Need help getting a Silvertone 1474 working

[podboy3]

I have a Silvertone 1474 that pretty much only makes a fuzz/static sound that you can barely hear a guitar through and I need some help and direction to get this thing working.
I have tackled a few amp builds (smaller stuff), reverb build, and have done some modding but that was quite a while ago and I found I have become rather rusty at this.....That and this amp came to me in this condition where the other builds were all new parts or newer working amps that I modded. I am not use to diagnosing an old point to point amp and am hoping I can get some help.

Dan

[52 Bill]

Looking into a point-to-point chassis can be intimidating, until you start to see how things are arranged. Get a copy of the schematic for your amp and familiarize yourself with the basic layout of the amp.

Start by checking the power supply for the correct voltage levels. Then start with the power amp and work forward to the preamps. Always remember the amp will not work if the power supply is dead. The signal will not pass through the amp unless the power amp works and then the preamp. Leave the FX circuits alone until the rest of the amp is working.

[podboy3]

I have the schematic and I will be going over it as well as going over it while I trace out the circuit in the amp (just so it sinks in).

Also, should this be brought up on a variac, and does it even matter since the idiot at Sam Ash turned it right on and tried "jamming" through it for 15 or 20 minutes while giving it a slight whack here and there because, and this is him saying this......."sometimes these old tube amps act up but usually all it needs is a solid thump on the top or side". OK, I let some back story leak and I don't want to write paragraphs of how I got this thing.
Back on track.
Should I bring it up with a variac or does it matter since it has already been turned on and nothing gave up the magic smoke?

[RWood]

Should I bring it up with a variac or does it matter since it has already been turned on and nothing gave up the magic smoke?

I wouldn't bother, but I would most likely replace the electrolytics anyway. Are they the red Planet caps? When I see them in 1484s I start saying my goodbyes straightway.

Btw, if/when you do find an amp that has not been turned on and you would like to use your variac, rig up a couple of diodes for a SS rectifier rather than use it with the tube rectifier. That way you don't have to worry about getting enough filament voltage to the tube before it produces any DC voltage. With two diodes and 3 gator clips you can go from pins 4 to 8 and 6 to 8 of the recto socket. Then monitor the DC voltage at pin 8 and you can easily control the slow ramp up in voltage. At least that's how I do it.
Of course it's easiest when you start with a SS rectified amp.

RWood

[podboy3]

Well, I thought I had the schematic but I don't. My amp is the 1474 chassis number 185.10411 and the schematic that is all over the place is for chassis number 185.10410. I know one of the tubes is different because I know what is labeled on but I am not sure if there are other changes that would make his amp a pain to work with,

[RWood]

Which tube is different?

You can do a recap without the schem. Yes, it is nice as a reference but not essential. I'd bet the two chassis are very close.

RWood

[podboy3]

It's looks like I am ok. I dug the amp out of the closet and pulled the chassis....on if you are looking at the back of the chassis on the left side there are 4 tubes, on the 185.10410 chassis there are three 12AX7's and a 6CG7 on the 185.10411 chassis they are 12AX7, 6CG7, 12AX7, 6CG7.
If you look on the Prowess Amplifiers Schematic you will see that the second tube is for the reverb. Why would they change it from a 12AX7 to a 6CG7?

Also, I have a Fender reverb unit that I built so I do not need the reverb on this.....Is it possible (with out messing with to much stuff) to use that 6CG6 with a potentiometer as an adjustable gain?

Another also......I do not see any caps that look obviously bad. Is it possible (if the guitar store clerk did not turn it on) that the caps could have been re-formed?

[rf7]

Why would they change it from a 12AX7 to a 6CG7?

Must have had a surplus of 6CG7s that month. It's not an uncommon tube to use for that.

Also, I have a Fender reverb unit that I built so I do not need the reverb on this.....Is it possible (with out messing with to much stuff) to use that 6CG6 with a potentiometer as an adjustable gain?

