Silvertone 1472 cap replacement list

[Prez!]

Hey guys I just picked up a really nice 1962 Silvertone 1472 all original the rear panel never removed. Sounds awesome but the Tremolo does not work. All tubes are original. The 6AU6 tube tests bad so I know it needs replacing. Does anyone have a list of capacitor values that are recommended to be replaced ? It is 50 years old I would like to keep the circuitry close to original. Are there any other parts that are recommended to be replaced. Thanks !

[Enzo]

ANy electrolytic cap is a candidate for replacement. The coupling caps, who knows. Ceramics and micas are probably OK< case by case if not. Your other coupling caps - anything like for example .022uf 400v - well, some of those held up real well, and others turned to sludge, in amps of that age. If you find a couple need replacing, then do them all.

If you have any of the old wax covered ones, I can pretty much guarantee they need to go.

[Chuck H]

Right. If this is to be a collectible and not played then replace the bad tube and leave it alone. This actually goes against any rational thinking of course, The amp "is" collectible. Not so much so as a vintage Fender or Marshall. Resale values tell all. If you want to play the amp you may as well get it into safe working condition. Which means retrofitting as needed and changing the power cord to a proper three prong grounded type.

If I bought an old VW Karman Ghia (Collectible, but not a 63 Mustang or 57 Chevy) and I wanted to drive it, I would probably put on new tires. But if I bought that 57 Chevy bone stock with original tires I might just leave it alone and not drive it. Point is...

With a Silvertone "I" would probably get it into safe working condition. Most people interested in that amp would be happier to have it "working" in like new condition than actually being in all original condition. But that's just MHO.

[Prez!]

Thanks for the replies. Looking at the schematic it apppears to have just one coupling or output cap for the 6v6GT's labled C9 10uf 25V. Does anyone know if Nichicon makes a Black Gate in this value. And also if you jump the mic jack and one instrument jack will it play thru both power tubes and give you 20 watts thru the speaker. Thanks again for the help.

[sgelectric]

Schematic for 1472

http://www.webphix.com/schematic%20h...ertone1472.pdf

[52 Bill]

Thanks for the replies. Looking at the schematic it apppears to have just one coupling or output cap for the 6v6GT's labled C9 10uf 25V. Does anyone know if Nichicon makes a Black Gate in this value. And also if you jump the mic jack and one instrument jack will it play thru both power tubes and give you 20 watts thru the speaker. Thanks again for the help.

The coupling caps are the ones that "couple" or connect one stage to another like C2, C3, C6, C7 and C8. C9 is a cathode bypass cap.

Both output tubes work all of the time, not one for each channel. One tube amplifies the top half of the signal and the other tube does the same for the bottom half of the signal. One tube pushes and the other tube pulls, this is why this circuit is sometimes called a push/pull design.

Jumping the input jacks will cause the signal to be amplified by an additional preamp section, so it will sound louder.

[Prez!]

The coupling caps are the ones that "couple" or connect one stage to another like C2, C3, C6, C7 and C8. C9 is a cathode bypass cap.

Both output tubes work all of the time, not one for each channel. One tube amplifies the top half of the signal and the other tube does the same for the bottom half of the signal. One tube pushes and the other tube pulls, this is why this circuit is sometimes called a push/pull design.

Jumping the input jacks will cause the signal to be amplified by an additional preamp section, so it will sound louder.

All that is very good to know that's so much for helping me out. If I jump the inputs jacks do you think the original speaker will hold up ?

[Chuck H]

Jumping the jacks may make the amp seem louder for a given volume control setting but it will not increase the maximum power of the amp. As long as your speakers are capable of the maximum power of the amp they will be fine.

[Brianbicknell]

Cap list for newbie?

Schematic for 1472

http://www.webphix.com/schematic%20h...ertone1472.pdf

Hey,

Just got a 1472 and want to look into doing a cap job. Anyone able to post a list of the actual caps (label and values) of what to replace (electrolytics and filter?). I'm not as knowledgable as you all when reading schematics!

Thanks!

[Chuck H]

The caps that should be replaced are circled in red. You can use values that are the next highest standard values available with no tonal detriment. The voltage rating should be equal or higher. You should also check power supply (and any other) resistors for "drift" and replace as needed.

I have included info on how to change to a three prong cord for safety.

Following the schematic to the extent that this information applies is the minimum of ability you should have if you intend to work on the amp.

[Brianbicknell]

Thanks so much! I'll order some parts and get on it. If the tremolo isn't working, should I replace those caps (as stated previously in the thread) as well?

Also, do you suggest a full tube replacement? There are some definite tube failure symptoms going on...

Thanks again!

[Brianbicknell]

Oops, one more thing: which are the resistors I should check? Thanks again!

[Chuck H]

Well... All of them really. Those old CC resistors are known to drift. Sometimes. Sometimes they stay put. Checking resistors in circuit won't always give you an accurate read. Best just to change to a three prong cord, replace any bad tubes, recap the power supply and then take voltage readings. If voltages are wrong/ish then there may be drifted resistors OR... Older design film caps can also go bad with age. Enzo covered this above. If a coupling cap is going bad it may leak DC voltage and ruin the bias for the following stage. This is usually detectable with voltage readings. So do the standard maintenance and then take voltage readings. If you don't know what they mean, post results here. We do.

[Riffraff]

I love those amps. I've got a pair of 1482s, a bone stock, mint '65 and a '67 I've done some work on. They are fun little amps.