silvertone twin twelve

[pontiacpete]

I'm working on a "sears silvertone twin twelve" the on that has the head tucked into the cabinet.
Right now it is humming like crazy and probably needs a cap job because everything in it is original.
The question I have comes up with this particular person who owns this, because he owns several vintage amps that are original and don't work.
That is: How original should I keep this amp? Should I bother trying to reform the caps or re-stuff them to keep the original appearance or should I just change them out with new lytics?
He is under the impression that if he, in the future, decides to sell them, a collector will open up the head and look to see if it's original or not.
Does anyone know if "amp collectors" are going to go that far? Or would they rather have a fully working refurbished amp?

pete

[52 Bill]

He is under the impression that if he, in the future, decides to sell them, a collector will open up the head and look to see if it's original or not. Does anyone know if "amp collectors" are going to go that far?

Some collectors already do this. Yes they will be looking for originality, but most want an amp that works, over an amp that just looks perfect. I know a guy that owns several "dead mint" vintage amps, that are unplayable because they need new caps. He feels that due to the overall condition of the amps, the originality is more important than the playability. So he will not fix these which to me is silly, but I don't own them, so to each his own. What is the overall condition of the amp?

I feel that the recent increased interest and value in old Silvertones has a lot to do with celebrity endorsement and nostalgia. The person looking to buy one will probably want one that works over one that looks "right".

If the owner is that concerned that it looks original, offer him the resoration service of re-stuffing the old cap sleeves with new caps. If he wants to spend the additional money, then do what he wants and charge him for your time and effort.

[scole]

a player wants one that works, he just wants to be cool. a collector wants a mint condition piece. even if the amp doesnt work a collector will still want it. collectors sit on things a few yaers and sell them. i would say if the amp is in good condition and all original, leave it allone. if its beat up, then fix it up and make a player out of it.

[guitician]

Are you sure it's the electrolytic caps? The amps that keep the caps out of the heat, are more apt to have good ones. I've got a 1484 that has all the original caps and is fine. They are the red paper covered "Planet Lyticap" "Dry Electrolytic Capacitor". I guess the paper cover insulates them from heat. Maybe a bad tube? Just looked at the schematic and there is a 5/10/20 uf/450V multi-section can next to the PT. It may have gone, and a replacement will not be as noticeable as "New".

[Jag]

I agree with 52Bill and SCole.

If the guy wants it as a "collector piece" and wants it all original, then he doesn't have many options. I doubt you'll get much out of trying to reform caps that old.

If he wants to play it, replace the caps.

About the only way he'll come close to a best of both worlds scenario is if you remove the old caps leaving them in tact and install new ones. Put the old caps in a baggie and he can have them put back in if he wants to sell it to a collector. It won't be "bone stock" in the strictest sense but will be close. It will be up to the collector to decide if that's close enough.

BTW, I was rummaging through my basement storage a couple of week ago and found an old Silvertone 1395 that I bought from a guy down the street when I first moved into our house. That was 13 years ago and I got it for 15 bucks. I played it a little bit and then put it in my storage room until I could change the caps and forgot about it. When I dug it out a couple of weeks ago, I replaced only the 'lytics and left everyting else as it was, including the tubes. I love that amp and haven't stopped playing it since. It's also kind of cool because, from what I've been able to discover, they were only made for one year ('57 or '58, can't remember which). It's pretty much the same thing as a 1396 only with 2 less output tubes and a 15" speaker.

[pontiacpete]

Thanks everyone.
The amp is in really great shape, the "Planet Lyticap" caps are looking nice and red and are like new. Come to find out after trying to fire it up with it's massive hum the amp hadn't been turned on in about 2 years. This leads me to believe that it's the caps.
However, I think I will start with checking the tubes and work from there. Next I'll jumper in some new caps for the 5/10/20 can and see if that brings it back to life.
I agree that the it's best to have a working amp and I will try to convince him of this. Pulling out the 'planet' caps and saving them might be a good idea.
thanks again for your opinions, much appreciated!
pete

[guitician]

Yeah, old amps should always be brought up slow with a variac, especially if it has diode rectification. Hum on the power section probably gets canceled by the P-P OT, so the 5/10/20 is more likely the culprit. Let us know how you make out.

