Potentiometer Rating

[dawsonaudio]

I am going to build a Silvertone 1482 amp. I was wondering if I needed 1/2 watt or if 1/4 audio taper potentiometers would work. I found some Alpha potentiometers at tubesandmore.com but they are rated at only 1/4 watt at 1meg in the audio taper. All the other resistors I have are 1/2 watt.

Thanks for the help.

Nate
[img863]http://www.geocities.ws/teleman28056/pi ... e_1482.gif[/img]

[M Fowler]

Either pot will work fine.

But I have a question for you. Are you using a thick faceplate on your build because those Alpha pots are short unless you have a silk screened or painted faceplate.

Good choice for longer shaft pots are Alpha for Mojotone or CTS for Mojotone
www.Mojotone.com and I do not work for Mojotone but after close to 100 builds I know what works. Burns pots are also 3/8" diameter x 3/8" long like the two pots above.

Just saying.

Mark

[dawsonaudio]

I'll just be using a thin chassis that I have lying around here. The amp section will be accessed from the back at the bottom so I won't need a heavy gauge for the face plate. I was also considering those CTS pots over the Alpha ones. I've never used those before. I'll check out mojotone tonight.

Thanks for the info.

Nate

[xtian]

I just refurbed a 1966 1484. What's the diff between the 1482 and 1484? Bigger trannies?

Anyway, I like the 1484 a lot. Put in a 360R cathode resistor for better bias, updated the filter caps, three-prong plug.


--EDIT--

Sorry! Mine IS the 1482.

[Stevem]

Use the 1/2 watt rated pot just for the fact that they are bigger and as such have a bigger resistive Carbon trace and last longer and less likely to brake if the shaft takes a hit!

Also make note to use your OTs 8 ohm or even the 16 ohm tap with the right speaker.
As with any OT they sound better and run cooler when you use the whole secondary winding, not the 4 ohm tap as the silvertone did even though the stock OT does / did have a 8 ohm tap!

Another nice mod to do when building one of these since both channels are in phase in to make one channel a brite one and then add another input Jack that links both channels so you do not need to use a jumper cable .

[pdf64]

..As with any OT they sound better and run cooler when you use the whole secondary winding, not the 4 ohm tap as the silvertone did even though the stock OT does / did have a 8 ohm tap..

This seems rather dodgy; please can you provide a little more detail as to what exactly you mean (eg to use the full secondary winding even if that results in a mismatch), and explain how you've come to this comclusion?

[xtian]

Another nice mod to do when building one of these since both channels are in phase in to make one channel a brite one and then add another input Jack that links both channels so you do not need to use a jumper cable.

This is a confusing issue with my 1482. The microphone jack works fine (uses V1a). The instrument jack works fine (uses V1b). But jumpering the two channels does nothing useful--does not provide any additional gain nor volume nor tonal difference.

If I was going to mod this amp, I'd cascade the gain stages.

[M Fowler]

I had to put in a new PT on my friends 1482 it was sizzling frying bacon sound and got rid of the tube rectifier while I was at it. Someone had been in there before me with all those radial caps.

Used MC 5e3 PT.

Currently I own a 1471 Silvertone neat little amp.

[xtian]

Here's mine, after replacing the can cap with radials. You can also see silicon diodes in place of the 6X4, but I removed them in favor of the 6X4 because voltage drop of tube recto is nice.

[Stevem]

Yes both channels are 100% the same and if you make one a brite channel by placing a .005uf cap across a 470k resistor off of one channels input jack output you then have yourself a brite channel that if you jump into you can blend in that tone.

In regards to the OT question the bottom line is that all multi speaker output tap transformers sound there best when you are running off of the highest impedance tap it is wired / made with, it will also last longer if you are driving it hard and run cooler in the process.