.2K/5W. That half watt 2.2K comes after the big 2.2K.
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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #137 on: November 20, 2020, 09:18:45 am »
something seems off
His blue blob...

I will have an updated photo soon.

Any suggestions on a simple program to make schematics on my PC? I am running ubuntu based linux... I can run *some* windows programs on it, but prefer a native linux program when available.

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #138 on: November 20, 2020, 09:39:30 am »
Quote
That half watt 2.2K
Thanks, the other one didn't have color codes  :icon_biggrin:
Went Class C for efficiency

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #139 on: November 20, 2020, 09:41:09 am »
suggest some shrink wrap on the 100 ohm, the lead is long bare and close to places it shouldn't touch
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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #140 on: November 20, 2020, 10:02:03 am »
Quote
That half watt 2.2K
Thanks, the other one didn't have color codes  :icon_biggrin:
Didn't need color codes. It was writ right on it. In big numbers.    :icon_biggrin:

BTW, txtune, can't you make your new wiring look like this? Much neater IMO.
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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #141 on: November 20, 2020, 10:17:10 am »
suggest some shrink wrap on the 100 ohm, the lead is long bare and close to places it shouldn't touch

Yes, I am going to shrink wrap the long leads on several of these before I solder them on.

BTW, txtune, can't you make your new wiring look like this? Much neater IMO.

Let me verify my connection points are correct first, then I will clean it up.  :new1:

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #142 on: November 20, 2020, 12:04:47 pm »
Do the photos in my previous post look correct, so far as connection points are concerned?

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #143 on: November 20, 2020, 12:10:34 pm »
Connections are correct, but jumper terminal U and O together. And reroute those wires to be close to the chassis, nor running on top of any resistors.
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #144 on: November 20, 2020, 12:43:04 pm »
Connections are correct, but jumper terminal U and O together. And reroute those wires to be close to the chassis, nor running on top of any resistors.

Got it. Let me work on this 'punch list'.

Jumper cap can terminals U and O together with short piece of wire.
Run existing wires beneath resistors, closer to chassis.
Install heat shrink on long resistor leads that are in close proximity to any other metal surface.

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #145 on: November 22, 2020, 01:34:35 pm »
Pic...
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #146 on: November 22, 2020, 01:55:08 pm »
Pic...

Wow, thanks Sluckey! That is about as clear cut as it gets.  I thought I would finish up on Friday, but the phone starting ringing and I got caught up with work.

What software did you use to create that?

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #147 on: November 22, 2020, 02:48:59 pm »
Visio
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #148 on: November 23, 2020, 10:23:01 am »
Pic...

See attached photos. What is suitable method to attach the 47uf cap leads to the 150ohm resistor leads? Short pieces of wire??

I will add some heat shrink to the 150 resistor as well.

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Re: Stromberg and Carlson ASR-120 - Replacement transformers?
« Reply #149 on: November 23, 2020, 11:19:02 am »
I'd put the cap like this. I also recommend to remove the big brown resistor from the cap can, put a ring lug on the end and bolt it to the chassis using the same screw that the green wire is attached. Even better, solder a green wire to the end of the brown resistor lead and put one ring lug on both, then solder the other end of the green wire to the cap can. Much neater IMO.
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

 


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