Silvertone 1482 Build

[dawsonaudio]

I'm just getting ready to order some parts for my Silvertone 1482 amp build. Quick question, the schematic calls for a 6x4 rectifier tube. I've got a 6ca4, 5u4 and 5ar4. Could I used the 6ca4 in place of the 6x4?

Thanks.

Nate

[Andy Le Blanc]

6ca4 looks close.... higher heater draw, 1A.... and a 9 pin socket
6x4 has a 7pin base and a .6 A heater

planning for the 9 pin socket is easy... double check that the extra current requirement won't be an issue.

[ampgeek]

Here is a nice little "tube swap" technical summary that might be helpful now and into the future.

Rock on,
Dave O.

[dawsonaudio]

So before I order the parts for the project, I already have power transformer I'd like to try and use from a Hammond M100 A0-29 amp. My second to last power transformer from my Hammond Parts Box. It has a 357 volt reading at the secondary unloaded. Will that be a little too high for a starting voltage for the Silvertone 1482 circuit? I'm not sure what the original pt specifications are. Here is the Silvertone 1482 schematic and the Hammond M100 circuit.

This is a quote I got from the web regarding the Hammond Transformer:
"According to my docs the AO29 is supposed to use a H-AO-22111-1 power transformer spec'ed at 355-0-355V unloaded and 320-0-320V @ 150mA, 5V @ 3A, 6.3V @ 4A. But I'm no Hammond expert and can't vouch for this info."

[img863]http://www.geocities.ws/teleman28056/pi ... e_1482.gif[/img]
[img:4000:2686]http://www.captain-foldback.com/Hammond ... 3_late.gif[/img][/b]

[10thTx]

DanElectro Centurian is pretty much the same amp as the 1482

http://el34world.com/charts/Schematics/ ... an_275.pdf

I had a Dano Centurian and loved it! I paralleled V1 and added a "one tube reverb". It was one of my favorite amps and the vibrato on it was incredible.

I owned a vintage Princeton Reverb during that same time and much preferred the Dano Centurian.

With respect, 10thtx

I included a Tube Data Cheat sheet that is useful in looking at rectifier options.

[10thTx]

Ah, I found a 1482 reverb schematic I drew up many yrs ago.

This is pretty much what I did with my Centurian. I used a typical fender replacement reverb trannie and tank as would be used on a Princeton Reverb.

with respect, 10thtx

I attached an editable SCH file schematic for you.

[dawsonaudio]

That's really cool of you. Thanks for those files. I'm going to be diving into building it this weekend.

Thanks again,
Nate

[dawsonaudio]

Hey, quick question...I'm trying to look at images off the web of the tone pot wiring, but I can't seem to get a clear picture of the wiring. I just wanted to confirm that the left terminal of the tone pot (pin1), looking at it with the pins at the top from the rear of the pot, connects to the .003 cap and then to ground. The wiper (pin2) will connect to the volume pot at pin 3 and then to the .01 cap. I'm assuming that pin 3 of both tone pots are not used. I'm looking at the original schematic and trying to figure out the wiring of these pots, but can't seem to figure it out.

I didn't know if the .003 cap should connect to the middle wiper terminal of the tone pot and the left pin pin connect to the .01 cap. That's what it looks like it should to in the schematic.

Thanks for the information.

Nate

[xtian]

I think you are correct.

[dawsonaudio]

So the .003 caps should connect to the middle wiper pin of the tone pots? My previous post had two options. Sorry about that. Just want to make sure it's correct.

[dawsonaudio]

Here are some photos of the amp assembled. Any glaring mistakes? I will triple check again before I start it up. Thanks for looking.

Nate

[img1440]http://www.serviceairsocal.com/1.jpg[/img]
[img1440]http://www.serviceairsocal.com/2.jpg[/img]
[img1440]http://www.serviceairsocal.com/3.jpg[/img]
[img1440]http://www.serviceairsocal.com/4.jpg[/img]
[/img]

[Stevem]

What is the temp rating of those caps to each side of the output tube Cathode resistor ?

I would move it off the board and wire it across the output tube sockets, it will not be as pretty, but the amps tone will not change when that heats up!

I would also be inclined to add some shrink tubing to each leg of those ciramic caps spanning the pots to ward off a potencial short should they move.

Other than these things let me say nice job on the build!

[dawsonaudio]

Those electrolytic caps are rated at 85 degrees. I'll move that 270ohm cathode resistor off the board and shrink tube those cap leads between the pots. Thanks for the tips.

[dawsonaudio]

Pretty neat guitar amp. Plugged it in and played it with a test speaker connected and it sounded pretty nice. Distorts pretty nicely. All the controls work with the exception of the tremolo. Not sure if the tremolo jack needs to be connected to get it going. Maybe I should add a dummy plug to get it working.

I still need to check the voltages and check the bias.

Now I need to build a small cabinet to mount everything in. Considering another speaker as the speaker I'm using came from my hammond parts assortment. It has a few small holes around the perimeter, but it sounds alright. I probably need a new speaker. Any suggestions? I think the transformer output is 16ohms.

[10thTx]

IF you find that you are NOT using both input jacks, then you could parallel V1 for 30% more gain and NO increase in floor noise.

Then add a 12AX7 and install reverb. And yes, I have put the reverb on the end of layout boards before as a mod and it has always worked fine for me.

I have NO agenda for you, just offering a way to get both reverb and vibrato on the same amp.

The James/Baxandall tone stack was used on the Dano Centurian and if you look at the Duncan Tone Stack calculator, you will find that it is remarkably versatile and can give both mid boost and mid scooped tones.

With respect, 10thtx