Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Platefire on December 13, 2016, 04:27:58 pm
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I have just posted on Schematics and Diagrams/Schematics a just created layout drawings of the Silvertone 1472. As far as I know there hasn't been any made up to this point---schematics yes but no layouts. I have requested the same guy to make one for the 1482 also and I am assisting him in identifying the difference in components. So hopefully I will be able to post one for the 1482 soon. Platefire
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Bob,
I posted a SCH schematic and layout for the 1482 (in 2006) right here: http://el34world.com/Forum/index.php?topic=568.0 (http://el34world.com/Forum/index.php?topic=568.0)
And there is a version to add a one tube reverb to it also.
The 1482 Silvertone and the Dano Centurian are pretty much the same amp except reverb & other minor differences.
with respect, Tubenit
* Correction, Platefire posted something for an original style layout point to point for the 1472. What I drew up was a paralleled turret board or
even the inexpensive tagboards.
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Thanks tubenit
The 1482 has always been special to me because it was my first experiences feeling the reaction of a tube amp to an electric guitar. Thanks for sharing your 1482/Centurian mods. It's always interesting to see how we can take these old amps and bring more up to modern standards. I'm sure happy with my #2 modded one and even my all stock #1.
On the layout I posted is a stock layout just to represent original factory build components and arrangement on the 1472. I got a little excited because to my knowledge an all original layout, I have never seen so far even though I have search for it. So hopefully the guy will make one for the 1482.
The wiring layout on the 1472 and 1482 is very similar except for a few components and especially PT.
The wiring is old style point to point in it's worst spaghetti form. So I think these layouts will be very helpful to folks studying these old circuits for the first time trying to figure them out. Platefire
(http://el34world.com/Forum/index.php?action=dlattach;topic=568.0;attach=62408;image) (http://el34world.com/Forum/index.php?action=dlattach;topic=568.0;attach=62407;image)
(http://el34world.com/Forum/Themes/default/images/icons/clip.gif) Silvertone 1472 Layout #1.jpg (http://el34world.com/Forum/index.php?action=dlattach;topic=568.0;attach=62407) (414.32 kB, 2200x1700 - viewed 1 times.)
(http://el34world.com/Forum/index.php?action=dlattach;topic=568.0;attach=62410;image) (http://el34world.com/Forum/index.php?action=dlattach;topic=568.0;attach=62409;image)
(http://el34world.com/Forum/Themes/default/images/icons/clip.gif) Silvertone 1472 Layout #2.jpg (http://el34world.com/Forum/index.php?action=dlattach;topic=568.0;attach=62409) (601.55 kB, 2200x1700 - viewed 2 times.)
(http://el34world.com/Forum/Themes/default/images/icons/clip.gif) Silvertone 1472 Component List.pdf (http://el34world.com/Forum/index.php?action=dlattach;topic=568.0;attach=62411) (47.82 kB - downloaded 1 times.)
On the right track now<><
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The links didn't work for me
Franco
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Those are not links but jpg files. I tried them with my phone and they wouldn't open but when I used my PC worked fine. I'm assuming my phone needs an app to open them. Platefire
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They work in the "Schematics and Diagrams" forum. They don't work in this forum!
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OK, didn't know that. I tried it and yes it works on my phone in schematics & Diagrams/Schematics. Thanks, sluckey
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> They don't work in this forum!
Ah-ha. Platefire, suggest you edit links to point to *messages* instead of message attachments.
> when I used my PC worked fine.
I will suspect you had the other section open in another browser tab, so in some sense "you were already there".
This is probably a side-effect of the code which does not serve image attachments to "external web sites", so Doug isn't paying to benefit other sites without a chance to sell his goods. Just that somehow that filter is confused what is "external".
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This I can see
(http://el34world.com/Forum/index.php?action=dlattach;topic=21254.0;attach=62390;image)
(http://el34world.com/Forum/index.php?action=dlattach;topic=21254.0;attach=62392;image)
http://el34world.com/Forum/index.php?action=dlattach;topic=21254.0;attach=62394 (http://el34world.com/Forum/index.php?action=dlattach;topic=21254.0;attach=62394)
Franco
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Good! Guess we are on the right track now---I hope :dontknow: Thanks for the Help!
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As an addendum to the previous post on this thread, I have attached a sheet noting the differences between the 1472 and 1482 circuits. So the 1472 is very close in physical layout of components as the 1482. Major difference was upgraded transformers and a few tweaks to the circuit. Attached is a pdf noting differences in component values that was added along with the upgraded transformers in the 1482. So you could use the previous attached 1472 layout with a 1482, just attach this pdf to the layout to clarify differences. Platefire
BTW-The picture is in reference to item 3d on attached pdf.
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I can combine all that stuff into one multi-page pdf if you like. Just tell me what you would like me to include.
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Yes, that would be great sluckey! I think the two layout drawings, the pdf sheet and the picture showing transformer hookup that is referenced in 3d of pdf. Thanks, Platefire
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Here you go. It's too big to be attached here. Just click the link. Let me know when you have it.
http://sluckeyamps.com/bargain/Platefire.pdf (http://sluckeyamps.com/bargain/Platefire.pdf)
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Thanks for the help sluckey! Got it. Platefire
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FWIW: this is what I did to my 1482 (I also upgraded the baffle board). Sometimes I jumper Ch's 1 & 2, and plug the guitar into Ch 2. It'a a real head turner at venues.
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jjasilli
That's interesting! What speaker are you running in it? Also how did the choke effect it? I've wondered how a choke would effect the existing circuit.
I got one that I leave all stock and another I do all the mods to. I see you put a 5E3 type tone stack on the instrument channel. That helps brighten it up. Here is my schematic of the #2 modded one. Platefire
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The speaker in my 1482 is a 12" Eminence Screamin' Eagle.
I love chokes. But I don't know how to describe what they do for tone.
Normally I'm not a fan of cathodyne PI's in guitar amps, but it seems to work here. Probably adds to a grungy overdrive tone.
Tonestack: We seem to have come to the same conclusion. The amp is dark, so we both kept one channel stock, and modded the other channel's tonestack like Tweed.
Preamp gain. Stock the 1482 1st gain stages have huge value plate resistors, 330K. I think this also contributes to dark tone. So I modded my bright Ch(2) closer to fender values.
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jjasilli
Yeah, I took another look at your schematic bright channel. See you got the voltage up a little over 200 on the plates. I bet that bought you a little clean head room, huh? With that and my NFB loops might get closer to a fender sound. My NFB loops, the lower resistor one works good with Humbucker PU and the higher NFB resistor works best with single coils---but I hardly ever use the NFB loops.
To brighten mine up a bit also, I made an open back back-plate for multi reasons: Brighter sound, place to store cord, foot pedal and speaker was deeper than the old Fisher Spkr so had to have it where the magnet could pertrude through. Got a Eminence Cannabis Rex in mine. Platefire