[pontiacpete]

Results: I started with the 5/10/20 can , put in new ones on a bread board, w/ new 68K resistors and clipped them in with clip leads. Still hummed. Then changed the 100uf/50v cap that's part of the bias supply. Still hummed. Then, went and changed out all the 100uf/150v planets and still got hum. Then I changed the last 2 'planets' the 25/25v in the pre amp. finally, No hum. When back and put the 5/10/20 can back in and the 100/150v back and no hum. Put two of the 100/150's that were first in line from the PT and got the hum again.
I'm sure there's an easier way to have done this but it's running again. I was a little surprised by the results.
The reverb is pretty bad. I opened up the tank and the spring was off the holder. Are this spring supposed to be draped over the folded copper sheets? with cardboard between the spring? Does anyone know what I describing... so badly?

[soundmasterg]

If you search at the Hoffman bbs back a couple years you'll find a couple big long posts on these amps. I modded and rebuilt my brother's into something much better sounding that stock. It took a long time, mainly due to that PITA layout those have, but it was worth it.

Stock these things sound somewhat midrangey and have an interesting aggression to their sound, but they're dark and will not do the nice crispy Fender clean at all...just not enough top end for that. The OT is greatly undersized and often blows. The inputs for channel 2 are right in front of the PT, and so these amps will always hum. If you increase gain in the preamp like I did, the hum gets exponentially worse. I had to elevate the heaters, do some shielding, and some other tricks to get the hum level down to an acceptable level. If you increase gain it also shifts the tone control range down to bass frequencies, so they have to be revoiced. The can cap is a 20/10/5 at 450v, and is NLA. You used to be able to get them custom made from Zack at Vibroworld, but he closed that down. You can get custom cans from Weber but you have to hog out the chassis hole to make them fit right. You can also use discrete caps in the chassis, or try to make them fit in the stock can. I happened to luck out for my brother's modded one and for my stock one and got some before Zack stopped doing them. The stock Planet caps were shit quality from the beginning only being guaranteed for one year as it says on the outisde of them, and surprisingly they last a long time, but they're still shit. Any new ecap will be better quality. Replace the diodes in the amp with 1N4007's too. Sometimes the ones in there will blow since they aren't rated as high as modern stuff. The sockets are lousy quality but work fine. They do tend to arc though. The brown caps in there are like the brown turd caps in silverface Fenders that everyone hates. They work but are lousy caps and the amp can be improved even with orange drops, but any new cap will improve the sound there. Most of the carbon comp resistors will have drifted and were cheapies back when they were made.....not on the level of AB's or other good brands. The trem on these sounds great, the reverb is one of the worst to ever go in a guitar amp. If it works, fine...leave it...if not, don't worry about it. Gut that section and stick in something else with those tubes....a gain stage.....a Fender reverb circuit like I did (had to make a taller head box though to add the Fender tank)...bottom line is the reverb sux in these and everyone knows it and expects that it won't work or if it will, it will sound bad. The pots are lousy quality though they work ok usually. It doesn't hurt to replace them with some good CTS or similar. These amps came with great quality tubes so if they still have original tubes, they're good to grab. They ran low voltages in the preamps on these, and bumping those up improves the sound. On my brother's, I bumped those up on channel two, and added an EF86 to channel 1, redid the whole layout of the tube order in the preamp, and changed every part in the amp. I also added adjustable bias which is a good mod to add, though you need to add a doubler to do it. My brother's 1484 kicks ass now....but if you want to keep it all stock for the guy, then just the e-caps and the diodes and any bad resistors and/or coupling caps and forget the reverb. These amps will always lag behind Fenders in price....they're cheap and do a particular sound, but its not as versatile as the Fenders. The do take pedals well, which is probably why the White Stripes guy likes them. My 2 cents.

Greg

[guitician]

Yeah, that spring just slips over the bent metal L-bracket. I think it's a piezoelectric crystal wafer on each end that makes this "Reverb" work. It has a BAD frequency response and sounds lousy. You said you replaced the 100/150's that are first in line. My schematic shows those caps all stacked in series connected to two secoundary windings in a dual voltage doubler. Do you have a schematic?

[pontiacpete]

yes, I have the schematic. What I meant by the first in line was wrong. The ones i first changed were actually the last 2 in series of the four. I guess I was looking at it as the physical placement next to the PT.
pete