Yes, but I'd change it to a 12AX7 if you were going to do that. Get the amp working as is first, then mod it.

Another also......I do not see any caps that look obviously bad. Is it possible (if the guitar store clerk did not turn it on) that the caps could have been re-formed?

Bad caps don't always look bad. Yes, you might have been able to get them to re-form, but they might have been too far gone to re-form anyways.

[podboy3]

Hey folks, I am bumping this back to the top since I am getting ready (again) to work on this and make it playable....I had it powered on last time but did not get to digging in and testing it due to me Mom passing, It was unexpected and tragic (she was in her 50's).....
...Anyway, I do have some things to share about what happened when I turned it on last time, I had a guitar plugged in to see what noise it would make and this is what I found.

The last time the was running all it made was fuzzing and static sounds at all volumes, even the lowest of settings.....This time when I strummed on the guitar it did not do either and it sounded normal. Is there any reason it would do this?
I did say it sounded normal, but I did not get the volume over three.....at three it was uncomfortably loud in our family room. So I turned it down to one which was the max I would put it for playing in the house. Can anyone who has one of these tell me if this is how loud their 1474 is.
Last thing, No matter what input I have the guitar going to I get sound from both the tremolo and the normal channel. If I turn both up I get a mix of both channels, turn the tremolo channel up and the normal all the way down I get just the tremolo channel, and if I reverse this with the tremolo all the way down and the normal channel up I get just the normal channels.

I made a chassis cradle and in the next day or two I will be pulling the chassis to get some readings, until then any thoughts, opinions, comments, or suggestions would be appreciated.

[Sweetfinger]

I am pretty sure that Danelectro went with the 6FQ7/6CG7 in those because it is an over-rated tube for what it does(usually reverb driver, phase inverter, or power tube driver). Sears would likely never need to replace the tube under warranty. As a general rule, all those old Silvertone amps are pretty easy on the tubes. A 1483 would take 6V6s if any other manufacturer had made it but they use 6L6s which would likely never come back for service. Almost every 1483 I've seen has had the original tubes in it, still strong.

[ampdoc1]

I know this is an old link, but you reference the differences between the 185.10411 and the 185.10410. Did you find the elusive 411 schematic? I think I had one years ago but can't find it anywhere in my reference materials or on the net.
Also, I have a couple of the 410s I bought on eBay 10 years ago which I'm reworking. They are the same model, same innards, same everything, but one has knobs with a silver inlay, while the other has identical knobs with a gold inlay. I haven't found any pics or references that shows these gold knobs, but am looking to replace one that is missing.

Thanks,
ampdoc
David Hicks

[52 Bill]

...identical knobs with a gold inlay. I haven't found any pics or references that shows these gold knobs, but am looking to replace one that is missing.

Thanks,
ampdoc
David Hicks

Are they really gold inserts or discolored silver ones?

Are you that David Hicks (GP, Mender, etc.)?

[ampdoc1]

I just wiped one, and it is gold colored. Maybe Silvertone just got an odd packet of these at some point in time.

I am that David Hicks. I've worked as an estimator on commercial Audio/Video systems since I closed my shop in 1995. But I still do the odd repair for friends. Fixing amps is now my hobby,..and collecting amps is my passion.

DEH

[52 Bill]

I've never seen gold ones, but who knows. Maybe they're more of them out there.

I'm glad to hear that you are still around, even if you're not directly involved in the business anymore. I had the pleasure of meeting you at a NAMM show when the Menders first came out. I immediately ordered some of each version. I still have one each of the Menders.

Anyway, good luck with the Silvertones.

[ampdoc1]

Bill,

No telling what you have, I sold 2 or 3 versions. Recently, a friend gave me a reissue Fender DL, so I dug out my parts and notes and made up a Mender. I was pleasantly surprised that the overdrive compares very well with my $1000 Gibson (Trace Elliot) Gold Tone amplifier.

If I can ever be of assistance, don't hesitate to contact me.

DEH